Network Working Group J. Yu
Request for Comments: 4694 NeuStar
Category: Standards Track October 2006
Network Working Group J. Yu
Request for Comments: 4694 NeuStar
Category: Standards Track October 2006
Number Portability Parameters for the "tel" URI
“电话”URI的号码可移植性参数
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 Internet Society (2006).
版权所有（C）互联网协会（2006年）。
Abstract
摘要
This document defines five parameters in the "tel" Uniform Resource Identifier (URI) to carry the number portability (NP)-related information. Those parameters can be passed to the next-hop network node after an NP database dip has been performed.
本文档在“tel”统一资源标识符（URI）中定义了五个参数，以携带与号码可移植性（NP）相关的信息。在执行NP数据库dip之后，可以将这些参数传递给下一跳网络节点。
Table of Contents
目录
1. Introduction ....................................................2
2. Conventions .....................................................3
3. Abbreviations ...................................................3
4. Formal Syntax ...................................................3
5. Normative Rules .................................................5
5.1. Handling "tel" URI with NP Parameter or Parameters .........6
5.2. Adding NP Parameter or Parameters to the "tel" URI .........8
5.2.1. Retrieving NP-related Information for a
Geographical Telephone Number .......................8
5.2.2. Retrieving NP-related Information for a
Freephone Number ....................................9
5.2.3. Adding Location Information about the Caller .......10
5.2.4. Adding NP Parameter or Parameters Due to
Protocol Conversion ................................10
6. Examples .......................................................11
7. Security Considerations ........................................13
8. Acknowledgements ...............................................13
9. IANA Considerations ............................................13
1. Introduction ....................................................2
2. Conventions .....................................................3
3. Abbreviations ...................................................3
4. Formal Syntax ...................................................3
5. Normative Rules .................................................5
5.1. Handling "tel" URI with NP Parameter or Parameters .........6
5.2. Adding NP Parameter or Parameters to the "tel" URI .........8
5.2.1. Retrieving NP-related Information for a
Geographical Telephone Number .......................8
5.2.2. Retrieving NP-related Information for a
Freephone Number ....................................9
5.2.3. Adding Location Information about the Caller .......10
5.2.4. Adding NP Parameter or Parameters Due to
Protocol Conversion ................................10
6. Examples .......................................................11
7. Security Considerations ........................................13
8. Acknowledgements ...............................................13
9. IANA Considerations ............................................13
10. References ....................................................14
10.1. Normative References .....................................14
10.2. Informative References ...................................14
10. References ....................................................14
10.1. Normative References .....................................14
10.2. Informative References ...................................14
Number portability (NP) [RFC3482] allows telephony subscribers to keep their telephone numbers when they change service provider (service provider portability), move to a new location (location portability), or change the subscribed services (service portability). The telephone numbers can be the geographical telephone numbers, mobile telephone numbers, freephone numbers, or other types of non-geographical telephone numbers. Some mobile telephone numbers are like geographical telephone numbers (e.g., those in North America) and others are of non-geographical nature but their routing is similar to the routing of geographical telephone numbers so they are not specifically mentioned in this document. The freephone numbers are also known as toll-free phone numbers. The called party who is assigned the freephone number pays the call charge when the caller dials the freephone number.
号码可移植性（NP）[RFC3482]允许电话用户在更改服务提供商（服务提供商可移植性）、移动到新位置（位置可移植性）或更改订阅的服务（服务可移植性）时保留其电话号码。电话号码可以是地理电话号码、移动电话号码、免费电话号码或其他类型的非地理电话号码。一些移动电话号码类似于地理电话号码（例如，北美的电话号码），而另一些则具有非地理性质，但其路由与地理电话号码的路由相似，因此本文件中未具体提及。免费电话号码也称为免费电话号码。被分配免费电话号码的被叫方在主叫方拨打免费电话号码时支付通话费。
NP impacts call signaling and routing. One impact is the need to carry the NP-related information in the "tel" Uniform Resource Identifier (URI) [RFC3966] for protocols such as the Session Initiation Protocol (SIP) [RFC3261] and H.323 [H323] after the NP database dip has been performed. Another impact is for a Voice over IP (VoIP) server to use the NP-related information in a received "tel" URI to determine routing.
