libjingle开发指南

About libjingle ................................................................................................................................... 2

libjingle Developer Guide .............................................................................................................. 3

Jingle and libjingle .................................................................................................................... 3

Prerequisites .............................................................................................................................. 3

Organization of the Documentation .......................................................................................... 4

Organization of the SDK ........................................................................................................... 4

Version Changelist ......................................................................................................................... 6

0.5.2 (January 11, 2011) ................................................................................................ 6

0.5.1 (November 2, 2010) ............................................................................................. 6

SSL Support ............................................................................................................................ 14

Connections ............................................................................................................................. 14

Transports, Channels, and Connections .................................................................................. 16

Candidates ............................................................................................................................... 18

Data Packets ............................................................................................................................ 20

Generic libjingle Applications ...................................................................................................... 21

Details of a Session Connection ........................................................................................ 25

Startup ............................................................................................................................ 25

Signing in ....................................................................................................................... 25

Connecting .................................................................................................................... 25

Logging ................................................................................................................................... 32

Voice Chat Sample Application .............................................................................................. 33

File Share Sample Application ................................................................................................ 33

libjingle License Agreement ........................................................................................................ 35

About libjingle

libjingle is a collection of open-source C++ code and sample applications that enables you to build a

peer-to-peer application. The code handles creating a network connection (through NAT and firewall

devices, relay servers, and proxies), negotiating session details (codecs, formats, etc.), and exchanging

data. It also provides helper tasks such as parsing XML, and handling network proxies. You could

documentation supplements the readme files included with the code.

We are providing this source code as part of our ongoing commitment to promoting consumer choice

and interoperability in Internet-based real-time-communications. This code is made available under

a Berkeley-style license, which means you are free to incorporate it into commercial and

non-commercial software and distribute it.

libjingle Developer Guide

The libjingle SDK consists of C++ source code and documentation that enable you to design

applications that connect and exchange data across a network (peer to peer data connections). The SDK

contains code and sample applications, a Visual Studio 2005 solution file for compiling on Windows

computers, configuration and makefiles for other operating systems and compilers, and compilation

use STUN servers, and to exchange either UDP or TCP data packets. You can use the code as provided,

or extend it fit your own specific needs, according to the Berkeley-style license.

Jingle and libjingle

libjingle was created at about the same time as the Jingle XMPP extension (XEP-0166). The libjingle

team created their own protocol to handle session negotiation, and later worked with the XMPP

Standards Foundation to standardize Jingle; thus, although the libjingle protocol and Jingle are very

similar, they are not the same, and are not interoperable.

The current version of the libjingle code still uses the original internal protocol, which is slightly

different from, and incompatible with, the Jingle specification. Nevertheless, it is close enough to

Jingle that it is worthwhile learning the Jingle specifications. Similar "close but not identical"

conditions exist for libjingle's audio content description (early version of Jingle Audio Content

Prerequisites

In order to use libjingle, you should be familiar with the XMPP protocol, general networking concepts,

and C++. Additionally, it helps to be familiar with the Jingle proposed extension (XEP-0166), and

other related extensions listed in Jingle and libjingle above.

The requirements to build and use libjingle are given in Creating a libjingle Application.

Organization of the Documentation

This documentation includes the following main topics:

 Important Concepts Describes some of the key concepts in libjingle. Very important if

this is your first experience with libjingle.

 Generic libjingle Applications Provides an overview of the main components of a

libjingle application, and some specifics about how a generic libjingle application creates a

peer-to-peer connection.

 Creating a libjingle Application Describes the key tasks that every libjingle application

legal mumbo jumbo.

 The example code uses SSL to transmit the password from the client to the XMPP server;

however, it does not provide any additional security (except turning off screen echo) to protect the

password on the client.