Network Working Group J. Heinanen
Request for Comments: 2697 Telia Finland
Category: Informational R. Guerin
University of Pennsylvania
September 1999
Network Working Group J. Heinanen
Request for Comments: 2697 Telia Finland
Category: Informational R. Guerin
University of Pennsylvania
September 1999
A Single Rate Three Color Marker
单速率三色标记
Status of this Memo
本备忘录的状况
This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.
本备忘录为互联网社区提供信息。它没有规定任何类型的互联网标准。本备忘录的分发不受限制。
Copyright Notice
版权公告
Copyright (C) The Internet Society (1999). All Rights Reserved.
版权所有（C）互联网协会（1999年）。版权所有。
Abstract
摘要
This document defines a Single Rate Three Color Marker (srTCM), which can be used as component in a Diffserv traffic conditioner [RFC2475, RFC2474]. The srTCM meters a traffic stream and marks its packets according to three traffic parameters, Committed Information Rate (CIR), Committed Burst Size (CBS), and Excess Burst Size (EBS), to be either green, yellow, or red. A packet is marked green if it doesn't exceed the CBS, yellow if it does exceed the CBS, but not the EBS, and red otherwise.
本文档定义了一个单速率三色标记（srTCM），它可以用作Diffserv流量调节器[RFC2475，RFC2474]中的组件。srTCM测量流量流，并根据三个流量参数（提交信息率（CIR）、提交突发大小（CBS）和过量突发大小（EBS）将其数据包标记为绿色、黄色或红色。如果数据包不超过CBS，则标记为绿色；如果数据包确实超过CBS，则标记为黄色，但不超过EBS，否则标记为红色。
The Single Rate Three Color Marker (srTCM) meters an IP packet stream and marks its packets either green, yellow, or red. Marking is based on a Committed Information Rate (CIR) and two associated burst sizes, a Committed Burst Size (CBS) and an Excess Burst Size (EBS). A packet is marked green if it doesn't exceed the CBS, yellow if it does exceed the CBS, but not the EBS, and red otherwise. The srTCM is useful, for example, for ingress policing of a service, where only the length, not the peak rate, of the burst determines service eligibility.
单速率三色标记（srTCM）测量IP数据包流并将其数据包标记为绿色、黄色或红色。标记基于提交的信息速率（CIR）和两个相关的突发大小，一个提交的突发大小（CBS）和一个多余的突发大小（EBS）。如果数据包不超过CBS，则标记为绿色；如果数据包确实超过CBS，则标记为黄色，但不超过EBS，否则标记为红色。例如，srTCM对于服务的进入监控是有用的，其中只有突发的长度而不是峰值速率确定服务合格性。
The Meter meters each packet and passes the packet and the metering result to the Marker:
仪表测量每个数据包，并将数据包和测量结果传递给标记器：
+------------+
| Result |
| V
+-------+ +--------+
| | | |
Packet Stream ===>| Meter |===>| Marker |===> Marked Packet Stream
| | | |
+-------+ +--------+
+------------+
| Result |
| V
+-------+ +--------+
| | | |
Packet Stream ===>| Meter |===>| Marker |===> Marked Packet Stream
| | | |
+-------+ +--------+
The Meter operates in one of two modes. In the Color-Blind mode, the Meter assumes that the packet stream is uncolored. In the Color-Aware mode the Meter assumes that some preceding entity has pre-colored the incoming packet stream so that each packet is either green, yellow, or red. The details of the pre-coloring process, including handling of error scenarios, and how the Meter determines the color of a pre-colored packet are DS domain specific and outside the scope of this document.
仪表以两种模式之一工作。在色盲模式下，仪表假设数据包流未着色。在颜色感知模式下，仪表假设前面的某个实体已对传入的数据包流预着色，以便每个数据包为绿色、黄色或红色。预着色过程的细节，包括错误场景的处理，以及仪表如何确定预着色数据包的颜色，是DS领域特有的，不在本文档的范围内。
The Marker (re)colors an IP packet according to the results of the Meter. The color is coded in the DS field [RFC2474] of the packet in a PHB specific manner (see section 4 for an example).
