[Serusers] Which SIP messages types use lookup("location")?

Jan Janak jan at iptel.org
Tue Mar 1 17:42:18 CET 2005


Only for requests that are not sent within a dialog, that rules out ACK,
BYE, NOTIFY.

The rest of the messages -- INVITE, REFER, SUBSCRIBER either establish a
dialog or are sent out of dialogs. 

If any of them contains pre-loaded route set (one or more Route header
fields) which will instruct your server to forward them elsewhere then
you will not call lookup("location") because loose_route would return
true and that is typically followed by t_relay. In such a case the route
of the request is determined by the sender and there is no need for you
to do user location lookup.

If they contain no Route header fields than it is up to you to decide
how to route them if the domain part of the Request-URI contains one of
domains or IP addresses your proxy is reponsible for. In this case the
proxy would probably use lookup("location") to find out the registered
contact.

If the domain part of the Request-URI does not contain one of your
domains or IP address, then it probably makes no sense to perform
lookup("location") because you would not have the contact of the
callee in the user location database anyway. In this case one could
either relay or reject the request, depending on the local policy.

  Jan.

On 23-02 12:12, Java Rockx wrote:
> Hi All,
> 
> Can anyone tell me for which message types I should call
> lookup("location") before t_relay()?
> 
> ACK
> BYE
> CANCEL
> INVITE
> NOTIFY
> REFER
> SUBSCRIBE
> 
> _______________________________________________
> Serusers mailing list
> serusers at lists.iptel.org
> http://lists.iptel.org/mailman/listinfo/serusers




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