Traversal Using Relays around NAT (TURN) Extensions for TCP Allocations
RFC 6062

Internet Engineering Task Force (IETF)                 S. Perreault, Ed.
Request for Comments: 6062                                      Viagenie
Category: Standards Track                                   J. Rosenberg
ISSN: 2070-1721                                              jdrosen.net
                                                           November 2010

Traversal Using Relays around NAT (TURN) Extensions for TCP Allocations

Abstract

   This specification defines an extension of Traversal Using Relays
   around NAT (TURN), a relay protocol for Network Address Translator
   (NAT) traversal.  This extension allows a TURN client to request TCP
   allocations, and defines new requests and indications for the TURN
   server to open and accept TCP connections with the client's peers.
   TURN and this extension both purposefully restrict the ways in which
   the relayed address can be used.  In particular, it prevents users
   from running general-purpose servers from ports obtained from the
   TURN server.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6062.

Perreault & Rosenberg        Standards Track                    [Page 1]
RFC 6062                        TURN TCP                   November 2010

Copyright Notice

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   document authors.  All rights reserved.

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   described in the Simplified BSD License.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Conventions  . . . . . . . . . . . . . . . . . . . . . . . . .  3
   3.  Overview of Operation  . . . . . . . . . . . . . . . . . . . .  4
   4.  Client Processing  . . . . . . . . . . . . . . . . . . . . . .  6
     4.1.  Creating an Allocation . . . . . . . . . . . . . . . . . .  6
     4.2.  Refreshing an Allocation . . . . . . . . . . . . . . . . .  7
     4.3.  Initiating a Connection  . . . . . . . . . . . . . . . . .  7
     4.4.  Receiving a Connection . . . . . . . . . . . . . . . . . .  7
     4.5.  Sending and Receiving Data . . . . . . . . . . . . . . . .  8
     4.6.  Data Connection Maintenance  . . . . . . . . . . . . . . .  8
   5.  TURN Server Behavior . . . . . . . . . . . . . . . . . . . . .  8
     5.1.  Receiving a TCP Allocate Request . . . . . . . . . . . . .  8
     5.2.  Receiving a Connect Request  . . . . . . . . . . . . . . .  9
     5.3.  Receiving a TCP Connection on a Relayed Transport
           Address  . . . . . . . . . . . . . . . . . . . . . . . . . 10
     5.4.  Receiving a ConnectionBind Request . . . . . . . . . . . . 11
     5.5.  Data Connection Maintenance  . . . . . . . . . . . . . . . 11
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 11
     6.1.  New STUN Methods . . . . . . . . . . . . . . . . . . . . . 11
     6.2.  New STUN Attributes  . . . . . . . . . . . . . . . . . . . 12
       6.2.1.  CONNECTION-ID  . . . . . . . . . . . . . . . . . . . . 12
     6.3.  New STUN Error Codes . . . . . . . . . . . . . . . . . . . 12
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 12
   8.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
     9.1.  Normative References . . . . . . . . . . . . . . . . . . . 12
     9.2.  Informative References . . . . . . . . . . . . . . . . . . 13

Perreault & Rosenberg        Standards Track                    [Page 2]
RFC 6062                        TURN TCP                   November 2010

1.  Introduction

   Traversal Using Relays around NAT (TURN) [RFC5766] is an extension to
   the Session Traversal Utilities for NAT [RFC5389] protocol.  TURN
   allows for clients to communicate with a TURN server and ask it to