Ranjith.V wrote:
> Hi Richard,
>
> No of m-lines (Media lines) MUST same in offer and answer. So Bob
> MUST not send D,E media information in 200-0K of INVITE
True. This applies to answers, not offers.
The offer in a reinvite must have *at least* as many m-lines as the
prior o/a.
The original scenario is a little unclear. When it says "with SDP media
A, B, C, D, E" it might mean 5 m-lines, or one m-line with five payload
types. I am assuming it meant five m-lines.
On that assumption the two shown answers are invalid.
I think this is what Ranjith is saying.
> Refer section 6 of RFC 3264
> "For each "m=" line in the offer, there MUST be a corresponding "m="
> line in the answer. The answer MUST contain exactly the same number
> of "m=" lines as the offer"
>
> If Bob want to send offer in 200 OK, he can send altogether different offer
> With out violating following condition.
Yes. This is where it would be fine for Bob to include all five m-lines
if it wants. Then, if Alice doesn't want D and E she may refuse them by
setting the port numbers to zero in the answer.
Paul
> "if the previous SDP had N "m=" lines, the new SDP MUST have at least N "m="
> lines"
>
> Please refer section 8 of RFC 3264 for more details.
>
> Regards
> Ranjith
>
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Richard Wu
> Sent: Monday, April 14, 2008 3:37 PM
> To: [email protected]
> Cc: Fu Siu Ming Claudio
> Subject: [Sip-implementors] RE-INVITE question 14.2
>
> Hi All,
>
> In RFC 3264 chapter 14.2
> "A UAS providing an offer in a 2xx (because the INVITE did not contain
> an offer) SHOULD construct the offer as if the UAS were making a brand
> new call, subject ....".
>
> Consider the following scenario:
>
> alice-----> INVITE with SDP media A, B, C ---> bob /* all are sendrecv */
>
> alice<----- 200OK with SDP media A, B, C, D, E ---- bob /* all are
> sendrecv */
>
> alice------ ACK ----> bob
>
> Then alice hold bob
>
> alice-----> INVITE with SDP media A, B, C ---> bob /* all are sendonly */
>
> alice<----- 200OK with SDP media A, B, C, D, E ---- bob /* all are
> recvonly */
>
> alice------ ACK ----> bob
>
> Afterwards,
> alice send a RE-INVITE with no SDP
>
> alice-----> INVITE with no SDP---> bob
> What should bob rely? Suppose bob support five medias A, B, C, D, and E.
>
> Thanks in advance.
>
> ichardR
>
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> This message (including any attachments) is for the named
> addressee(s)'s use only. It may contain sensitive, confidential,
> private proprietary or legally privileged information intended for a
> specific individual and purpose, and is protected by law. If you are
> not the intended recipient, please immediately delete it and all copies
> of it from your system, destroy any hard copies of it
> and notify the sender. Any use, disclosure, copying, or distribution of
> this message and/or any attachments is strictly prohibited.
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> _______________________________________________
> Sip-implementors mailing list
> [email protected]
> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
>
> "DISCLAIMER: This message is proprietary to Aricent and is intended solely
> for the use of
> the individual to whom it is addressed. It may contain privileged or
> confidential information and should not be
> circulated or used for any purpose other than for what it is intended. If you
> have received this message in error,
> please notify the originator immediately. If you are not the intended
> recipient, you are notified that you are strictly
> prohibited from using, copying, altering, or disclosing the contents of this
> message. Aricent accepts no responsibility for
> loss or damage arising from the use of the information transmitted by this
> email including damage from virus."
>
> _______________________________________________
> Sip-implementors mailing list
> [email protected]
> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
>
_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