NP影响呼叫信令和路由。一个影响是在执行NP数据库dip之后，对于诸如会话发起协议（SIP）[rfc326]和H.323[H323]之类的协议，需要在“tel”统一资源标识符（URI）[RFC3966]中携带NP相关信息。另一个影响是IP语音（VoIP）服务器使用接收到的“电话”URI中的NP相关信息来确定路由。
A routing number is associated with a geographical or mobile telephone number that has been ported out from a donor carrier to another carrier. A donor carrier is the initial carrier where a geographical telephone number was allocated before ever being ported. A "non-ported" geographical or mobile telephone number does not have any routing number associated with it because the first N digits of the geographical or mobile telephone number can be used for routing. A routing number can also be used to indicate the switch or network node that originates a call or service similar to the Jurisdiction Information Parameter in Signaling System Number 7 (SS7) Integrated Services Digital Network User Part (ISUP). The "rn" parameter carries the routing number information. The "rn-context" parameter describes how the "rn" parameter value should be interpreted when the value is not a "global-rn" as is discussed in Section 4.
路由号码与一个地理或移动电话号码相关联，该号码已从一个捐赠运营商转移到另一个运营商。捐赠运营商是初始运营商，在该运营商中，地理电话号码在被移植之前已分配。“非移植”地理或移动电话号码没有任何与之关联的路由号码，因为地理或移动电话号码的前N位数字可用于路由。路由号码还可用于指示发起呼叫或服务的交换机或网络节点，该呼叫或服务类似于信令系统7号（SS7）综合业务数字网络用户部分（ISUP）中的辖区信息参数。“rn”参数携带路由号码信息。“rn context”参数描述了当“rn”参数值不是第4节中讨论的“全局rn”时，应如何解释该值。
The NP database dip indicator is used to inform the downstream servers or switches during call setup that there is no need to perform the NP database dip for a geographical telephone number again. The "npdi" parameter carries such an indicator.
NP数据库dip指示器用于在呼叫设置期间通知下游服务器或交换机无需再次对地理电话号码执行NP数据库dip。“npdi”参数带有这样一个指示器。
A Carrier Identification Code (CIC) identifies the current freephone service provider for a freephone number. This parameter can also be used to carry the pre-subscribed or dialed long-distance carrier information; however, that is outside the scope of this document. The "cic" parameter carries the CIC information. The "cic-context" parameter describes how the "cic" parameter value should be interpreted when the value is not a "global-cic" as is discussed in Section 4.
运营商识别码（CIC）用于识别当前免费电话服务提供商的免费电话号码。该参数还可用于携带预订阅或已拨的长途载波信息；但是，这超出了本文件的范围。“cic”参数携带cic信息。“cic上下文”参数描述了当“cic”参数值不是第4节中讨论的“全局cic”时，应如何解释该值。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照RFC 2119[RFC2119]中所述进行解释。
ABNF Augmented Backus-Naur Form ANSI American National Standards Institute CIC Carrier Identification Code (also cic) CIP Carrier Identification Parameter FCI Forward Call Indicator GAP Generic Address Parameter GSTN Global Switched Telephone Network HTML HyperText Markup Language IC Identification Code ISUP Integrated Services Digital Network User Part JIP Jurisdiction Information Parameter NP Number Portability NPDB Number Portability Database npdi NP Database Dip Indicator rn Routing Number PNTI Ported Number Translation Indicator SIP Session Initiation Protocol SS7 Signaling System Number 7 URI Uniform Resource Identifier VoIP Voice over IP
ABNF增强的Backus Naur表格ANSI美国国家标准协会CIC承运人识别码（也称为CIC）CIP载波识别参数FCI前向呼叫指示器GAP通用地址参数GSTN全球交换电话网HTML超文本标记语言IC识别码ISUP综合业务数字网络用户部分JIP管辖权信息参数NP号码可移植性NPDB号码可移植性数据库npdi NP数据库Dip指示符rn路由号码PNTI端口号码转换指示符SIP会话启动协议SS7信令系统号码7 URI统一资源标识符IP语音
The following syntax specification uses the Augmented Backus-Naur Form (ABNF) as described in RFC 4234 [RFC4234] and defines the five parameters, rn, npdi, cic, rn-context and cic-context, by extending the "parameter" production rule of the "tel" URI defined in [RFC3966].
