Linphone smart contact list, a major new feature

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Linphone’s address book becomes a smart contact list : you can now quickly and clearly see which of your friends have a account.

Linphone imports your contacts’ phone numbers from your phone’s address book and automatically tags with a Linphone icon the contacts who have created an account on free SIP service.
You can also filter your contacts to only display such Linphone users.


Linphone’s SIP account manager, named « Assistant », has been modified to allow the creation of your Linphone account with your phone number. 
You can register with your phone number only, or with a specific username and your phone number. In this case your phone number will be linked to this username and your contacts can either reach you with your username or your phone number.

From a technical standpoint, the smart address book is realized by leveraging on IETF standards related to SIP presence support:

  • RFC5367 - Subscriptions to Request-Contained Resource Lists in the Session Initiation Protocol (SIP)
  • RFC4479 - A Data Model for Presence
  • RFC6665 - SIP-specific event notification
  • RFC1951 - SIP body compression 
  • RFC5621 - Message Body Handling in the Session Initiation Protocol

Our team conducted a significant development effort to implement this new feature and related standards in the Liblinphone library, as well as a new cloud component of our Flexisip product: Flexisip Presence server.
Our free SIP service demonstrates this new technology, which is now available in our catalog of products.


Easier communication, as Linphone users part of your phone's address book are automatically identified.
Up-to-date list of your Linphone contacts : the list is automatically updated as new Linphone users register to the service.
Faster and safer account registration, by simply entering your phone number and the validation code received by SMS.


With the functionality « Link your account », it is possible to link an existing Linphone account to a phone number.
Phone numbers are verified through a 4-digit validation code, which is sent by SMS when accounts are created or configured.