[Serusers] Loose Routing / Record-Route/Route Qeustions

Hello, i am currently trying to understand what exactly "loose routing" is and what exactly "loose_route" does. According to the admin manual and several postings from iptel.org members on this this piece of code should be at the very top of every routing script right after the sanity checks: # subsequent messages within a dialog should take the # path determined by record-routing if ( loose_route() ) { t_relay(); break; }; AFAIK a proxy determines if a request should be "loose routed" by looking at the "Record-Route"/"lr=on" option. Questions: If i have this statement bevore any authentication checks, dont i risk to have an open relay? Its easy to append a "lr=on" to every request. When exactly is "loose_route == TRUE" I cant find any real info about this either in the admin doc, nor in the according modules README file. I did understood what "Record-Route:" does, but what does "Route:" do i.e. wheres the difference between both?! Does every "subsequent" message belonging to a (statefull) sip call get evaluatet in SERs main route block? (As long as its record-routed off course and the proxy "sees" it). best regards, Arnd