Internet Engineering Task Force (IETF) R. Jesske
Request for Comments: 8606 Deutsche Telekom
Updates: 3326 June 2019
Category: Standards Track
ISSN: 2070-1721
Internet Engineering Task Force (IETF) R. Jesske
Request for Comments: 8606 Deutsche Telekom
Updates: 3326 June 2019
Category: Standards Track
ISSN: 2070-1721
ISDN User Part (ISUP) Cause Location Parameter for the SIP Reason Header Field
SIP原因标头字段的ISDN用户部分（ISUP）原因位置参数
Abstract
摘要
The SIP Reason header field is defined to carry ISUP (ISDN User Part) cause values as well as SIP response codes. Some services in SIP networks may need to know the ISUP location where the call was released in the PSTN (Public Switched Telephone Network) to correctly interpret the reason of release. This document updates RFC 3326 by adding a location parameter for this purpose.
SIP原因报头字段定义为携带ISUP（ISDN用户部分）原因值以及SIP响应代码。SIP网络中的某些服务可能需要知道在PSTN（公共交换电话网络）中释放呼叫的ISUP位置，以正确解释释放原因。本文档通过为此目的添加位置参数来更新RFC 3326。
Status of This Memo
关于下段备忘
This is an Internet Standards Track document.
这是一份互联网标准跟踪文件。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。有关互联网标准的更多信息，请参见RFC 7841第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8606.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问https://www.rfc-editor.org/info/rfc8606.
Copyright Notice
版权公告
Copyright (c) 2019 IETF Trust and the persons identified as the document authors. All rights reserved.
版权（c）2019 IETF信托基金和被确定为文件作者的人员。版权所有。
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(https://trustee.ietf.org/license-info)自本文件出版之日起生效。请仔细阅读这些文件，因为它们描述了您对本文件的权利和限制。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 5
7. Security Considerations . . . . . . . . . . . . . . . . . . . 5
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
8.1. Registration of the Location Parameter for the Reason
Header Field . . . . . . . . . . . . . . . . . . . . . . 6
9. Normative References . . . . . . . . . . . . . . . . . . . . 6
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
6. Privacy Considerations . . . . . . . . . . . . . . . . . . . 5
7. Security Considerations . . . . . . . . . . . . . . . . . . . 5
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
8.1. Registration of the Location Parameter for the Reason
Header Field . . . . . . . . . . . . . . . . . . . . . . 6
9. Normative References . . . . . . . . . . . . . . . . . . . . 6
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 7
Section 3.4 of [RFC3326] describes a SIP message flow for canceling an INVITE request when a REL (release) message is received from the ISUP side. That document specifies the SIP Reason header field [RFC3326] that is used to indicate the reason of release. The reason of release indicates why a SIP Dialog or a PSTN call, in cases where the call was interworked to the PSTN, was terminated. The termination may be normal, based on a failure within an entity (e.g. temporary failure) or caused by other factors (e.g., congestion). The reason may be a SIP response or an ISUP release cause as specified within [Q.850]. [RFC6432] specifies that an ISUP [Q.850] cause code can be carried within a SIP response, but not the Q.850 location information. The [Q.850] location information identifies the part of the ISUP network where the call was released.
[RFC3326]的第3.4节描述了当从ISUP端接收到REL（释放）消息时取消INVITE请求的SIP消息流。该文档指定用于指示发布原因的SIP原因标头字段[RFC3326]。释放原因表示在呼叫与PSTN互通的情况下，SIP对话或PSTN呼叫终止的原因。终止可能是正常的，基于实体内的故障（例如临时故障）或由其他因素（例如拥塞）引起。原因可能是[Q.850]中规定的SIP响应或ISUP释放原因。[RFC6432]指定可以在SIP响应中携带ISUP[Q.850]原因代码，但不能携带Q.850位置信息。[Q.850]位置信息标识ISUP网络中释放呼叫的部分。
This document adds a location value parameter to the reason-extension parameter defined in [RFC3326] so that the [Q.850] location value can be interworked from the PSTN. The interworking from the PSTN needs only to include the location received by the interworking gateway. [Q.850] describes the definitions of the cause code values and the locations used in ISDN and DSS1 (Digital Subscriber Signalling System No. 1) environments. The cause code is used for identifying the reason of release of a call, and the location identifies where the call was released.
