Subject: [Sipping] a question about 3pcc

From: wenkai <[email-masked]>
Date: Thu, 09 Jan 2003 19:44:48 +0800

Hi,
The following is the "Mid-Call Announcement" call flow from "draft-ietf-sipping-3pcc-02.txt". 
After hanging up with the media server, the controller reconnects the Pre-Paid user to the called party. I think the media stream(stream 3) established between Pre-Paid user and the Called Party maybe is not the same as the original media stream(stream 1).
In practice, maybe we want to have the same media codec as original one when we restore a call.
Could you please give the call flow to reach this requirment?

Best Regards
Kevin

     Pre-Paid User        Controller         Called Party        Media Server
          |                   |                   |                   |
          |..........stream 1.....................|                   |
          |                   |(1) INV SDP c=0    |                   |
          |                   |------------------>|                   |
          |                   |(2) 200 answer1    |                   |
          |                   |<------------------|                   |
          |                   |(3) ACK            |                   |
          |                   |------------------>|                   |
          |(4) INV no SDP     |                   |                   |
          |<------------------|                   |                   |
          |(5) 200 offer2     |                   |                   |
          |------------------>|                   |                   |
          |                   |(6) INV offer2     |                   |
          |                   |-------------------------------------->|
          |                   |(7) 200 answer2    |                   |
          |                   |<--------------------------------------|
          |(8) ACK answer2    |                   |                   |
          |<------------------|                   |                   |
          |                   |(9) ACK            |                   |
          |                   |-------------------------------------->|
          |(10) RTP           |                   |                   |
          |..........stream 2.........................................|
          |                   |(11) BYE           |                   |
          |                   |-------------------------------------->|
          |                   |(12) 200 OK        |                   |
          |                   |<--------------------------------------|
          |                   |(13) INV no SDP    |                   |
          |                   |------------------>|                   |
          |                   |(14) 200 offer3    |                   |
          |                   |<------------------|                   |
          |(15) INV offer3'   |                   |                   |
          |<------------------|                   |                   |
          |(16) 200 answer3'  |                   |                   |
          |------------------>|                   |                   |
          |                   |(17) ACK answer3'  |                   |
          |                   |------------------>|                   |
          |(18) ACK           |                   |                   |
          |<------------------|                   |                   |
          |(19) RTP           |                   |                   |
          |..........stream 3.....................|                   |