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Saúl Ibarra Corretgé, 11/09/2012 11:59 am


Middleware API

This chapter describes the Middleware API for SIP SIMPLE client SDK that can be used for developing a user interface (e.g. Graphical User Interface). The Middleware provides a non-blocking API that communicates with the user interface asynchronously by using Notifications. For its configuration, the Middleware uses the Configuration API.

Middleware Architecture

SIPApplication

Implemented in source:sipsimple/application.py

Implements a high-level application responsable for starting and stopping various sub-systems required to implement a fully featured SIP User Agent application. The SIPApplication class is a Singleton and can be instantiated from any part of the code, obtaining a reference to the same object. The SIPApplication takes care of initializing the following components:

The attributes in this class can be set and accessed on both this class and its subclasses, as they are implemented using descriptors which keep single value for each attribute, irrespective of the class from which that attribute is set/accessed. Usually, all attributes should be considered read-only.

methods

__init__(self)

Instantiates a new SIPApplication.

start(self, storage)

Starts the SIPApplication which initializes all the components in the correct order. The storage is saved as an attribute which other entities like the Configuration Manager will use to take the appropriate backend. If any error occurs with loading the configuration, the exception raised by the ConfigurationManager is propagated by this method and SIPApplication can be started again. After this, any fatal errors will result in the SIPApplication being stopped and unusable, which means the whole application will need to stop. This method returns as soon as the twisted thread has been started, which means the application must wait for the SIPApplicationDidStart notification in order to know that the application started.

stop(self)

Stop all the components started by the SIPApplication. This method returns immediately, but a SIPApplicationDidEnd notification is sent when all the components have been stopped.

attributes

running

True if the SIPApplication is running (it has been started and it has not been told to stop), False otherwise.

storage

Holds an object which implements the ISIPSimpleStorage interface which will be used to provide a storage facility to other middleware components.

local_nat_type

String containing the detected local NAT type.

alert_audio_mixer

The AudioMixer object created on the alert audio device as defined by the configuration (by SIPSimpleSettings.audio.alert_device).

alert_audio_bridge

An AudioBridge where IAudioPort objects can be added to playback sound to the alert device.

alert_audio_device

An AudioDevice which corresponds to the alert device as defined by the configuration. This will always be part of the alert_audio_bridge.

voice_audio_mixer

The AudioMixer object created on the voice audio device as defined by the configuration (by SIPSimpleSettings.audio.input_device and SIPSimpleSettings.audio.output_device).

voice_audio_bridge

An AudioBridge where IAudioPort objects can be added to playback sound to the output device or record sound from the input device.

voice_audio_device

An AudioDevice which corresponds to the voice device as defined by the configuration. This will always be part of the voice_audio_bridge.

*notifications *

SIPApplicationWillStart

This notification is sent just after the configuration has been loaded and the twisted thread started, but before any other components have been initialized.

timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPApplicationDidStart

This notification is sent when all the components have been initialized. Note: it doesn't mean that all components have succeeded, for example, the account might not have registered by this time, but the registration process will have started.

timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPApplicationWillEnd

This notification is sent as soon as the stop() method has been called.

timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPApplicationDidEnd

This notification is sent when all the components have been stopped. All components have been given reasonable time to shutdown gracefully, such as the account unregistering. However, because of factors outside the control of the middleware, such as network problems, some components might not have actually shutdown gracefully; this is needed because otherwise the SIPApplication could hang indefinitely (for example because the system is no longer connected to a network and it cannot be determined when it will be again).

timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPApplicationFailedToStartTLS

This notification is sent when a problem arises with initializing the TLS transport. In this case, the Engine will be started without TLS support and this notification contains the error which identifies the cause for not being able to start the TLS transport.

timestamp:

A datetime.datetime object indicating when the notification was sent.

error:

The exception raised by the Engine which identifies the cause for not being able to start the TLS transport.

Storage API

Different middleware components may need to store data, i.e. configuration files or XCAP documents. The Storage API defines a collection of backends which other components will use to store their data.

API Definition

The Storage API currently requires the following attributes to be defined as per the ISIPSimpleStorage interface:

configuration_backend

The backend used for storing the configuration.

xcap_storage_factory

Factory used to create XCAP storage backends for each account.

Provided implementations

Two storage implementations are provided: FileStorage and MemoryStorage both located in the sipsimple.storage module.

SIP Sessions

SIP sessions are supported by the sipsimple.session.Session class and independent stream classes, which need to implement the sipsimple.streams.IMediaStream interface. The Session class takes care of the signalling, while the streams offer the actual media support which is negotiated by the Session. The streams which are implemented in the SIP SIMPLE middleware are provided in modules within the sipsimple.streams package, but they are accessible for import directly from sipsimple.streams. Currently, the middleware implements two types of streams, one for RTP data, with a concrete implementation in the AudioStream class, and one for MSRP sessions, with concrete implementations in the ChatStream, FileTransferStream and DesktopSharingStream classes. However, the application can provide its own stream implementation, provided they respect the IMediaStream interface.

The sipsimple.streams module also provides a mechanism for automatically registering media streams in order for them to be used for incoming sessions. This is explained in more detail in MediaStreamRegistry.

SessionManager

Implemented in source:sipsimple/session.py

The sipsimple.session.SessionManager class is a singleton, which acts as the central aggregation point for sessions within the middleware.
Although it is mainly used internally, the application can use it to query information about all active sessions.
The SessionManager is implemented as a singleton, meaning that only one instance of this class exists within the middleware. The SessionManager is started by the SIPApplication and takes care of handling incoming sessions and closing all sessions when SIPApplication is stopped.

attributes

sessions

A property providing a copy of the list of all active Sesssion objects within the application, meaning any Session object that exists globally within the application and is not in the NULL or TERMINATED state.

methods

__init__(self)

Instantiate a new SessionManager object.

start(self)

Start the SessionManager in order to be able to handle incoming sessions. This method is called automatically when SIPApplication is started. The application should not call this method directly.

stop(self)

End all connected sessions. This method is called automatically when SIPApplication is stopped. The application should not call this method directly.

Session

Implemented in source:sipsimple/session.py

A sipsimple.session.Session object represents a complete SIP session between the local and a remote endpoints. Both incoming and outgoing sessions are represented by this class.

A Session instance is a stateful object, meaning that it has a state attribute and that the lifetime of the session traverses different states, from session creation to termination. State changes are triggered by methods called on the object by the application or by received network events. These states and their transitions are represented in the following diagram:

Although these states are crucial to the correct operation of the Session object, an application using this object does not need to keep track of these states, as a set of notifications is also emitted, which provide all the necessary information to the application.

The Session is completely independent of the streams it contains, which need to be implementations of the sipsimple.streams.IMediaStream interface. This interface provides the API by which the Session communicates with the streams. This API should not be used by the application, unless it also provides stream implementations or a SIP INVITE session implementation.

methods

__init__(self, account)

Creates a new Session object in the None state.

account:

The local account to be associated with this Session.

connect(self, to_header, routes, streams, is_focus=False, subject=None)

Will set up the Session as outbound and propose the new session to the specified remote party and move the state machine to the outgoing state.
Before contacting the remote party, a SIPSessionNewOutgoing notification will be emitted.
If there is a failure or the remote party rejected the offer, a SIPSessionDidFail notification will be sent.
Any time a ringing indication is received from the remote party, a SIPSessionGotRingIndication notification is sent.
If the remote party accepted the session, a SIPSessionWillStart notification will be sent, followed by a SIPSessionDidStart notification when the session is actually established.
This method may only be called while in the None state.

to_header:

A sipsimple.core.ToHeader object representing the remote identity to initiate the session to.

routes:

An iterable of sipsimple.util.Route objects, specifying the IP, port and transport to the outbound proxy.
These routes will be tried in order, until one of them succeeds.

streams:

A list of stream objects which will be offered to the remote endpoint.

is_focus:

Boolean flag indicating if the isfocus parameter should be added to the Contact header according to RFC 4579.

subject:

Session subject. If not None a Subject header will be added with the specified value.

send_ring_indication(self)

Sends a 180 provisional response in the case of an incoming session.

accept(self, streams)

Calling this methods will accept an incoming session and move the state machine to the accepting state.
When there is a new incoming session, a SIPSessionNewIncoming notification is sent, after which the application can call this method on the sender of the notification.
After this method is called, SIPSessionWillStart followed by SIPSessionDidStart will be emitted, or SIPSessionDidFail on an error.
This method may only be called while in the incoming state.

streams:

A list of streams which needs to be a subset of the proposed streams which indicates which streams are to be accepted. All the other proposed streams will be rejected.

reject(self, code=603, reason=None)

Reject an incoming session and move it to the terminating state, which eventually leads to the terminated state.
Calling this method will cause the Session object to emit a SIPSessionDidFail notification once the session has been rejected.
This method may only be called while in the incoming state.

code:

An integer which represents the SIP status code in the response which is to be sent. Usually, this is either 486 (Busy) or 603 (Decline/Busy Everywhere).

reason:

The string which is to be sent as the SIP status reason in the response, or None if PJSIP's default reason for the specified code is to be sent.

accept_proposal(self, streams)

When the remote party proposes to add some new streams, signaled by the SIPSessionGotProposal notification, the application can use this method to accept the stream(s) being proposed.
After calling this method a SIPSessionGotAcceptProposal notification is sent, unless an error occurs while setting up the new stream, in which case a SIPSessionHadProposalFailure notification is sent and a rejection is sent to the remote party. As with any action which causes the streams in the session to change, a SIPSessionDidRenegotiateStreams notification is also sent.
This method may only be called while in the received_proposal state.

streams:

A list of streams which needs to be a subset of the proposed streams which indicates which streams are to be accepted. All the other proposed streams will be rejected.

reject_proposal(self, code=488, reason=None)

When the remote party proposes new streams that the application does not want to accept, this method can be used to reject the proposal, after which a SIPSessionGotRejectProposal or SIPSessionHadProposalFailure notification is sent.
This method may only be called while in the received_proposal state.

code:

An integer which represents the SIP status code in the response which is to be sent. Usually, this is 488 (Not Acceptable Here).

reason:

The string which is to be sent as the SIP status reason in the response, or None if PJSIP's default reason for the specified code is to be sent.

add_stream(self, stream)

Proposes a new stream to the remote party.
Calling this method will cause a SIPSessionGotProposal notification to be emitted.
After this, the state machine will move into the sending_proposal state until either a SIPSessionGotAcceptProposal, SIPSessionGotRejectProposal or SIPSessionHadProposalFailure notification is sent, informing the application if the remote party accepted the proposal. As with any action which causes the streams in the session to change, a SIPSessionDidRenegotiateStreams notification is also sent.
This method may only be called while in the connected state.

remove_stream(self, stream)

Stop the stream and remove it from the session, informing the remote party of this. Although technically this is also done via an SDP negotiation which may fail, the stream will always get remove (if the remote party refuses the re-INVITE, the result will be that the remote party will have a different view of the active streams than the local party).
This method may only be called while in the connected state.

cancel_proposal(self)

This method cancels a proposal of adding a stream to the session by sending a CANCEL request. A SIPSessionGotRejectProposal notification will be sent with code 487.

hold(self)

Put the streams of the session which support the notion of hold on hold.
This will cause a SIPSessionDidChangeHoldState notification to be sent.
This method may be called in any state and will send the re-INVITE as soon as it is possible.

unhold(self)

Take the streams of the session which support the notion of hold out of hold.
This will cause a SIPSessionDidChangeHoldState notification to be sent.
This method may be called in any state and will send teh re-INVITE as soon as it is possible.

end(self)

This method may be called any time after the Session has started in order to terminate the session by sending a BYE request.
Right before termination a SIPSessionWillEnd notification is sent, after termination SIPSessionDidEnd is sent.

transfer(self, target_uri, replaced_session=None)

