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Summary:ASTERISK-08059: [patch] INVITE w/Replaces - Require: header interop issue
Reporter:John Riordan (john)Labels:
Date Opened:2006-11-03 13:10:29.000-0600Date Closed:2011-06-07 14:07:22
Priority:MinorRegression?No
Status:Closed/CompleteComponents:Channels/chan_sip/Interoperability
Versions:Frequency of
Occurrence
Related
Issues:
Environment:Attachments:( 0) patch-chan_sip-require-replaces.diff
Description:Issue:
Many SIP stacks, including at least one Polycom and one Resiprocate (EyeBeam) got the option name wrong; they use "replace" when they should use "replaces". While these stacks support the Replaces header, they fail when Asterisk requires the "replaces" option by including the Require: header in an INIVTE w/Replaces.

Patch:
Since use of the Require header is optional, I suggest leaving it out for now so that Asterisk can SIP transfer calls with these broken UAs.
RFC 3891 Sec 6.2 states:
  UAs that want explicit failure notification if
  Replaces is not supported MAY include the "replaces"
  option in a Require header field.
Comments:By: Olle Johansson (oej) 2006-11-04 12:36:48.000-0600

And from cc-transfer:

In case the triggered INVITE is routed to a
  different User Agent than the Transfer Target, the Require: replaces
  header field should be used in the triggered INVITE.  (This is to
  prevent an incorrect User Agent which does not support Replaces from
  ignoring the Replaces and answering the INVITE without a dialog
  match.)
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I have seen the bad header in Polycom, but haven't stumpled into issues
with it. Which version of the firmware denies the Invite because of this?

Btw, I've alerted Polycom of this and they told me they changed the
firmware.
By: John Riordan (john) 2006-11-06 09:53:49.000-0600

The explanation from cc-transfer with respect to preventing UA from incorrectly answering the INVITE w/Replaces presents a strong enough case for me to humbly withdraw this issue and apologize for bringing it up. Clearly this is a case where attempting to accomadate broken UAs is not worth it.

I don't have the firmware version on the Polycom (poor note taking).
The eyeBeam version which rejects the calls is eyeBeam 1.1 3006o for Mac.
By: Olle Johansson (oej) 2006-11-08 01:35:42.000-0600

Thanks for the feedback and thank you for contributing to Asterisk!

/Olle