route[3]
{
        log(1, "Entering route[3]...");
        fix_nated_register();

        save_noreply("location");
        #save("location");

        # snom 200: Contact: <sip:klaus@192.168.2.22:5060;transport=udp;line=50b9439q>;q=1.0
        #                      \1        \2       \3    \4   \5
        if ( subst('/^Contact:(.*)<sip:([^@]+)@([^;]*);(.*)>(.*)$/Contact:\1<sip:\2_\3@83.136.32.80;\4>\5/ig') ) {
                log(1, "Contact in REGISTER rewritten - SNOM style\n");
        }

        #                      \1        \2       \3    \4
        if ( subst('/^Contact:(.*)<sip:([^@]+)@([^;]*)>(.*)$/Contact:\1<sip:\2_\3@83.136.32.80>\4/ig') ) {
                log(1, "Contact in REGISTER rewritten - SIPURA style\n");
        }

        #Contact: <sip:84.20.178.249:10247>;methods="INVITE, MESSAGE, INFO, OPTIONS, BYE, CANCEL, ACK, REFER"
        #                      \1       \2   \3
        if ( subst('/^Contact:(.*)<sip:([^@]+)>(.*)$/Contact:\1<sip:_\2@83.136.32.80>\3/ig') ) {   #Messenger style contact without username
                log(1, "Contact in REGISTER rewritten - RTC API style\n");
        }

        t_on_reply("3");
        t_relay();
        log(1, "... leaving route[3]");
        break;
}

onreply_route[3]
{
        log(1, "Entering onreply_route[3]...\n");

        #                      \1         \2   \3   \4
        if ( subst('/^Contact:(.*)<sip:_(.*?)@(.*)>(.*)$/Contact:\1<sip:\2>\4/ig') ) { #Messenger style contact without username
                log(1, "Contact in REGISTER response rewritten - RTC API style\n");
        }

        #                      \1        \2      \3    \4     \5   \6
        if ( subst('/^Contact:(.*)<sip:([^@]+)_(.*?)@([^;]*);(.*)>(.*)$/Contact:\1<sip:\2@\3;\5>\6/ig') ) {
                log(1, "Contact in REGISTER respone rewritten - SNOM style\n");
        };

        #                      \1        \2      \3   \4   \5
        if ( subst('/^Contact:(.*)<sip:([^@]+)_(.*?)@([^;]*)>(.*)$/Contact:\1<sip:\2@\3>\5/ig') ) {
                log(1, "Contact in REGISTER respone rewritten - SIPURA style\n");
        };

        log(1, "leaving onreply_route(3)\n");
}