[Serusers] Some questions on "loose_route"

[Franz Edler]

Hi all again,

from various examples in the SER admin_guide and my own SIP knowledge-base I
conclude, that the action "loose-route()" is responsible for correct routing
of those requests, that are not destined to the proxy (host of Request-URI
is not the proxy) and that have a proper Route-header indicating
"loose-routing".

As such the action "loose_route()" should be sufficient to modify the
Request in such a way, that the following action "t-relay()" finishes
processing of the request. Therefore the action short sequence 
	... if (loose_route()) { t_relay(); break; };
does all, what is necessary for loose routing of those requests.

My problem is, that I could not produce a condition, where "loose_route()"
evaluates to true, so that the action block { t_relay(); break; } is
executed. I expect, that in a simple call-scenario with one record-routing
SIP proxy (SER) the routing of the ACK- and the BYE-method should trigger
the above mentioned "loose_route()" action. But unfortunately it does not.
Why?

Please help (in best case confirm) my understanding of "loose_route()".

Franz