"Basic Level of Interoperability for Session Initiation Protocol (SIP) Services (BLISS) Problem Statement", Jonathan Rosenberg, 3-Nov-08. ( bytes)

The Session Initiation Protocol (SIP) has been designed as a general purpose protocol for establishing and managing multimedia sessions. It provides many core functions and extensions in support of features such as transferring of calls, parking calls, and so on. However, interoperability of more advanced features between different vendors has been poor. This document describes the reason behind these interoperability problems, and presents a framework for addressing them.

"An Analysis of Automatic Call Handling Implementation Issues in the Session Initiation Protocol (SIP)", John Elwell, 3-Nov-08. ( bytes)

This discusses problems associated with automatic call handling (ACH) when using the Session Initiation Protocol (SIP). This work is being discussed on the bliss@ietf.org mailing list.

"Call Completion for Session Initiation Protocol (SIP)", Dale Worley, Martin Huelsemann, Denis Alexeitsev, 20-Jun-08. ( bytes)

The features "call completion on busy subscriber" and "call completion on no reply" allow the calling party of a failed call to be notified when the called party becomes available to receive a call. This document describes an architecture for implementing these features in the Session Initiation Protocol: "Call completion" implementations at the caller's and callee's endpoints cooperate to place the caller's request for call completion into a queue at the callee's endpoint, and, when a caller's request is ready to be serviced, re-attempt the original, failed call.

"Shared Appearances of a Session Initiation Protocol (SIP) Address of Record (AOR)", Alan Johnston, Mohsen Soroushnejad, Venkatesh Venkataramanan, 2-Nov-08. ( bytes)

This document describes the requirements and implementation of a group telephony feature commonly known as Bridged Line Appearance (BLA) or Multiple Line Appearance (MLA), or Shared Call/Line Appearance (SCA). When implemented using the Session Initiation Protocol (SIP), it is referred to as Shared Appearances (SA) of an Address of Record (AOR) since SIP does not have the concept of lines. This feature is commonly offered in IP Centrex services and IP-PBX offerings and is likely to be implemented on SIP IP telephones and SIP feature servers used in a business environment. This document lists requirements and compares implementation options for this feature. Extensions to the SIP dialog event package are proposed.

Return to Internet-Draft directory.

Return to IETF home page.