[SIPForum-discussion] Regarding 491 request pending

[Prem chandiran]

Hi All,

may i know why 491 request pending is sent for UPDATE, as per rfc 33 11 "If
an UPDATE is received that contains an offer, and the UAS has generated an
offer (in an UPDATE, PRACK or INVITE) to which it has not yet received an
answer, the UAS MUST reject the UPDATE with a 491 response." below is the
call flow

UA UA1
| |
| INVITE(with offer) |
------------------------------------------> |
| |
| 100 Trying |
<-------------------------------------------|
| |
| 183 (with Answer) |
 <-------------------------------------------|
| |
| UPDATE(With Offer) |
<-------------------------------------------|
| |
| 491 Request Pending |
------------------------------------------> |

UA sends an offer in invite for that UA1 respond with answer in 183 then
UA1 triggers UPDATE with offer UA is sending 491. Please let me know what
might be wrong.

Thanks all...

Regards,
Prem Chandiran
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sipforum.org/pipermail/discussion/attachments/20120929/dc2e86cd/attachment-0002.html>