1 / 6

NAT Traversal for P2PSIP

NAT Traversal for P2PSIP. Philip Matthews Avaya. Establishing new Peer Protocol connection. Step 2.ICE Offer/Answer exchange via Overlay Routing (or via a Peer Protocol Relay). 3. ICE connectivity checks. The result is a connection between X and Y. P2PSIP Network. 2. 3. Peer X. Peer Y.

hashim
Télécharger la présentation

NAT Traversal for P2PSIP

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. NAT Traversal for P2PSIP Philip Matthews Avaya

  2. Establishing new Peer Protocol connection Step 2.ICE Offer/Answer exchange via Overlay Routing (or via a Peer Protocol Relay) 3. ICE connectivity checks. The result is a connection between X and Y. P2PSIP Network 2. 3. Peer X Peer Y 4. Step 1. Gather ICE candidates Peer W Peer Protocol messages ICE connectivity check messages

  3. Issue: Finding STUN/TURN servers • Naive solution: • Define a “STUN” and a “TURN” service • A peer W that is willing to act as a STUN / TURN server inserts a record into the distributed database under the key “STUN” or “TURN” • Peers looking for such a peer retrieve the list of peers offering the service and select one. • Problem: Node W responsible for holding these records will probably melt down under all the Put and Get traffic. • This is the “Popular Services Problem”

  4. Issue: Finding STUN/TURN servers (2) Two solns proposed so far: • Draft-jiang-p2psip-sep • A peer T advertizes its STUN/TURN server through Overlay Maint msgs. Peers receiving this info remember it for later use. • Draft-bryan-p2psip-reload • A peer X looking for a STUN/TURN server picks a spot in the hash space at random, and asks the peer nearest to that location if it supports STUN/TURN. If not, peer X picks another spot and tries again. • Con: As the number of peers offering the service decreases, the work to find such a peer increases.

  5. Issue: Large msgs over UDP How to send large Peer Protocol msgs over UDP? • Option 1: Rely on IP fragmentation • Con: Some NATs cannot handle receiving out-of-order fragments • How big a problem is this really • Option 2: Fragment at Peer Protocol layer • Con: Extra complexity • Con: Must limit to 576 bytes unless we do PMTUD. • Con: Are we just re-inventing IP fragmentation? • Option 3: Only run over TCP • Con: Today, success rate of direct connection (without TURN server) slightly lower for TCP than UDP

  6. Issue: NAT Traversal for Apps • Option 1: Each app implements its own NAT traversal scheme • Con: Lots of per-app work; scheme must take Overlay into account. • Option 2: An app explicitly asks Peer Protocol to set up a direct connection for its use. • Con: App must be modified to call Peer Protocol in appropriate spots. • Option 3: App uses special IP address to identify remote peer; packet intercepted below transport layer and sent over dynamically established connection to remote peer. • Con: Not transparent for apps that imbed addresses in protocol message.

More Related