Subject: [sipcore] Via 'received' parameter (was Re: WGLC: draft-ietf-sipcore-sip-websocket-02)

From: José Luis Millán <[email-masked]>
Date: Wed, 29 Aug 2012 00:47:49 +0200

Hi,

Is it convenient for a SIP WebSocket Server to strictly satisfy 18.2.1
and  18.2.2 sections in [RFC 3261] ?

The WebSocket connection  may traverse one or more HTTP elements
before reaching the SIP WebSocket Server. In this case, the Via
'received' parameter will point to a non SIP element.

Additionally, many SIP WebSocket Clients won't act as SIP WebSocket
Servers. They won't allow receiving WebSocket connections.

Trying to establish a new connection to the address represented in the
Via 'received' parameter,  as stated in section 18.2.2 of  [RFC 3261],
won't succeed in any of the scenarios defined above. For this reason,
it may be reasonable to relax 18.2.1 and 18.2.2 sections of [RFC 3261]
by stating something like:

"
SIP WebSocket Server implementations MAY decide not to add the Via
'received' parameter to received SIP requests, in which case the
server transaction MUST NOT attempt to open a connection for sending a
response.
"

It might be worth saying that:

"
It is RECOMMENDED that SIP WebSocket Server implementations do not add
the Via 'received' parameter to SIP requests when acting as edge
proxies.
"

Regards,