XEP-0208: Bootstrapping Implementation of Jingle

This document provides guidelines to client developers for bootstrapping implementation of Jingle technologies.


WARNING: This Informational document is Experimental. Publication as an XMPP Extension Protocol does not imply approval of this proposal by the XMPP Standards Foundation. Implementation of the best practice or protocol profile described herein is encouraged in exploratory implementations, although production systems should not deploy implementations of this protocol until it advances to a status of Draft.


Document Information

Series: XEP
Number: 0208
Publisher: XMPP Standards Foundation
Status: Experimental
Type: Informational
Version: 0.2
Last Updated: 2007-05-11
Approving Body: XMPP Council
Dependencies: XMPP Core, XEP-0166
Supersedes: None
Superseded By: None
Short Name: N/A
Wiki Page: <http://wiki.jabber.org/index.php/Bootstrapping Implementation of Jingle (XEP-0208)>

Author Information

Peter Saint-Andre

Email: stpeter@jabber.org
JabberID: stpeter@jabber.org

Legal Notice

This XMPP Extension Protocol is copyright 1999 - 2007 by the XMPP Standards Foundation (XSF) and is in full conformance with the XSF's Intellectual Property Rights Policy <http://www.xmpp.org/extensions/ipr-policy.shtml>. This material may be distributed only subject to the terms and conditions set forth in the Creative Commons Attribution License (<http://creativecommons.org/licenses/by/2.5/>).

Discussion Venue

The preferred venue for discussion of this document is the Standards discussion list: <http://mail.jabber.org/mailman/listinfo/standards>.

Relation to XMPP

The Extensible Messaging and Presence Protocol (XMPP) is defined in the XMPP Core (RFC 3920) and XMPP IM (RFC 3921) specifications contributed by the XMPP Standards Foundation to the Internet Standards Process, which is managed by the Internet Engineering Task Force in accordance with RFC 2026. Any protocol defined in this document has been developed outside the Internet Standards Process and is to be understood as an extension to XMPP rather than as an evolution, development, or modification of XMPP itself.

Conformance Terms

The following keywords as used in this document are to be interpreted as described in RFC 2119: "MUST", "SHALL", "REQUIRED"; "MUST NOT", "SHALL NOT"; "SHOULD", "RECOMMENDED"; "SHOULD NOT", "NOT RECOMMENDED"; "MAY", "OPTIONAL".


Table of Contents


1. Introduction
2. Protocol Flow
3. Security Considerations
4. IANA Considerations
5. XMPP Registrar Considerations
    5.1. Protocol Namespaces
    5.2. Jingle Content Description Formats
6. XML Schema
Notes
Revision History


1. Introduction

Jingle [1] defines a framework for using XMPP to negotiate and manage out-of-band media sessions. Unfortunately, most developers of XMPP clients have limited experience with multimedia applications such as voice and video, making it difficult to get started with implementation of Jingle technologies. Therefore this document provides a simple transport and session type that client developers can use to bootstrap Jingle implementations.

Note: The methods specified herein are provided for experimentation and unit testing only. They are not intended for inclusion in released software or production environments.

2. Protocol Flow

The intent of this simple Jingle profile is to enable exchange of data using the Echo Protocol specified in RFC 862 [2], but using a port other than 7 (the default port for this experimental usage is 17777). The protocol flow is as follows. (The following examples use Jingle Raw UDP Transport Method [3] as the transport protocol; although it is possible to complete echo protocol exchanges via TCP, that is deemed less useful and there is no Jingle transport for direct TCP exchanges.)

Example 1. Initiatior Creates Session

<iq from='romeo@montague.net/orchard' to='juliet@capulet.com/balcony' id='jingle1' type='set'>
  <jingle xmlns='http://www.xmpp.org/extensions/xep-0166.html#ns'
          action='session-initiate'
          initiator='romeo@montague.net/orchard'
          sid='a73sjjvkla37jfea'>
    <content creator='initiator' name='echo-this'>
      <description xmlns='http://www.xmpp.org/extensions/xep-0208.html#ns'/>
      <transport xmlns='http://www.xmpp.org/extensions/xep-0177.html#ns'>
        <candidate ip='10.1.1.104' port='17777' generation='0'/>
      </transport>
    </content>
  </jingle>
</iq>
  

Example 2. Receiver Provisionally Accepts the Session Request

<iq from='juliet@capulet.com/balcony' to='romeo@montague.net/orchard' type='result' id='jingle1'/>
  

If no negotiation is required (e.g., to modify the port number or transport protocol), the receiver simply accepts the session request. (Alternatively, if the receiver wants to use a port other 17777, it SHOULD negotiate the port using a Jingle content-add action; see XEP-0166 for details and examples.)