Proposes a blind call transfer to a new target URI or assisted transfer to an URI belonging to an already established session.

accept_transfer(self)

Accepts an incoming call transfer request.

reject_transfer(self, code=486, *reason_=None)

Rejects an incoming call transfer request.

attributes

state

The state the object is currently in, being one of the states from the diagram above.

account

The sipsimple.account.Account or sipsimple.account.BonjourAccount object that the Session is associated with.
On an outbound session, this is the account the application specified on object instantiation.

direction

A string indicating the direction of the initial negotiation of the session.
This can be either None, "incoming" or "outgoing".

transport

A string representing the transport this Session is using: "udp", "tcp" or "tls".

start_time

The time the session started as a datetime.datetime object, or None if the session was not yet started.

stop_time

The time the session stopped as a datetime.datetime object, or None if the session has not yet terminated.

on_hold

Boolean indicating whether the session was put on hold, either by the local or the remote party.

remote_user_agent

A string indicating the remote user agent, if it provided one.
Initially this will be None, it will be set as soon as this information is received from the remote party (which may be never).

local_identity

The sipsimple.core.FrozenFromHeader or sipsimple.core.FrozenToHeader identifying the local party, if the session is active, None otherwise.

remote_identity

The sipsimple.core.FrozenFromHeader or sipsimple.core.FrozenToHeader identifying the remote party, if the session is active, None otherwise.

streams

A list of the currently active streams in the Session.

proposed_streams

A list of the currently proposed streams in the Session, or None if there is no proposal in progress.

conference

A ConferenceHandler object instance (or Null). It can be later used to add/remove participants from a remote conference.

subject

The session subject as a unicode object.

replaced_session

A Session object instance (or Null). It can be used for assisted call transfer.

transfer_handler

A TransferHandler object instance (or Null). It is used for managing the call transfer process.

transfer_info

A TransferInfo object instance (or Null). It is used for describing the details of a call transfer operation.

notifications

SIPSessionNewIncoming

Will be sent when a new incoming Session is received.
The application should listen for this notification to get informed of incoming sessions.

timestamp:

A datetime.datetime object indicating when the notification was sent.

streams:

A list of streams that were proposed by the remote party.

SIPSessionNewOutgoing

Will be sent when the application requests a new outgoing Session.

timestamp:

A datetime.datetime object indicating when the notification was sent.

streams:

A list of streams that were proposed to the remote party.

SIPSessionGotRingIndication

Will be sent when an outgoing Session receives an indication that a remote device is ringing.

timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPSessionGotProvisionalResponse

Will be sent whenever the Session receives a provisional response as a result of sending a (re-)INVITE.

timestamp:

A datetime.datetime object indicating when the notification was sent.

code:

The SIP status code received.

reason:

The SIP status reason received.

SIPSessionWillStart

Will be sent just before a Session completes negotiation.
In terms of SIP, this is sent after the final response to the INVITE, but before the ACK.

timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPSessionDidStart

Will be sent when a Session completes negotiation and all the streams have started.
In terms of SIP this is sent after the ACK was sent or received.

timestamp:

A datetime.datetime object indicating when the notification was sent.

streams:

The list of streams which now form the active streams of the Session.

SIPSessionDidFail

This notification is sent whenever the session fails before it starts.
The failure reason is included in the data attributes.
This notification is never followed by SIPSessionDidEnd.

timestamp:

A datetime.datetime object indicating when the notification was sent.

originator:

A string indicating the originator of the Session. This will either be "local" or "remote".

code:

The SIP error code of the failure.

reason:

A SIP status reason.

failure_reason:

A string which represents the reason for the failure, such as "user_request", "missing ACK", "SIP core error...".

SIPSessionWillEnd

Will be sent just before terminating a Session.

timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPSessionDidEnd

Will be sent always when a Session ends as a result of remote or local session termination.

timestamp:

A datetime.datetime object indicating when the notification was sent.

originator:

A string indicating who originated the termination. This will either be "local" or "remote".

end_reason:

A string representing the termination reason, such as "user_request", "SIP core error...".

SIPSessionDidChangeHoldState

Will be sent when the session got put on hold or removed from hold, either by the local or the remote party.

timestamp:

A datetime.datetime object indicating when the notification was sent.

originator:

A string indicating who originated the hold request, and consequently in which direction the session got put on hold.

on_hold:

True if there is at least one stream which is on hold and False otherwise.

partial:

True if there is at least one stream which is on hold and one stream which supports hold but is not on hold and False otherwise.

SIPSessionGotProposal

Will be sent when either the local or the remote party proposes to add streams to the session.

timestamp:

A datetime.datetime object indicating when the notification was sent.

originator:

The party that initiated the stream proposal, can be either "local" or "remote".

streams:

A list of streams that were proposed.

SIPSessionGotRejectProposal

Will be sent when either the local or the remote party rejects a proposal to have streams added to the session.

timestamp:

A datetime.datetime object indicating when the notification was sent.

originator:

The party that initiated the stream proposal, can be either "local" or "remote".

code:

The code with which the proposal was rejected.

reason:

The reason for rejecting the stream proposal.

streams:

The list of streams which were rejected.

SIPSessionGotAcceptProposal

Will be sent when either the local or the remote party accepts a proposal to have stream( added to the session.

timestamp:

A datetime.datetime object indicating when the notification was sent.

originator:

The party that initiated the stream proposal, can be either "local" or "remote".

streams:

The list of streams which were accepted.

proposed_streams:

The list of streams which were originally proposed.

SIPSessionHadProposalFailure

Will be sent when a re-INVITE fails because of an internal reason (such as a stream not being able to start).

timestamp:

A datetime.datetime object indicating when the notification was sent.

failure_reason:

The error which caused the proposal to fail.

streams:

The streams which were part of this proposal.

SIPSessionDidRenegotiateStreams

Will be sent when a media stream is either activated or deactivated.
An application should listen to this notification in order to know when a media stream can be used.

timestamp:

A datetime.datetime object indicating when the notification was sent.

action:

A string which is either "add" or "remove" which specifies what happened to the streams the notificaton referes to

streams:

A list with the streams which were added or removed.

SIPSessionDidProcessTransaction

Will be sent whenever a SIP transaction is complete in order to provide low-level details of the progress of the INVITE dialog.

timestamp:
A datetime.datetime object indicating when the notification was sent.

originator:

The initiator of the transaction, "local" or "remote".

method:

The method of the request.

code:

The SIP status code of the response.

reason:

The SIP status reason of the response.

ack_received:

This attribute is only present for INVITE transactions and has one of the values True, False or "unknown". The last value may occur then PJSIP does not let us know whether the ACK was received or not.

SIPSessionTransferNewOutgoing

Will be sent whenever a SIP session initiates an outgoing call transfer request.

timestamp:

A datetime.datetime object indicating when the notification was sent.

transfer_destination:

The destination SIP URI of the call transfer request.

transfer_source:

The source SIP URI of the call transfer request.

SIPSessionTransferDidStart

Will be sent whenever a call transfer has been started.

timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPSessionTransferDidFail

Will be sent whenever a call transfer request has failed.

timestamp:

A datetime.datetime object indicating when the notification was sent.

code:

The SIP failure code reported by the SIP stack.

reason:

The reason of the failure as a string.

As an example for how to use the Session object, the following provides a basic Python program that initiates an outgoing SIP session request see Minimalist Session Example code.

IMediaStream

Implemented in source:"sipsimple/streams/__init__.py"

This interface describes the API which the Session uses to communicate with the streams. All streams used by the Session must respect this interface.

methods

__init__(self, account)

Initializes the generic stream instance.

new_from_sdp(cls, account, remote_sdp, stream_index)

A classmethod which returns an instance of this stream implementation if the sdp is accepted by the stream or None otherwise.

account:

The sipsimple.account.Account or sipsimple.account.BonjourAccount object the session which this stream would be part of is associated with.

remote_sdp:

The FrozenSDPSession which was received by the remote offer.

stream_index:

An integer representing the index within the list of media streams within the whole SDP which this stream would be instantiated for.

get_local_media(self, for_offer)

Return an SDPMediaStream which represents an offer for using this stream if for_offer is True and a response to an SDP proposal otherwise.

for_offer:

True if the SDPMediaStream will be used for an SDP proposal and False if for a response.

initialize(self, session, direction)

Initializes the stream. This method will get called as soon as the stream is known to be at least offered as part of the Session. If initialization goes fine, the stream must send a MediaStreamDidInitialize notification or a MediaStreamDidFail notification otherwise.

session:

The Session object this stream will be part of.

direction:

"incoming" if the stream was created because of a received proposal and "outgoing" if a proposal was sent. Note that this need not be the same as the initial direction of the Session since streams can be proposed in either way using re-INVITEs.

start(self, local_sdp, remote_sdp, stream_index)

Starts the stream. This method will be called as soon is known to be used in the Session (eg. only called for an incoming proposal if the local party accepts the proposed stream). If starting succeeds, the stream must send a MediaStreamDidStart notification or a MediaStreamDidFail notification otherwise.

local_sdp:

The FrozenSDPSession which is used by the local endpoint.

remote_sdp:

The FrozenSDPSession which is used by the remote endpoint.

stream_index:

An integer representing the index within the list of media streams within the whole SDP which this stream is represented by.

validate_update(self, remote_sdp, stream_index)

This method will be called when a re-INVITE is received which changes the parameters of the stream within the SDP. The stream must return True if the changes are acceptable or False otherwise. If any changed streams return False for a re-INVITE, the re-INVITE will be refused with a negative response. This means that streams must not changed any internal data when this method is called as the update is not guaranteed to be applied even if the stream returns True.

remote_sdp:

The FrozenSDPSession which is used by the remote endpoint.

stream_index:

An integer representing the index within the list of media streams within the whole SDP which this stream is represented by.

update(self, local_sdp, remote_sdp, stream_index)

This method is called when the an SDP negotiation initiated by either the local party or the remote party succeeds. The stream must update its internal state according to the new SDP in use.

local_sdp:

The FrozenSDPSession which is used by the local endpoint.

remote_sdp:

The FrozenSDPSession which is used by the remote endpoint.

stream_index:

An integer representing the index within the list of media streams within the whole SDP which this stream is represented by.

hold(self)

Puts the stream on hold if supported by the stream. Typically used by audio and video streams. The stream must immediately stop sending/receiving data and calls to get_local_media() following calls to this method must return an SDP which reflects the new hold state.

unhold(self)

Takes the stream off hold. Typically used by audio and video streams. Calls to get_local_media() following calls to this method must return an SDP which reflects the new hold state.

deactivate(self)

This method is called on a stream just before the stream will be removed from the Session (either as a result of a re-INVITE or a BYE). This method is needed because it avoids a race condition with streams using stateful protocols such as TCP: the stream connection might be terminated before the SIP signalling announces this due to network routing inconsistencies and the other endpoint would not be able to distinguish between this case and an error which caused the stream transport to fail. The stream must not take any action, but must consider that the transport being closed by the other endpoint after this method was called as a normal situation rather than an error condition.

end(self)

Ends the stream. This must close the underlying transport connection. The stream must send a MediaStreamWillEnd just after this method is called and a MediaStreamDidEnd as soon as the operation is complete. This method is always be called by the Session on the stream if at least the initialize() method has been called. This means that once a stream sends the MediaStreamDidFail notification, the Session will still call this method.

attributes

type (class attribute)

A string identifying the stream type (eg: "audio", "video").

priority (class attribute)

An integer value indicating the stream priority relative to the other streams types (higher numbers have higher priority).

hold_supported

True if the stream supports hold

on_hold_by_local

True if the stream is on hold by the local party

on_hold_by_remote

True if the stream is on hold by the remote

on_hold

True if either on_hold_by_local or on_hold_by_remote is true

notifications

These notifications must be generated by all streams in order for the Session to know the state of the stream.

MediaStreamDidInitialize

Sent when the stream has been successfully initialized.