以下语法规范使用RFC 4234[RFC4234]中所述的增广Backus-Naur形式（ABNF），并通过扩展[RFC3966]中定义的“tel”URI的“参数”生成规则，定义了五个参数rn、npdi、cic、rn上下文和cic上下文。
parameter =/ rn / cic / npdi
rn = ";rn=" (global-rn / local-rn)
npdi = ";npdi"
cic = ";cic=" (global-cic / local-cic)
global-rn = global-hex-digits
local-rn = 1*hex-phonedigit rn-context
rn-context = ";rn-context=" rn-descriptor
rn-descriptor = domainname / global-hex-digits
global-hex-digits = "+" 1*3(DIGIT) *hex-phonedigit
hex-phonedigit = HEXDIG / visual-separator
visual-separator = "-" / "." / "(" / ")"
domainname = *( domainlabel "." ) toplabel ["."]
domainlabel = alphanum
/ alphanum *( alphanum / "-" ) alphanum
toplabel = ALPHA / ALPHA *( alphanum / "-" ) alphanum
alphanum = ALPHA / DIGIT
global-cic = global-hex-digits
local-cic = 1*hex-phonedigit cic-context
cic-context = ";cic-context=" rn-descriptor
parameter =/ rn / cic / npdi
rn = ";rn=" (global-rn / local-rn)
npdi = ";npdi"
cic = ";cic=" (global-cic / local-cic)
global-rn = global-hex-digits
local-rn = 1*hex-phonedigit rn-context
rn-context = ";rn-context=" rn-descriptor
rn-descriptor = domainname / global-hex-digits
global-hex-digits = "+" 1*3(DIGIT) *hex-phonedigit
hex-phonedigit = HEXDIG / visual-separator
visual-separator = "-" / "." / "(" / ")"
domainname = *( domainlabel "." ) toplabel ["."]
domainlabel = alphanum
/ alphanum *( alphanum / "-" ) alphanum
toplabel = ALPHA / ALPHA *( alphanum / "-" ) alphanum
alphanum = ALPHA / DIGIT
global-cic = global-hex-digits
local-cic = 1*hex-phonedigit cic-context
cic-context = ";cic-context=" rn-descriptor
The "rn", "npdi", or "cic" parameter each can appear in the "tel" URI at most once.
“rn”、“npdi”或“cic”参数在“tel”URI中最多出现一次。
The first "hex-phonedigit" value in "local-rn" or "local-cic" MUST be a hex-decimal digit.
“本地rn”或“本地cic”中的第一个“十六进制phonedigit”值必须是十六进制十进制数字。
For a "global-rn", the routing number information after "+" MUST begin with a valid E.164 [E164] country code. Hexadecimal digit is allowed after the country code in the "global-rn".
对于“全局rn”，在“+”之后的路由号码信息必须以有效的E.164[E164]国家代码开头。“global rn”中的国家代码后允许使用十六进制数字。
For a "local-rn", the routing number in the "rn" parameter MUST be interpreted according to the "rn-context". For example, if a national routing number is in the "rn" parameter, the "rn-context" MUST contain a valid E.164 country code after "+" if it is in the "global-hex-digits" format. Hexadecimal digit is allowed in the "local-rn".
对于“本地rn”，必须根据“rn上下文”解释“rn”参数中的路由编号。例如，如果国家路由号码在“rn”参数中，“rn上下文”必须在“+”之后包含有效的E.164国家代码（如果是“全局十六进制数字”格式）。“本地rn”中允许十六进制数字。
For a "global-cic", the CIC information after "+" MUST begin with a valid E.164 country code.
对于“全球cic”，在“+”之后的cic信息必须以有效的E.164国家代码开头。
For a "local-cic", the CIC value in the "cic" parameter MUST be interpreted according to the "cic-context". For example, if the national CIC value is in the "cic" parameter, the "cic-context" MUST contain a valid E.164 country code after "+" if it is in the "global-hex-digits" format.
对于“本地cic”，必须根据“cic上下文”解释“cic”参数中的cic值。例如，如果国家CIC值在“CIC”参数中，“CIC上下文”必须在“+”之后包含有效的E.164国家代码（如果是“全局十六进制数字”格式）。
The inclusion of the visual separator in the "rn" or "cic" is optional.
