Re: [sipcore] Last Call: <draft-ietf-sipcore-status-unwanted-04.txt> (A SIP Response Code for Unwanted Calls) to Proposed Standard

Isn't it assumed that a Reason header is preserved e2e with error responses?

On 3/21/17 3:51 PM, Dale R. Worley wrote:
> Adam Roach <adam@nostrum.com> writes:
>> To be clear (and this is an easy mistake to make, since the sections and
>> their contained steps are huge), Pete is referring to the long-form
>> version of step 6 in section 16.7 here. See RFC 3261, page 111.
>
> Ah, there's a tension between this paragraph:
>
>          The stateful proxy MUST choose the "best" final response among
>          those received and stored in the response context.
>
> and this one:
>
>          3-6xx responses are delivered hop-by-hop.  When issuing a 3-6xx
>          response, the element is effectively acting as a UAS, issuing
>          its own response, usually based on the responses received from
>          downstream elements.  An element SHOULD preserve the To tag
>          when simply forwarding a 3-6xx response to a request that did
>          not contain a To tag.
>
> But if many implementations take "choose the best final response" to
> mean only re-sending the response code, we have a problem.
>
> OTOH, it's quite possible to reserve a *set* of 6xx response codes to
> carry the decline-type.  The only allocated 6xx responses are 600
> (generic), 603, 604, and 606.
>
> Dale
>
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