标记（重新）根据仪表的结果为IP数据包着色。颜色以PHB特定方式编码在数据包的DS字段[RFC2474]中（示例见第4节）。
A companion document [RFC2698] describes another three color marker, called a Two Rate Three Color Maker (trTCM), where packets are marked based on two rates and two burst sizes.
附带文档[RFC2698]描述了另一种三色标记，称为双速率三色标记器（trTCM），其中基于两个速率和两个突发大小标记数据包。
The srTCM is configured by setting its mode and by assigning values to three traffic parameters: a Committed Information Rate (CIR), a Committed Burst Size (CBS), and an Excess Burst Size (EBS).
srTCM通过设置其模式并将值分配给三个流量参数来配置：提交信息速率（CIR）、提交突发大小（CBS）和过量突发大小（EBS）。
The CIR is measured in bytes of IP packets per second, i.e., it includes the IP header, but not link specific headers.
CIR以每秒IP数据包的字节为单位进行测量，即它包括IP报头，但不包括特定于链路的报头。
The CBS and the EBS and are measured in bytes. The CBS and EBS must be configured so that at least one of them is larger than 0. It is recommended that when the value of the CBS or the EBS is larger than 0, it is larger than or equal to the size of the largest possible IP packet in the stream.
CBS和EBS和以字节为单位测量。必须配置CBS和EBS，以便其中至少有一个大于0。建议当CBS或EBS的值大于0时，它大于或等于流中最大可能IP分组的大小。
The behavior of the Meter is specified in terms of its mode and two token buckets, C and E, which both share the common rate CIR. The maximum size of the token bucket C is CBS and the maximum size of the token bucket E is EBS.
电表的行为是根据其模式和两个令牌桶C和E来指定的，这两个令牌桶都共享公共速率CIR。令牌桶C的最大大小是CBS，令牌桶E的最大大小是EBS。
The token buckets C and E are initially (at time 0) full, i.e., the token count Tc(0) = CBS and the token count Te(0) = EBS. Thereafter, the token counts Tc and Te are updated CIR times per second as follows:
令牌桶C和E最初（在时间0时）已满，即令牌计数Tc（0）=CBS和令牌计数Te（0）=EBS。此后，令牌计数Tc和Te每秒更新CIR次，如下所示：
o If Tc is less than CBS, Tc is incremented by one, else
o 如果Tc小于CBS，则Tc将增加1，否则
o if Te is less then EBS, Te is incremented by one, else
o 如果Te小于EBS，则Te增加1，否则
o neither Tc nor Te is incremented.
o Tc和Te都不递增。
When a packet of size B bytes arrives at time t, the following happens if the srTCM is configured to operate in the Color-Blind mode:
当大小为B字节的数据包在时间t到达时，如果srTCM配置为在色盲模式下工作，则会发生以下情况：
o If Tc(t)-B >= 0, the packet is green and Tc is decremented by B down to the minimum value of 0, else
o 如果Tc（t）-B>=0，则数据包为绿色，Tc由B递减至最小值0，否则
o if Te(t)-B >= 0, the packets is yellow and Te is decremented by B down to the minimum value of 0, else
o 如果Te（t）-B>=0，则数据包为黄色，Te由B递减至最小值0，否则
o the packet is red and neither Tc nor Te is decremented.
o 数据包为红色，Tc和Te均未递减。
When a packet of size B bytes arrives at time t, the following happens if the srTCM is configured to operate in the Color-Aware mode:
当大小为B字节的数据包在时间t到达时，如果srTCM配置为在颜色感知模式下工作，则会发生以下情况：
o If the packet has been precolored as green and Tc(t)-B >= 0, the packet is green and Tc is decremented by B down to the minimum value of 0, else
o 如果数据包已预着色为绿色且Tc（t）-B>=0，则数据包为绿色且Tc由B递减至最小值0，否则
o If the packet has been precolored as green or yellow and if Te(t)-B >= 0, the packets is yellow and Te is decremented by B down to the minimum value of 0, else
o 如果数据包已预着色为绿色或黄色，并且如果Te（t）-B>=0，则数据包为黄色，并且Te由B递减至最小值0，否则
o the packet is red and neither Tc nor Te is decremented.
