[SIPForum-discussion] Regarding SDP in 180 and 200

[RajeshK.R 71316]

Hi Sword,

   What will happen if UAS sending 180 SDP reliably? Whether UAC will contine with 180 SDP only in this case, even UAS sending different SDP in 200 ?  What the statement "The UAC MUST treat the first  session description it receives as the answer, and MUST ignore any session descriptions in subsequent responses to the initial  INVITE" in RFC 3261 means?

Regards
Rajesh

******************************************************************************************
 This email and its attachments contain confidential information from HUAWEI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!
 *****************************************************************************************

----- Original Message -----
From: Sword Chen <swordchen at posteritytech.com>
Date: Tuesday, December 18, 2007 10:14 am
Subject: Re: [SIPForum-discussion] Regarding SDP in 180 and 200

> Hi, Man,
> 
> I don't think so, the 18X is not reliable response, so the UAC 
> will take the 200 SDP when the called party answered.
> like
> 
> 180:
> G729
> 
> 200:
> G723
> 
> after get the 180 message the UAC will decode the RTP in G729 
> format, and that is the same as the 183 message,
> once the UAC got the 200 message, it must change the codec from 
> G729 to G723. we ready tested this case.
> 
> :D
>  ----- Original Message ----- 
>  From: Rajesh 
>  To: discussion at sipforum.org 
>  Sent: Tuesday, December 18, 2007 11:45 AM
>  Subject: [SIPForum-discussion] Regarding SDP in 180 and 200
> 
> 
>  Hi all,
> 
>    If SDP in 180 and 200 responses are different, How UAC should 
> behave? According to RFC 3261 "If the initial offer is in an 
> INVITE, the answer MUST be in a reliable non-failure message from 
> UAS back to UAC which is correlated to that INVITE. For this 
> specification, that is only the final 2xx response to that INVITE. 
> That same exact answer MAY also be placed in any provisional 
> responses sent prior to the answer. The UAC MUST treat the first 
> session description it receives as the answer, and MUST ignore any 
> session descriptions in subsequent responses to the initial 
> INVITE."  
> 
>   
> 
>  What I understood from this one means, if SDP in 180 and 200 are 
> different also, UAC will take SDP in 180 as answer. Is it like 
> that? What will happen if 180 with SP is not sending reliably ?
> 
>   
> 
>  Thanks in Advance
> 
>  Rajesh
> 
>   
> 
>  Rajesh K R
> 
>  Software Engineer
> 
>  Huawei Technologies
> 
>  Bangalore
> 
>  Mob:009779803359762
> 
>   
> 
> 
> 
> -------------------------------------------------------------------
> -----------
> 
> 
>  _______________________________________________
>  This is the SIP Forum discussion mailing list
>  TO UNSUBSCRIBE, or edit your delivery options, please visit 
> http://sipforum.org/mailman/listinfo/discussion  Post to the list 
> at discussion at sipforum.org
>