本文档将位置值参数添加到[RFC3326]中定义的原因扩展参数中，以便[Q.850]位置值可以从PSTN互通。来自PSTN的互通只需要包括互通网关接收到的位置。[Q.850]描述了ISDN和DSS1（数字用户信号系统1号）环境中使用的原因码值和位置的定义。原因代码用于识别释放呼叫的原因，位置用于识别释放呼叫的位置。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“建议”、“不建议”、“可”和“可选”在所有大写字母出现时（如图所示）应按照BCP 14[RFC2119][RFC8174]所述进行解释。
The primary intent of the parameter defined in this specification is for use in IMS (IP Multimedia Subsystem) networks defined by 3GPP, but it is also open to be used by any other networks that include ISUP interworking gateways and use Q.850 reason codes. The purpose of this parameter is to hold the location of the call release so that it can be transported from the originating PSTN entity to the SIP entity via a response or BYE message. The ISDN location is defined in [Q.850].
本规范中定义的参数的主要目的是在3GPP定义的IMS（IP多媒体子系统）网络中使用，但它也可供包括ISUP互通网关和使用Q.850原因码的任何其他网络使用。此参数的目的是保留呼叫释放的位置，以便通过响应或BYE消息将其从发起PSTN实体传输到SIP实体。ISDN位置在[Q.850]中定义。
As defined by [RFC6432], any SIP Response message, with the exception of 100 (Trying), MAY contain a Reason header field with a Q.850 [Q.850] cause code.
根据[RFC6432]的定义，任何SIP响应消息（100（尝试）除外）都可能包含带有Q.850[Q.850]原因代码的原因头字段。
This specification adds a parameter with the ISUP location value defined in [Q.850] to the Reason header field that identifies the location of the call release in ISUP. The location is a 4-bit value that reflects the possible locations where an ISUP call is released. Some values are spare or reserved for national use. The Augmented BNF (ABNF) [RFC5234] for this parameter is shown in Figure 1.
本规范将[Q.850]中定义的具有ISUP位置值的参数添加到识别ISUP中呼叫释放位置的原因标头字段中。位置是一个4位值，反映了ISUP调用释放的可能位置。有些值是备用的或保留供国家使用。图1显示了此参数的增强BNF（ABNF）[RFC5234]。
reason-extension =/ isup-cause-location isup-cause-location = "location" EQUAL isup-location-value
原因扩展=/isup-cause-location isup-cause-location=“location”等于isup-location值
isup-location-value =
"U" / ; for 0 0 0 0 user
"LPN" / ; for 0 0 0 1 private network serving the local user
"LN" / ; for 0 0 1 0 public network serving the local user
"TN" / ; for 0 0 1 1 transit network
"RLN" / ; for 0 1 0 0 public network serving the remote user
"RPN" / ; for 0 1 0 1 private network serving the remote user
"LOC-6" / ; for 0 1 1 0 spare
"INTL" / ; for 0 1 1 1 international network
"LOC-8" / ; for 1 0 0 0 spare
"LOC-9" / ; for 1 0 0 1 spare
"BI" / ; for 1 0 1 0 network beyond interworking point
"LOC-11" / ; for 1 0 1 1 spare
"LOC-12" / ; for 1 1 0 0 reserved for national use
"LOC-13" / ; for 1 1 0 1 reserved for national use
"LOC-14" / ; for 1 1 1 0 reserved for national use
"LOC-15" ; for 1 1 1 1 reserved for national use
isup-location-value =
"U" / ; for 0 0 0 0 user
"LPN" / ; for 0 0 0 1 private network serving the local user
"LN" / ; for 0 0 1 0 public network serving the local user
"TN" / ; for 0 0 1 1 transit network
"RLN" / ; for 0 1 0 0 public network serving the remote user
"RPN" / ; for 0 1 0 1 private network serving the remote user
"LOC-6" / ; for 0 1 1 0 spare
"INTL" / ; for 0 1 1 1 international network
"LOC-8" / ; for 1 0 0 0 spare
"LOC-9" / ; for 1 0 0 1 spare
"BI" / ; for 1 0 1 0 network beyond interworking point
"LOC-11" / ; for 1 0 1 1 spare
"LOC-12" / ; for 1 1 0 0 reserved for national use
"LOC-13" / ; for 1 1 0 1 reserved for national use
"LOC-14" / ; for 1 1 1 0 reserved for national use
"LOC-15" ; for 1 1 1 1 reserved for national use
Figure 1: ABNF for isup-cause-location
图1:isup原因位置的ABNF
Note: These are the location values defined within [Q.850]. The 'LOC-*' names are the wire codepoints for the values currently left as 'spare' or 'reserved' in [Q.850]; these will continue to be the wire codepoints in the case of future allocation or national usage of the such values.