在“rn”或“cic”中包含可视分隔符是可选的。
There are two distinct uses for the "tel" URI. In one use, the "tel" URI appears in a piece of static content. For example, it might appear in a HyperText Markup Language (HTML) page or a presence document. In another use, the "tel" URI appears in call signaling protocols, such as SIP and H.323, where it is used to guide routing of the call setup messages. The "tel" URI extensions defined in this document are targeted at call signaling protocols. When a "tel" URI is placed in static content, the parameters defined here SHOULD NOT be present, and any entity receiving them SHOULD remove them prior to using the tel URI.
“tel”URI有两种不同的用途。在一次使用中，“tel”URI出现在一段静态内容中。例如，它可能出现在超文本标记语言（HTML）页面或状态文档中。在另一用途中，“tel”URI出现在呼叫信令协议中，例如SIP和H.323，其中它用于指导呼叫建立消息的路由。本文档中定义的“tel”URI扩展针对呼叫信令协议。在静态内容中放置“tel”URI时，此处定义的参数不应存在，任何接收它们的实体都应在使用tel URI之前删除它们。
Within the context of signaling protocols, these parameters are meant for usage between call signaling entities, called network nodes, among which there is a trust relationship. Since parameters inserted by one network node can impact the routing of a request at a downstream node, processing of these parameters depends on trusting that the upstream element properly followed the rules defined here. A call signaling protocol can verify that an upstream element is part of its circle of trust through hop-by-hop integrity mechanisms. See Section 7, Security Considerations, for more information. If a network node receives a call signaling message from an element it does not trust, it SHOULD ignore the parameters.
在信令协议的上下文中，这些参数用于呼叫信令实体（称为网络节点）之间的使用，其中存在信任关系。由于一个网络节点插入的参数可能会影响下游节点的请求路由，因此这些参数的处理取决于是否信任上游元素正确遵循此处定义的规则。呼叫信令协议可以通过逐跳完整性机制验证上游元素是其信任圈的一部分。有关更多信息，请参见第7节“安全注意事项”。如果网络节点从其不信任的元素接收到呼叫信令消息，则应忽略参数。
This section discusses how a network node handles a received "tel" URI that contains one or more of the parameters defined in this document or has accessed an NP database for a freephone number or geographical telephone number and needs to add some of the parameters defined in this document to a "tel" URI.
本节讨论网络节点如何处理接收到的“tel”URI，该URI包含本文档中定义的一个或多个参数，或者访问了免费电话号码或地理电话号码的NP数据库，并且需要将本文档中定义的一些参数添加到“tel”URI中。
In countries where there is no freephone number portability or geographical telephone number portability, the call routing can be based on the leading digits of the freephone number or geographical telephone number. This document does not describe those scenarios.
在没有免费电话号码可移植性或地理电话号码可移植性的国家/地区，呼叫路由可以基于免费电话号码或地理电话号码的前导数字。本文档不描述这些场景。
Please note that two accesses to the freephone databases are normally done for routing a call to a freephone number. The first one is done by the originating network that queries a freephone database for the CIC information so that the call can be routed to the serving freephone service provider of the called freephone number. When the call reaches the serving freephone provider, the second database access is performed to map the freephone number to a geographical telephone number and/or internal routing information. This document does not address the case where internal routing information is returned.
请注意，通常会对freephone数据库进行两次访问，以便将呼叫路由到freephone号码。第一个是由发起网络完成的，发起网络查询免费电话数据库中的CIC信息，以便呼叫可以路由到被呼叫免费电话号码的服务免费电话服务提供商。当呼叫到达服务免费电话提供商时，执行第二数据库访问以将免费电话号码映射到地理电话号码和/或内部路由信息。本文档不涉及返回内部路由信息的情况。
The first freephone database contains the CIC information for all the active freephone numbers, whereas the second one usually contains mapping information only for those freephone numbers served by a freephone service provider. Because the originating carrier may provide freephone service, its freephone database would contain the CIC information for all the active freephone numbers plus the mapping information for those freephone numbers it serves. This document refers to the two database accesses as "the first freephone database access" and "the second freephone database access".
第一个freephone数据库包含所有活动freephone号码的CIC信息，而第二个数据库通常只包含由freephone服务提供商提供服务的那些freephone号码的映射信息。由于始发运营商可能提供免费电话服务，其免费电话数据库将包含所有活动免费电话号码的CIC信息以及其服务的免费电话号码的映射信息。本文档将两次数据库访问称为“第一次freephone数据库访问”和“第二次freephone数据库访问”。
When handling the "rn" and "cic" parameters and the phone numbers in the "tel" URI for purposes such as database access and routing, the visual separators in them are removed before using the information in them.
