This functionality enables users to have the Rich Communication Suite client installed on various devices; for example, on smartphones (e.g. iPhone or android) and at the same time on a desktop PC, Mac or tablets (e.g. iPad) using the same account. Incoming calls and messages are forked and ring on all devices; a user can answer from any terminal. The mechanism also works with the PUSH notification framework. PUSH notifications are sent only to those devices which are not online while the softswitch still sends the SIP call directly to the others which are registered to the server.
The implementation is based on the +sip.instance feature tag contained in the Contact header of the SIP Register request and identifies each unique User Agent instance.
When a user logs in on a particular mobile device (smartphone, tablet) for the first time, a unique ID is obtained from the device’s parameters. The ID is then sent to the Web API and stored in the user’s profile/ devices table. The administrator can set a limit on the number of devices per user; in the Vippie client, for example, the limit is set to 4 devices. In addition to mobile terminals a user can log in from a desktop PC, Mac and the Web. In this case, however, the instance ID is the same regardless of the computer being used. This means that a user can be registered from only one desktop at a time; his previous session will be overridden.
Every attempt at registering from a device which does not contain an authorized sip.instance will be rejected on the softswitch. Management of the devices and associated instance IDs stored in a user’s profile are available from the User Portal.
A user can use the same public ID across all his devices or log in using a different ID on a second or other terminal. The private (main) identity remains the same. Public IDs represent how a user is presented to others and how he can be discovered. Allowed IDs include phone numbers (with verification by SMS or phone call), Vippie ID (a service id, username) and social nickname from facebook and google +.
The feature is available in VoipSwitch’s Rich Communication Suite client for iOS (from version 2.6), Android (from 2.17) and also desktop clients for Mac and PC.