北京电信IP城域网QoS策略的分析与实施
摘要
用户需求不同导致的差异化服务使得运营商在其IP网络中部署QoS的动机越来越迫切,以中国电信集团网络发展部为主的管理单位提出了《关于在IP网络中部署IP QoS业务的指导意见》,对现有IP网络的流量类型、业务种类、产品定义、带宽分配、优先级设置等方面提出了部署建议。本文主要针对中国电信的上述要求,以北京电信城域网为试点,研究通过软件工程实践的理论来指导如何在Juniper路由器上通过控制代码的编制实现QoS功能。
本文首先基于当前网络运营商常规的建网和运营模式限定了研究范围,明确了网络应用环境是Native IP,并且采用基于逐跳转发PHB的区分服务体系结构(Diffserv-differentiated services)模式,由于当前技术发展水平的局限性,本文没有涉及到如何通过软件编程实现对QoS领域中时延、抖动和丢包的控制,本文只专注在QoS的带宽控制领域。
本文的研究思路首先是从Juniper路由器的软件架构入手,分析了其BSD UNIX操作系统+JUNOS应用软件的模式,JUNOS软件由多个后台进程组成,涉及到QoS的进程是运行在路由器转发引擎中的Forwarding进程。如果需要外界实现对数据流QoS的控制,需要一个交互界面,进而指出JUNOS CLI命令行接口就是前台网络管理员与JUNOS软件后台运行的转发(Forwarding)进程之间的人机交互接口。
JUNOS CLI是一种有特定格式的控制逻辑,以一种计算机高级语言的形式呈现,类似C语言,并且具备高级语言的很多特点。本文以C语言作为对比和参考,介绍了JUNOS CLI这种特定的计算机语言的各种特点,例如面向过程、结构化、非数值计算、函数类型、数据格式等。因此网络管理员通过编写CLI控制代码,经JUNOS翻译为路由器可执行的机器代码,实现人们希望达到的QoS控制效果。
基于以上特点,本文结合软件工程实践中软件生命周期的理论,从问题定义、需求分析,到概要设计、编码实现,以及软件的测试、运营和维护全过程来研究在Juniper路由器上的IP QoS实现。
最终这个研究成果经过Lab测试验证可行,并于2008年第二季度成功在北京电信生产网络中部署,随着运营商对IP QoS运营经验的不断丰富,以及用户对QoS需求的多样性,未来这个研究还会逐步深入,更加细化和丰富QoS解决方案。
ISPs need to implement QoS function in their networks to meet customers requirements. As a guide of QoS deployment, a series of QoS parameters, include traffic type, service category, bandwidth allocation and priority have been defined by China-telecomm. Based on all these requirements mentioned above, the paper is focused on the method of how to make QoS works on the Juniper router by software engineering solution.
The network modeling and scenario is under native IP environment and based on Diffserv mode. The other three QoS metrics (delay, jitter and package loss rate) is not emphasized on this paper due to the current technical limitation.
Beginning from software architecture studying, this thesis analyzed Juniper router's software architecture which is BSD UNIX + JUNOS. JUNOS contains multiple processes, all QoS involved operations is related with a daemon named as "forwarding process" which run in package forwarding engine, the network operators can input any QoS control instructions by command line interface (CLI), CLI is a kind of Man-Machine interface.
The QoS control instructions is a proprietary, router-specific computer language that is similar to C: process-oriented, structural arithmetic, non-numerical computation, function-based, and special data structure, etc.
The studying gives us a QoS solution on Juniper router followed on software lifecycle model: issue definition, requirements analyzing, high-level design, coding, testing and implementation.
The studying has been tested by Lab successfully and deployed in Beijing telecom metro-area network in Q2 2008.
本文首先基于当前网络运营商常规的建网和运营模式限定了研究范围,明确了网络应用环境是Native IP,并且采用基于逐跳转发PHB的区分服务体系结构(Diffserv-differentiated services)模式,由于当前技术发展水平的局限性,本文没有涉及到如何通过软件编程实现对QoS领域中时延、抖动和丢包的控制,本文只专注在QoS的带宽控制领域。
本文的研究思路首先是从Juniper路由器的软件架构入手,分析了其BSD UNIX操作系统+JUNOS应用软件的模式,JUNOS软件由多个后台进程组成,涉及到QoS的进程是运行在路由器转发引擎中的Forwarding进程。如果需要外界实现对数据流QoS的控制,需要一个交互界面,进而指出JUNOS CLI命令行接口就是前台网络管理员与JUNOS软件后台运行的转发(Forwarding)进程之间的人机交互接口。
JUNOS CLI是一种有特定格式的控制逻辑,以一种计算机高级语言的形式呈现,类似C语言,并且具备高级语言的很多特点。本文以C语言作为对比和参考,介绍了JUNOS CLI这种特定的计算机语言的各种特点,例如面向过程、结构化、非数值计算、函数类型、数据格式等。因此网络管理员通过编写CLI控制代码,经JUNOS翻译为路由器可执行的机器代码,实现人们希望达到的QoS控制效果。
基于以上特点,本文结合软件工程实践中软件生命周期的理论,从问题定义、需求分析,到概要设计、编码实现,以及软件的测试、运营和维护全过程来研究在Juniper路由器上的IP QoS实现。
最终这个研究成果经过Lab测试验证可行,并于2008年第二季度成功在北京电信生产网络中部署,随着运营商对IP QoS运营经验的不断丰富,以及用户对QoS需求的多样性,未来这个研究还会逐步深入,更加细化和丰富QoS解决方案。
ISPs need to implement QoS function in their networks to meet customers requirements. As a guide of QoS deployment, a series of QoS parameters, include traffic type, service category, bandwidth allocation and priority have been defined by China-telecomm. Based on all these requirements mentioned above, the paper is focused on the method of how to make QoS works on the Juniper router by software engineering solution.
