Tristan Matthews | 0a329cc | 2013-07-17 13:20:14 -0400 | [diff] [blame] | 1 | /* $Id$ */ |
| 2 | /* |
| 3 | * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 18 | */ |
| 19 | |
| 20 | /** |
| 21 | @defgroup PJNATH_ICE ICE: Interactive Connectivity Establishment |
| 22 | @brief Interactive Connectivity Establishment (ICE) |
| 23 | @ingroup PJNATH |
| 24 | */ |
| 25 | |
| 26 | /** |
| 27 | @defgroup PJNATH_ICE_STREAM_TRANSPORT ICE stream transport |
| 28 | @brief Transport for media streams using ICE |
| 29 | @ingroup PJNATH_ICE |
| 30 | */ |
| 31 | |
| 32 | /** |
| 33 | @defgroup PJNATH_ICE_SESSION ICE Session |
| 34 | @brief Transport Independent ICE Session |
| 35 | @ingroup PJNATH_ICE |
| 36 | */ |
| 37 | |
| 38 | /** |
| 39 | @addtogroup PJNATH_ICE |
| 40 | \section org Library organizations |
| 41 | |
| 42 | See <b>Table of Contents</b> below. |
| 43 | |
| 44 | \section ice_intro_sec Introduction to ICE |
| 45 | |
| 46 | Interactive Connectivity Establishment (ICE) is the ultimate |
| 47 | weapon a client can have in its NAT traversal solution arsenals, |
| 48 | as it promises that if there is indeed one path for two clients |
| 49 | to communicate, then ICE will find this path. And if there are |
| 50 | more than one paths which the clients can communicate, ICE will |
| 51 | use the best/most efficient one. |
| 52 | |
| 53 | ICE works by combining several protocols (such as STUN and TURN) |
| 54 | altogether and offering several candidate paths for the communication, |
| 55 | thereby maximising the chance of success, but at the same time also |
| 56 | has the capability to prioritize the candidates, so that the more |
| 57 | expensive alternative (namely relay) will only be used as the last |
| 58 | resort when else fails. ICE negotiation process involves several |
| 59 | stages: |
| 60 | |
| 61 | - candidate gathering, where the client finds out all the possible |
| 62 | addresses that it can use for the communication. It may find |
| 63 | three types of candidates: host candidate to represent its |
| 64 | physical NICs, server reflexive candidate for the address that |
| 65 | has been resolved from STUN, and relay candidate for the address |
| 66 | that the client has allocated from a TURN relay. |
| 67 | - prioritizing these candidates. Typically the relay candidate will |
| 68 | have the lowest priority to use since it's the most expensive. |
| 69 | - encoding these candidates, sending it to remote peer, and |
| 70 | negotiating it with offer-answer. |
| 71 | - pairing the candidates, where it pairs every local candidates |
| 72 | with every remote candidates that it receives from the remote peer. |
| 73 | - checking the connectivity for each candidate pairs. |
| 74 | - concluding the result. Since every possible path combinations are |
| 75 | checked, if there is a path to communicate ICE will find it. |
| 76 | |
| 77 | |
| 78 | \section icestrans_sec Using ICE transport |
| 79 | |
| 80 | The \ref PJNATH_ICE_STREAM_TRANSPORT is a ready to use object which |
| 81 | performs the above ICE operations as well as provides application with |
| 82 | interface to send and receive data using the negotiated path. |
| 83 | |
| 84 | Please see \ref PJNATH_ICE_STREAM_TRANSPORT on how to use this object. |
| 85 | |
| 86 | |
| 87 | \section ice_owntransport_sec Creating custom ICE transport |
| 88 | |
| 89 | If the \ref PJNATH_ICE_STREAM_TRANSPORT is not suitable for use |
| 90 | for some reason, you will need to implement your own ICE transport, |
| 91 | by combining the \ref PJNATH_ICE_SESSION with your own means to |
| 92 | send and receive packets. The \ref PJNATH_ICE_STREAM_TRANSPORT |
| 93 | provides the best example on how to do this. |
| 94 | |
| 95 | |
| 96 | \section ice_samples_sec Samples |
| 97 | |
| 98 | The \ref ice_demo_sample sample demonstrates how to use |
| 99 | \ref PJNATH_ICE_STREAM_TRANSPORT <b>without</b> using signaling |
| 100 | protocol such as <b>SIP</b>. It provides interactive user interface |
| 101 | to create and manage the ICE sessions as well as to exchange SDP |
| 102 | with another ice_demo instance. |
| 103 | |
| 104 | Also see <b>\ref samples_page</b> for other samples. |
| 105 | */ |
| 106 | |
| 107 | |