110 likes | 237 Views
PPSP NAT traversal. draft-li-ppsp-nat-traversal-00. Lichun Li , Jun Wang, Yu Meng {li.lichun1, wang.jun17,meng.yu}@ zte.com.cn. Terminology. STUN/TURN/proxy/relay peer special PPSP peers providing NAT traversal services User nodes or super nodes deployed by the operator STUN peer
E N D
PPSP NAT traversal draft-li-ppsp-nat-traversal-00 Lichun Li, Jun Wang, Yu Meng {li.lichun1, wang.jun17,meng.yu}@zte.com.cn
Terminology • STUN/TURN/proxy/relay peer • special PPSP peers providing NAT traversal services • User nodes or super nodes deployed by the operator • STUN peer • Provides STUN service • TURN peer • provides relay service in TURN layer • application agnostic relay • Proxy peer • relays PPSP message in PPSP layer • Application specific relay (similar to HTTP/SIP proxy, RELOAD peer) • Relay peer • A peer providing relay services: a TURN peer, proxy peer or both. • Candidate (from ICE RFC5245) • A transport address that is a potential point of contact for receipt of media. • Relayed candidate (from ICE) • A peer’s relayed candidate is the address assigned by its TURN server. • Proxy candidate • A peer's proxy candidate is the address of its serving proxy peer.
PPSP network applying NAT traversal solution • Peers may gather reflexive/relayed candidates from STUN/TURN servers • Peer list contains candidates and peer ID.
NAT traversal • One-direction connectivity checks are PPSP checks or modified ICE checks • Standard ICE connectivity checks require exchanging ICE parameters • Optional ICE process for optimizing communication path
Standard ICE • Peers must exchange ICE parameters with offer/answer model • ICE check connectivity with STUN binding messages. • user name fragments and passwords exchanged in offer/answer phase • Testing relayed candidate • Add permission in TURN server
One-direction ICE connectivity check without offer/answer • Authentication change • Don’t use STUN name fragment. Put the whole STUN user name & password in peer list • A adds permission in B’s serving TURN peer by some means
One-direction PPSP connectivity check • Compared with ICE connectivity check, PPSP connectivity check • can use PPSP’s own authentication method, and avoid the STUN/TURN authentication problem • uses PPSP messages instead of STUN binding messages • uses proxy candidate instead of relayed candidate
Media Traversal of NAT • ICE parameters can be exchanged with PPSP messages • MediaAttach messages may be relayed by proxy/TURN peer
Requirements for PPSP • Tracker protocol MUST • allow STUN/TURN/proxy ability report • allow STUN/TURN/proxy peer list query • allow reporting candidates • contain candidates in peer list • allow tracker instructing peer to work in NAT-traversal/no-NAT-traversal mode? • Peer protocol MUST • allow exchanging ICE parameters • contain candidates in peer list • If one-direction connectivity is checked • in ICE layer, we need to modify ICE and TURN. • In PPSP layer, peer protocol MUST • allow connectivity check in PPSP layer • allow PPSP message relay • allow obtaining and maintaining proxy candidate • allow STUN/TURN/proxy peer list exchange
Next Steps • Get more comments • Refine NAT traversal solution • Design NAT-traversal required messages in details
Thank you! Questions?