[SIPForum-techwg] Question re Application Server

[Vincent]

Hi Chris,
     Could u help me out with call flows and explaining
     1) how a Sip Application Server plays a role in SIP Call Waiting
Service.
     2) Can Application Server(acting as a proxy) initiate 180 Ringing by
itself.
     3) And can Application Server add Alert-Info header field in 180
Ringing and
        INVITE messages in order to implement Call Waiting Service.

  with regards
  Vincent P.