Network Working Group M. Tuexen
Request for Comments: 4820 Muenster Univ. of Applied Sciences
Category: Standards Track R. Stewart
P. Lei
Cisco Systems, Inc.
March 2007
Network Working Group M. Tuexen
Request for Comments: 4820 Muenster Univ. of Applied Sciences
Category: Standards Track R. Stewart
P. Lei
Cisco Systems, Inc.
March 2007
Padding Chunk and Parameter for the Stream Control Transmission Protocol (SCTP)
流控制传输协议（SCTP）的填充块和参数
Status of This Memo
关于下段备忘
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
本文件规定了互联网社区的互联网标准跟踪协议，并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态，请参考当前版本的“互联网官方协议标准”（STD 1）。本备忘录的分发不受限制。
Copyright Notice
版权公告
Copyright (C) The IETF Trust (2007).
版权所有（C）IETF信托基金（2007年）。
Abstract
摘要
This document defines a padding chunk and a padding parameter and describes the required receiver side procedures. The padding chunk is used to pad a Stream Control Transmission Protocol (SCTP) packet to an arbitrary size. The padding parameter is used to pad an SCTP INIT chunk to an arbitrary size.
本文档定义了填充块和填充参数，并描述了所需的接收器端过程。填充块用于将流控制传输协议（SCTP）数据包填充到任意大小。padding参数用于将SCTP INIT块填充到任意大小。
Table of Contents
目录
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Padding Chunk (PAD) . . . . . . . . . . . . . . . . . . . . . . 2
4. Padding Parameter (PAD) . . . . . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
5.1. A New Chunk Type . . . . . . . . . . . . . . . . . . . . . 4
5.2. A New Parameter Type . . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . . 4
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 4
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.1. Normative References . . . . . . . . . . . . . . . . . . . 5
8.2. Informative References . . . . . . . . . . . . . . . . . . 5
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Padding Chunk (PAD) . . . . . . . . . . . . . . . . . . . . . . 2
4. Padding Parameter (PAD) . . . . . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
5.1. A New Chunk Type . . . . . . . . . . . . . . . . . . . . . 4
5.2. A New Parameter Type . . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . . 4
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 4
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.1. Normative References . . . . . . . . . . . . . . . . . . . 5
8.2. Informative References . . . . . . . . . . . . . . . . . . 5
This document defines a padding chunk and a padding parameter and describes the required receiver side procedures. The padding chunk is used to pad an SCTP packet to an arbitrary size. The padding parameter is used to pad an SCTP INIT chunk to an arbitrary size. The usage of the PAD chunk for path MTU discovery is described in PMTU [4]. The inappropriate usage of the PAD parameter or PAD chunk can result in wasted bandwidth.
本文档定义了填充块和填充参数，并描述了所需的接收器端过程。填充块用于将SCTP数据包填充到任意大小。padding参数用于将SCTP INIT块填充到任意大小。PMTU[4]中描述了用于路径MTU发现的焊盘块的用法。PAD参数或PAD块的不当使用会导致带宽浪费。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL", when they appear in this document, are to be interpreted as described in RFC 2119 [1].
本文件中出现的关键词“必须”、“不得”、“必需”、“应”、“不应”、“建议”、“不建议”、“可”和“可选”应按照RFC 2119[1]中的说明进行解释。
This chunk is used to pad an SCTP packet. A PAD chunk can be used to enlarge the packet by 4 to 65536 bytes in steps of 4 bytes. An SCTP packet MAY contain multiple PAD chunks.
此区块用于填充SCTP数据包。PAD块可用于以4字节的步长将数据包放大4到65536字节。SCTP数据包可以包含多个PAD块。
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 0x84 | Flags=0 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
\ Padding Data /
/ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 0x84 | Flags=0 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
\ Padding Data /
/ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1
图1
Type: 1 byte (unsigned integer) This value MUST be set to 0x84 for all PAD chunks.
类型：1字节（无符号整数）对于所有焊盘块，此值必须设置为0x84。
Flags: 1 byte (unsigned integer) This value SHOULD be set to zero on transmit and MUST be ignored on receipt.
标志：1字节（无符号整数）此值在传输时应设置为零，在接收时必须忽略。
Length: 2 bytes (unsigned integer) This value holds the length of the Padding Data plus 4.
长度：2字节（无符号整数）此值保存填充数据的长度加上4。
Padding Data: n bytes (unsigned integer) This holds the Padding Data. The Padding Data MUST be ignored by the receiver.
填充数据：n个字节（无符号整数）它保存填充数据。接收器必须忽略填充数据。
The receiver of the PAD chunk MUST discard this chunk and continue processing the rest of the chunks in the packet. Please note that this is also the required processing behavior for any unknown chunk having the same highest-order two bits of the type as the PAD chunk.
PAD块的接收者必须丢弃该块并继续处理数据包中的其余块。请注意，这也是任何未知块（与焊盘块具有相同类型的最高阶两位）所需的处理行为。
This parameter is used to pad an INIT chunk. A PAD parameter can be used to enlarge the INIT chunk by 4 bytes as the minimum to the maximum size of the INIT chunk in steps of 4 bytes. An INIT chunk MAY contain multiple PAD parameters.