MediaStreamDidStart

Sent when the stream has been successfully started.

MediaStreamDidFail

Sent when the stream has failed either as a result of calling one of its methods, or during the normal operation of the stream (such as the transport connection being closed).

MediaStreamWillEnd

Sent immediately after the end() method is called.

MediaStreamDidEnd

Sent when the end() method finished closing the stream.

MediaStreamRegistrar

This is a convenience metaclass which automatically registers a defined class with the MediaStreamRegistry. In order to use this class, one simply needs to use it as the metaclass of the new stream.

 1from zope.interface import implements
 2
 3from sipsimple.streams import IMediaStream, MediaStreamRegistrar
 4
 5class MyStream(object):
 6  __metaclass__ = MediaStreamRegistrar
 7
 8  implements(IMediaStream)
 9
10[...] 

AudioStream

Implemented in source:sipsimple/streams/rtp.py

The AudioStream is an implementation of IMediaStream which supports audio data using the AudioTransport and RTPTransport of the SIP core. As such, it provides all features of these objects, including ICE negotiation. An example SDP created using the AudioStream is provided below:

Content-Type: application/sdp
Content-Length:  1093

v=0
o=- 3467525278 3467525278 IN IP4 192.168.1.6
s=blink-0.10.7-beta
c=IN IP4 80.101.96.20
t=0 0
m=audio 55328 RTP/AVP 104 103 102 3 9 0 8 101
a=rtcp:55329 IN IP4 80.101.96.20
a=rtpmap:104 speex/32000
a=rtpmap:103 speex/16000
a=rtpmap:102 speex/8000
a=rtpmap:3 GSM/8000
a=rtpmap:9 G722/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:esI6DbLY1+Aceu0JNswN9Z10DcFx5cZwqJcu91jb
a=crypto:2 AES_CM_128_HMAC_SHA1_32 inline:SHuEMm1BYJqOF4udKl73EaCwnsI57pO86bYKsg70
a=ice-ufrag:2701ed80
a=ice-pwd:6f8f8281
a=candidate:S 1 UDP 31 80.101.96.20 55328 typ srflx raddr 192.168.1.6 rport 55328
a=candidate:H 1 UDP 23 192.168.1.6 55328 typ host
a=candidate:H 1 UDP 23 10.211.55.2 55328 typ host
a=candidate:H 1 UDP 23 10.37.129.2 55328 typ host
a=candidate:S 2 UDP 30 80.101.96.20 55329 typ srflx raddr 192.168.1.6 rport 55329
a=candidate:H 2 UDP 22 192.168.1.6 55329 typ host
a=candidate:H 2 UDP 22 10.211.55.2 55329 typ host
a=candidate:H 2 UDP 22 10.37.129.2 55329 typ host
a=sendrecv

As an implementation of IAudioPort, an AudioStream can be added to an AudioBridge to send or to read audio data to/from other audio objects. It is connected to the voice AudioMixer (SIPApplication.voice_audio_mixer) so it can only be added to bridges using the same AudioMixer. It also contains an AudioBridge on the bridge attribute which always contains an AudioDevice corresponding to the input and output devices; when the stream is active (started and not on hold), the bridge also contains the stream itself and when recording is active, the stream contains a WaveRecorder which records audio data.

methods

start_recording(self, filename=None)

If an audio stream is present within this session, calling this method will record the audio to a .wav file.
Note that when the session is on hold, nothing will be recorded to the file.
Right before starting the recording a SIPSessionWillStartRecordingAudio notification will be emitted, followed by a SIPSessionDidStartRecordingAudio.
This method may only be called while the stream is started.

filename:

The name of the .wav file to record to.
If this is set to None, a default file name including the session participants and the timestamp will be generated using the directory defined in the configuration.

stop_recording(self)

This will stop a previously started recording.
Before stopping, a SIPSessionWillStopRecordingAudio notification will be sent, followed by a SIPSessionDidStopRecordingAudio.

send_dtmf(self, digit)

If the audio stream is started, sends a DTMF digit to the remote party.

digit:

This should a string of length 1, containing a valid DTMF digit value (0-9, A-D, * or #).

attributes

sample_rate

If the audio stream was started, this attribute contains the sample rate of the audio negotiated.

codec

If the audio stream was started, this attribute contains the name of the audio codec that was negotiated.

srtp_active

If the audio stream was started, this boolean attribute indicates if SRTP is currently being used on the stream.

ice_active

True if the ICE candidates negotiated are being used, False otherwise.

local_rtp_address

If an audio stream is present within the session, this attribute contains the local IP address used for the audio stream.

local_rtp_port

If an audio stream is present within the session, this attribute contains the local UDP port used for the audio stream.

remote_rtp_address_sdp

If the audio stream was started, this attribute contains the IP address that the remote party gave to send audio to.

remote_rtp_port_sdp

If the audio stream was started, this attribute contains the UDP port that the remote party gave to send audio to.

remote_rtp_address_received

If the audio stream was started, this attribute contains the remote IP address from which the audio stream is being received.

remote_rtp_port_received

If the audio stream was started, this attribute contains the remote UDP port from which the audio stream is being received.

local_rtp_candidate_type

The local ICE candidate type which was selected by the ICE negotiation if it succeeded and None otherwise.

remote_rtp_candidate_type

The remote ICE candidate type which was selected by the ICE negotiation if it succeeded and None otherwise.

recording_filename

If the audio stream is currently being recorded to disk, this property contains the name of the .wav file being recorded to.

notifications

AudioStreamDidChangeHoldState

Will be sent when the hold state is changed as a result of either a SIP message received on the network or the application calling the hold()/unhold() methods on the Session this stream is part of.

timestamp:

A datetime.datetime object indicating when the notification was sent.

originator:

A string representing the party which requested the hold change, "local" or "remote"

on_hold:

A boolean indicating the new hold state from the point of view of the originator.

*AudioStreamWillStartRecordingAudio_

Will be sent when the application requested that the audio stream be recorded to a .wav file, just before recording starts.

timestamp:

A datetime.datetime object indicating when the notification was sent.

filename:

The full path to the .wav file being recorded to.

AudioStreamDidStartRecordingAudio

Will be sent when the application requested that the audio stream be recorded to a .wav file, just after recording started.

timestamp:

A datetime.datetime object indicating when the notification was sent.

filename:

The full path to the .wav file being recorded to.

AudioStreamWillStopRecordingAudio

Will be sent when the application requested ending the recording to a .wav file, just before recording stops.

timestamp:

A datetime.datetime object indicating when the notification was sent.

filename:

The full path to the .wav file being recorded to.

AudioStreamDidStopRecordingAudio

Will be sent when the application requested ending the recording to a .wav file, just after recording stoped.

timestamp:

A datetime.datetime object indicating when the notification was sent.

filename:

The full path to the .wav file being recorded to.

AudioStreamDidChangeRTPParameters

This notification is sent when the RTP parameters are changed, such as codec, sample rate, RTP port etc.

timestamp:

A datetime.datetime object indicating when the notification was sent.

AudioStreamGotDTMF

Will be send if there is a DMTF digit received from the remote party on the audio stream.

timestamp:

A datetime.datetime object indicating when the notification was sent.

digit:

The DTMF digit that was received, in the form of a string of length 1.

AudioStreamICENegotiationStateDidChange

This notification is proxied from the RTPTransport and as such has the same data as the RTPTransportICENegotiationStateDidChange.

AudioStreamICENegotiationDidSucceed

This notification is proxied from the RTPTransport and as such has the same data as the RTPTransportICENegotiationDidSucceed.

AudioStreamICENegotiationDidFail

This notification is proxied from the RTPTransport and as such has the same data as the RTPTransportICENegotiationDidFail.

AudioStreamDidTimeout

This notification is proxied from the RTPTransport. It's sent when the RTP transport did not receive any data after the specified amount of time (rtp.timeout setting in the Account).

MSRPStreamBase

Implemented in source:sipsimple/streams/msrp.py

The MSRPStreamBase is used as a base class for streams using the MSRP protocol. Within the SIP SIMPLE middleware, this hold for the ChatStream, FileTransferStream and DesktopSharingStream classes, however the application can also make use of this class to implement some other streams based on the MSRP protocol as a transport.

methods

Of the methods defined by the IMediaStream interface, only the new_from_sdp method is not implemented in this base class and needs to be provided by the subclasses. Also, the subclasses can defined methods of the form _handle_XXX, where XXX is a MSRP method name in order to handle incoming MSRP requests. Also, since this class registers as an observer for itself, it will receive the notifications it sends so subclasses can define methods having the signature _NH_<notification name>(self, notification) as used throughout the middleware in order to do various things at the different points within the life-cycle of the stream.

attributes

The attributes defined in the IMediaStream interface which are not provided by this class are:
  • type
  • priority

In addition, the following attributes need to be defined in the subclass in order for the MSRPStreamBase class to take the correct decisions

media_type

The media type as included in the SDP (eg. "message", "application").

accept_types

A list of the MIME types which should be accepted by the stream (this is also sent within the SDP).

accept_wrapped_types

A list of the MIME types which should be accepted by the stream while wrapped in a message/cpim envelope.

use_msrp_session

A boolean indicating whether or not an MSRPSession should be used.

notifications

While not technically notifications of MSRPStreamBase, these notifications are sent from the middleware on behalf of the MSRPTransport used by a stream in the former case, and anonymously in the latter.

MSRPTransportTrace

This notification is sent when an MSRP message is received for logging purposes.

timestamp:

A datetime.datetime object indicating when the notification was sent.

direction:

The direction of the message, "incoming" or "outgoing".

data:

The MSRP message as a string.

MSRPLibraryLog

This notification is sent anonymously whenever the MSRP library needs to log any information.

timestamp:

A datetime.datetime object indicating when the notification was sent.

message:

The log message as a string.

level:

The log level at which the message was written. One of the levels DEBUG, INFO, WARNING, ERROR, CRITICAL from the application.log.level object which is part of the python-application library.

ChatStream

Implemented in source:sipsimple/streams/msrp.py

sipsimple.streams.msrp.ChatStream implements session-based Instant Messaging (IM) over MSRP. This class performs the following functions:

  • automatically wraps outgoing messages with Message/CPIM if that's necessary according to accept-types
  • unwraps incoming Message/CPIM messages; for each incoming message, the ChatStreamGotMessage notification is posted
  • composes iscomposing payloads and reacts to those received by sending the ChatStreamGotComposingIndication notification

An example of an SDP created using this class follows:

Content-Type: application/sdp
Content-Length:   283

v=0
o=- 3467525214 3467525214 IN IP4 192.168.1.6
s=blink-0.10.7-beta
c=IN IP4 192.168.1.6
t=0 0
m=message 2855 TCP/TLS/MSRP *
a=path:msrps://192.168.1.6:2855/ca7940f12ddef14c3c32;tcp
a=accept-types:message/cpim text/* application/im-iscomposing+xml
a=accept-wrapped-types:*

methods

__init__(self, account, direction='sendrecv')

Initializes the ChatStream instance.

send_message(self, content, content_type='text/plain', recipients=None, courtesy_recipients=None, subject=None, timestamp=None, required=None, additional_headers=None)

Sends an IM message. Prefer Message/CPIM wrapper if it is supported. If called before the connection was established, the messages will be
queued until the stream starts.
Returns the generated MSRP message ID.

content:

The content of the message.

content_type:

Content-Type of wrapped message if Message/CPIM is used (Content-Type of MSRP message is always Message/CPIM in that case);

otherwise, Content-Type of MSRP message.

recipients:

The list of CPIMIdentity objects which will be used for the To header of the CPIM wrapper. Used to override the default which depends on the remote identity.

May only differ from the default one if the remote party supports private messages. If it does not, a ChatStreamError will be raised.

courtesy_recipients:

The list of CPIMIdentity objects which will be used for the cc header of the CPIM wrapper.

