flash p2p(RTMFP)协议

adobe在2012-12-13公开了flash p2p的协议，最新的更新是2013-4-15.
http://tools.ietf.org/html/draft-thornburgh-adobe-rtmfp-06
在http://www.rtfmp.net上有协议的链接。

翻译第一段：

1. 简介

Adobe的RTMFP是为在IP网络中的点对点数据传输服务设计的。RTMFP能高效的传输实时消息（譬如实时视频，音频和数据）和大块的数据，支持CS结构和P2P结构。主要特性有：独立的并行消息流，保证了高优先级的消息先传输；消息的可靠性保证（类似于UDP中实现TCP的机制）；多点拥塞控制；内置的安全策略。会话的复用和设计可以支持UDP打洞(UDP hole-punching)，简化了p2p系统的NAT穿透机制。

支持RTMFP的产品有FlashPlayer，AIR和AMS（之前叫FMS），都是Adobe的产品，它们都是用RTMFP作为基础的传输协议。在写这个文章的时候，FlashPlayer已经在数十亿的PC上安装了。

这个文档描述了RTMFP的细节。

1. Introduction

Adobe's Secure Real-Time Media Flow Protocol (RTMFP) is intended for
use as an endpoint-to-endpoint data transport service in IP networks.
It has features that make it well suited to the transport of real-
time media (such as low-delay video, audio, and data) as well as bulk
data, and for client-server as well as peer-to-peer (P2P)
communication. These features include independent parallel message
flows which may have different delivery priorities, variable message
reliability (from TCP-like full reliability to UDP-like best effort),
multi-point congestion control, and built-in security. Session
multiplexing and facilities to support UDP hole-punching simplify
Network Address Translator (NAT) traversal in peer-to-peer systems.

RTMFP is implemented in Flash Player, Adobe Integrated Runtime (AIR),
and Adobe Media Server (AMS, formerly Flash Media Server or FMS), all
from Adobe Systems Incorporated, and is used as the foundation
transport protocol for real-time and P2P communication in those
products. At the time of writing, the Adobe Flash Player runtime is
installed on more than one billion end-user desktop computers.

This memo describes the syntax and operation of the Secure Real-Time
Media Flow Protocol.