rfc2793.txt

本程序为在linux下实现FTP传输文件的实现

这是一个没有冗余的T140 RTP包的例子

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V=2|P|X| CC=0  |M|   T140 PT   |       顺序号               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      时间戳 (1000Hz)                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|           同步源 (SSRC) 标识符                            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+                      T.140 编码数据                       +
|                                                           |
+                                               +---------------+
|                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

	
	这是一个携带冗余数据的RTP 包的例子

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |V=2|P|X| CC=0  |M|  "RED" PT   |   主序号                   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      原始数据时间戳                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           同步源 (SSRC) 标识符                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |1|   T140 PT   |            "R" 时间戳位移  |      "R" 块长度|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |0|   T140 PT   |                                            |
   +-+-+-+-+-+-+-+-+                                            +
   |                                                           |
   +               "R" T.140 编码冗余数据                      +
   |                                                           |
   +                                               +---------------+
   |                                               |            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+               +
   |                "P" T.140 编码原始数据                       |
   +                                                           +
   +                                               +---------------+
   |                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+   
   附图：RTP文本包的例子
5．安全性考虑
既然本负载格式的目的是在文本交谈中携带文本，加密的安全性度量就变得十分重要。
文本传输的数量很少，这样我们可以选择任何加密方法来对T.140会话或者整个RTP包进
行加密。如果数据包中包含了冗余数据，要使用同RFC 2198一样的安全性考虑。
6.  MIME Media Type Registrations

   本文档描述了一种新的RTP负载名称和相应的MIME类型，T140 (text/t140).
6.1  Registration of MIME media type text/t140
   MIME media type name: text
   MIME subtype name: t140
   必需参数: 无
   可选参数: 无
   编码考虑: 按RFC 2793规定传输T140文本。
   安全性考虑：无
   互操作考虑: 无
   已发行规范: ITU-T建议T.140，RFC 2793.
   使用该媒体类型的应用:
     文本通信终端和文本会议工具。
   附加信息: 无
     Magic number(s): 无
     文件扩展: 无
     Macintosh文件类型码: 无
   联系办法:
     Gunnar Hellstrom
     e-mail: [e-mail]
   预期使用: COMMON
     Author                      / Change controller:
     Gunnar Hellstrom            | IETF avt WG
     [e-mail] | c/o Steve Casner [e-mail]
鸣谢
感谢 Stephen Casner 和 Colin Perkins 在本文写作时给予的细查和建议。
   	感谢Ericsson公司的Mickey Nasiri提供的实验环境。
   	感谢Michele Mizarro验证了负载格式的可用性。
作者地址
Gunnar Hellstrom
   	Omnitor AB
   	Alsnogatan 7, 4 tr
   	SE-116 41 Stockholm
   	Sweden
   	Phone: [phone]
   	Fax:   [phone]
   	EMail: [e-mail]
参考
   [1]  ITU-T Recommendation T.140 (1998) - Text conversation protocol
        for multimedia application, with amendment 1, (2000).
   [2]  Schulzrinne, H., Casner, S., Frederick, R. and V. Jacobson,
        "RTP: A Transport Protocol for Real-Time Applications", RFC
        1889, January 1996.
   [3]  Perkins, C., Kouvelas, I., Hardman, V., Handley, M. and J.
        Bolot, "RTP Payload for Redundant Audio Data", RFC 2198,
        September 1997.
   [4]  Bradner, S., "Key words for use in RFCs to Indicate Requirement
        Levels", BCP 14, RFC 2119, March 1997.
   [5]  ISO/IEC 10646-1: (1993), Universal Multiple Octet Coded
        Character Set.
   [6]  Yergeau, F., "UTF-8, a transformation format of ISO 10646",  RFC
       2279, January 1998.
版权说明
Copyright (C) The Internet Society (2000).  All Rights Reserved.

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致谢
Funding for the RFC Editor function is currently provided by the Internet Society.





RFC2793—— RTP Payload for Text Conversation	用于文本交谈的RTP负载


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RFC文档中文翻译计划