May only be specified if the remote party supports private messages and CPIM is supported. If it does not, a ChatStreamError will be raised.

subject:

A string or MultilingualText which specifies the subject and its translations to be added to the CPIM message. If CPIM is not supported, a ChatStreamError will be raised.

required:

A list of strings describing the required capabilities that the other endpoint must support in order to understand this CPIM message. If CPIM is not supported, a ChatStreamError will be raised.

additional_headers:

A list of MSRP header objects which will be added to this CPIM message. If CPIM is not supported, a ChatStreamError will be raised.

timestamp:

A datetime.datetime object representing the timestamp to put on the CPIM wrapper of the message.

When set to None, a default one representing the current moment will be added.

These MSRP headers are used to enable end-to-end success reports and to disable hop-to-hop successful responses:

Failure-Report: partial
Success-Report: yes

send_composing_indication(self, state, refresh, last_active=None, recipients=None)

Sends an is-composing message to the listed recipients.

state:

The state of the endpoint, "active" or "idle".

refresh:

How often the local endpoint will send is-composing indications to keep the state from being reverted to "idle".

last_active:

A datatime.datetime object representing the moment when the local endpoint was last active.

recipients:

The list of CPIMIdentity objects which will be used for the To header of the CPIM wrapper. Used to override the default which depends on the remote identity.

May only differ from the default one if the remote party supports private messages. If it does not, a ChatStreamError will be raised.

set_local_nickname(self, nickname)

Sets the nickname to be used in this MSRP session.

nickname:

The nickname to be set. It may rise ChatStreamError if the sream is not initialized or nicknames are not supported.

notifications

ChatStreamGotMessage

Sent whenever a new incoming message is received,

timestamp:

A datetime.datetime object indicating when the notification was sent.

message:

A ChatMessage or CPIMMessage instance, depending on whether a CPIM message was received or not.

ChatStreamDidDeliverMessage

Sent when a successful report is received.

timestamp:

A datetime.datetime object indicating when the notification was sent.

message_id:

Text identifier of the message.

code:

The status code received. Will always be 200 for this notification.

reason:

The status reason received.

chunk:

A msrplib.protocol.MSRPData instance providing all the MSRP information about the report.

ChatStreamDidNotDeliverMessage

Sent when a failure report is received.

timestamp:

A datetime.datetime object indicating when the notification was sent.

message_id:

Text identifier of the message.

code:

The status code received.

reason:

The status reason received.

chunk:

A msrplib.protocol.MSRPData instance providing all the MSRP information about the report.

ChatStreamDidSendMessage

Sent when an outgoing message has been sent.

timestamp:

A datetime.datetime object indicating when the notification was sent.

message:

A msrplib.protocol.MSRPData instance providing all the MSRP information about the sent message.

ChatStreamGotComposingIndication

Sent when a is-composing payload is received.

timestamp:

A datetime.datetime object indicating when the notification was sent.

state:

The state of the endpoint, "active" or "idle".

refresh:

How often the remote endpoint will send is-composing indications to keep the state from being reverted to "idle". May be None.

last_active:

A datatime.datetime object representing the moment when the remote endpoint was last active. May be None.

content_type:

The MIME type of message being composed. May be None.

sender:

The ChatIdentity or CPIMIdentity instance which identifies the sender of the is-composing indication.

recipients:

The ChatIdentity or CPIMIdentity instances list which identifies the recipients of the is-composing indication.

FileTransferStream

Implemented in source:sipsimple/streams/msrp.py

The FileTransferStream supports file transfer over MSRP according to RFC5547. An example of SDP constructed using this stream follows:

Content-Type: application/sdp
Content-Length:   383

v=0
o=- 3467525166 3467525166 IN IP4 192.168.1.6
s=blink-0.10.7-beta
c=IN IP4 192.168.1.6
t=0 0
m=message 2855 TCP/TLS/MSRP *
a=path:msrps://192.168.1.6:2855/e593357dc9abe90754bd;tcp
a=sendonly
a=accept-types:*
a=accept-wrapped-types:*
a=file-selector:name:"reblink.pdf" type:com.adobe.pdf size:268759 hash:sha1:60:A1:BE:8D:71:DB:E3:8E:84:C9:2C:62:9E:F2:99:78:9D:68:79:F6

methods

__init__(self, account, file_selector=None)

Instantiate a new FileTransferStream. If this is constructed by the application for an outgoing file transfer, the file_selector argument must be present.

account:

The sipsimple.account.Account or sipsimple.account.BonjourAccount instance which will be associated with the stream.

file_selector:

The FileSelector instance which represents the file which is to be transferred.

notifications

FileTransferStreamDidDeliverChunk

This notification is sent for an outgoing file transfer when a success report is received about part of the file being transferred.

timestamp:

A datetime.datetime object indicating when the notification was sent.

message_id:

The MSRP message ID of the file transfer session.

chunk:

An msrplib.protocol.MSRPData instance represented the received REPORT.

code:

The status code received. Will always be 200 for this notification.

reason:

The status reason received.

transferred_bytes:

The number of bytes which have currently been successfully transferred.

file_size:

The size of the file being transferred.

FileTransferStreamDidNotDeliverChunk

timestamp:

A datetime.datetime object indicating when the notification was sent.

This notification is sent for an outgoing file transfer when a failure report is received about part of the file being transferred.

message_id:

The MSRP message ID of the file transfer session.

chunk:

An msrplib.protocol.MSRPData instance represented the received REPORT.

code:

The status code received.

reason:

The status reason received.

FileTransferStreamDidFinish

This notification is sent when the incoming or outgoing file transfer is finished.

timestamp:

A datetime.datetime object indicating when the notification was sent.

FileTransferStreamGotChunk

This notificaiton is sent for an incoming file transfer when a chunk of file data is received.

timestamp:

A datetime.datetime object indicating when the notification was sent.

content:

The file part which was received, as a str.

content_type:

The MIME type of the file which is being transferred.

transferred_bytes:

The number of bytes which have currently been successfully transferred.

file_size:

The size of the file being transferred.

IDesktopSharingHandler

This interface is used to describe the interface between a IDesktopSharingHandler, which is responsible for consuming and producing RFB data, and the DesktopSharingStream which is responsible for transporting the RFB data over MSRP. The middleware provides four implementations of this interface:
  • InternalVNCViewerHandler
  • InternalVNCServerHandler
  • ExternalVNCViewerHandler
  • ExternalVNCServerHandler

methods

initialize(self, stream)

This method will be called by the DesktopSharingStream when the stream has been started and RFB data can be transported. The stream has two attributes which are relevant to the IDesktopSharingHandler: incoming_queue and outgoing_queue. These attributes are eventlet.coros.queue instances which are used to transport RFB data between the stream and the handler.

attributes

type
"active" or "passive" depending on whether the handler represents a VNC viewer or server respectively.

notifications

DesktopSharingHandlerDidFail

This notification must be sent by the handler when an error occurs to notify the stream that it should fail.

context:

A string describing when the handler failed, such as "reading", "sending" or "connecting".

failure:

A twisted.python.failure.Failure instance describing the exception which led to the failure.

reason:

A string describing the failure reason.

InternalVNCViewerHandler

This is a concrete implementation of the IDesktopSharingHandler interface which can be used for a VNC viewer implemented within the application.

methods

send(self, data)

Sends the specified data to the stream in order for it to be transported over MSRP to the remote endpoint.

data:

The RFB data to be transported over MSRP, in the form of a str.

notifications

DesktopSharingStreamGotData

This notification is sent when data is received over MSRP.

data:

The RFB data from the remote endpoint, in the form of a str.

InternalVNCServerHandler

This is a concrete implementation of the IDesktopSharingHandler interface which can be used for a VNC server implemented within the application.

methods

send(self, data)

Sends the specified data to the stream in order for it to be transported over MSRP to the remote endpoint.

data:

The RFB data to be transported over MSRP, in the form of a str.

notifications

DesktopSharingStreamGotData

This notification is sent when data is received over MSRP.

data:

The RFB data from the remote endpoint, in the form of a str.

ExternalVNCViewerHandler

This implementation of IDesktopSharingHandler can be used for an external VNC viewer which connects to a VNC server using TCP.

methods

__init__(self, address=("localhost", 0), connect_timeout=3)

This instantiates a new ExternalVNCViewerHandler which is listening on the provided address, ready for the external VNC viewer to connect to it via TCP. After this method returns, the attribute address can be used to find out exactly on what address and port the handler is listening on. The handler will only accept one conenction on this address.

address:

A tuple containing an IP address/hostname and a port on which the handler should listen. Any data received on this socket will then be forwarded to the stream and any data received from the stream will be forwarded to this socket.

attributes

address

A tuple containing an IP address and a port on which the handler is listening.

ExternalVNCServerHandler

This implementation of IDesktopSharingHandler can be used for an external VNC server to which handler will connect using TCP.

methods

__init__(self, address, connect_timeout=3)

This instantiates a new ExternalVNCServerHandler which will connect to the provided address on which a VNC server must be listening before the stream using this handler starts.

address:

A tuple containing an IP address/hostname and a port on which the VNC server will be listening. Any data received on this socket will then be forwared to the stream and any data received form the stream will be forwarded to this socket.

connect_timeout:

How long to wait to connect to the VNC server before giving up.

DesktopSharingStream

Implemented in source:sipsimple/streams/msrp.py

This stream implements desktop sharing using MSRP as a transport protocol for RFB data.

There is no standard defining this usage but is fairly easy to implement in clients that already support MSRP. To traverse a NAT-ed router, a MSRP relay configured for the called party domain is needed. Below is an example of the Session Description Protocol used for establishing a Desktop sharing session:

m=application 2855 TCP/TLS/MSRP *
a=path:msrps://10.0.1.19:2855/b599b22d1b1d6a3324c8;tcp
a=accept-types:application/x-rfb
a=rfbsetup:active

methods

__init__(self, acount, handler)

Instantiate a new DesktopSharingStream.

account:

The sipsimple.account.Account or sipsimple.account.BonjourAccount instance this stream is associated with.

handler:

An object implementing the IDesktopSharingHandler interface which will act as the handler for RFB data.

attributes

handler

This is a writable property which can be used to get or set the object implementing IDesktopSharingHandler which acts as the handler for RFB data. For incoming DesktopSharingStreams, this must be set by the application before the stream starts.

incoming_queue

A eventlet.coros.queue instance on which incoming RFB data is written. The handler should wait for data on this queue.

outgoing_queue

A eventlet.coros.queue instance on which outgoing RFB data is written. The handler should write data on this queue.

ConferenceHandler

This class is internal to the Session and provied the user with the ability to invite participants to a conference hosted by the remote endpoint.

Adding and removing participants is performed using a REFER request as explained in RFC 4579, section 5.5.

In addition, the ConferenceHandler will subscribe to the conference event in order to get information about participants in the conference.

methods

add_participant(self, participant_uri)

Send a REFER request telling the server to invite the participant specified in participant_uri to join the ongoing conference.

remove_participant(self, participant_uri)

Send a REFER request telling the server to remove the participant specified in participant_uri from the ongoing conference.

notifications

All notifications are sent with the Session object as the sender.

SIPSessionGotConferenceInfo

This notification is sent when a NOTIFY is received with a valid conferene payload.

timestamp:

A datetime.datetime object indicating when the notification was sent.

conference_info:

The Conference payload object.

SIPConferenceDidAddParticipant

This notification is sent when a participant was successfully added to the conference.

timestamp:

A datetime.datetime object indicating when the notification was sent.

participant:

URI of the participant added to the conference.

SIPConferenceDidNotAddParticipant

This notification is sent when a participant could not be added to the conference.

timestamp:

A datetime.datetime object indicating when the notification was sent.

participant:

URI of the participant added to the conference.

code:

SIP response code for the failure.

reason:

Reason for the failure.

