But that's not the only use-case for Contact - the Contact URI of Alice can be used at any time later for an out-of-dialog request to Alice, and at that point it suddenly needs a full sips path to Alice. For example in a REFER case.
-hadriel On Sep 15, 2011, at 10:25 AM, Iñaki Baz Castillo wrote: > 2011/9/15 Olle E. Johansson <o...@edvina.net>: >> This means thet the request URI of the ACK will be using SIPS, and then >> section 8.1.1.8 comes into play >> and requires the other side to also use a SIPS uri in their contact. >> >> In this case, both UAs need a TLS certificate. > > No, that's incorrect. I show two call flows in which TLS is just used > by one of the enpoints. > > > > CASE 1) > - Alice uses TLS. > - Bob uses UDP. > - Proxy/registrar does loose-routing. > - Alice calls Bob, Bob answers and later Bob hangs up. > > > F1 INVITE Alice -> SIP Proxy (transport TLS) > > INVITE sip:b...@atlanta.com SIP/2.0 > Via: SIP/2.0/TLS 93.12.40.105:20565;branch=z9hG4bK56sdasks > From: sip:al...@atlanta.com;tag=asdyka899 > To: sip:b...@atlanta.com > Call-ID: asidkj3ss > CSeq: 1 INVITE > Max-Forwards: 70 > Contact: <sips:alice@93.12.40.105:20565;transport=tcp> > Content-Type: application/sdp > > > F2 100 Trying SIP Proxy -> Alice (transport TLS) > > SIP/2.0 100 Trying > Via: SIP/2.0/TLS 93.12.40.105:20565;branch=z9hG4bK56sdasks > From: sip:al...@atlanta.com;tag=asdyka899 > To: sip:b...@atlanta.com > Call-ID: asidkj3ss > CSeq: 1 INVITE > > > F3 INVITE SIP Proxy -> Carol (transport UDP) > > INVITE sip:bob@77.123.45.23:5060 SIP/2.0 > Via: SIP/2.0/UDP 100.100.100.100;branch=z9hG4bKhjhjqw32c > Via: SIP/2.0/TLS 93.12.40.105:20565;branch=z9hG4bK56sdasks > Record-Route: <sip:100.100.100.100;transport=udp>, > <sips:100.100.100.100;transport=tcp> > From: sip:al...@atlanta.com;tag=asdyka899 > To: sip:b...@atlanta.com > Call-ID: asidkj3ss > CSeq: 1 INVITE > Max-Forwards: 69 > Contact: <sips:alice@93.12.40.105:20565;transport=tcp> > Content-Type: application/sdp > > > F4 200 OK Carol -> SIP Proxy (transport UDP) > > SIP/2.0 200 OK > Via: SIP/2.0/UDP 100.100.100.100;branch=z9hG4bKhjhjqw32c > Via: SIP/2.0/TLS 93.12.40.105:20565;branch=z9hG4bK56sdasks > Record-Route: <sip:100.100.100.100;transport=udp>, > <sips:100.100.100.100;transport=tcp> > From: sip:al...@atlanta.com;tag=asdyka899 > To: sip:b...@atlanta.com;tag=bmqkjhsd > Call-ID: asidkj3ss > CSeq: 1 INVITE > Max-Forwards: 69 > Contact: <sip:bob@77.123.45.23:5060;transport=udp> > Content-Type: application/sdp > > > F5 200 OK SIP Proxy -> Alice (transport TLS) > > SIP/2.0 200 OK > Via: SIP/2.0/TLS 93.12.40.105:20565;branch=z9hG4bK56sdasks > Record-Route: <sip:100.100.100.100;transport=udp>, > <sips:100.100.100.100;transport=tcp> > From: sip:al...@atlanta.com;tag=asdyka899 > To: sip:b...@atlanta.com;tag=bmqkjhsd > Call-ID: asidkj3ss > CSeq: 1 INVITE > Max-Forwards: 69 > Contact: <sip:bob@77.123.45.23:5060;transport=udp> > Content-Type: application/sdp > > > F6 ACK Alice -> SIP Proxy (transport TLS) > > ACK sip:bob@77.123.45.23:5060;transport=udp SIP/2.0 > Via: SIP/2.0/TLS 93.12.40.105:20565;branch=z9hG4bKhgqqp090 > Route: <sips:100.100.100.100;transport=tcp>, > <sip:100.100.100.100;transport=udp> > From: sip:al...@atlanta.com;tag=asdyka899 > To: sip:b...@atlanta.com;tag=bmqkjhsd > Call-ID: asidkj3ss > CSeq: 1 ACK > Max-Forwards: 70 > > > F7 ACK SIP Proxy -> Carol (transport UDP) > > ACK sip:bob@77.123.45.23:5060;transport=udp SIP/2.0 > Via: SIP/2.0/UDP 100.100.100.100;branch=z9hG4bKhwpoc80zzx > Via: SIP/2.0/TLS 93.12.40.105:20565;branch=z9hG4bKhgqqp090 > From: sip:al...