注：这些是[Q.850]中定义的位置值。“LOC-*”名称是[Q.850]中当前保留为“备用”或“保留”的值的导线代码点；在未来分配或国家使用此类值的情况下，这些将继续作为导线代码点。
The UAC or UAS SHALL include the location parameter in a request or response when setting up the Reason header field with a [Q.850] cause when the ISUP [Q.850] location is available.
当ISUP[Q.850]位置可用时，UAC或UAS在设置带有[Q.850]原因的原因标头字段时，应在请求或响应中包含位置参数。
The use of the location parameter is restricted to Q.850 cause values. Other values MUST be ignored if present.
位置参数的使用仅限于Q.850原因值。如果存在，则必须忽略其他值。
The following example shows a SIP 404 response message containing a Reason header field with a [Q.850] cause value and an isup-cause-location value. The 404 Response will be sent when a gateway receives an ISUP release with a [Q.850] cause set to 1, meaning Unallocated (unassigned) number, i.e., the number is not known in the PSTN.
以下示例显示了SIP 404响应消息，其中包含带有[Q.850]原因值和isup原因位置值的原因标头字段。当网关接收到ISUP释放且[Q.850]原因设置为1时，将发送404响应，这意味着未分配（未分配）号码，即PSTN中不知道该号码。
SIP/2.0 404 Not Found
Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bKx5st
Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK4321
From: Alice <sips:alice@atlanta.example.com>;tag=1234567
To: Bob <sips:bob@biloxi.example.com>;tag=765432
Call-ID: 12345600@atlanta.example.com
CSeq: 1 INVITE
Reason: Q.850;cause=1;text="Unallocated (unassigned) number";
location=LN
Content-Length: 0
SIP/2.0 404 Not Found
Via: SIP/2.0/TCP proxy.example.com:5060;branch=z9hG4bKx5st
Via: SIP/2.0/TCP 192.0.2.3:5060;branch=z9hG4bK4321
From: Alice <sips:alice@atlanta.example.com>;tag=1234567
To: Bob <sips:bob@biloxi.example.com>;tag=765432
Call-ID: 12345600@atlanta.example.com
CSeq: 1 INVITE
Reason: Q.850;cause=1;text="Unallocated (unassigned) number";
location=LN
Content-Length: 0
Figure 2: Example of a Location in the Reason Header Field
图2:Reason Header字段中的位置示例
While the addition of the location parameter provides an indicator of the entity that added the location in the signaling path, it provides little more exposure than the [Q.850] cause itself. The ISUP location value itself will not reveal the identity of the originating or terminating party of the call. It shows only the ISUP network location of the device that released the call. The ISUP location does not show the physical location of the caller or callee.
虽然位置参数的添加提供了在信令路径中添加位置的实体的指示符，但它提供的曝光量仅比[Q.850]原因本身多一点。ISUP位置值本身不会显示呼叫的发起方或终止方的身份。它仅显示释放呼叫的设备的ISUP网络位置。ISUP位置不显示呼叫者或被呼叫者的物理位置。
This document doesn't change any of the security considerations described in [RFC3326]. The addition of the location parameter provides an indicator of the [Q.850] location where the call was released within the PSTN. This information may be used for specific location-driven services but does not create any additional security constraints. Because the [Q.850] location is very imprecise, the [Q.850] location value itself will not add any major security constraints. The use of this parameter is not restricted to a specific architecture.
本文档不会更改[RFC3326]中描述的任何安全注意事项。位置参数的添加提供了PSTN内呼叫释放的[Q.850]位置的指示器。此信息可用于特定的位置驱动服务，但不会产生任何额外的安全约束。因为[Q.850]位置非常不精确，[Q.850]位置值本身不会添加任何主要的安全约束。此参数的使用不限于特定的体系结构。
[RFC3398] describes detailed security considerations due to interworking between ISUP and SIP. Beyond these considerations, the addition of the location does not introduce new security concerns. The location shows the network part where the call was released. Knowing this does not increase the possibilities of extended fraud scenarios.
[RFC3398]描述了由于ISUP和SIP之间的互通而引起的详细安全注意事项。除了这些考虑之外，添加位置不会带来新的安全问题。该位置显示了释放呼叫的网络部分。了解这一点并不会增加扩展欺诈场景的可能性。
IANA has registered a new SIP header parameter in the "Header Field Parameters and Parameter Values" subregistry of the "Session Initiation Protocol (SIP) Parameters" registry <https://www.iana.org/assignments/sip-parameters>, per the guidelines in [RFC3968]:
IANA已在“会话启动协议（SIP）参数”注册表的“header Field Parameters and parameter Values”子域中注册了一个新的SIP header参数<https://www.iana.org/assignments/sip-parameters>，根据[RFC3968]中的指南：
Header Field: Reason
标题字段：原因
Parameter Name: location
参数名称：位置
Predefined Values: Yes
预定义值：是
Reference: RFC 8606
参考：RFC 8606
[Q.850] ITU-T, "Usage of cause and location in the Digital Subscriber Signalling System No. 1 and the Signalling System No. 7 ISDN user part", Recommendation ITU-T Q.850, October 2018, <https://www.itu.int/rec/T-REC-Q.850>.
