SIP in higher education

[Rob McCartney <>]

This probably isn't the answer you want, but looking at the source at
/<ser source root>/modules/rr says that loose_route() follows the 
conventions in RFC3261:

"A proxy is said to be loose routing if it follows the procedures 
defined in this specification for processing of the Route header field. 
 These procedures separate the destination of the request (present in 
the Request-URI) from the set of proxies that need to be visited along 
the way (present in the Route header field).  A proxy compliant to these 
mechanisms is also known as a loose router. "[RFC3261]

It looks like the original strict routing "rule caused proxies to 
destroy the contents of the Request-URI when a Route header field was 
present.  Strict routing behavior is not used in this specification, in 
favor of a loose routing behavior." [RFC3261]


There is mention in some of the config examples that this is done to 
keep people from spoofing the route to get onto the PSTN.


As to why your config is better than the one in the cookbook, the 
loose_route() will fail (return -1) if there is no route header, if it 
cannot parse the URI, or if there is any trouble grabbing the next hop 
from the route header. So the config should look like yours, at least in 
my [uninformed, newbie] opinion. t_relay() sends the request to the 
address currently in the URI (which is rewritten by, among other things, 
loose_route()). I'm sure this is probably a case of SER updating 
functions in a way that didn't break an older config. The function calls 
seem to still be somewhat in flux.



I've got to get my SIP server up in the next week or so and since Alan 
threw down the gauntlet at the conference, I'll be posting my SER config 
for everyone to heckle. If you will post yours (anyone) before I do, 
I'll give you a GMail invite. I have 2 invites left so get them while 
they're hot.


cheers
rob



On 6/25/2004 3:16 PM, Alan Crosswell wrote:

> This time you should see my intended CC:
>
> -------- Original Message --------
> Subject: loose_route question in cookbook
> Date: Fri, 25 Jun 2004 14:31:50 -0400
> From: Alan Crosswell 
> <>
> To: Jeremy George 
> <>
> CC: 
>
>
> Jeremy,
>
> In the cookbook it says:
>
> # separate the destination r-uri from the set of proxies that must be 
> traversed
>   loose_route();
>
> while in my ser.cfg that comes from I guess a iptel.org example it says:
>     # loose-route processing
>     if (loose_route()) {
>     t_relay();
>     break;
>     };
>
> Can you explain what this is all about?
> /a