Keith Robinson wrote:
>
> I think the SIP spec (bis-02) is ambiguous on the contents of the Request-URI
> which has (will) lead to different implementations; in section 2, the following
> is written :
>
> "SIP URLs are used within SIP messages to indicate the originator (From),
> current destination (Request-URI) .............."
>
> and in section 4.3 the following is written :
>
> "It [Request-URI] indicates the user or service to which this request is being
> addressed"
>
> >From the point of view of a UA, the current destination may be a very different
> thing from the user or service being addressed. Using the current destination
> definition, a UA may well put the address of the local outbound proxy into the
> Request-URI, using the definition as per 4.3 would lead them to putting in the
> logical identity of the user (or service).
>
> When refering to current destination, does it mean the next hop destination or
> the current logical destination ?
Current SIP destination. The outbound proxy is by definition not a SIP
destination (with its own SIP URL). Thus, putting its address in the
request URI makes no sense. I would prefer not to introduce yet another
term ("logical destination"), as this increases complexity. The
definition of the outbound proxy is that it differs from the Request-URI
address, so I'm not sure how much confusion there can be. (If you stick
the address of the proxy in the request-URI, it's no longer an outbound
proxy.)
--
Henning Schulzrinne http://www.cs.columbia.edu/~hgs
