Re: [sipcore] #29: B2BUAs passing H-I through?, #28 UAC adds initial HI

"Worley, Dale R (Dale)" <> Fri, 17 September 2010 18:05 UTC

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From: "Worley, Dale R (Dale)" <>
To: Mary Barnes <>
Date: Fri, 17 Sep 2010 14:02:38 -0400
Thread-Topic: [sipcore] #29: B2BUAs passing H-I through?, #28 UAC adds initial HI
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Subject: Re: [sipcore] #29: B2BUAs passing H-I through?, #28 UAC adds initial HI
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From: Mary Barnes []

There is text that says that a UAC can add History-Info in section
4.1, which is the text Hadriel refers to in the original issue.
   "Normally, UACs are not expected to include a History-Info header
in an initial
   request as it is more of a Proxy function; the main reason it is
   allowed is for B2BUAs who are performing proxy-like functions such as

Issue #29 suggests this should to be stated normatively (as well as
including this in the UAS section). It seems to me that we can make
that a MAY strength. It's not clear to me that we need to add anything
to the proxy section for B2BUAs as I really don't want to get into
trying to define B2BUA behavior beyond what is absolutely necessary in
this document.

Well, strictly speaking, a B2BUA isn't a proxy.  The behavior we want to enable is part of the UAC function of the B2BUA.  But it seems to me that we want to enable this behavior normatively, and describe it much more clearly.  The current text mentions it only in passing, and while "there is only one thing that it could mean", that is not a good specification.