Design and Implementation of SIP Network and Client Services for Enabling Collaborative Applications

The Session Initiation Protocol (SIP) has been widely adopted for VoIP and Instant Messaging systems. However, the deployment has been primarily on a per-application basis. In this paper, we describe the design and implementation of a generic SIP client service and API that is available to all applications and provides unified mechanisms for functions like conference joins, pub-sub, call transfers etc. The service allows a user to plug in a softphone of his choice, and to use any one of multiple softphones, IP or PSTN phones on a per-session basis. We demonstrate the utility of this API by enhancing the user experience for existing applications as well as describing new converged applications. This client service is supported on the network side by prototyping a number of building blocks in addition to integrating a commercially available packet-audio mixer.

By: Aameek Singh, Priya Mahadevan, Arup Acharya, Zon-Yin Shae

Published in: RC23148 in 2004


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