RFC 5626 (Outbound) hard to understand non-register request processing
Iñaki Baz Castillo <ibc <at> aliax.net>
2011-10-14 11:52:23 GMT
Hi, RFC 5626 section 5.3 "Forwarding Non-REGISTER Requests" says:
5.3. Forwarding Non-REGISTER Requests
When an edge proxy receives a request, it applies normal routing
procedures with the following additions. If the edge proxy receives
a request where the edge proxy is the host in the topmost Route
header field value, and the Route header field value contains a flow
token, the proxy follows the procedures of this section. Otherwise
the edge proxy skips the procedures in this section, removes itself
from the Route header field, and continues processing the request.
And then in section 5.3.2 "Processing Outgoing Requests" (which is
*into* section 5.3) it talks about:
If the edge proxy receives an outgoing dialog-forming request, the
edge proxy can use the presence of the "ob" URI parameter in the
UAC's Contact URI (or topmost Route header field) to determine if the
edge proxy needs to assist in mid-dialog request routing.
The problem is that an initial INVITE/SUBSCRIBE sent from a outbound
SIP client won't have a flow token in a Route header, so the text in
5.3 suggests doing nothing special for such request. The reader could
then ignore section 5.3.2 in which, clearly, the edge proxy should
assist in-dialog request routing for this initial request (by adding a
flow token in the Record-Route).
Do I miss something? or the text is indeed confusing?
Iñaki Baz Castillo
<ibc <at> aliax.net>
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