[asterisk-bugs] [Asterisk 0013037]: Asterisk incorrectly requires an ACK of it's response to an OPTIONS request

[noreply at bugs.digium.com]

The following issue requires your FEEDBACK. 
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http://bugs.digium.com/view.php?id=13037 
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Reported By:                rnbrady
Assigned To:                
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Project:                    Asterisk
Issue ID:                   13037
Category:                   Channels/chan_sip/General
Reproducibility:            always
Severity:                   tweak
Priority:                   normal
Status:                     feedback
Asterisk Version:           1.4.18 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             07-09-2008 10:17 CDT
Last Modified:              07-10-2008 18:19 CDT
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Summary:                    Asterisk incorrectly requires an ACK of it's
response to an OPTIONS request
Description: 
An OPTIONS request from a peer to Asterisk generates a response. Because
this is a non-INVITE request, the peer is not required to ACK the response
from Asterisk.

However, if the peer does not ACK the response, Asterisk responds to
subsequent re-INVITES with a 491 Request Pending. This is probably because
of RFC3261 section 14.2:

   A UAS that receives an INVITE on a dialog while an INVITE it had sent
   on that dialog is in progress MUST return a 491 (Request Pending)
   response to the received INVITE.

Now an OPTIONS request is supposed to be treated just like an INVITE in
most respects. However, it is strictly speaking a non-INVITE request and
therefore does not require an ACK.

The result is that if a peer uses an OPTIONS request to test whether a
re-INVITE will succeed, when it actually does the re-INVITE, it fails with
a 491.
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Issue History 
Date Modified   Username       Field                    Change               
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07-10-08 18:19  file           Status                   new => feedback     
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