[Serusers] Forwarding - why append_branch() ?

Hello, perhaps somebody can explain for me why first example works without append_branch() and second example NEED append_branch() to work? In 1. example i rewrite Request-URI in main-route-block. SER calls the new URI successfully. If i make append_branch() here, SER craches. In 2. example i rewrite Request-URI in failure-block. If i do not make append_branch() here, SER does not call the new URI. With append_branch() everything is all right, SER calls successfully the new URI. 1. example ------------------------- modparam("tm", "fr_inv_timer", 10) # set fr_inv_timer to 10 seconds ... route{ ... if (lookup("location")) { ... route(1); break; } else if (method == "INVITE" ) { revert_uri(); avp_db_load("$ruri","s:redirect_number01"); t_on_failure("2"); attr2uri("redirect_number01"); t_relay(); break; } } ------------------------- 2. example (same ser.cfg) ------------------------- failure_route[1] # entered when fr_inv_timer hits, 408 Timeout { revert_uri(); avp_db_load("$ruri","s:redirect_number01"); t_on_failure("2"); attr2uri("redirect_number01"); append_branch(); # why necessary? t_relay(); break; } } ------------------------- Alex -- Lust, ein paar Euro nebenbei zu verdienen? Ohne Kosten, ohne Risiko! Satte Provisionen f�r GMX Partner: http://www.gmx.net/de/go/partner