SIPConferenceDidRemoveParticipant

This notification is sent when a participant was successfully removed from the conference.

timestamp:

A datetime.datetime object indicating when the notification was sent.

participant:

URI of the participant removed from the conference.

SIPConferenceDidNotRemoveParticipant

This notification is sent when a participant could not be removed from the conference.

timestamp:

A datetime.datetime object indicating when the notification was sent.

participant:

URI of the participant removed from the conference.

code:

SIP response code for the failure.

reason:

Reason for the failure.

SIPConferenceGotAddParticipantProgress

This notification is sent when a NOTIFY is received indicating the status of the add participant operation.

timestamp:

A datetime.datetime object indicating when the notification was sent.

participant:

URI of the participant whose operation is in progress.

code:

SIP response code for progress.

reason:

Reason associated with the response code.

SIPConferenceGotRemoveParticipantProgress

This notification is sent when a NOTIFY is received indicating the status of the remove participant operation.

timestamp:

A datetime.datetime object indicating when the notification was sent.

participant:

URI of the participant whose operation is in progress.

code:

SIP response code for progress.

reason:

Reason associated with the response code.

Address Resolution

The SIP SIMPLE middleware offers the sipsimple.lookup module which contains an implementation for doing DNS lookups for SIP proxies, MSRP relays, STUN servers and XCAP servers. The interface offers both an asynchronous and synchronous interface. The asynchronous interface is based on notifications, while the synchronous one on green threads. In order to call the methods in a asynchronous manner, you just need to call the method and wait for the notification which is sent on behalf of the DNSLookup instance. The notifications sent by the DNSLookup object are DNSLookupDidSucceed and DNSLookupDidFail. In order to call the methods in a synchronous manner, you need to call the wait method on the object returned by the methods of DNSLookup. This wait method needs to be called from a green thread and will either return the result of the lookup or raise an exception.

The DNSLookup object uses DNSManager, an object that will use the system nameservers and it will fallback to Google's nameservers (8.8.8.8 and 8.8.4.4) in case of failure.

DNS Manager

This object provides DNSLookup with the nameserver list that will be used to perform DNS lookups. It will probe the system local nameservers and check if they are able to do proper lookups (by querying sip2sip.info domain). If the local nameservers are not able to do proper lookups Google nameservers will be used and another probing operation will be scheduled. Local nameservers are always preferred.

methods

__init__(self)

Instantiate the DNSManager object (it's a Singleton).

start(self)

Start the DNSManager. It will start the probing process to determine the suitable nameservers to use.

stop(self)

Stop the DNS resolution probing.

notifications

DNSResolverDidInitialize

This notification is sent when the nameservers to use for probing (and further DNS lookups) have been set for the first time.

timestamp:

A datetime.datetime object indicating when the notification was sent.

nameservers:

The list of nameservers that was set on the DNS Manager.

DNSNameserversDidChange

This notification is sent when the nameservers to use for probing (and further DNS lookups) have changed as a result of the probing process.

timestamp:

A datetime.datetime object indicating when the notification was sent.

nameservers:

The list of nameservers that was set on the DNS Manager.

DNS Lookup

This object implements DNS lookup support for SIP proxies according to RFC3263 and MSRP relay and STUN server lookup using SRV records. The object initially does NS record queries in order to determine the authoritative nameservers for the domain requested; these authoritative nameservers will then be used for NAPTR, SRV and A record queries. If this fails, the locally configured nameservers are used. The reason for doing this is that some home routers have broken NAPTR and/or SRV query support.

methods

__init__(self)

Instantiate a new DNSLookup object.

lookup_service(self, uri, service, timeout=3.0, lifetime=15.0)

Perform an SRV lookup followed by A lookups for MSRP relays or STUN servers depending on the service parameter. If SRV queries on the uri.host domain fail, an A lookup is performed on it and the default port for the service is returned. Only the uri.host attribute is used. The return value is a list of (host, port) tuples.

uri:

A (Frozen)SIPURI from which the host attribute is used for the query domain.

service:

The service to lookup servers for, "msrprelay" or "stun".

timeout:

How many seconds to wait for a response from a nameserver.

lifetime:

How many seconds to wait for a response from all nameservers in total.

lookup_sip_proxy(self, uri, supported_transports, timeout=3.0, lifetime=15.0)

Perform a RFC3263 compliant DNS lookup for a SIP proxy using the URI which is considered to point to a host if either the host attribute is an IP address, or the port is present. Otherwise, it is considered a domain for which NAPTR, SRV and A lookups are performed. If NAPTR or SRV queries fail, they fallback to using SRV and A queries. If the transport parameter is present in the URI, this will be used as far as it is part of the supported transports. If the URI has a sips schema, then only the TLS transport will be used as far as it doesn't conflict with the supported transports or the transport parameter. The return value is a list of Route objects containing the IP address, port and transport to use for routing in the order of preference given by the supported_transports argument.

uri:

A (Frozen)SIPURI from which the host, port, parameters and secure attributes are used.

supported_transports:

A sublist of ['udp', 'tcp', 'tls'] in the application's order of preference.

timeout:

How many seconds to wait for a response from a nameserver.

lifetime:

How many seconds to wait for a response from all nameservers in total.

lookup_xcap_server(self, uri, timeout=3.0, lifetime=15.0)

Perform a TXT DNS query on xcap.<uri.host> and return all values of the TXT record which are URIs with a scheme of http or https. Only the uri.host attribute is used. The return value is a list of strings representing HTTP URIs.

uri:

A (Frozen)SIPURI from which the host attribute is used for the query domain.

timeout:

How many seconds to wait for a response from a nameserver.

lifetime:

How many seconds to wait for a response from all nameservers in total.

notifications

DNSLookupDidSucceed

This notification is sent when one of the lookup methods succeeds in finding a result.

timestamp:

A datetime.datetime object indicating when the notification was sent.

result:

The result of the DNS lookup in the format described in each method.

DNSLookupDidFail

This notification is sent when one of the lookup methods fails in finding a result.

timestamp:

A datetime.datetime object indicating when the notification was sent.

error:

A str object describing the error which resulted in the DNS lookup failure.

DNSLookupTrace

This notification is sent several times during a lookup process for each individual DNS query.

timestamp:

A datetime.datetime object indicating when the notification was sent.

query_type:

The type of the query, "NAPTR", "SRV", "A", "NS" etc.

query_name:

The name which was queried.

answer:

The answer returned by dnspython, or None if an error occurred.

error:

The exception which caused the query to fail, or None if no error occurred.

context:

The name of the method which was called on the DNSLookup object.

service:

The service which was queried for, only available when context is "lookup_service".

uri:

The uri which was queried for.

nameservers:

The list of nameservers that was used to perform the lookup.

Route

This is a convinience object which contains sufficient information to identify a route to a SIP proxy. This object is returned by DNSLookup.lookup_sip_proxy and can be used with the Session or a (Frozen)RouteHeader can be easily constructed from it to pass to one of the objects in the SIP core handling SIP dialogs/transactions (Invitation, Subscription, Request, Registration, Message, Publication). This object has three attributes which can be set in the constructor or after it was instantiated. They will only be documented as arguments to the constructor.

methods

__init__(self, address, port=None, transport='udp')

Creates the Route object with the specified parameters as attributes.
Each of these attributes can be accessed on the object once instanced.

address:

The IPv4 address that the request in question should be sent to as a string.

port:

The port to send the requests to, represented as an int, or None if the default port is to be used.

transport:

The transport to use, this can be a string of either "udp", "tcp" or "tls" (case insensitive).

get_uri(self)

Returns a SIPURI object which contains the adress, port and transport as parameter. This can be used to easily construct a RouteHeader:

    route = Route("1.2.3.4", port=1234, transport="tls")
    route_header = RouteHeader(route.get_uri())

SIP Accounts

Account Management is implemented in source:sipsimple/account.py (sipsimple.account module) and offers support for SIP accounts registered at SIP providers and SIP bonjour accounts which are discovered using mDNS.

AccountManager

The sipsimple.account.AccountManager is the entity responsible for loading and keeping track of the existing accounts. It is a singleton and can be instantiated anywhere, obtaining the same instance. It cannot be used until its start method has been called.

methods

__init__(self)

The __init__ method allows the AccountManager to be instantiated without passing any parameters. A reference to the AccountManager can be obtained anywhere before it is started.

start(self)

This method will load all the existing accounts from the configuration. If the Engine is running, the accounts will also activate. This method can only be called after the ConfigurationManager has been started. A SIPAccountManagerDidAddAccount will be sent for each account loaded. This method is called automatically by the SIPApplication when it initializes all the components of the middleware.

stop(self)

Calling this method will deactivate all accounts managed by the AccountManager. This method is called automatically by the SIPApplication when it stops.

has_account(self, id)

This method returns True if an account which has the specifed SIP ID (must be a string) exists and False otherwise.

get_account(self, id)

Returns the account (either an Account instance or the BonjourAccount instance) with the specified SIP ID. Will raise a KeyError if such an account does not exist.

get_accounts(self)

Returns a list containing all the managed accounts.

iter_accounts(self)

Returns an iterator through all the managed accounts.

find_account(self, contact_uri)

Returns an account with matches the specified contact_uri which must be a sipsimple.core.SIPURI instance. Only the accounts with the enabled flag set will be considered. Returns None if such an account does not exist.

notifications

SIPAccountManagerDidAddAccount

This notification is sent when a new account becomes available to the AccountManager. The notification is also sent when the accounts are loaded from the configuration.

timestamp:

A datetime.datetime object indicating when the notification was sent.

account:

The account object which was added.

SIPAccountManagerDidRemoveAccount

This notification is sent when an account is deleted using the delete method.

timestamp:

A datetime.datetime object indicating when the notification was sent.

account:

The account object which was deleted.

SIPAccountManagerDidChangeDefaultAccount

This notification is sent when the default account changes.

timestamp:

A datetime.datetime object indicating when the notification was sent.

old_account:

This is the account object which used to be the default account.

account:

This is the account object which is the new default account.

Account

The sipsimple.account.Account objects represent the SIP accounts which are registered at SIP providers. It has a dual purpose: it acts as both a container for account-related settings and as a complex object which can be used to interact with various per-account functions, such as presence, registration etc. This page documents the latter case, while the former is explained in the Configuration API.

There is exactly one instance of Account per SIP account used and it is uniquely identifiable by its SIP ID, in the form user@domain. It is a singleton, in the sense that instantiating Account using an already used SIP ID will return the same object. However, this is not the recommended way of accessing accounts, as this can lead to creation of new ones; the recommended way is by using the AccountManager. The next sections will use a lowercase, monospaced account to represent an instance of Account.

states

The Account objects have a setting flag called enabled which, if set to False will deactivate it: none of the internal functions will work in this case; in addition, the application using the middleware should not do anything with a disabled account. After changing it's value, the save() method needs to be called, as the flag is a setting and will not be used until this method is called:

account.enabled = True
account.save()

The Account objects will activate automatically when they are loaded/created if the enabled flag is set to True and the sipsimple.engine.Engine is running; if it is not running, the accounts will activate after the engine starts.

In order to create a new account, just create a new instance of Account with an id which doesn't belong to any other account.

The other functions of Account which run automatically have other enabled flags as well. They will only be activated when both the global enabled flag is set and the function-specific one. These are:

Account.sip.register.enabled

This flag controls the automatic registration of the account. The notifications SIPAccountRegistrationDidSucceed, SIPAccountRegistrationDidFail and SIPAccountRegistrationDidEnd are used to inform the status of this registration.

Account.presence.enabled

This flag controls the automatic subscription to buddies for the presence and dialog events and the publication of data for the presence event.

Account.message_summary.enabled

This flag controls the automatic subscription to the message-summary event in order to find out about voicemail messages.

