At 02:46 PM 1/2/2004, Franz Edler wrote: yes yes yes, that's what it is supposed to do. Hard to say -- a trivial reason is you left out "record_route" from your script, another reason is a phone does not generate proper subsequent requests. If you post your config file and messages, perhaps someone on the mailing list will look at these. -jiri

On 02-01 14:46, Franz Edler wrote: Not really. loose_route() implements record routing. Because it must be backwards compatible with strict routers, it implements both, loose routing and strict routing. It should process all messages that contain Route header fields, even those that have hostname or IP of the proxy in Request-URI (it can happen). You should call loose_route() on every message unless you know what you are really doing. I think that this one deserves some explanation. The reason why if (loose_route()) { t_relay(); } is needed and why just loose_route(); is not sufficient is as follows: In some situations, SER needs to insert two Route header fields -- we call this double record-routing. It is necessary, for example, when a request comes over UDP and ser sends it over TCP. Suppose the following situation: A -- UDP -- SER -- TCP -- B A sends a SIP message over UDP to ser and ser forwards the message over TCP to B. Later if B sends a message within dialog, you usually want it to go the same way -- that means it should be sent over TCP to ser and ser forwards it over UDP to be. To achieve this, ser needs to add two Record-Route header fields, one with UDP transport and one with TCP transport, they will look like this: Record-Route: <sip:ser@1.2.3.4;r2;transport=TCP> Record-Route: <sip:ser@1.2.3.4;r2> (the only difference is in the parameters). Client B sees the "TCP" Record-Route first and sends the further messages over TCP. Client A reverses the order of the header fields and sees the "UDP" Route first. Because the ser in the middle created both headers, it also has to remove both resulting Route header fields. That's what r2 parameter is for -- it tells ser that another Route header field follows and it should be removed as well. Unfortunately there are broken implementations in the wild that strip parameters that they don't know -- in this case the r2 parameter. ser will not remove the 2nd Route if the parameter is missing, instead it would forward the message to it. In some cases it doesn't harm -- the message will just spiral through the same proxy one more time. Now the tough part -- in some cases it does harm -- for example when there are some strict routers along the path. In this case the message would contain the IP address of ser in the Request-URI (from the 2nd Route). In most config files, loose_route() is usually followed by a condition like this: if (uri==myself) and that condition would match (because there is the IP of ser in the Request-URI). That's wrong, because mid-dialog requests should not be processed in this part of script. loose_route() returns true in this case and you must make sure that if (uri==myself) is not reached. That's the reason why t_relay() is called inside the condition -- message contained Route headers and shouldn't be processed by the script. See above, this condition is a sort of safety net and normaly it is not triggered. You should have t_relay(); at the end of your script which will take care of all other record-routed requests. See the default config file for more details. Jan.