Help for Blink QT for Windows and Linux

To use Blink you need a SIP account from a SIP service provider. Similar to using an email program, you must configure Blink with the account you have obtained from your service provider. If things do not work the way you expect, there can be several reasons. The cause may be located by Blink software itself, the network connectivity or the SIP Service Provider. While Blink may not be bug free, based on experience so far most of the problems are related to the network connectivity (packet loss, presence of a broken SIP ALG router) or/and the SIP Service Provider (most provider only support Voice calls). It is not the end-user who should understand the mechanics about how things work, so the main responsibility of making sure that things work correct falls into the hands of the SIP service provider who must properly setup its SIP infrastructure. To eliminate some possible causes, try to use the built-in accounts provided by Blink, all features are known to be working using these accounts.

For help about Blink Pro/Lite on MacOSX see "Help for Blink Pro"


  • Multiple SIP accounts
  • Bonjour neighborhood discovery
  • SIP server discovery using DNS (NAPTR, SRV, A records lookup)
  • Audio calls (Opus, G.722, G.711, Speex, GSM, ilBC codecs)
  • Video calls (H.264 and VP8 codecs)
  • Chat sessions (MSRP protocol)
  • File Transfer (MSRP protocol)
  • Multiparty audio conference (both client and server)
  • Multiparty chat conference (MSRP switch client)
  • SIMPLE Presence (XCAP, Publish, RLS subscribe)
  • Contacts management (XCAP)
  • Google contacts integration
  • Voicemail notifications
  • Call history, recording, redial and hold
  • ICE NAT traversal
  • SDES and ZRTP encryption for RTP streams
  • Hotplug audio device detection (Windows)

Connectivity Problems

If you encounter connectivity problems like inability to receive incoming calls or failure to make outbound calls, you should obtain the SIP trace logs and contact your SIP Service Provider and ask for the reason.

SIP Trace Logs

SIP Protocol trace can be enabled in menu Blink -> Preferences -> Logging -> SIP trace. The location of the trace file is:

  • Linux: ~/.blink/logs/sip_trace.txt
  • Windows XP: C:\Documents and Settings\Username\Application Data\Blink\logs\sip_trace.txt
  • Windows Vista and 7: C:\Users\Username\AppData\Roaming\Blink\logs\sip_trace.txt

Reporting Problems

Go to Blink Support Forum

Please report your OS name and version and Blink version. You can find Blink version in menu Blink -> About.

Program Exceptions

On Linux, Blink program exceptions are logged to standard error (if running from a terminal).

On Windows, Blink exceptions are logged to output.log, which is located in different places dependin on the Windows version:
  • Windows XP: C:\Documents and Settings\Username\Application Data\Blink\logs\output.log
  • Windows Vista and 7: C:\Users\Username\AppData\Roaming\Blink\logs\output.log

These files can easily be accessed from the Window -> Logs menu.

Crash Reports

On Linux, in case of a crash, a core file is generated in the user home directory. If no dump is generated, add to the user profile ulimit -c unlimited

On Windows XP, crash dump files can be found in the folowing folder: C:\Documents and Settings\All Users\Application Data\Microsoft\Dr Watson, the filenames are called drwtsn32.log and user.dmp. The dump file user.dmp can be analyzed with the Windows Debugger. Load the file user.dmp in Windows Debugger and type !analyze -v to obtain a backtrace. Click here for instructions on how to use the debugger.

Configuration File

Blink accounts and settings are stored in a flat-text configuration file.

It is critical that you do not edit this file manually. If you did and Blink does not start you must delete the file and start all over again. The location of the configuration file is:

  • Linux: ~/.blink/logs/config
  • Windows XP: C:\Documents and Settings\Username\Application Data\Blink\config
  • Windows Vista and 7: C:\Users\Username\AppData\Roaming\Blink\config

If you send the configuration file to us for debugging, use a text editor to strip the passwords and Google token.

SIP Accounts

To use Blink you need a SIP Account. At first start, Blink shows the Add Account wizard that helps you configure the initial SIP Account.

If you do not have a SIP Account, Blink can create one for you using the free service provided by SIP2SIP. For more information about this service visit

If you already have a SIP Account, select this option then enter the SIP address in the form of user@domain and password. The SIP registrar of the domain is then automatically located in the DNS.

