[SIPForum-discussion] Is the preference codec 0 ?

[雨 陈]

Hi All, 
  there is a call flow of modifying session between two different softswitch:
  User A           User B    
  |  RTP Established   |
  |<=============>|     
                     |  INVITE [SDP]       |  the offer SDP m= audio 9256 RTP/ATP 8 0 97          
                     |------------------------>|            
                     |             100               |
                     |<------------------------|          
                     |                                   |
                     |       200 [SDP]          |  the answer SDP m= audio 10054 RTP/AVP 0
                     |<------------------------|            
                     |            ACK             |  
                     |------------------------>|    
   
  Well, according to RFC3264, the preference codec should be present at first. So, the User A would like to choose PT=8 (PCMA), while the User B just afford PT=0 (PCMU). 
   
  MY QUESTION IS:  Did they modify the session sucessfully? and if so, is the audio codec they  had negotiated  PT=0 (PCMU) ?  
   
   
  Thanks & Regards
   
  Nora

       
---------------------------------
 雅虎邮箱，您的终生邮箱！
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sipforum.org/pipermail/discussion/attachments/20080827/772a6dcb/attachment-0002.html>