The network modeling and scenario is under native IP environment and based on Diffserv mode. The other three QoS metrics (delay, jitter and package loss rate) is not emphasized on this paper due to the current technical limitation.
Beginning from software architecture studying, this thesis analyzed Juniper router's software architecture which is BSD UNIX + JUNOS. JUNOS contains multiple processes, all QoS involved operations is related with a daemon named as "forwarding process" which run in package forwarding engine, the network operators can input any QoS control instructions by command line interface (CLI), CLI is a kind of Man-Machine interface.
The QoS control instructions is a proprietary, router-specific computer language that is similar to C: process-oriented, structural arithmetic, non-numerical computation, function-based, and special data structure, etc.
The studying gives us a QoS solution on Juniper router followed on software lifecycle model: issue definition, requirements analyzing, high-level design, coding, testing and implementation.
The studying has been tested by Lab successfully and deployed in Beijing telecom metro-area network in Q2 2008.
引文
[1]Harry Reynolds 《JNCIE-Juniper Networks Certified Internet Expert Study Guide》Sybex 2003 P619-695
[2]Tim Szigeti,Christina Hattingh 《End-to-End QoS Network Design》 Cisco Press 2005 P10-17,P161
[3]Srinivas Vegesna 《IP Quality of Service》 Cisco Press 2004 P16
[4]胡捷 《IP QoS与操作系统进、线程调度机制之间的关联性分析》 《通信世界》34期 总第287期 2006年9月11日
[5]李彤 《IP网络实施QoS的策略分析》 《邮电设计技术》2006-9-12
[6]向渝,雷维礼 《IP QoS综合服务模型研究》 《电讯技术》 第41卷第3期 2001年
[7]许毅,李腊 《基于IP网络QoS的基本策略及实现》 《武汉理工大学学报:交通科学与工程版》第26卷第6期 2002年
[8]J.Postel.RFC0791-September 1981 Internet Protocol美国IETF 1981
[9]P.Almquist.RFC1349-July 1992.Type of Service in the Internet Protocol Suite.美国 IETF 1992
[10]O.Bonaventure,S.De Cnodder.RFC2963-October 2000 A Rate Adaptive Shaper for Differentiated Services 美国 IETF 2000
[11]K.Nichols,B.Carpenter.RFC3086-April 2001 Definition of Differentiated Services Per Domain Behaviors and Rules for their Specification美国IETF 2001
[12]D.Grossman.RFC3260-April 2002 New Terminology and Clarifications for Diffserv美国IETF 2002
[13]O.Aboul-Magd,S.Rabie.RFC4115- July 2005 A Differentiated Service Two-Rate,Three-Color Marker with Efficient Handling of in-Profile Traffic美国IETF 2005
[2]Tim Szigeti,Christina Hattingh 《End-to-End QoS Network Design》 Cisco Press 2005 P10-17,P161
[3]Srinivas Vegesna 《IP Quality of Service》 Cisco Press 2004 P16
[4]胡捷 《IP QoS与操作系统进、线程调度机制之间的关联性分析》 《通信世界》34期 总第287期 2006年9月11日
[5]李彤 《IP网络实施QoS的策略分析》 《邮电设计技术》2006-9-12
[6]向渝,雷维礼 《IP QoS综合服务模型研究》 《电讯技术》 第41卷第3期 2001年
[7]许毅,李腊 《基于IP网络QoS的基本策略及实现》 《武汉理工大学学报:交通科学与工程版》第26卷第6期 2002年
[8]J.Postel.RFC0791-September 1981 Internet Protocol美国IETF 1981
[9]P.Almquist.RFC1349-July 1992.Type of Service in the Internet Protocol Suite.美国 IETF 1992
[10]O.Bonaventure,S.De Cnodder.RFC2963-October 2000 A Rate Adaptive Shaper for Differentiated Services 美国 IETF 2000
[11]K.Nichols,B.Carpenter.RFC3086-April 2001 Definition of Differentiated Services Per Domain Behaviors and Rules for their Specification美国IETF 2001
[12]D.Grossman.RFC3260-April 2002 New Terminology and Clarifications for Diffserv美国IETF 2002
[13]O.Aboul-Magd,S.Rabie.RFC4115- July 2005 A Differentiated Service Two-Rate,Three-Color Marker with Efficient Handling of in-Profile Traffic美国IETF 2005