@techreport{anil-sipping-bla-04,
    number =    {draft-anil-sipping-bla-04},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-anil-sipping-bla/04/},
    author =    {Anil Kumar},
    title =     {{Implementing Multiple Line Appearances using the Session Initiation Protocol (SIP)}},
    pagetotal = 46,
    year =      2007,
    month =     mar,
    day =       6,
    abstract =  {This document describes the implementation of a group telephony feature commonly known as Bridged Line Appearance (BLA), Multiple Line Appearance (MLA), or Shared Call/Line Appearance (SCA). When implemented using the Session Initiation Protocol (SIP), it is referred to as Multiple Appearances. This feature is commonly offered in the 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 specification defines a new SIP dialog event package tag "appearance" and a method for a group of SIP user agents to coordinate the identification of appearances between them using SIP dialog package subscriptions.},
}