[SIPForum-discussion] Multiple 183 w/SDP along with PRACK

[Stephen James]

This is perfectly valid, but not very useful. There may be a PSTN interconnect down the line that is sending multiple call progress messages resulting in the behavior that you see. 

Sent from my iPad

> On Jul 9, 2014, at 5:01 PM, NK <nitinkapoorr at gmail.com> wrote:
> 
> Dear All,
> 
> I have call flow like where Vendor sends 183 w/SDP included Rseq and customer sents the PRACK and 200 OK from vendor.
> 
> After that vendor is again sending 1~2 183 w/SDP where it is not changing anything in SDP but only asking for PRACK by sending RSEQ. I checked the RFC , but cannot see anything like which says UAS cannot send multiple 183 w/SDP.
> 
> Can you please help on this, whether any  UAS can send multiple 183 w/SDP where it is asking for PRACK? Is it valid call flow, because i cannot see anything RFC.
> 
> Regards,
> Nitin Kapoor
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