此参数用于填充INIT块。PAD参数可用于将INIT块放大4个字节，作为INIT块的最小大小，以4个字节的步长放大到最大大小。INIT块可能包含多个PAD参数。
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter Type = 0x8005 | Parameter Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ /
\ Padding Data \
/ /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter Type = 0x8005 | Parameter Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ /
\ Padding Data \
/ /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2
图2
Parameter Type: 2 bytes (unsigned integer) This value MUST be set to 0x8005.
参数类型：2字节（无符号整数）此值必须设置为0x8005。
Parameter Length: 2 bytes (unsigned integer) This value holds the length of the Padding Data plus 4.
参数长度：2字节（无符号整数）此值保存填充数据的长度加上4。
The PAD parameter MAY be included only in the INIT chunk. It MUST NOT be included in any other chunk. The receiver of the PAD parameter MUST silently discard this parameter and continue processing the rest of the INIT chunk. This means that the size of the generated COOKIE parameter in the INIT-ACK MUST NOT depend on the existence of the PAD parameter in the INIT chunk. A receiver of a PAD parameter MUST NOT include the PAD parameter within any State Cookie parameter it generates.
PAD参数只能包含在INIT块中。它不能包含在任何其他块中。PAD参数的接收者必须悄悄地放弃该参数，并继续处理INIT块的其余部分。这意味着INIT-ACK中生成的COOKIE参数的大小不能取决于INIT块中是否存在PAD参数。PAD参数的接收者不得在其生成的任何状态Cookie参数中包含PAD参数。
This document is the reference for all registrations described in this section. All registrations have been listed in the document available at sctp-parameters [3]. The changes are described below.
本文件是本节所述所有注册的参考文件。sctp参数[3]提供的文件中列出了所有注册。下文介绍了这些变化。
A chunk type for the PAD chunk has been assigned by IANA. The value has been assigned as described in Figure 1. The following has been added to the "CHUNK TYPES" table of sctp-parameters [3]:
IANA已为焊盘区块分配了区块类型。该值已按图1所示分配。以下内容已添加到sctp参数[3]的“块类型”表中：
CHUNK TYPES
块类型
ID Value Chunk Type Reference
-------- ---------- ---------
132(0x84) Padding Chunk (PAD) [RFC4820]
ID Value Chunk Type Reference
-------- ---------- ---------
132(0x84) Padding Chunk (PAD) [RFC4820]
A parameter type has been assigned for the PAD parameter by IANA. The value has been assigned as described in Figure 2. The following has been added to the "CHUNK PARAMETER TYPES" table in sctp-parameters [3]:
IANA已为PAD参数指定了参数类型。该值已按图2所示分配。以下内容已添加到sctp参数[3]中的“区块参数类型”表中：
INIT Chunk Parameter Types
初始化块参数类型
Chunk Parameter Type Value
-------------------- -----
Padding 32773(0x8005)
Chunk Parameter Type Value
-------------------- -----
Padding 32773(0x8005)
This document does not add any additional security considerations to the ones given in RFC 2960 [2].
本文件未在RFC 2960[2]中给出的安全注意事项之外添加任何其他安全注意事项。
The authors wish to thank Matthew J. Zekauskas and Lars Eggert for their invaluable comments.
作者希望感谢Matthew J.Zekauskas和Lars Eggert的宝贵评论。
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[1] Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[2] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer, H., Taylor, T., Rytina, I., Kalla, M., Zhang, L., and V. Paxson, "Stream Control Transmission Protocol", RFC 2960, October 2000.
[2] Stewart，R.，Xie，Q.，Morneault，K.，Sharp，C.，Schwarzbauer，H.，Taylor，T.，Rytina，I.，Kalla，M.，Zhang，L.，和V.Paxson，“流控制传输协议”，RFC 29602000年10月。
[3] "IANA registry", <http://www.iana.org/assignments/sctp-parameters>.
[3] “IANA注册表”<http://www.iana.org/assignments/sctp-parameters>.
[4] Mathis, M. and J. Heffner, "Packetization Layer Path MTU Discovery", RFC 4821, March 2007.
[4] Mathis，M.和J.Heffner，“打包层路径MTU发现”，RFC 48212007年3月。
Authors' Addresses
作者地址
Michael Tuexen Muenster Univ. of Applied Sciences Stegerwaldstr. 39 48565 Steinfurt Germany
Michael Tuexen Muenster应用科学大学Stegerwaldstr。39 48565德国斯坦福德
EMail: tuexen@fh-muenster.de
EMail: tuexen@fh-muenster.de
Randall R. Stewart Cisco Systems, Inc. 4875 Forest Drive Suite 200 Columbia, SC 29206 USA
Randall R.Stewart Cisco Systems，Inc.4875 Forest Drive Suite 200哥伦比亚，SC 29206美国
EMail: rrs@cisco.com
EMail: rrs@cisco.com
Peter Lei Cisco Systems, Inc. 955 Happfield Dr. Arlington Heights, IL 60004 US
Peter Lei思科系统公司，美国伊利诺伊州阿灵顿高地Happfield博士955号，邮编60004
Phone: +1 773 695-8201
EMail: peterlei@cisco.com
Phone: +1 773 695-8201
EMail: peterlei@cisco.com
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完整版权声明
Copyright (C) The IETF Trust (2007).
版权所有（C）IETF信托基金（2007年）。
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