[SIPForum-discussion] difference in the sdp for the calls !!

[PIERRE Laurent]

Hello,

1>what are the codecs  and the dtmf  methods being advertised in scenario 1
?
8 0 18 100 means :
8 relates to the G711alaw codec as PCMA
0 relates to the G711ulaw codec as PCMU
18 relates to the G729 codec
The payload format uses the payload type number 100  and the implementation
can handle the DTMF tones (events 0 through 15)

2>what are the codecs  and the dtmf  methods being advertised in scenario 2
?
18 106 4 8 0 means :
18 relates to the G729 codec
The payload format uses the payload type number 106  and the implementation
can handle the DTMF tones (events 0 through 15)
8 relates to the G711alaw codec as PCMA
0 relates to the G711ulaw codec as PCMU

3>what is a=sendrecv ?
RFC3264 indicates  " For a sendrecv stream, the offer SHOULD indicate those
codecs that the offerer is willing to send and receive with."

4>also anything else that you can point out  that is different in the 2
sdps   ?
the type of media attribute and the order are differente :  8 0 18 100 and
18 106 4 8 0


Regards

--
Laurent PIERRE
http://www.linkedin.com/in/lpierre

-----------------------------------------------------------------------------------------------------
2011/12/3 virajith <vir356 at rediffmail.com>
>
>
> Dear all,
>
> I have  a query in relation to  2 different types of  sdp received in
the INVITE from  a sip provider for  incoming calls.
>
> Scenario 1
> =========>
>
> =======sdp  for few  calls==========
>
> v=0
> o=- 2341457 1 IN IP4 60.234.18.158
> s=-
> c=IN IP4 60.234.18.158
> t=0 0
> m=audio 30006 RTP/AVP 8 0 18 100
> a=fmtp:18 annexb=no
> a=fmtp:100 0-15
> a=ptime:20
> a=rtpmap:100 telephone-event/8000
>
> ===============================
>
>
> Scenario 2
> =========>
>
> ===========sdp for other calls===========
>
> v=0
> o=default 1322426685 1322426685 IN IP4 60.234.18.158
> s=-
> c=IN IP4 60.234.18.158
> t=0 0
> m=audio 30002 RTP/AVP 18 106 4 8 0
> a=sendrecv
> a=rtpmap:106 telephone-event/8000
> a=fmtp:106 0-15
> a=maxptime:90
>
> ============================================
>
>
> Now the questions I have is the following...
>
> 1>what are the codecs  and the dtmf  methods being advertised in scenario
1 ?
>
> 2>what are the codecs  and the dtmf  methods being advertised in scenario
2 ?
>
> 3>what is a=sendrecv ?
>
> 4>also anything else that you can point out  that is different in the
2 sdps   ?
>
>
> Thanks,
> Vir
>
>
>
>
>
>
> Follow Rediff Deal ho jaye! to get exciting offers in your city everyday.
>
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