摘要
目前IP网正发生深刻变化，宽带IP的出现起了决定性作用。因为必须有足
够的带宽，才能在同一个网络中同时传输语音、数据和图像。实时音频、视频多
媒体应用进入IP网络的一个关键问题是多媒体服务的QoS问题。由于TCP/IP协
议本身只提供一种“Best-effort”级别的服务，对QoS支持很少，“Best-effort”
级别的服务往往会导致实时应用出现延迟抖动、分组丢失率高，从而极大地影响
了实时应用的运行效果，因此必须研究可行的、高效的基于IP网络的QoS控制
机制，能依据网络当前状态自适应地整定多媒体实时应用的QoS。
我们课题组经过多年努力，已经成功开发了“ GUT桌面视频会议系统”并投
入试用，在此基础上，我们进行了实时音频、视频在IP网络上的自适应QoS机
制的研究。在本课题里，我在GUT的基础上，开发了一个集话音、视频传播、
聊天室、电子白板、邮件发送等于一身的IP网络实时交互软件——IPPhone，以
IPPhone为实验平台，进行了优先级调度、Qos映射、Qos协商、Qos接入、Qos
自适应整定，以及话音分组缓冲区自适应控制等多项关于多媒体服务质量课题的
研究，在IPPhone中形成了一套适用于IP分组网络的自适应QoS管理机制，它
采用基于多媒体优先级节的优先级调度算法、自适应Qos控制算法和自适应缓冲
区分配算法，利用QoS分层机制和重协商工作，在应用层上完成，独立于底层
网络协议。实验数据收集在以太网上进行，编程基于Windows Socket 2和GQOS。
本文论述了高速网络技术和未来的宽带IP网络，IPPhone的软件模块结构、
关键实现技术，自适应QoS管理框架，基于多媒体优先级节的优先级调度，自
适应QoS控制和自适应缓冲区分配等。
本课题的研究和开发工作基于宽带IP网络和网络多媒体业务快速发展的现
状，对充分利用IP网络带宽，改善实时多媒体业务在IP网上的服务质量有重大
意义，对QoS理论算法研究也有重大意义。
Now IP technology is developing rapidly, the most impressed is Wide Band IP. Once provided
enough bandwidth, it can transfer audio, image and data simultaneously in an identical network.
The key difficulty of real-time audio and video application running over LP network is QoS of
multimedia services. Because TCP/IP protocol just provides services of “Best-effort”level, lacking
of QoS supporting, it always causes latency uttering, packet loss in real-time multimedia application
and affects the qualities of real-time application deeply. It is necessary to research feasible, effective
QoS management mechanism over IP, which can adjust QoS requirement adaptively when the
network resources have changed.
Our research group has developed a desktop conferencing system name “GUT”which has
been used in some cases. We have done some research about adaptive QoS management of real-
time audio and video over IP base on it. I have developed a real-time communication software-IPPhone, which have functions of audio, video, chat room, whiteboard, e-mail and address book..
An adaptive QoS management mechanism over IP has come into being in JPPhone, which adopts
priority scheduling algorithm based on multimedia priority session and adaptive QoS control
algorithm and adaptive buffer management algorithm, works with QoS level model and QoS
renegotiation, is independent of low level network protocol. The experiment data are gathered over
Ethernet. The software is programmed with Wmdows Sockets 2 and GQOS interface.
This article describes the software module structures and the chief technology of IPPhone,
adaptive QoS management mechanism, priority scheduling algorithm based on priority session,
adaptive QoS control and adaptive buffer control and so on.
The research and development of this subject is dependent on development of Wide Band
network and network multimedia services, will make benefit to the network bandwidth utilizing and
quality of services of multimedia services over IP, has identical contribution to the research of QoS
theory study.
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