为了数据库访问和路由等目的处理“tel”URI中的“rn”和“cic”参数以及电话号码时，会在使用其中的信息之前删除其中的可视分隔符。
When a network node handles a "tel" URI that contains invalid "rn" or "cic" information, it may release the call or drop the invalid parameter and access the appropriate NP database or freephone database to see whether it can retrieve a valid routing number for a geographical telephone number or valid CIC for the freephone number.
当网络节点处理包含无效“rn”或“cic”信息的“tel”URI时，它可能会释放呼叫或删除无效参数，并访问适当的NP数据库或freephone数据库，以查看它是否可以检索地理电话号码的有效路由号码或freephone号码的有效cic。
When a "tel" URI is received from an untrusted source, a network node MAY redo the NPDB query.
当从不受信任的源接收到“tel”URI时，网络节点可以重做NPDB查询。
SIP [RFC3261] has mechanisms in place to detect routing loops due to URI re-writing, and the new parameters added here work within these established contexts. The "npdi" parameter in the URI that indicates a NPDB query has already been done can also prevent routing loop. Other protocols considering using these "tel" URI parameters SHOULD ensure that they have mechanisms in place to detect loops when re-writing the "tel" URI.
由于要在此处重新写入SIP[C3261]中的新路由机制，因此在此处添加了新的路由机制。URI中的“npdi”参数表示NPDB查询已经完成，也可以防止路由循环。考虑使用这些“tel”URI参数的其他协议应确保它们在重写“tel”URI时具有检测循环的机制。
If the "tel" URI contains the "npdi" parameter, the network node MUST NOT retrieve the NP-related information for geographical telephone numbers even if it is set to do so.
如果“tel”URI包含“npdi”参数，则网络节点不得检索地理电话号码的NP相关信息，即使已设置为这样做。
If the "tel" URI contains the "cic" parameter whose CIC value is different from the one this network node is associated with, this network node MUST NOT retrieve the NP-related information for the geographical telephone number or perform the first freephone database access for the freephone number in the "tel" URI.
如果“tel”URI包含cic值不同于此网络节点关联的参数的“cic”参数，则此网络节点不得检索地理电话号码的NP相关信息，或对“tel”URI中的免费电话号码执行第一次免费电话数据库访问。
For the "cic" and "rn" parameters and either a freephone number or geographical telephone number, the order of processing is to look for the "cic" parameter first for call routing. If the CIC information is not useful or the "cic" parameter does not exist, then the next
对于“cic”和“rn”参数以及免费电话号码或地理电话号码，处理顺序是首先查找呼叫路由的“cic”参数。如果CIC信息无效或“CIC”参数不存在，则下一个
step is to look for the "rn" parameter. If the information in the "rn" parameter is not useful or the "rn" parameter does not exist, then the freephone number or geographical telephone number is used.
步骤是查找“rn”参数。如果“rn”参数中的信息无效或“rn”参数不存在，则使用免费电话号码或地理电话号码。
If the network node does not know how to route based on the "cic" or "rn" parameter, the local policies MUST decide whether to stop the call processing or continue the call processing by ignoring the invalid/unknown information.
如果网络节点不知道如何基于“cic”或“rn”参数进行路由，则本地策略必须通过忽略无效/未知信息来决定是停止呼叫处理还是继续呼叫处理。
When looking for the "cic" parameter and that parameter exists in the "tel" URI:
查找“cic”参数且该参数存在于“tel”URI中时：
- The network node MUST ignore the "cic" parameter if the CIC identifies a carrier or service provider associated with that node and look for the "rn" parameter for making the routing decision. It MUST remove the "cic" parameter when it routes the call to the next-hop network node that belongs to another carrier or service provider.
- 如果cic识别与该节点相关联的载波或服务提供商，则网络节点必须忽略“cic”参数，并查找“rn”参数以做出路由决策。当它将呼叫路由到属于另一运营商或服务提供商的下一跳网络节点时，必须删除“cic”参数。
- The network node MUST invoke special handling process if the "cic" parameter contains a code that requires such a treatment. For example, a CIC value of "0110" in the response to a freephone DB query in North America indicates "local, translated geographical telephone number provided". In this particular example, the "cic" parameter is ignored. Please note that this particular CIC value of "+1-0110" normally will not appear in the call setup message. It is given as an example to show that such special CIC values may exist. The exact code values and the handling of them are outside the scope of this document.