@atlanta.com;tag=asdyka899 > To: sip:b...@atlanta.com;tag=bmqkjhsd > Call-ID: asidkj3ss > CSeq: 1 ACK > Max-Forwards: 69 > > > F8 BYE Carol -> SIP Proxy (transport UDP) > > BYE sips:alice@93.12.40.105:20565;transport=tcp SIP/2.0 > Via: SIP/2.0/UDP 77.123.45.23;branch=z9hG4bKbiuiansd001 > Route: <sip:100.100.100.100;transport=udp>, > <sips:100.100.100.100;transport=tcp> > From: sip:b...@atlanta.com;tag=bmqkjhsd > To: sip:al...@atlanta.com;tag=asdyka899 > Call-ID: asidkj3ss > CSeq: 1201 BYE > Max-Forwards: 70 > > > F9 BYE SIP Proxy -> Alice (transport TLS) > > BYE sips:alice@93.12.40.105:20565;transport=tcp SIP/2.0 > Via: SIP/2.0/TLS 100.100.100.100;branch=z9hG4bKmma01m3r5 > Via: SIP/2.0/UDP 77.123.45.23;branch=z9hG4bKbiuiansd001 > From: sip:b...@atlanta.com;tag=bmqkjhsd > To: sip:al...@atlanta.com;tag=asdyka899 > Call-ID: asidkj3ss > CSeq: 1201 BYE > Max-Forwards: 69 > > > F10 200 OK Alice -> SIP Proxy (transport TLS) > > SIP/2.0 200 OK > Via: SIP/2.0/TLS 100.100.100.100;branch=z9hG4bKmma01m3r5 > Via: SIP/2.0/UDP 77.123.45.23;branch=z9hG4bKbiuiansd001 > From: sip:b...@atlanta.com;tag=bmqkjhsd > To: sip:al...@atlanta.com;tag=asdyka899 > Call-ID: asidkj3ss > CSeq: 1201 BYE > > > F11 200 OK SIP Proxy -> Carol (transport UDP) > > SIP/2.0 200 OK > Via: SIP/2.0/UDP 77.123.45.23;branch=z9hG4bKbiuiansd001 > From: sip:b...@atlanta.com;tag=bmqkjhsd > To: sip:al...@atlanta.com;tag=asdyka899 > Call-ID: asidkj3ss > CSeq: 1201 BYE > > > > > > > > CASE 2) > - Alice uses TLS. > - Bob uses UDP. > - Proxy/registrar does loose-routing. > - Bob calls Alice, Alice answers and later Alice hangs up. > > > F1 INVITE Bob -> SIP Proxy (transport UDP) > > INVITE sip:al...@atlanta.com SIP/2.0 > Via: SIP/2.0/UDP 77.123.45.23:5060;branch=z9hG4bK56sdasks > From: sip:b...@atlanta.com;tag=asdyka899 > To: sip:al...@atlanta.com > Call-ID: asidkj3ss > CSeq: 1 INVITE > Max-Forwards: 70 > Contact: <sip:bob@77.123.45.23:5060;transport=udp> > Content-Type: application/sdp > > > F2 100 Trying SIP Proxy -> Bob (transport TLS) > > SIP/2.0 100 Trying > Via: SIP/2.0/UDP 77.123.45.23:5060;branch=z9hG4bK56sdasks > From: sip:b...@atlanta.com;tag=asdyka899 > To: sip:al...@atlanta.com > Call-ID: asidkj3ss > CSeq: 1 INVITE > > > F3 INVITE SIP Proxy -> Alice (transport TLS) > > INVITE sips:alice@93.12.40.105:20565 SIP/2.0 > Via: SIP/2.0/TLS 100.100.100.100;branch=z9hG4bKhjhjqw32c > Via: SIP/2.0/UDP 77.123.45.23:5060;branch=z9hG4bK56sdasks > Record-Route: <sips:100.100.100.100;transport=tcp>, > <sip:100.100.100.100;transport=udp> > From: sip:b...@atlanta.com;tag=asdyka899 > To: sip:al...@atlanta.com > Call-ID: asidkj3ss > CSeq: 1 INVITE > Max-Forwards: 69 > Contact: <sip:bob@77.123.45.23:5060;transport=udp> > Content-Type: application/sdp > > > F4 200 OK Alice -> SIP Proxy (transport TLS) > > SIP/2.0 200 OK > Via: SIP/2.0/TLS 100.100.100.100;branch=z9hG4bKhjhjqw32c > Via: SIP/2.0/UDP 77.123.45.23:5060;branch=z9hG4bK56sdasks > Record-Route: <sips:100.100.100.100;transport=tcp>, > <sip:100.100.100.100;transport=udp> > From: sip:b...@atlanta.com;tag=asdyka899 > To: sip:al...@atlanta.com;tag=bmqkjhsd > Call-ID: asidkj3ss > CSeq: 1 INVITE > Max-Forwards: 69 > Contact: <sips:alice@93.12.40.105:20565;transport=tcp> > Content-Type: application/sdp > > > F5 200 OK SIP Proxy -> Bob (transport UDP) > > SIP/2.0 200 OK > Via: SIP/2.0/UDP 77.123.45.23:5060;branch=z9hG4bK56sdasks > Record-Route: <sips:100.100.100.100;transport=tcp>, > <sip:100.100.100.100;transport=udp> > From: sip:b...