[Serusers] MSRTC DLL Bug with SER --- More information, Possibly SER not RFC 3261 compliant??

Andrew Mee andrew at healthshare.net.au
Mon Aug 23 02:49:51 UTC 2004

 From MS RTC Newsgroup:

...The issue here is that the BYE sent by test1 gets routed back to 
test1. This
is because RTC1.2 does strict routing. However, on the proxy on the other
hand does only loose routing and does not provide backward compatibility as
provisioned in RFC 3261. Test1 receives this BYE out of the blue and a
result sends a 481....

According to RFC 3261:

16.4 Route Information Preprocessing

   The proxy MUST inspect the Request-URI of the request.  If the
   Request-URI of the request contains a value this proxy previously
   placed into a Record-Route header field (see Section 16.6 item 4),
   the proxy MUST replace the Request-URI in the request with the last
   value from the Route header field, and remove that value from the
   Route header field.  The proxy MUST then proceed as if it received
   this modified request.

      This will only happen when the element sending the request to the
      proxy (which may have been an endpoint) is a strict router.  This
      rewrite on receive is necessary to enable backwards compatibility
      with those elements.  It also allows elements following this
      specification to preserve the Request-URI through strict-routing
      proxies (see Section

      This requirement does not obligate a proxy to keep state in order
      to detect URIs it previously placed in Record-Route header fields.
      Instead, a proxy need only place enough information in those URIs
      to recognize them as values it provided when they later appear.


I am trying to write a patch to fix this and I am having limited 
success, perhaps someone would be better at this?

Andrew Mee

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