[SIPForum-discussion] 183 Session Progress without SDP

[nitin kapoor]

Dear All,

We are facing one problem where we are getting two 183 session for 1 INVITE.
UAC sending the INVITE to Switch and switch has forwarded the same invite to
UAS. Then UAS first send the 183 Session progress without SDP and after 2
Sec its sends the another 183 Session Progress with SDP which is something i
am not able to understand.

1) Can you please tell me on which cases UAS sends the two 183 Session
progress like this.( with SDP & without SDP)?
2) Is this the correct behaviour?

I checked this on RFC3261 and another sip pdf but unable to search it.

Please find the attached Traces.

Thanks
Nitin Kapoor
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