You may configure Blink to use multiple SIP Accounts. To configure a new SIP Account, go to menu Blink->Accounts->Add Account.... The Add Account window shows up and you can repeat the steps described above.

After you have configured an account, you can see the status of the registration in the account list of Main Window window. Solid color means that the account has successfully registered, gray color means that the registration has failed or is in progress.

To edit the properties of existing accounts go to menu Blink -> Accounts -> Manage accounts.

Main Interface

Blink presents a Contacts driven interface as the main window. The design allows to locate a Contact then to start an action for it, for example to start an audio call.

Hover the mouse over the GUI elements to see a short description of their function.

SIP Account

You can select the SIP Account used as identity for outbound sessions in the Accounts drop down box presented on the top of the main interface.

Bonjour Account

Bonjour Account is a special type of account that is designed to announce itself and discover other neighbours on the local area network. This account does not require a server or SIP service in order to operate.

Bounjour account can be enabled or disabled in menu Blink -> Accounts

Search Bar

The Search bar is used for finding an existing contact or for entering a SIP address or telephone number.

To search for a local contact in Blink's Contacts List or the syncronized Google Contacts, type text in the Search Bar. You may select a Contact that matched the typed text or use the typed text as the Contact for the next action.

Use the buttons presented at the bottom of the main window to start a session to the current selected Contact or press on Add Contact to add the typed address to the Contacts List.

Pressing enter after antering text in the search bar will start an audio call to that address.

If you have registered a SIP Account with Blink, you can search for SIP addresses of other Blink users in menu Tools -> Search for people....

Presence Bar

You can use the elements in this section of the interface to change your presence state.

Panel Switcher

This button can be used to switch between the Contacts and Calls panel.

Contacts List

Contacts are organized into Groups. Groups can be collapsed or expanded by clicking on their left-side triangle.

Right click on a Group or Contact to see all possible actions for each of them.

Clicking on Return key or double-clicking a Contact will start the default session type depending on the preferred media configured for each Contact. The default action is to start an audio call.

Google Contacts

The group named Google Contacts displays addresses synced with the Google gmail service. To enable Google Contacts syncronization, go to menu_ Tools->Enable Google Contacts_. When prompted type in your Google account credentials. You can disable the Google Contacts from the same menu.

Bonjour Neighbours

Bonjour Neighbours appear in the Contacts List as a separate Group. When selecting_ Bonjour_ as the default account,_ Bonjour Neighbours_ group is expanded and moved on top of the Contacts list. When changing back to a regular SIP Account, the groups in the Contacts list reshuffle to their previous positions.

Action Buttons

Use the buttons presented at the bottom of the main window to start a session to the current selected Contact.

Add Contact

You can add a Contact to the Contacts List by clicking on the + button presented on the bottom left of the main interface. Add Contact window appears. The contacts can be stored either locally on the computer that runs Blink or the storage server for the SIP accounts that have XCAP storage feature enabled.

Edit Contact

You can edit a Contact by right clicking on it and select Edit menu option. Edit Contact window appears. To set the_ Icon for the Contact_, click on the Icon area, a file selection dialog appears. If Subscribe to Presence is enabled and the contact publishes its own icon, the icon is automatically retrieved from the network. If a local icon is selected, it will overwrite the network provided icon.

Silent Button

Use this button to disable the audible ringtones caused by incoming session request.

Alert Panel

Incoming session requests bring up the Alert Panel. Click on the Accept Button to accept a session request. There are two options for rejecting an incoming session request:

  • Click on the Reject button. The session is rejected with SIP response code 603 and all other SIP devices registered for the same account stop ringing. Forwarding to voicemail or other destinations, when available in the SIP server is also cancelled. You must use this option to terminate all call processing associated with the request.
  • Click on the Busy button. Blink sends a 486 code back to the caller and stops ringing, other SIP devices keep ringing and forwarding to other destinations remains active as set in the SIP server. You must use this option when you want to pick up the call at a different location or allow the Server to perform other pre-configured routing decisions.
  • Click on the Escape key. Blink stops ringing and does nothing else with regards to SIP signaling. Use this option when you do not want to take any decission about the call but you do not want to be disturbed by the ring tone either.

The currently selected input and output audio devices are showed for incoming audio session requests.

Audio Calls

Blink has no traditional telephone dialpad, nor you will need one to interact with it. As computers have physical keyboards displaying a classic 12 key dial-pad is a poor design choice for a modern graphical user interface of a rich communications SIP client.