- 如果“cic”参数包含需要这种处理的代码，则网络节点必须调用特殊处理过程。例如，在北美对freephone DB查询的响应中，CIC值为“0110”表示“提供了本地翻译的地理电话号码”。在此特定示例中，“cic”参数被忽略。请注意，“+1-0110”的特定CIC值通常不会出现在呼叫设置消息中。文中给出了一个例子来说明这种特殊的CIC值可能存在。准确的代码值及其处理不在本文档的范围内。
- Otherwise, the network node MUST make the routing decision based on the CIC. The network node MUST NOT remove the "cic" parameter unless it is handing over the call to the carrier or service provider identified by the CIC and the local policies require it to remove the "cic" parameter. How the call is actually routed based on the CIC value in the "cic" parameter is outside the scope of this document.
- 否则，网络节点必须根据CIC做出路由决策。网络节点不得删除“cic”参数，除非它正在将呼叫移交给cic标识的运营商或服务提供商，并且本地策略要求它删除“cic”参数。根据“CIC”参数中的CIC值实际路由呼叫的方式超出了本文档的范围。
When looking for the "rn" parameter and that parameter exists in the "tel" URI:
查找“rn”参数且该参数存在于“tel”URI中时：
- If the routing number in the "rn" parameter points to this network node (e.g., the call has reached the intended network node), this network node MUST look for the freephone number or geographical telephone number for making the routing decision. It MUST remove the "rn" parameter when setting up the call to the next-hop network node regardless if that next-hop network node is in the same or different network.
- 如果“rn”参数中的路由号码指向该网络节点（例如，呼叫已到达预期的网络节点），则该网络节点必须查找免费电话号码或地理电话号码，以便做出路由决策。在设置对下一跳网络节点的呼叫时，无论该下一跳网络节点位于同一网络还是不同网络中，都必须删除“rn”参数。
- If the routing number in the "rn" parameter points to a network this network node is in (e.g., in some countries the routing number gets the call to the serving carrier network where another NP database access is required to locate the serving switch), this network node MUST look for the freephone number or geographical telephone number for making the routing decision. The network node MAY access the NP database for routing information if it is set to do so. It MUST remove the "rn" parameter if the next-hop network node belongs to another carrier or service provider.
- 如果“rn”参数中的路由号码指向该网络节点所在的网络（例如，在某些国家，路由号码获得对服务运营商网络的呼叫，其中需要另一个NP数据库访问来定位服务交换机），此网络节点必须查找免费电话号码或地理电话号码，以便做出路由决策。如果网络节点被设置为访问NP数据库以获取路由信息，则网络节点可以访问NP数据库。如果下一跳网络节点属于其他运营商或服务提供商，则必须删除“rn”参数。
- Otherwise, the network node MUST make the routing decision based on the routing number in the "rn" parameter. How the call is actually routed based on the routing number in the "rn" parameter is outside the scope of this document.
- 否则，网络节点必须根据“rn”参数中的路由编号做出路由决策。根据“rn”参数中的路由号码实际路由呼叫的方式超出了本文档的范围。
When the "cic" or "rn" parameter is not used for routing, the network node uses the freephone number or geographical telephone number for making routing decisions. It may access the NP database if it is set to do so, or it may route the call to a designated network node that will access the NP database, or it may route the call based on the local routing table. How the call is handled at this stage is outside the scope of this document. See Section 5.2 for rules in adding the parameter or parameters defined in this document to the "tel" URI if the network node is set to access the NP database.
当“cic”或“rn”参数不用于路由时，网络节点使用免费电话号码或地理电话号码来做出路由决策。如果设置为访问NP数据库，它可以访问NP数据库，或者它可以将呼叫路由到将访问NP数据库的指定网络节点，或者它可以基于本地路由表路由呼叫。在此阶段如何处理呼叫超出了本文档的范围。如果网络节点被设置为访问NP数据库，则将本文档中定义的一个或多个参数添加到“tel”URI中的规则请参见第5.2节。
There are two cases in terms of NP database access. One is for a geographical telephone number and the other is for a freephone number. They are discussed in Sections 5.2.1 and 5.2.2 for a "tel" URI that is used for routing.