@atlanta.com;tag=asdyka899 > To: sip:al...@atlanta.com;tag=bmqkjhsd > Call-ID: asidkj3ss > CSeq: 1 INVITE > Max-Forwards: 69 > Contact: <sips:alice@93.12.40.105:20565;transport=tcp> > Content-Type: application/sdp > > > F6 ACK Bob -> SIP Proxy (transport UDP) > > ACK sips:alice@93.12.40.105:20565;transport=tcp SIP/2.0 > Via: SIP/2.0/TLS 77.123.45.23:5060;branch=z9hG4bKhgqqp090 > Route: <sip:100.100.100.100;transport=udp>, > <sips:100.100.100.100;transport=tcp> > From: sip:b...@atlanta.com;tag=asdyka899 > To: sip:al...@atlanta.com;tag=bmqkjhsd > Call-ID: asidkj3ss > CSeq: 1 ACK > Max-Forwards: 70 > > > F7 ACK SIP Proxy -> Alice (transport TLS) > > ACK sips:alice@93.12.40.105:20565;transport=tcp SIP/2.0 > Via: SIP/2.0/TLS 100.100.100.100;branch=z9hG4bKhwpoc80zzx > Via: SIP/2.0/UDP 77.123.45.23:5060;branch=z9hG4bKhgqqp090 > From: sip:b...@atlanta.com;tag=asdyka899 > To: sip:al...@atlanta.com;tag=bmqkjhsd > Call-ID: asidkj3ss > CSeq: 1 ACK > Max-Forwards: 69 > > > F8 BYE Alice -> SIP Proxy (transport TLS) > > BYE sip:bob@77.123.45.23:5060;transport=udp SIP/2.0 > Via: SIP/2.0/TLS 77.123.45.23;branch=z9hG4bKbiuiansd001 > Route: <sips:100.100.100.100;transport=tcp>, > <sip:100.100.100.100;transport=udp> > From: sip:al...@atlanta.com;tag=bmqkjhsd > To: sip:b...@atlanta.com;tag=asdyka899 > Call-ID: asidkj3ss > CSeq: 1201 BYE > Max-Forwards: 70 > > > F9 BYE SIP Proxy -> Bob (transport UDP) > > BYE sip:bob@77.123.45.23:5060;transport=udp SIP/2.0 > Via: SIP/2.0/UDP 100.100.100.100;branch=z9hG4bKmma01m3r5 > Via: SIP/2.0/TLS 77.123.45.23;branch=z9hG4bKbiuiansd001 > From: sip:al...@atlanta.com;tag=bmqkjhsd > To: sip:b...@atlanta.com;tag=asdyka899 > Call-ID: asidkj3ss > CSeq: 1201 BYE > Max-Forwards: 69 > > > F10 200 OK Bob -> SIP Proxy (transport UDP) > > SIP/2.0 200 OK > Via: SIP/2.0/UDP 100.100.100.100;branch=z9hG4bKmma01m3r5 > Via: SIP/2.0/TLS 77.123.45.23;branch=z9hG4bKbiuiansd001 > From: sip:al...@atlanta.com;tag=bmqkjhsd > To: sip:b...@atlanta.com;tag=asdyka899 > Call-ID: asidkj3ss > CSeq: 1201 BYE > > > F11 200 OK SIP Proxy -> Alice (transport TLS) > > SIP/2.0 200 OK > Via: SIP/2.0/TLS 77.123.45.23;branch=z9hG4bKbiuiansd001 > From: sip:al...@atlanta.com;tag=bmqkjhsd > To: sip:b...@atlanta.com;tag=asdyka899 > Call-ID: asidkj3ss > CSeq: 1201 BYE > > > > > These flows are inspired in real scenarios, so both are real and working > flows. > > > -- > Iñaki Baz Castillo > <i...@aliax.net> > _______________________________________________ > Sip mailing list https://www.ietf.org/mailman/listinfo/sip > This list is essentially closed and only used for finishing old business. > Use sip-implement...@cs.columbia.edu for questions on how to develop a SIP > implementation. > Use dispa...@ietf.org for new developments on the application of sip. > Use sipc...@ietf.org for issues related to maintenance of the core SIP > specifications. _______________________________________________ Sip mailing list https://www.ietf.org/mailman/listinfo/sip This list is essentially closed and only used for finishing old business. Use sip-implement...@cs.columbia.edu for questions on how to develop a SIP implementation. Use dispa...@ietf.org for new developments on the application of sip. Use sipc...@ietf.org for issues related to maintenance of the core SIP specifications.
