Hi Gang A quick search via google did not reveal any useful hits. Kamailio 5.7.6 CPE (TLS) => SBC (UDP) => Registrar (UDP) => Core CPE uses a sips contact URI to register, no transport attribute! sips:315996608@172.29.255.11:5061 SBC uses Path functionality. Situation: Call to CPE I see the registrar adding this Record-Route: Record-Route: <sips:registrar-ip;lr;ftag=6159862378> The SBC is adding a r2=on Record-Route to indicate the change between UDP and TLS. The Route-Set received by the CPE then is: INVITE sips:315996608@172.29.255.11:5061 SIP/2.0 Record-Route: <sips:sbc-ip:5061;transport=tls;r2=on;lr;ftag=6159862378> Record-Route: <sips:sbc-ip;r2=on;lr;ftag=6159862378> Record-Route: <sips:registrar-ip;lr;ftag=6159862378> Record-Route: <sip:core-ip;lr;ftag=6159862378> 180 Ringing req 100rel is making it back as the Via header look right. But when the remote side is sending a PRACK, is has to follow the Routeset which if I am not mistaking, is not making it back because because the CORE does not know how to send this via TLS to the Registrar. Core logging: prepare_new_uac(): can't fwd to af 2, proto 3 (no corresponding listening socket) IMHO already the 2nd Record-Route added by the Registrar should not contain a sips: URI but a sip: URI (reflecting the transport attribute not being present, defaulting to UDP) Is this a known issue? Mit freundlichen Grüssen -Benoît Panizzon- -- I m p r o W a r e A G - Leiter Commerce Kunden ______________________________________________________ Zurlindenstrasse 29 Tel +41 61 826 93 00 CH-4133 Pratteln Fax +41 61 826 93 01 Schweiz Web http://www.imp.ch ______________________________________________________