NP数据库访问有两种情况。一个是地理电话号码，另一个是免费电话号码。第5.2.1节和第5.2.2节讨论了用于路由的“tel”URI。
Section 5.2.3 discusses a special case where the "rn" parameter is added to a "tel" URI that is associated with the first network node that handles the call request from the caller. Section 5.2.4 discusses the addition of the parameter or parameters defined in this document to the "tel" URI due to protocol conversion.
第5.2.3节讨论了一种特殊情况，“rn”参数被添加到“tel”URI中，该URI与处理呼叫者呼叫请求的第一个网络节点关联。第5.2.4节讨论了由于协议转换而将本文档中定义的一个或多个参数添加到“tel”URI中的问题。
5.2.1. Retrieving NP-related Information for a Geographical Telephone Number
5.2.1. 检索地理电话号码的NP相关信息
When a network node accesses an NP database for a geographical telephone number:
当网络节点访问NP数据库以获取地理电话号码时：
- If the network node retrieves a routing number, it MUST add the "rn" parameter to the "tel" URI to carry the routing number information in the "global-rn" or "local-rn" format. It MUST also add the "npdi" parameter.
- 如果网络节点检索路由号码，它必须将“rn”参数添加到“tel”URI中，以携带“global rn”或“local rn”格式的路由号码信息。它还必须添加“npdi”参数。
- If the network node does not retrieve a routing number (e.g., for a non-ported geographical telephone number), it MUST add the "npdi" parameter to the "tel" URI.
- 如果网络节点没有检索路由号码（例如，对于非端口的地理电话号码），则必须将“npdi”参数添加到“tel”URI中。
The network node MUST follow the rules described in Section 5.1 for using the information in the "tel" URI to make the routing decision.
网络节点必须遵循第5.1节中描述的规则，以便使用“tel”URI中的信息做出路由决策。
When a network node performs the first or second freephone database access for a freephone number:
当网络节点对免费电话号码执行第一次或第二次免费电话数据库访问时：
- If the network node retrieves a CIC that identifies a carrier or service provider associated with that network node, or indicates that a geographic number is supplied (e.g., "+1-0110" means "local, translated geographical telephone number provided"), it would have retrieved a geographical telephone number. The network node MUST NOT add the "cic" parameter and MUST replace the freephone number in the "tel" URI with the retrieved geographical telephone number in either the "global-number" or "local-number" format.
- 如果网络节点检索到识别与该网络节点相关联的运营商或服务提供商的CIC，或指示提供了地理号码（例如，“+1-0110”表示“提供的本地翻译地理电话号码”），则其将检索到地理电话号码。网络节点不得添加“cic”参数，并且必须用检索到的“全局号码”或“本地号码”格式的地理电话号码替换“tel”URI中的免费电话号码。
Some freephone databases may not return the geographical telephone number but internal routing information in a proprietary format (e.g., switch ID and trunk group ID). That case is outside the scope of this document.
某些freephone数据库可能不会返回地理电话号码，而是以专有格式返回内部路由信息（例如交换机ID和中继组ID）。该案例超出了本文件的范围。
- If the network node retrieves a CIC that belongs to another freephone service provider, the network node MUST add the "cic" parameter to the "tel" URI that contains the CIC in the "global-cic" or "local-cic" format.
- 如果网络节点检索到属于另一个freephone服务提供商的CIC，则网络节点必须将“CIC”参数添加到包含“全局CIC”或“本地CIC”格式CIC的“tel”URI中。
The originating carrier may have business agreements with a freephone service provider to return the geographical telephone number in addition to the CIC. When a geographical telephone number is returned, the network node MUST replace the freephone number in the "tel" URI with the returned geographical telephone number in either the "global-number" or "local-number" format.
发起运营商可能与免费电话服务提供商签订业务协议，以在CIC之外返回地理电话号码。当返回地理电话号码时，网络节点必须用返回的“全局号码”或“本地号码”格式的地理电话号码替换“电话”URI中的免费电话号码。
- If the network node retrieves a geographical telephone number (which is the typical case for the second freephone database access), the network node MUST replace the freephone number in the "tel" URI with the retrieved geographical telephone number in either the "global-number" or "local-number" format.