o 数据包为红色，Tc和Te均未递减。
Note that according to the above rules, marking of a packet with a given color requires that there be enough tokens of that color to accommodate the entire packet. Other marking policies are clearly possible. The above policy was chosen in order guarantee a
注意，根据上述规则，使用给定颜色标记数据包需要有足够的该颜色标记来容纳整个数据包。其他标记策略显然是可能的。选择上述保单是为了保证
deterministic behavior where the volume of green packets is never smaller than what has been determined by the CIR and CBS, i.e., tokens of a given color are always spent on packets of that color.
确定性行为，其中绿色数据包的容量从不小于CIR和CBS确定的容量，即，给定颜色的令牌始终用于该颜色的数据包。
The actual implementation of a Meter doesn't need to be modeled according to the above formal specification.
仪表的实际实现不需要根据上述正式规范进行建模。
The Marker reflects the metering result by setting the DS field of the packet to a particular codepoint. In case of the AF PHB [RFC2597], the color can be coded as the drop precedence of the packet.
该标记通过将分组的DS字段设置为特定码点来反映计量结果。在AF PHB[RFC2597]的情况下，可以将颜色编码为分组的丢弃优先级。
The srTCM can be used to mark a packet stream in a service, where different, decreasing levels of assurances (either absolute or relative) are given to packets which are green, yellow, or red. For example, a service may discard all red packets, because they exceeded both the committed and excess burst sizes, forward yellow packets as best effort, and forward green packets with a low drop probability.
srTCM可用于标记服务中的分组流，其中对绿色、黄色或红色分组给出不同的、递减的保证级别（绝对或相对）。例如，服务可以丢弃所有的红包，因为它们超过了提交的和多余的突发大小，将黄包作为最大努力转发，并以较低的丢弃概率转发绿包。
The srTCM has no known security concerns.
srTCM没有已知的安全问题。
[RFC2698] Heinanen, J. and R. Guerin, "A Two Rate Three Color Marker", RFC 2698, September 1999.
[RFC2698]Heinanen，J.和R.Guerin，“双速率三色标记”，RFC 26981999年9月。
[RFC2597] Heinanen, J., Baker, F., Weiss, W. and J. Wroclawski, "Assured Forwarding PHB Group", RFC 2597, June 1999.
[RFC2597]Heinanen，J.，Baker，F.，Weiss，W.和J.Wroclawski，“保付PHB集团”，RFC 25971999年6月。
[RFC2474] Nichols, K., Blake, S., Baker, F. and D. Black, "Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers", RFC 2474, December 1998.
[RFC2474]Nichols，K.，Blake，S.，Baker，F.和D.Black，“IPv4和IPv6标头中区分服务字段（DS字段）的定义”，RFC 2474，1998年12月。
[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z. and W. Weiss, "An Architecture for Differentiated Services", RFC 2475, December 1998.
[RFC2475]Blake，S.，Black，D.，Carlson，M.，Davies，E.，Wang，Z.和W.Weiss，“差异化服务架构”，RFC 24751998年12月。
Juha Heinanen Telia Finland, Inc. Myyrmaentie 2 01600 Vantaa, Finland
Juha Heinanen Telia Finland，Inc.Myyrmaentie 2 01600 Vantaa，芬兰
EMail: jh@telia.fi
EMail: jh@telia.fi
Roch Guerin University of Pennsylvania Department of Electrical Engineering, Rm 376 GRW 200 South 33rd Street Philadelphia, PA 19104
宾夕法尼亚大学电气工程系，费城南第三十三街376号200号，19104
EMail: guerin@ee.upenn.edu
EMail: guerin@ee.upenn.edu
Copyright (C) The Internet Society (1999). All Rights Reserved.
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Acknowledgement
确认
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