Hi Nitin

This is a perfectly legal scenario, the 2nd ReINVITE is essentially a Stop Fax 
/ Revert to Audio ReINVITE.

We have seen this behavior with many T.38 vendors.

Regards
Tarun Gupta


-----Original Message-----
From: sip-implementors-boun...@lists.cs.columbia.edu 
[mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of NK
Sent: Friday, July 31, 2015 12:30 PM
To: Kumar, Puneet (Puneet)
Cc: sip-implementors@lists.cs.columbia.edu
Subject: Re: [Sip-implementors] SIP Reinvite after T38 Negotitaion

Hi Puneet,

Below is the SDP for Fax Re-invite from Vendor (UAS) after audio call 
established with initial offer.

*T.38 RE INVITE SDP*


v=0
o=HuaweiSoftX3000 32970986 32970988 IN IP4 1.1.1.1 s=Sip Call c=IN IP4 1.1.1.1
t=0 0
m=image 41046 udptl t38
a=T38FaxVersion:0
a=T38MaxBitRate:14400
a=T38FaxRateManagement:transferredTCF
a=T38FaxUdpEC:t38UDPRedundancy
m=audio 41128 RTP/AVP 8 0 101
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:101 telephone-event/8000
a=ptime:20
a=silenceSupp:off - - - -
a=ecan:fb on -
a=fax
a=fmtp:101 0-15


*200 OK SDP for T.38 Re invite*


v=0
o=Sonus_UAC 10922 10626 IN IP4 1.1.1.1
s=-
c=IN IP4 1.1.1.1
t=0 0
m=image 6334 udptl t38
a=T38FaxVersion:0
a=T38MaxBitRate:14400
a=T38FaxRateManagement:transferredTCF
a=T38FaxMaxBuffer:262
a=T38FaxMaxDatagram:90
a=sendrecv
m=audio 0 RTP/AVP 8 0 101
a=rtpmap:8 PCMA/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:101 telephone-event/8000
a=sendrecv
a=ptime:20
a=silenceSupp:off - - - -


*This is the Re-invite SDP after T38 Invite*

v=0
o=HuaweiSoftX3000 32970986 32970989 IN IP4 1.1.1.1 s=Sip Call c=IN IP4 1.1.1.1
t=0 0
m=audio 41046 RTP/AVP 18 101
a=rtpmap:18 G729/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=fmtp:18 annexb=no

Regards,
Nitin Kapoor

On Fri, Jul 31, 2015 at 2:48 AM, Kumar, Puneet (Puneet) <pune...@avaya.com>
wrote:

> Hi Nitin,
>
> For reINVITE for fax, is far-end converting "m=audio" line to "m=image" ?
>
> Can you share the SDP in both reINVITE's.
>
> Thanks,
> Puneet
>
> -----Original Message-----
> From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:
> sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of NK
> Sent: Friday, July 31, 2015 11:32 AM
> To: sip-implementors@lists.cs.columbia.edu
> Subject: [Sip-implementors] SIP Reinvite after T38 Negotitaion
>
> Dear All,
>
> It is legal to send re-invite after sending T.38 when negotiation is
> already done.
>
> Below is the scenario.
>
> UA ---------> INVITE
> UA  <------100 Trying
> UA <------- 180 w/SDP
> UA <------- 200 OK
> UA  ----------> (Re-invite for fax with T.38) UA <------100 Trying UA
> <-----------200 OK *UA <---------- RE-INVITE wSDP G.729* *UA
> ---------> 488*
>
> Now after this another re-invite is coming (in green) with G.729 Codec
> and i am rejecting this with SIP 488.
>
> Anyone observed this kind of scenario earlier?
>
> Can you please advise and help on this.
>
> Thank you in advance.
>
> Regards
> Nitin Kapoor
> _______________________________________________
> Sip-implementors mailing list
> Sip-implementors@lists.cs.columbia.edu
>
> https://urldefense.proofpoint.com/v2/url?u=https-3A__lists.cs.columbia
> .edu_mailman_listinfo_sip-2Dimplementors&d=AwICAg&c=BFpWQw8bsuKpl1SgiZ
> H64Q&r=MpUJwczUGVfrfzzrKZS6B5RFgsQraA_BMVc2YztX3Gk&m=A4aV5E2mvyj-yPDeU
> yK6vrfY6BujtRe4gwymOROxduM&s=AgL6vuPFPgil3UGHFMxI_him1MuOJE24FIyl4ekme
> y0&e=
>
_______________________________________________
Sip-implementors mailing list
Sip-implementors@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/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
Sip-implementors@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors

Reply via email to