Example 3. Receiver Definitively Accepts the Session Request

<iq from='juliet@capulet.com/balcony' to='romeo@montague.net/orchard' id='jingle2' type='set'>
  <jingle xmlns='http://www.xmpp.org/extensions/xep-0166.html#ns'
          action='session-accept'
          initiator='romeo@montague.net/orchard'
          sid='a73sjjvkla37jfea'/>
</iq>
  

Example 4. Initiating Entity Acknowledges Definitive Acceptance

<iq type='result' to='juliet@capulet.com/balcony' from='romeo@montague.net/orchard' id='accept1'/>
  

The parties may now exchange data using the echo protocol in order to test the connection.

Note: Protocol flows for additional use cases (e.g., renegotiation) may be added to future versions of this specification.

3. Security Considerations

As noted, the methods specified herein are provided for experimental use only and are not intended for inclusion in released software or production environments.

On some operating systems, access to the root or administrative user may be necessary in order to use the echo protocol over TCP or UDP port 7; therefore it is RECOMMENDED to use port 17777 instead.

4. IANA Considerations

This document requires no interaction with the Internet Assigned Numbers Authority (IANA) [4].

5. XMPP Registrar Considerations

5.1 Protocol Namespaces

Because this specification defines an experimental protocol that is to be used only for bootstrapping purposes, the XMPP Registrar [5] shall not issue a permanent namespace upon approval of this specification. Therefore, its associated namespace shall always be "http://www.xmpp.org/extensions/xep-0208.html#ns".

5.2 Jingle Content Description Formats

The XMPP Registrar shall include "echo" in its registry of Jingle content description formats. The registry submission is as follows:

<content>
  <name>echo</name>
  <desc>A bootstrapping method for exchanging echo protocol data (see RFC 862).</desc>
  <doc>XEP-0208</doc>
</content>
    

6. XML Schema

<?xml version='1.0' encoding='UTF-8'?>

<xs:schema
    xmlns:xs='http://www.w3.org/2001/XMLSchema'
    targetNamespace='http://www.xmpp.org/extensions/xep-0208.html#ns'
    xmlns='http://www.xmpp.org/extensions/xep-0208.html#ns'
    elementFormDefault='qualified'>

  <xs:element name='description' type='empty'/>

  <xs:simpleType name='empty'>
    <xs:restriction base='xs:string'>
      <xs:enumeration value=''/>
    </xs:restriction>
  </xs:simpleType>

</xs:schema>
  

Notes

1. XEP-0166: Jingle <http://www.xmpp.org/extensions/xep-0166.html>.

2. RFC 862: Echo Protocol <http://tools.ietf.org/html/rfc0862>.

3. XEP-0177: Jingle Raw UDP Transport Method <http://www.xmpp.org/extensions/xep-0177.html>.

4. The Internet Assigned Numbers Authority (IANA) is the central coordinator for the assignment of unique parameter values for Internet protocols, such as port numbers and URI schemes. For further information, see <http://www.iana.org/>.

5. The XMPP Registrar maintains a list of reserved protocol namespaces as well as registries of parameters used in the context of XMPP extension protocols approved by the XMPP Standards Foundation. For further information, see <http://www.xmpp.org/registrar/>.


Revision History

Version 0.2 (2007-05-11)

Specified use of port 17777 as default.

(psa)

Version 0.1 (2007-04-10)

Initial published version.

(psa)

Version 0.0.2 (2007-03-23)

Changed echo namespace to be a content description format only; defined basic direct-tcp transport for bootstrapping purposes only.

(psa)

Version 0.0.1 (2007-02-27)

First draft.

(psa)

END