[Q.850]ITU-T，“数字用户信令系统1号和信令系统7号ISDN用户部分中原因和位置的使用”，建议ITU-T Q.850，2018年10月<https://www.itu.int/rec/T-REC-Q.850>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/info/rfc2119>.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，DOI 10.17487/RFC2119，1997年3月<https://www.rfc-editor.org/info/rfc2119>.
[RFC3326] Schulzrinne, H., Oran, D., and G. Camarillo, "The Reason Header Field for the Session Initiation Protocol (SIP)", RFC 3326, DOI 10.17487/RFC3326, December 2002, <https://www.rfc-editor.org/info/rfc3326>.
[RFC3326]Schulzrinne，H.，Oran，D.，和G.Camarillo，“会话启动协议（SIP）的原因头字段”，RFC 3326，DOI 10.17487/RFC3326，2002年12月<https://www.rfc-editor.org/info/rfc3326>.
[RFC3398] Camarillo, G., Roach, A., Peterson, J., and L. Ong, "Integrated Services Digital Network (ISDN) User Part (ISUP) to Session Initiation Protocol (SIP) Mapping", RFC 3398, DOI 10.17487/RFC3398, December 2002, <https://www.rfc-editor.org/info/rfc3398>.
[RFC3398]Camarillo，G.，Roach，A.，Peterson，J.，和L.Ong，“综合业务数字网（ISDN）用户部分（ISUP）到会话发起协议（SIP）的映射”，RFC 3398，DOI 10.17487/RFC3398，2002年12月<https://www.rfc-editor.org/info/rfc3398>.
[RFC3968] Camarillo, G., "The Internet Assigned Number Authority (IANA) Header Field Parameter Registry for the Session Initiation Protocol (SIP)", BCP 98, RFC 3968, DOI 10.17487/RFC3968, December 2004, <https://www.rfc-editor.org/info/rfc3968>.
[RFC3968]Camarillo，G.“会话启动协议（SIP）的Internet分配号码管理局（IANA）头字段参数注册表”，BCP 98，RFC 3968，DOI 10.17487/RFC3968，2004年12月<https://www.rfc-editor.org/info/rfc3968>.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, DOI 10.17487/RFC5234, January 2008, <https://www.rfc-editor.org/info/rfc5234>.
[RFC5234]Crocker，D.，Ed.和P.Overell，“语法规范的扩充BNF:ABNF”，STD 68，RFC 5234，DOI 10.17487/RFC5234，2008年1月<https://www.rfc-editor.org/info/rfc5234>.
[RFC6432] Jesske, R. and L. Liess, "Carrying Q.850 Codes in Reason Header Fields in SIP (Session Initiation Protocol) Responses", RFC 6432, DOI 10.17487/RFC6432, November 2011, <https://www.rfc-editor.org/info/rfc6432>.
[RFC6432]Jeske，R.和L.Liess，“在SIP（会话启动协议）响应的原因头字段中携带Q.850代码”，RFC 6432，DOI 10.17487/RFC6432，2011年11月<https://www.rfc-editor.org/info/rfc6432>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8174]Leiba，B.，“RFC 2119关键词中大写与小写的歧义”，BCP 14，RFC 8174，DOI 10.17487/RFC8174，2017年5月<https://www.rfc-editor.org/info/rfc8174>.
Acknowledgments
致谢
Thanks to Michael Kreipl, Thomas Belling, Marianne Mohali, Peter Daws, Paul Kyzivat, Dale Worley, Yehoshua Gev, and Keith Drage for the comments and review.
感谢Michael Kreipl、Thomas Belling、Marianne Mohali、Peter Daws、Paul Kyzivat、Dale Worley、Yehoshua Gev和Keith Drage的评论和评论。
Author's Address
作者地址
Roland Jesske Deutsche Telekom Heinrich-Hertz Str, 3-7 Darmstadt 64295 Germany
罗兰·杰西克德国电信海因里希·赫兹大街3-7号，达姆施塔特64295德国
Email: r.jesske@telekom.de
URI: www.telekom.de
Email: r.jesske@telekom.de
URI: www.telekom.de