The save() method needs to be called after changing these flags in order for them to take effect. The methods available on Account objects are inherited from SettingsObject.

attributes

The following attributes can be used on an Account object and need to be considered read-only.

id

This attribute is of type sipsimple.configuration.datatypes.SIPAddress (a subclass of str) and contains the SIP id of the account. It can be used as a normal string in the form user@domain, but it also allows access to the components via the attributes username and domain.

  account.id # 'alice@example.com'
  account.id.username # 'alice'
  account.id.domain # 'example.com'

contact

This attribute can be used to construct the Contact URI for SIP requests sent on behalf of this account. It's type is sipsimple.core.ContactURIFactory. It can be indexed by a URi type plus a string representing a transport ('udp', 'tcp', 'tls') or a sipsimple.util.Route object which will return a sipsimple.core.SIPURI object with the appropriate IP, port and transport. URI types are: NoGRUU, PublicGRUU, TemporaryGRUU, PublicGRUUIfAvailable and TemporaryGRUUIfAvailable. They can be imported from sipsimple.core. The username part is a randomly generated 8 character string consisting of lowercase letters; but it can be chosen by passing it to init when building the ContactURIFactory object.

  account.contact # 'ContactURIFactory(username=hnfkybrt)'
  account.contact.username # 'hnfkybrt'
  account.contact['udp'] # <SIPURI "sip:hnfkybrt@10.0.0.1:53024">
  account.contact['tls'] # <SIPURI "sip:hnfkybrt@10.0.0.1:54478;transport=tls">

credentials

This attribute is of type sipsimple.core.Credentials which is built from the id.username attribute and the password setting of the Account. Whenever this setting is changed, this attribute is updated.

  account.credentials # <Credentials for 'alice'>

tls_credentials

This attribute of type X509Credentials returns the TLS credentials object which is later used when establishing MSRP connections, for example.

uri

This attribute is of type sipsimple.core.SIPURI which can be used to form a FromHeader associated with this account. It contains the SIP ID of the account.

  account.uri # <SIPURI "sip:alice@example.com">

voicemail_uri

This attribute contains a string object representing the URI which is set as the subscription target for the message-summary event.

other

registered

Returns True if the account has registred, False otherwise.

mwi_active

Returns True if the account has an active subscription to the message-summary event, False otherwise.

presence_state

Property which can be used to get or set the presence state for the account. The presence state needs to be a PIDF object from the sipsimple.payloads module. The account itself takes care of the publication process.

dialog_state

Property which can be used to get or set the dialog state for the account. The dialog state needs to be a DialogInfo object from the sipsimple.payloads module. The account itself takes care of the publication process.

notifications

CFGSettingsObjectDidChange

This notification is sent when the save() method is called on the account after some of the settings were changed. As the notification belongs to the SettingsObject class, it is exaplained in detail in SettingsObject Notifications.

SIPAccountWillActivate

This notification is sent when the Account is about to be activated, but before actually performing any activation task. See SIPAccountDidActivate for more detail.

SIPAccountDidActivate

This notification is sent when the Account activates. This can happen when the Account is loaded if it's enabled flag is set and the Engine is running, and at any later time when the status of the Engine changes or the enabled flag is modified.

SIPAccountWillDeactivate

This notification is sent when the Account is about to be deactivated, but before performing any deactivation task. See SIPAccountDidDeactivate for more detail.

SIPAccountDidDeactivate

This notification is sent when the Account deactivates. This can happend when the Engine is stopped or when the enabled flag of the account is set to False.

SIPAccountWillRegister

This notification is sent when the account is about to register for the first time.

SIPAccountRegistrationWillRefresh

This notification is sent when a registration is about to be refreshed.

SIPAccountRegistrationDidSucceed

This notification is sent when a REGISTER request sent for the account succeeds (it is also sent for each refresh of the registration). The data contained in this notification is:

contact_header:

The Contact header which was registered.

contact_header_list:

A list containing all the contacts registered for this SIP account.

expires:

The amount in seconds in which this registration will expire.

registrar:

The sipsimple.util.Route object which was used.

SIPAccountRegistrationDidFail

This notification is sent when a REGISTER request sent for the account fails. It can fail either because a negative response was returned or because PJSIP considered the request failed (e.g. on timeout). The data contained in this notification is:

error:

The reason for the failure of the REGISTER request.

retry_after:

The amount in seconds as a float after which the registration will be tried again.

SIPAccountRegistrationDidEnd

This notification is sent when a registration is ended (the account is unregistered). The data contained in this notification is:

registration:

The sipsimple.core.Registration object which ended.

SIPAccountRegistrationDidNotEnd

This notification is sent when a registration fails to end (the account is not unregistered). The data contained in this notification is:

code:

The SIP status code received.

reason:

The SIP status reason received.

registration:

The sipsimple.core.Registration object which ended.

SIPAccountRegistrationGotAnswer

This notification is sent whenever a response is received to a sent REGISTER request for this account. The data contained in this notification is:

code:

The SIP status code received.

reason:

The SIP status reason received.

registration:

The sipsimple.core.Registration object which was used.

registrar:

The sipsimple.util.Route object which was used.

SIPAccountGotMessageSummary

This notification is sent when a NOTIFY is received with a message-summary payload. The data contained in this notification is:

message_summary:

A sipsimple.payloads.messagesummary.MessageSummary object with the parsed payload from the NOTIFY request.

SIPAccountGotPresenceWinfo

This notification is sent when a NOTIFY is received with a presence.winfo payload. The data contained in this notification is:

version:

The version number of the received document.

state:

Indicates if the received state is full or partial.

watcher_list:

A sipsimple.payloads.watcherinfo.WatcherList object with the parsed information from the NOTIFY request.

SIPAccountGotDialogWinfo

This notification is sent when a NOTIFY is received with a dialog.winfo payload. The data contained in this notification is:

version:

The version number of the received document.

state:

Indicates if the received state is full or partial.

watcher_list:

A sipsimple.payloads.watcherinfo.WatcherList object with the parsed information from the NOTIFY request.

SIPAccountGotPresenceState

This notification is sent when a NOTIFY is received with a presence payload. The data contained in this notification is:

version:

The version number of the received document.

full_state:

Boolean flag indicating if the received state is full or partial.

resource_map:

Dictionary mapping SIP URIs to sipsimple.payloads.rlsnotify.Resource instances which contain all presence documents associated with them.

SIPAccountGotDialogState

This notification is sent when a NOTIFY is received with a dialog payload. The data contained in this notification is:

version:

The version number of the received document.

full_state:

Boolean flag indicating if the received state is full or partial.

resource_map:

Dictionary mapping SIP URIs to sipsimple.payloads.rlsnotify.Resource instances which contain all dialog-info documents associated with them.

BonjourAccount

The sipsimple.account.BonjourAccount represents the SIP account used for P2P mode; it does not interact with any server. The class is a singleton, as there can only be one such account on a system. Similar to the Account, it is used both as a complex object, which implements the functions for bonjour mode, as well as a container for the related settings.

states

The BonjourAccount has an enabled flag which controls whether this account will be used or not. If it is set to False, none of the internal functions will be activated and, in addition, the account should not be used by the application. The bonjour account can only activated if the Engine is running; once it is started, if the enabled flag is set, the account will activate. When the BonjourAccount is activated, it will broadcast the contact address on the LAN and discover its neighbours sending notifications as this happens.

attributes

The following attributes can be used on a BonjourAccount object and need to be considered read-only.

id

This attribute is of type sipsimple.configuration.datatypes.SIPAddress (a subclass of str) and contains the SIP id of the account, which is 'bonjour@local'. It can be used as a normal string, but it also allows access to the components via the attributes username and domain.

  bonjour_account.id # 'bonjour@local'
  bonjour_account.id.username # 'bonjour'
  bonjour_account.id.domain # 'local'

contact

This attribute can be used to construct the Contact URI for SIP requests sent on behalf of this account. It's type is sipsimple.account.ContactURIFactory. It can be indexed by a string representing a transport ('udp', 'tcp', 'tls') or a sipsimple.util.Route object which will return a sipsimple.core.SIPURI object with the appropriate IP, port and transport. The username part is a randomly generated 8 character string consisting of lowercase letters; but it can be chosen by passing it to init when building the ContactURIFactory object.

  bonjour_account.contact # 'ContactURIFactory(username=lxzvgack)'
  bonjour_account.contact.username # 'lxzvgack'
  bonjour_account.contact['udp'] # <SIPURI "sip:lxzvgack@10.0.0.1:53024">
  bonjour_account.contact['tls'] # <SIPURI "sip:lxzvgack@10.0.0.1:54478;transport=tls">

credentials

This attribute is of type sipsimple.core.Credentials object which is built from the contact.username attribute; the password is set to the empty string.

  bonjour_account.credentials # <Credentials for 'alice'>

uri

This attribute is of type sipsimple.core.SIPURI which can be used to form a FromHeader associated with this account. It contains the contact address of the bonjour account:

  bonjour_account.uri # <SIPURI "sip:lxzvgack@10.0.0.1">

notifications

BonjourAccountDidAddNeighbour

This notification is sent when a new Bonjour neighbour is discovered.

service_description:

BonjourServiceDescription object uniquely identifying this neighbour in the mDNS library.

display_name:

The name of the neighbour as it is published.

host:

The hostname of the machine from which the Bonjour neighbour registered its contact address.

uri:

The contact URI of the Bonjour neighbour, as a FrozenSIPURI object.

timestamp:

A datetime.datetime object indicating when the notification was sent.

BonjourAccountDidUpdateNeighbour

This notification is sent when an existing Bonjour neighbour has updates its published data.

service_description:

BonjourServiceDescription object uniquely identifying this neighbour in the mDNS library.

display_name:

The name of the neighbour as it is published.

host:

The hostname of the machine from which the Bonjour neighbour registered its contact address.

uri:

The contact URI of the Bonjour neighbour, as a FrozenSIPURI object.

timestamp:

A datetime.datetime object indicating when the notification was sent.

BonjourAccountDidRemoveNeighbour

This notification is sent when a Bonjour neighbour unregisters.

service_description:

The BonjourServiceDescription object, which uniquely identifies a neighbour, that got unregistered.

BonjourAccountDiscoveryDidFail

This notification is sent once per transport when the Bonjour account has failed to perform the discovery process for the indicated transport.

reason:

String defining the reason of the failure.

transport:

String specifying the transport for which the discovery failed.

timestamp:

A datetime.datetime object indicating when the notification was sent.

BonjourAccountDiscoveryFailure

This notification is sent once per transport when the Bonjour account has encountered a problem while browsing the list of neighbours for the indicated transport.

error:

String defining the error of the failure.

transport:

String specifying the transport for which the neighbour resoution failed.

timestamp:

A datetime.datetime object indicating when the notification was sent.

BonjourAccountRegistrationDidEnd

This notification is sent once per transport when the Bonjour account unregisters its contact address for the indicated transport using mDNS.

transport:

String specifying the transport for which the registration ended.

timestamp:

A datetime.datetime object indicating when the notification was sent.

BonjourAccountRegistrationDidFail

This notification is sent once per transport when the Bonjour account fails to register its contact address for the indicated transport using mDNS.

reason:

A human readable error message.

transport:

String specifying the transport for which the registration failed.

timestamp:

A datetime.datetime object indicating when the notification was sent.

BonjourAccountRegistrationUpdateDidFail

This notification is sent once per transport when the Bonjour account fails to update its data for the indicated transport using mDNS.

reason:

A human readable error message.

transport:

String specifying the transport for which the registration update failed.

timestamp:

A datetime.datetime object indicating when the notification was sent.

BonjourAccountRegistrationDidSucceed

This notification is sent once per transport when the Bonjour account successfully registers its contact address for the indicated transport using mDNS.

name:

The contact address registered.

transport:

String specifying the transport for which the registration succeeded.

timestamp:

A datetime.datetime object indicating when the notification was sent.

BonjourAccountWillInitateDiscovery

This notification is sent when the Bonjour account is about to start the discovery process for the indicated transport.

transport:

String specifying the transport for which the discovery will be started.

timestamp:

A datetime.datetime object indicating when the notification was sent.

