> From: Henry Peter [[email protected]]
> 
> > From: Worley, Dale R (Dale) [mailto:[email protected]]
> > 
> > The practice is fairly well standardized, but not exactly as described
> > (or at least implied) by RFC 3261.
> 
> [Henry Peter] If it were standardized so I would not have the
> situation I am facing where I am hearing from a vendor that 70 is
> expected in an OPTION no matter where the req-uri points to (in fact
> it does precisely to the IP and Port and hence no forwarding
> expected and even if one does that is a different matter of
> initiating a new OPTION; from the sender point of view, the OPTION
> is strictly to the next hop and expects a response or not.
> 
> Worse yet the reference for 70 is being given to RFC 3261!  The
> Max-Forwards cannot stand by itself...it needs a context such as the
> OPTIONS and where the req-uri points to ...these are not clearly
> stated...

The reference is not relevant because:  (1) As Paul pointed out, 3261
says SHOULD not MUST, so UACs are allowed to use different values, and
(2) After a request has passed through one or more proxies,
Max-Forwards will have been decremented before it reaches the UAS, so
RFC 3261-conforming devices must accept requests with Max-Forwards
values smaller than 70.

> Only reason that we may not hear much problems about SIP OPTIONS is
> because probably everywhere 70 is used...but does it make it right?  )

Actually, the value 20 is commonly used.  Many vendors decided early
on that 70 was much higher than was needed for practical
implementations.

> [Henry Peter] Dale, you can see that you had to make so many
> statements to clarify and this is precisely expected in an RFC for
> standard-practice or related.  Why is it not that the draft that
> already exists on this moving towards an RFC?

Because (1) The deviations from RFC 3261 are small (i.e., a UA can
respond 200 to an OPTIONS even if it cannot accept an incoming
INVITE), and (2) Nobody has volunteered to write this draft.  (Are you
volunteering to do so?)

Dale

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