[OpenSIPS-Users] "received=" parameter in Via

[Alex Massover]

Hi!

OpenSIPS implement this logic:

/* Via special params:
 * requests:
 * - if the address in via is different from the src_ip or an existing
 *   received=something is found, received=src_ip is added (and any preexisting
 *   received is deleted). received is added as the first via parameter if no
 *   receive is previously present or over the old receive.


But RFC 3581 says that:
4.  Server Behavior
   The server behavior specified here affects the transport processing
   defined in Section 18.2 of SIP [1].
   When a server compliant to this specification (which can be a proxy
   or UAS) receives a request, it examines the topmost Via header field
   value.  If this Via header field value contains an "rport" parameter
   with no value, it MUST set the value of the parameter to the source
   port of the request.  This is analogous to the way in which a server
   will insert the "received" parameter into the topmost Via header
   field value.  In fact, the server MUST insert a "received" parameter
   containing the source IP address that the request came from, even if
   it is identical to the value of the "sent-by" component.  Note that
   this processing takes place independent of the transport protocol.

As far as I understand it means that "received" should be added always.


I'm trying to understand what is the reason for not adding "received" when ip address in Via is the same like src_ip?

--
Best Regards,
Alex Massover



 
 
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