BonjourAccountWillRegister

This notification is sent just before the Bonjour account starts the registering process for the indicated transport.

transport:

String specifying the transport for which the registration will be started.

timestamp:

A datetime.datetime object indicating when the notification was sent.

CFGSettingsObjectDidChange

This notification is sent when the save() method is called on the account after some of the settings were changed. As the notification belongs to the SettingsObject class, it is exaplained in detail in SettingsObject Notifications.
timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPAccountWillActivate

This notification is sent when the BonjourAccount is about to be activated, but before actually performing any activation task. See SIPAccountDidActivate for more detail.

timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPAccountDidActivate

This notification is sent when the BonjourAccount activates. This can happen when the BonjourAccount is loaded if it's enabled flag is set and the Engine is running, and at any later time when the status of the Engine changes or the enabled flag is modified.

timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPAccountWillDeactivate

This notification is sent when the BonjourAccount is about to be deactivated, but before performing any deactivation task. See SIPAccountDidDeactivate for more detail.
timestamp:

A datetime.datetime object indicating when the notification was sent.

SIPAccountDidDeactivate

This notification is sent when the BonjourAccount deactivates. This can happend when the Engine is stopped or when the enabled flag of the account is set to False.
timestamp:

A datetime.datetime object indicating when the notification was sent.

Audio

The high-level audio API hides the complexity of using the low-level PJMEDIA interface. This is implemented in the sipsimple.audio module and contains the following components:
  • IAudioPort: an interface describing an object capable of producing and/or consuming audio data.
  • AudioDevice: an object conforming to the IAudioPort interface which describes a physical audio device.
  • AudioBridge: a collection of objects conforming to IAudioPort which connects all of them in a full mesh.
  • WavePlayer: an object conforming to the IAudioPort interface which can playback the audio data from a .wav file.
  • WaveRecorder: an object conforming to the IAudioPort interface which can record audio data to a .wav file.

IAudioPort

The IAudioPort interface describes an object capable of producing and/or consuming audio data. This can be a dynamic object, which changes its role during its lifetime and notifies such changes using a notification, which is part of the interface.

attributes

mixer

The AudioMixer this audio object is connected to. Only audio objects connected to the same mixer will be able to send audio data from one to another.

consumer_slot

An integer representing the slot (see AudioMixer) which this object uses to consume audio data, or None if this object is not a consumer.

producer_slot

An integer representing the slot (see AudioMixer) which this object uses to produce audio data, or None if this object is not a producer.

notifications

AudioPortDidChangeSlots

This notification needs to be sent by implementations of this interface when the slots it has change, so as to let the AudioBridges it is part of know that reconnections need to be made.

consumer_slot_changed:

A bool indicating whether the consumer slot was changed.

producer_slot_changed:

A bool indicating whether the producer slot was changed.

old_consumer_slot:

The old slot for consuming audio data. Only required if consumer_slot_changed is True.

new_consumer_slot:

The new slot for consuming audio data. Only required if consumer_slot_changed is True.

old_producer_slot:

The old slot for producing audio data. Only required if producer_slot_changed is True.

new_producer_slot:

The new slot for producing audio data. Only required if producer_slot_changed is True.

AudioDevice

The AudioDevice represents the physical audio device which is part of a AudioMixer, implementing the IAudioPort interface. As such, it can be uniquely identified by the mixer it represents.

methods

__init__(self, mixer, input_muted=False, output_muted=False):

Instantiates a new AudioDevice which represents the physical device associated with the specified AudioMixer.

mixer:

The AudioMixer whose physical device this object represents.

input_muted:

A boolean which indicates whether this object should act as a producer of audio data.

output_muted:

A boolean which indicates whether this object should act as a consumer of audio data.

attributes

input_muted

A writable property which controls whether this object should act as a producer of audio data. An AudioPortDidChange slots notification is sent when this attribute is changed to force connections to be reconsidered within the AudioBridges this object is part of.

output_muted

A writable property which controls whether this object should act as a consumer of audio data. An AudioPortDidChange slots notification is sent when this attribute is changed to force connections to be reconsidered within the AudioBridges this object is part of.

AudioBridge

The AudioBridge is the basic component which is able to connect IAudioPort implementations. It acts as a container which connects as the producers to all the consumers which are part of it. An object which is both a producer and a consumer of audio data will not be connected to itself. Being an implementation of IAudioPort itself, an AudioBridge can be part of another AudioBridge. The AudioBridge does not keep strong references to the ports it contains and once the port's reference count reaches 0, it is automatically removed from the AudioBridge.

Note: although this is not enforced, there should never be any cycles when connecting AudioBridges.

methods

__init__(self, mixer)

Instantiate a new AudioBridge which uses the specified AudioMixer for mixing.

add(self, port)

Add an implementation of IAudioPort to this AudioBridge. This will connect the new port to all the existing ports of the bridge. A port cannot be added more than once to an AudioBridge; thus, this object acts like a set.

remove(self, port)

Remove a port from this AudioBridge. The port must have previously been added to the AudioBridge, otherwise a ValueError is raised.

WavePlayer

A WavePlayer is an implementation of IAudioPort which is capable of producing audio data read from a .wav file. This object is completely reusable, as it can be started and stopped any number of times.

methods

__init__(self, mixer, filename, volume=100, loop_count=1, pause_time=0, initial_play=True)

Instantiate a new WavePlayer which is capable of playing a .wav file repeatedly. All the parameters are available as attributes of the object, but should not be changed once the object has been started.

mixer:

The AudioMixer this object is connected to.

filename:

The full path to the .wav file from which audio data is to be read.

volume:

The volume at which the file should be played.

loop_count:

The number of times the file should be played, or 0 for infinity.

pause_time:

How many seconds to wait between successive plays of the file.

initial_play:

Whether or not the file to play once the WavePlayer is started, or to wait pause_time seconds before the first play.

start(self)

Start playing the .wav file.

stop(self)

Stop playing the .wav file immediately.

play(self)

Play the .wav file. This method is an alternative to the start/stop methods, it runs on a waitable green thread. One may call play().wait() in order to green-block waiting for the file playback to end.

attributes

is_active

A boolean indicating whether or not this WavePlayer is currently playing.

notifications

WavePlayerDidStart

This notification is sent when the WavePlayer starts playing the file the first time after the start() method has been called.

timestamp:

A datetime.datetime object indicating when the notification was sent.

WavePlayerDidEnd

This notification is sent when the WavePlayer is done playing either as a result of playing the number of times it was told to, or because the stop() method has been called.

timestamp:

A datetime.datetime object indicating when the notification was sent.

WavePlayerDidFail

This notification is sent when the WavePlayer is not capable of playing the .wav file.

timestamp:

A datetime.datetime object indicating when the notification was sent.

error:

The exception raised by the WaveFile which identifies the cause for not being able to play the .wav file.

WaveRecorder

A WaveRecorder is an implementation of IAudioPort is is capable of consuming audio data and writing it to a .wav file. Just like WavePlayer, this object is reusable: once stopped it can be started again, but if the filename attribute is not changed, the previously written file will be overwritten.

methods

__init__(self, mixer, filename)

Instantiate a new WaveRecorder.

mixer:

The AudioMixer this WaveRecorder is connected to.

filename:

The full path to the .wav file where this object should write the audio data. The file must be writable. The directories up to the file will be created if possible when the start() method is called.

start(self)

Start consuming audio data and writing it to the .wav file. If this object is not part of an AudioBridge, not audio data will be written.

stop(self)

Stop consuming audio data and close the .wav file.

attributes

is_active

A boolean indicating whether or not this WaveRecorder is currently recording audio data.

Conference

Conference support is implemented in the sipsimple.conference module. Currently, only audio conferencing is supported.

AudioConference

This class contains the basic implementation for audio conferencing. It acts as a container for AudioStream objects which it will connect in a full mesh, such that all participants can hear all other participants.

methods

__init__(self)

Instantiates a new AudioConference which is ready to contain AudioStream objects.

add(self, stream)

Add the specified AudioStream object to the conference.

remove(self, stream)

Removes the specified AudioStream object from the conference. Raises a ValueError if the stream is not part of the conference.

hold(self)

Puts the conference "on hold". This means that the audio device will be disconnected from the conference: all the participants will be able to continue the conference, but the local party will no longer contribute any audio data and will not receive any audio data using the input and output devices respectively. This does not affect the hold state of the streams in any way.

unhold(self)

Removes the conference "from hold". This means that the audio device will be reconnected to the conference: all the participants will start to hear the local party and the local party will start to hear all the participants. This does not affect the hold state of the streams in any way.

attributes

bridge

An AudioBridge which this conference uses to connect all audio streams. It can be used by the application to play a wav file using a WavePlayer to all the participants or record the whole conference using a WaveRecorder.

on_hold

A boolean indicating whether or not the conference is "on hold".

streams

The list of streams which are part of this conference. The application must not manipulate this list in any way.

XCAP support

The sipsimple.xcap module offers a high level API for managing XCAP resources to other parts of the middleware or to the applications built on top of the middleware. The XCAP resources
which can be managed by means of this module are:
  • contact list, by means of the resource-lists and rls-services XCAP applications
  • presence policies, by means of the org.openmobilealliance.pres-rules or pres-rules XCAP applications
  • dialoginfo policies, by means of the org.openxcap.dialog-rules XCAP application
  • status icon, by means of the org.openmobilealliance.pres-content XCAP application
  • offline status, by means of the pidf-manipulation XCAP application

The module works with OMA-compliant XCAP servers. Not all applications need to be available on the XCAP server, although it is obvious that only those that are will be managed. The required applications are: org.openmobilealliance.pres-rules, resource-lists and rls-services. The central entity for XCAP resource management is the XCAPManager, whose API relies on a series of objects describing
the resources stored on the XCAP server.

Contact

Implemented in source:"sipsimple/xcap/__init__.py"

A Contact is the representation of a person, containing a list of URIs with additional information stored about them, central to the XCAP contact list management. Information about a contact is stored in the resource-lists, rls-services and org.openmobilealliance.pres-rules applications mainly.

attributes

id

A unique identifier for the contact. Should be composed of a sufficiently random string across multiple instances.

name

A human-readable name which can be associated with the contact. This is stored using the display-name standard resource-lists element.

uris

A list of sipsimple.account.xcap.ContactURI instances.

dialog

A sipsimple.account.xcap.EventHandling instance which specifies the policy for this contact, and a boolean flag that indicates whether a subscription to the dialog event is desired.

presence

A sipsimple.account.xcap.EventHandling instance which specifies the policy for this contact, and a boolean flag that indicates whether a subscription to the presence event is desired.

attributes

A dictionary containing additional name, value pairs which the middleware or the application can use to store any information regarding this contact. This is stored through a custom AG-Projects
extension to resource-lists.

methods

__init__(self, id, name, uris, presence_handling=None, dialog_handling=None, **attributes)

Initializes a new Contact instance. If presence_handling and dialog_handling are set to None then defaults are created with a default policy and the subscription boolean flag set to False.

Policy

Implemented in source:"sipsimple/xcap/__init__.py"

A Policy is similar to a Contact but instead of representing a physical person, it represents a policy which is applied to a single URI.

attributes

id

A unique identifier for the policy. Should be composed of a sufficiently random string across multiple instances.

name

A human-readable name which can be associated with the policy.

uri

A string object representing the URI of this policy.

dialog

A sipsimple.account.xcap.EventHandling instance which specifies the policy for this policy, and a boolean flag that indicates whether a subscription to the dialog event is desired.

presence

A sipsimple.account.xcap.EventHandling instance which specifies the policy for this policy, and a boolean flag that indicates whether a subscription to the presence event is desired.

attributes

A dictionary containing additional name, value pairs which the middleware or the application can use to store any information regarding this policy. This is stored through a custom AG-Projects
extension to resource-lists.

methods

__init__(self, id, name, uri, presence_handling=None, dialog_handling=None, **attributes)

Initializes a new Policy instance. If presence_handling and dialog_handling are set to None then defaults are created with a default policy and the subscription boolean flag set to False.