To start an Audio Call, select an existing contact or enter a SIP address or telephone number in the search bar.

Once text is entered in the search bar just press enter to start and audio call to that address.

Once a Contact is selected, click on the Green Handset located at the bottom of the main interface or right click and select Start Audio call from the contextual menu. For each new call an entry is added to the Calls panel.

When starting and audio call, the main interface switches from the Contacts list to the Calls panel. You can toggle between the two panels by using the button presented on the top of the main interface. The number of active calls sessions is presented at the bottom of the Contacts list.

To switch between multiple calls just click on another call in the Calls panel. When switching to a particular call, the audio stream is connected to the input and output device and all other audio calls are put on hold.

To mute your microphone click on the bottom right microphone icon. To un-mute click it again.

The shortcut key for hold is Control+Space.

The shortcut key for hangup is Control+ESC (Linux only).

The shortcut key for redial is Control+R.


Dial tones are used to interact with PBX and IVR systems or legacy PSTN gateways. To send DTMF tones, focus the Audio Call by clicking on it. The current call is already focused if you just started it. What you then type on the keyboard is automatically translated into DTMF tones. Alpha-numeric keys are translated into numeric DTMF keys as they are on a numeric telephone keypad.


To hangup, click on the Red handset displayed for each audio call in the right hand side of the Calls panel.

Call Recording

To record an audio call click on the Black circle. While recording, the circle will toggle between red and black. Recordings are stored as .wav files in the following locations:

  • Linux: ~/.blink/recordings/
  • Windows XP: C:\Documents and Settings\Username\Application Data\Blink\recordings\
  • Windows Vista and 7: C:\Users\Username\AppData\Roaming\Blink\recordings\

Calling to PSTN

To dial a telephone number, just enter a number in the Search Bar followed by Return key.

When dialing numbers by selecting entries from the Google Contacts it is recommended that you store your numbers in international E.164 format (that is + followed by the number).

If you have created a SIP Account with Blink, you can call to PSTN numbers if you have a positive credit. You can use a Credit Card to add Credit to your account in menu Tools -> Buy prepaid credit.... You may request the assignment of a PSTN Caller Id by sending an request to the support email address. Recognized number formats are + or 00 followed by the Country Code and then Subscriber Number.

If you use another SIP Account than the one provided by Blink, access to the PSTN is subject to the support provided by your SIP service provider. The number format depends as well on the conventions imposed by the SIP service provider in question.

When dialing telephone numbers, you can replace the + prefix or add an optional prefix with your own values by editing the section Blink -> Accounts -> Manage accounts -> Advanced.

Audio Conference

Drag and drop audio calls on top of each other to create a Conference or use the button presented at the botton at the Calls panel to start a Conference with all active audio calls.

Add new participants to a Conference by dragging Contacts from the Contacts list onto add the green area highlighed on top of the Contacts list.

Each participant can be muted individually by pressing on the microphone symbol that appears on each conferenced session.

To end an Audio Conference drag the calls out of the conference area or press the Conference button again.

There can be multiple active Audio Conferences at any given time, you can use drag and drop to group calls together in different conferences.

Call Transfer

Blink can perform both unattended and attended call transfers.

To perform an unattended call transfer, make sure the call you want to transfer is the active one. Then switch to your contact list, lookup the contact where you want to transfer, right click on it and select "Transfer Active Call" from the context menu. If you want to transfer to a particular URI of that contact, expand it and right click on the desired URI.

To perform an attended call transfer, you need to have a call with both the person you want transferred, as well as with the person where you want the call to be transferred to. After that start by dragging the session with the person you want to transfer towards the session with person where the call has to be transferred and then drop it on that session while holding the Alt key.

The progress and the result of the transfer is displayed on the session tile. If the transfer is succesful, the original call is automatically terminated, else you can continue with it. After a transfer is initiated, you can either wait for the transfer to finish or close the original call. In both cases the transfer will continue as intended, but if you close the original call you won't be able to see the transfer progress anymore and you will not know if it succeeded or not.


To edit Blink general preferences and manage the SIP accounts, open menu Blink -> Preferences.

The Preferences are split in Accounts, Audio, Chat, File Transfer, Alerts, Logging and Advanced. Each SIP account has its own set of properties.

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