RE: [Sip-implementors] Offer-answer queries

Fri, 12 Dec 2003 05:00:25 -0800

Title: Message

Ranjit is correct – if you wanted to be this specific on codecs used – don’t bother with the offer in the original INVITE.

 

Chris.

 

 

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Sent: 12 December 2003 11:46
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: RE: [Sip-implementors] Offer-answer queries

 

Hi

     The accepted codec gets reflectd in 200 OK. so there is no need to send negotiated codecs in ACK. If no offer is sent in INVITE by caller, then the callee send his offer in 200 OK and the negotiated codec should be sent by caller in ACK

 

 

Thanks & Regards
Ranjit
Wipro Technologies
E-City, Bangalore
Ph: 8520408/16 extn: 2173

 

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Prabha
Sent: Friday, December 12, 2003 4:42 PM
To: [EMAIL PROTECTED]
Cc: Jonathan Rosenberg
Subject: [Sip-implementors] Offer-answer queries

Hello,

 

I have a question regarding the SDP part of the Invite request.

 

 suppose user agent  "A" wants to talk to user agent "B", he sends a INVITE

 request to B.  the SDP part of the invite request is as follows,

 

 

 v= 0

 o= A 1464112736 1464112736 IN IP4 151.209.33.190

 s=Calling

 c=IN IP4 pgs-477

 t=0 0

 m=audio 2074 RTP/AVP 0 3 5

 a=rtpmap:0 PCMU/8000

 a=rtpmap:3 GSM/4000

 a=rtpmap:5 ADPCM/4000

 

 If user agent accepts the request and agrees to talk to user agent A, he

 sends a OK response with SDP as followed.

 

 v= 0

 o= B1464112736 1464112736 IN IP4 151.209.33.194

 s=Answering the call

 c=IN IP4 pgs-451

 t=0 0

 m=audio 2074 RTP/AVP  3 5

 a=rtpmap:3 GSM/4000

 a=rtpmap:5 ADPCM/4000

 

 now why can’t the user agent A send an ACK by selecting one of the coders specified in answer AS

mentioned below ?

 

v= 0

 o= A 1464112736 1464112736 IN IP4 151.209.33.190

 s=Calling

 c=IN IP4 pgs-477

 t=0 0

 m=audio 2074 RTP/AVP  3

a=rtpmap:3 GSM/4000

 

than analyzing the payload type (PT) header field in the RTP Packet.

 

Thanks in advance

Prabha N



This message has been scanned for viruses by MailControl, a service from BlackSpider Technologies.

Confidentiality Notice


The information contained in this electronic message and any attachments to this message are intended
for the exclusive use of the addressee(s) and may contain confidential or privileged information. If
you are not the intended recipient, please notify the sender at Wipro or [EMAIL PROTECTED] immediately
and destroy all copies of this message and any attachments.

_______________________________________________
Sip-implementors mailing list
[EMAIL PROTECTED]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors

Reply via email to