1. Can SIP benefit from HIP (or vice versa)? Exchanging Host Identities in SIP Hannes Tschofenig, Vesa Torvinen, Joerg Ott, Henning Schulzrinne, Tom Henderson, Gonzalo Camarillo

2. Scope SIP / RTP Proxy SIP Signaling Traffic — Securing SIP signaling using HIP — Traversing NATs/Firewalls located between SIP proxies using HIP — Exchanging Host Identities in SIP between the end points — Using HITs instead of IP addresses or FQDNs in SIP/SDP Data Traffic — Securing the end-to-end communication via HIP (using IPsec or ???) — E2E NAT/Firewall traversal — Multi-homing and mobility capabilities SIP Trapezoid Proxy

3. Draft Content Exchanging Host Identities in SIP Host Identities / Host Identity Tags are exchanged in HIP (via SIP hops) End-to-end communication experiences HIP benefits Host Identities can be tight to the SIP URIs Cached locally at the end host (for future communication) "Purpose-Built-Key Idea" HIP Exchange Proxy SIP Proxy HIT/HI AliceBob RTP (SIP,...) HIT/HI

4. Next Steps Investigating the details — Draft mentions the usefulness of replacing IP addresses with Host Identities. Implementation work