Group

Implemented in source:"sipsimple/xcap/__init__.py"

A Group is a toplevel element which represents a logical entity for grouping contacts together.

attributes

id

A unique identifier for the group. Should be composed of a sufficiently random string across multiple instances.

name

A human-readable name which can be associated with the group.

contacts

A list of Contact objects.

attributes

A dictionary containing additional name, value pairs which the middleware or the application can use to store any information regarding this policy. This is stored through a custom AG-Projects
extension to resource-lists.

methods

__init__(self, id, name, contacts, **attributes)

Initializes a new Group instance.

Addressbook

Implemented in source:"sipsimple/xcap/__init__.py"

An Adressbook is a collection of contacts, groups and policies.

attributes

contacts

A list of Contact objects.

groups

A list of Group objects.

policies

A list of Policy objects.

methods

__init__(self, contacts, groups, policies)

Initializes a new Addressbook instance.

Icon

Implemented in source:"sipsimple/xcap/__init__.py"

An Icon instance represents a status icon stored using the org.openmobilealliance.pres-content application.

attributes

data

The binary data of the image, as a string.

mime_type

The MIME type of the image, one of image/jpeg, image/gif or image/png.

description

An optional description of the icon.

location

An HTTP URI which can be used by other users to download the status icon of the local user. If the XCAP server returns the custom X-Alternative-Location header in its GET and PUT
responses, that is used otherwise the XCAP URI of the icon is used.

methods

__init__(self, data, mime_type, description=None, location=None)

Initializes a new Icon instance.

OfflineStatus

Implemented in source:"sipsimple/xcap/__init__.py"

An OfflineStatus instance represents data stored using the pidf-manipulation application.

attributes

pidf

A sipsimple.payloads.pidf.PIDF instance which is stored in XCAP.

methods

__init__(self, pidf)

Initializes a new OfflineStatus instance.

XCAPManager

Implemented in source:"sipsimple/xcap/__init__.py"

The XCAPManager is the central entity used to manage resource via the XCAP protocol. It uses a storage factory provided by SIPApplication through the Storage API. It has state machine as described in the following diagram:

The load method needs to be called just once in order to load the data from the cache. Once this is done, the start and stop methods can be called as needed. Initially in the stopped state,
the start method will result in a transition to the initializing state. While in the initializing state, the XCAP manager will try to connect to the XCAP server and retrieve the
capabilities (xcap-caps application). It will then initiate a SUBSCRIBE for the xcap-diff event and transition to the fetching state. In the fetching state, it
will try retrieve all the documents from the XCAP server, also specifying the ETag of the last known version. If none of the documents changed and this is not the first fetch, it transitions to the
insync state. Otherwise, it inserts a normalize operation at the beginning of the journal (described below) and transitions to the updating state. In the updating state, it
applies the operations from the journal which were not applied yet on the currently known documents and tries to push the documents, specifying the Etag of the last known version. If an operation
fails due to a document having been modified, it marks all the operations in the journal as not being applied and transitions to the fetching state; if any other error occurs, the update is
retried periodically. If the update succeeds, data is extracted from the documents and the XCAPManagerDidReloadData notification is sent. The XCAPManager then transitions to the insync
state. A call to the stop method will result in a transition to the stopping state, termination of any existing SUBSCRIBE dialog and a transition to the stopped state.

Modifications to the settings which control the XCAPManager can result in either a transition to the initializing state or the termination of any previous SUBSCRIBE dialog and creation of a new
one.

The subscription to the xcap-diff event allows the XCAPManager to be notified when the documents it manages are modified remotely. If the subscription fails, a fetch of all the documents is
tried and the subscription is retried in some time. This allows the XCAPManager to reload the documents when they are modified remotely even if xcap-diff event is not supported by the provider. If subscription for xcap-diff event fails, a fetch of all the documents will be tried every 2 minutes.

The XCAPManager keeps the documents as they are stored on the XCAP server along with their ETags in an on-disk cache. All operations are made using the conditional If-Match and
If-None-Match headers such that remote modifications the XCAPManager does not know about are not overwritten and bandwidth and processing power are not wasted by GET operations when a document
is not modified.

Operations which the XCAPManager can be asked to apply to modify the documents are kept in a journal. This journal is saved to disk, such that operations which cannot be applied when requested due
to server problems or lack of connectivity are retried even after application restarts. In addition, the high-level defined operations and the journal allow the modifications to be applied even if the
document stored on the XCAP server are modified. Put differently, operations do depend on a specific version of the documents and the XCAPManager will try to apply them irrespective of the format
of the document.

configuration

Account.id, Account.auth.username, Account.auth.password

These are used both for the xcap-diff subscription and the XCAP server connection.

Account.sip.subscribe_interval

This controls the Expires header used for the subscription, although a 423 response from the server can result in a larger Expires value being used.

Account.xcap.xcap_root

This specifies the XCAP root used for contacting the XCAP server and managing the resources. If this setting is None, a TXT DNS query is made for the xcap subdomain of the SIP account's
domain. The result is interpreted as being an XCAP root. Example record for account :

  xcap.example.org.    IN  TXT     "https://xcap.example.org/xcap-root" 

SIPSimpleSettings.sip.transport_list

This controls the transports which can be used for the subscription.

methods

__init__(self, account)

Initializes an XCAPManager for the specified account.

init(self)

Initializes the XCAPManager before it can be started.

start(self)

Starts the XCAPManager. This will result in the subscription being started, the XCAP server being contacted and any operations in the journal being applied. This method must be called in a green
thread.

stop(self)

Stops the XCAPManager from performing any tasks. Waits until the xcap-diff subscription, if any, is terminated. This method must be called in a green thread.

transaction(self)

Return as XCAPTransaction context manager object for running a piece of code within a transaction.

start_transaction(self)

This allows multiple operations to be queued and not applied immediately. All operations queued after a call to this method will not be applied until the commit_transaction method is called.
This does not have the same meaning as a relational database transaction, since there is no rollback operation.

commit_transaction(self)

Applies the modifications queued after a call to start_transaction. This method needs to be called the exact same number of times the start_transaction method was called. Does not have
any effect if start_transaction was not previously called.

The following methods results in XCAP operations being queued on the journal:

add_group(self, group)

Add a group.

update_group(self, group, attributes)

Update the specified group with the given attributes.

remove_group(self, group)

Remove the specified group.

add_contact(self, contact)

Adds a new contact, described by a Contact object. Requests to add a contact to some OMA reserved presence policies (wp_prs_unlisted, wp_prs_allow_unlisted, wp_prs_block_anonymous, wp_prs_allow_own) is ignored.

update_contact(self, contact, attributes)

Modifies a contact's properties. The keywords can be any of the Contact attributes, with the same meaning. Requests to add a contact to some OMA reserved presence policies (wp_prs_unlisted, wp_prs_allow_unlisted, wp_prs_block_anonymous, wp_prs_allow_own) is ignored.

remove_contact(self, contact)

Removes the specified contact.

add_contact_uri(self, contact, uri)

Add the specified URI to the specified contact.

update_contact_uri(self, contact, uri, attributes)

Update the specified URI.

remove_contact_uri(self, contact, uri)

Remove the specified URI from the specified contact.

add_group_member(self, group, contact)

Adds the specified contact to the specified group. A contact may be added to multiple groups.

remove_group_member(self, group, contact)

Removes the specified contact from the specified group.

add_policy(self, policy)

Adds a new policy, described by a Policy object.

update_policy(self, policy, attributes)

Modifies a presence policy's properties. The keywords can be any of the PresencePolicy attributes, with the same meaning.

remove_policy(self, policy)

Removes the specified policy.

set_status_icon(self, icon)

Sets the status icon using the information from the Icon object specified. The location attribute is ignored. The MIME type must be one of image/gif, image/png or image/jpeg. If the argument is None, the status icon is deleted.

set_offline_status(self, status)

Sets the offline status using the information from the OfflineStatus object specified. If the argument is None, the offline status document is deleted.

notifications

XCAPManagerWillStart

This notification is sent just after calling the start method.

XCAPManagerDidStart

This notification is sent after the XCAPManager has started doing its tasks (contacting the XCAP server, subscribing to xcap-diff event). This notification does not mean that
any of these operations were successful, as the XCAPManager will retry them continuously should they fail.

XCAPManagerWillEnd

This notification is sent just after calling the stop method.

XCAPManagerDidEnd

This notification is sent when the XCAPManager has stopped performing any tasks. This also means that any active xcap-diff subscription has been terminated.

XCAPManagerDidDiscoverServerCapabilities

This notification is sent when the XCAPManager contacts an XCAP server for the first time or after the connection is reset due to configuration changes. The data of the notification contains
information about the server's capabilities (obtained using the xcap-caps application).

auids:

A list of string representing the AUIDs supported by the server.

XCAPManagerDidReloadData

This notification is sent when the XCAPManager synchronizes with the XCAP server. The data of the notification contains objects representing the data as it is stored on the XCAP server.

addressbook:

A sipsimple.account.xcap.Addressbook object instance.

presence_rules:

A sipsimple.account.xcap.PresenceRules object. Currently it only contains the default policy.

dialog_rules:

A sipsimple.account.xcap.DialogRules object. Currently it only contains the default policy.

status_icon:

A StatusIcon object if one is stored, None otherwise.

offline_status:

A OfflineStatus object if offline status information is stored, None otherwise.

XCAPManagerDidChangeState

This notification is sent when the XCAPManager transitions from one state to another.

prev_state:

The old state of the XCAPManager, a string.

state:

The new state of the XCAPManager, a string.

Addressbook API

Implemented in source:"sipsimple/addressbook.py"

The Addressbook API is used to manage the contact list in SIP SIMPLE SDK. It stores contacts locally and uses the XCAP API underneath to synchronize the contacts between instances.

AddressbookManager

It's the central point to the addressbook. It stores the contacts and takes care of the synchronization.

methods:

has_contact(self, id)

Returns True if the given id belongs to a existing contact, False otherwise.

get_contact(self, id)

Returns the Contact instance for the given id.

get_contacts(self)

Returns the full list of contacts.

has_group(self, id)

Returns True if the given id belongs to a existing group, False otherwise.

get_group(self, id)

Returns the Group instance for the given id.

get_groups(self)

Returns the full list of groups.

has_policy(self, id)

Returns True if the given id belongs to a existing policy, False otherwise.

get_policy(self, id)

Returns the Policy instance for the given id.

get_policies(self)

Returns the full list of policies.

transaction(self)

Returns an instance of MultiAccountTransaction, which can be used as a context manager to apply multiple changes to the addressbook in a single shot.

notifications:

AddressbookManagerDidAddContact

This notification is sent when the AddressbookManager adds a new contact.

contact:

The added Contact object.

AddressbookManagerDidRemoveContact

This notification is sent when the AddressbookManager removes a contact.

contact:

The removed Contact object.

AddressbookManagerDidAddGroup

This notification is sent when the AddressbookManager adds a new group.

group:

The added Group object.

AddressbookManagerDidRemoveGroup

This notification is sent when the AddressbookManager removes a group.

group:

The removed Group object.

AddressbookManagerDidAddPolicy

This notification is sent when the AddressbookManager adds a new policy.

policy:

The added Policy object.

AddressbookManagerDidRemovePolicy

This notification is sent when the AddressbookManager removes a policy.

policy:

The removed Policy object.

sipsimple-middleware.png - Middleware Architecture (208.3 kB) Adrian Georgescu, 09/10/2010 02:01 pm

sipsimple-core-invite-state-machine-2.png (156.1 kB) Tijmen de Mes, 04/19/2012 03:46 pm