1 /**@name OpenH323 Libaray
3 This is a Open Source class library for the development of applications
4 that wish to use the H.323 protocol for multi-media communications over
7 @memo A Class Libarary implementing the H.323 Protocol.
9 @author Equivalence Pty. Ltd.
16 {\Large{\bf OpenH323 Class Library}}
25 {\Large{\bf OpenH323 Architecture}}
28 The fundamental object of the ownership hierarchy is of the H323Endpoint
29 class. An application would typically have one instance of a descendant of
30 this class. The application defined descendant would set up defaults for
31 various H323 parameters (timeouts etc), the most important of which is the
32 capability table which defines the codecs and channel types the application
33 is capable of handling.
35 Also created by the application in the H323Endpoint would be instances of one
36 or more descendants of the H323Listener class. There is a descendant of this
37 class for each protocol that is supported. For example H323ListenerIP would
38 be for Internet use. Each listener spawns a thread that monitors its protocol
39 and when a new incoming call is detected, creates an instance of a
40 H323Transport class descendent. As for the H323Listener class, there is a
41 descendent for each protocol supported, eg H323TransportIP.
43 When the first PDU arrives on a H323Transport using the Q.931 and H.225
44 protocols, there is a call reference that identifies the connection that has
45 been made. These connections are embodied by the H323Connection class, which
46 contains all of the state information for a connection between H323 endpoints.
47 The H323Endpoint instance keeps track of these active connections. If there
48 is no connection for the call reference number already, a new one is created
49 and H323 signalling negotiations begun.
51 An application would often have the system create an instance of a descendant
52 of the H323Connection class, rather than that class itself. This is so that
53 any of a large number of virtual methods may be overridden. These virtual
54 methods are "callback" functions by the library to allow the application to
55 either obtain information or modify the behaviour at various phases of the
56 protocol negotiations. For example, there is a callback for when an incoming
57 call is in progress and the application user should be "alerted". This is
58 highly application specific being anything from a simple audible beep to
59 displaying a pop up window with bells and whistles.
61 The H323Negotiator classes are used to maintain the state and functionality
62 of each command or variable defined by the H.245 protocol. Their main reason
63 for existence is actually to reduce the scope of the h225.h and h245.h files,
64 which define many hundreds of classes. A user of the H323Connection class
65 thus does not have to include all of these classes on every compilation unit.
67 During some of the H.245 negotiations, logical channels may be created, both
68 by the remote endpoint and by the local application. The H323Channel class
69 descendants represents this. A typical use of one of these classes is to open
70 a stream of encoded audio data. The H323Channel class would create a
71 H323Codec using the H323Capability that was passed during the protocol
76 /**@name Using OpenH323
77 Detailed tutorials will be forthcoming.
82 /**@name Class Reference
84 @memo Documentation on all classes.
87 //@Include: include/h323.h
88 //@Include: include/h323ep.h
89 //@Include: include/h323con.h
90 //@Include: include/transports.h
91 //@Include: include/gkserver.h
92 //@Include: include/gkclient.h
93 //@Include: include/channels.h
94 //@Include: include/mediafmt.h
95 //@Include: include/h323caps.h
96 //@Include: include/h323t120.h
97 //@Include: include/h323t38.h
98 //@Include: include/codecs.h
99 //@Include: include/h263codec.h
100 //@Include: include/h261codec.h
101 //@Include: include/lid.h
102 //@Include: include/ixjlid.h
103 //@Include: include/vpblid.h
104 //@Include: include/rtp.h
105 //@Include: include/jitter.h
106 //@Include: include/h323rtp.h
107 //@Include: include/h323neg.h
108 //@Include: include/h323pdu.h
109 //@Include: include/h450pdu.h
110 //@Include: include/h225ras.h
111 //@Include: include/h235auth.h
112 //@Include: include/guid.h
113 //@Include: include/t120proto.h
114 //@Include: include/t38proto.h
115 //@Include: include/q931.h
116 //@Include: include/x224.h
118 //@Include: plugins/audio/GSM0610/inc/gsm.h
119 //@Include: plugins/audio/LPC_10/lpc10.h
120 //@Include: plugins/audio/Speex/libspeex/lpc.h