> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, March 22, 2001 11:36 AM
> To: [EMAIL PROTECTED]
> Subject: [Sip-implementors] Muting a call
>
>
>
>
> Hello,
> I had a very basic doubt with respect to muting a media
> stream using SDP.
>
> From the draft, in order to mute a stream, one should reINVITE and
> set the connection attribute of the corresponding codecs to 0.0.0.0.
That is for hold. Mute is a purely local operation that requires no
signaling (i.e., turn off the speaker).
>
> What i want to know is, in the 200 OK to such a reINVITE, what
> does the callee place in the c= line. For eg.
>
>
> INVITE sip:[EMAIL PROTECTED] SIP/2.0
> .....
> v=...
> o=...
> c=0.0.0.0
> t=...
> m=audio 6060 RTP/AVP 0
> m=audio 6060 RTP/AVP 3
>
>
>
>
>
>
> SIP/2.0 200 OK
> .....
> v=...
> o=...
> c=???????????
> t=...
> m=audio 7777 RTP/AVP 0
> m=audio 7777 RTP/AVP 3
>
>
> Should it be 0.0.0.0 or can it be the original IP on which it is
> listening.
Its you're choice. If a phone wishes to stop receiving media as well, when
its been asked to stop sending media (which is the case for a re-INVITE with
0.0.0.0 in the c line), it can return 0.0.0.0 in the 200 OK. Or, if it
wishes still to receive media, it can return a regular IP address as before.
Many phones appear to return 0.0.0.0 in response to a hold.
> Also, if individual codecs are muted (say c= attribute
> of the GSM codec is set to 0.0.0.0),
codecs are not muted. Media streams (i.e., m lines) are muted.
> should the 200 OK response
> reflect the c=0.0.0.0 against the (successfully) muted streams...
> or can it retain the original c= line.
Same question as above, and same answer. Either is fine.
>
> I would think that the very fact that the 200 OK has been sent
> by the remote end means that muting succeeded. An explicit
> c=0.0.0.0 line is not required in the 200 Ok. Am i right about this?
So long as we are clear about what it means for "muting succeeded". When I
send a re-INVITE with SDP c line of 0.0.0.0, that means "don't send me
media., i.e., you're on hold". The 200 OK acknowledges that the recipient
will not send media any longer, nothing more.
-Jonathan R.
---
Jonathan D. Rosenberg 72 Eagle Rock Ave.
Chief Scientist First Floor
dynamicsoft East Hanover, NJ 07936
[EMAIL PROTECTED] FAX: (973) 952-5050
http://www.cs.columbia.edu/~jdrosen PHONE: (973) 952-5000
http://www.dynamicsoft.com
_______________________________________________
Sip-implementors mailing list
[EMAIL PROTECTED]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
