Other NAT traversal protocols

Traversal Using Relay Nat (TURN)

A. La Torre Yurkov’s Master's thesis: Implementation of Traversal Using Relay Nat for SIP based VoIP [Yurkov 2006] describes TURN, its implementation, and performance. TURN is specified in RFC 5766.

ICE

Another protocol for NAT traversal is “Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal for Offer/Answer Protocol” as specified in RFC 5245.

RFC 6544: TCP Candidates with Interactive Connectivity Establishment (ICE)
RFC 6336 : IANA Registry for Interactive Connectivity Establishment (ICE) Options

Slide Notes

La Torre Yurkov, Implementation of Traversal Using Relay Nat for SIP based VoIP, Master Thesis, Royal Institute of Technology (KTH), Institution for Microelectronics and Information Technology, Stockholm, Sweden, February 2006 http://www.minisip.org/publications/Thesis_LaTorreYurkov_feb2006.pdf Links to an external site.

R. Mahy, P. Matthews, and J. Rosenberg, “Traversal Using Relays around NAT (TURN): Relay Extensions to Session Traversal Utilities for NAT (STUN)”, Internet Request for Comments, RFC Editor, RFC 5766 (Proposed Standard), ISSN 2070-1721, April 2010 http://www.rfc-editor.org/rfc/rfc5766.txt Links to an external site.

J. Rosenberg, “Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal for Offer/Answer Protocols”,Internet Request for Comments, RFC Editor, RFC 5245 (Proposed Standard), ISSN 2070-1721, April 2010 http://www.rfc-editor.org/rfc/rfc5245.txt Links to an external site.

J. Rosenberg, A. Keranen, B. B. Lowekamp, and A. B. Roach, ‘TCP Candidates with Interactive Connectivity Establishment (ICE)’, Internet Request for Comments, vol. RFC 6544 (Proposed Standard), Mar. 2012 [Online]. Available: http://www.rfc-editor.org/rfc/rfc6544.txt Links to an external site.

M. Westerlund and C. Perkins, ‘IANA Registry for Interactive Connectivity Establishment (ICE) Options’, Internet Request for Comments, vol. RFC 6336 (Proposed Standard), Jul. 2011 [Online]. Available: http://www.rfc-editor.org/rfc/rfc6336.txt Links to an external site.

Transcript

[slide378] We talked about TURN, and La Torre Yurkov did a thesis about that. A later technique was introduced called ICE, Interactive Connectivity Establishment. And the idea here is that ICE says, well, initially I don't know, should I use TURN, which only works in a certain subset of cases, or should I use STUN, which works in another set, or what should I do? Well, ICE says, well, let me try them all. Let me see if I can figure out what kind of NAT it is, and then use the right solution. Why do we want to figure out what kind of NAT it is? Well, if we know the kind of NAT, we can know how to solve the problem. What do we want to avoid? Unnecessarily having to use a relay. So that means we need to try STUN first, and then try TURN second, rather than reverse.