- 如果网络节点检索地理电话号码（这是第二次免费电话数据库访问的典型情况），则网络节点必须将“tel”URI中的免费电话号码替换为检索到的“全局号码”或“本地号码”格式的地理电话号码。
When a geographical telephone number is returned in the response, it is possible that the NP-related information for that geographical telephone number could also be returned. In that case, the network node MUST add the "npdi" parameter and MUST add
当在响应中返回地理电话号码时，也可能返回该地理电话号码的NP相关信息。在这种情况下，网络节点必须添加“npdi”参数，并且必须添加
the "rn" parameter to contain the routing number in either the "global-rn" or "local-rn" format only when the routing number is available.
“rn”参数，仅当路由号码可用时，才包含“全局rn”或“本地rn”格式的路由号码。
The network node MUST follow the rules described in Section 5.1 for using the information in the "tel" URI to make the routing decision.
网络节点必须遵循第5.1节中描述的规则，以便使用“tel”URI中的信息做出路由决策。
In SS7 ISUP, the JIP identifies the switch that originates the call, and the information in it may be used by the serving carrier to determine the call charge to the caller or by the involved carriers to determine the settlement amount between them.
在SS7 ISUP中，JIP识别发起呼叫的交换机，其中的信息可由服务运营商用于确定呼叫方的呼叫费用，或由相关运营商用于确定它们之间的结算金额。
A network node that is the first to handle the call request from the caller MAY include the "rn" parameter to the "tel" URI associated with the caller, if one exists. For example, if the network node is a Global Switched Telephone Network (GSTN) gateway that receives an ISUP message that contains the JIP, the correct location information in the JIP can be placed in the "rn" parameter of the "tel" URI that is associated with the caller.
第一个处理来自呼叫者的呼叫请求的网络节点可以将“rn”参数包括到与呼叫者相关联的“tel”URI（如果存在的话）。例如，如果网络节点是接收包含JIP的ISUP消息的全球交换电话网络（GSTN）网关，则JIP中的正确位置信息可以放置在与呼叫者相关联的“tel”URI的“rn”参数中。
Please note that the information in the "rn" parameter may not be authenticated; therefore, the use of the information by the recipient of the "tel" URI for anything related to charging is done at its own risk.
请注意，“rn”参数中的信息可能未经验证；因此，“tel”URI的接收者使用该信息进行任何与收费相关的操作都有其自身的风险。
A GSTN gateway needs to convert between SS7 ISUP and the VoIP protocol such as SIP or H.323. This type of network node MUST map between the corresponding ISUP parameters and the parameters defined in this document associated with the "tel" URI for routing and MAY map between the corresponding ISUP parameters and the parameters defined in this document that are in the "tel" URI associated with the caller.
GSTN网关需要在SS7 ISUP和VoIP协议（如SIP或H.323）之间转换。这种类型的网络节点必须在相应的ISUP参数和本文档中定义的与用于路由的“tel”URI相关联的参数之间映射，并且可以在相应的ISUP参数和本文档中定义的与调用者相关联的“tel”URI中的参数之间映射。
Since ISUP support for NP depends on the individual country, the following discussion applies to a situation when a network node is to map between the NP information in the American National Standards Institute (ANSI) ISUP and the NP-related parameters in the "tel" URI.
由于ISUP对NP的支持取决于单个国家，以下讨论适用于网络节点在美国国家标准协会（ANSI）ISUP中的NP信息和“tel”URI中的NP相关参数之间映射的情况。
For a ported geographical telephone number, the network node MUST convert the routing number in the ISUP Called Party Number parameter to a routing number in either the "global-rn" or "local-rn" format and carry it in the "rn" parameter for a "tel" URI that is used for routing. The network node MUST convert the phone number that is marked as the "ported number" in the ISUP Generic Address Parameter
对于移植的地理电话号码，网络节点必须将ISUP被叫方号码参数中的路由号码转换为“全局rn”或“本地rn”格式的路由号码，并将其携带在用于路由的“tel”URI的“rn”参数中。网络节点必须转换ISUP通用地址参数中标记为“端口号”的电话号码
(GAP) to a phone number in either the "global-number" or "local-number" format [RFC3966] and put it in the global-number-digits or local-number-digits (see [RFC3966]) part of the "tel" URI that is used for routing.
（GAP）到“全局号码”或“本地号码”格式的电话号码[RFC3966]，并将其放入用于路由的“电话”URI的全局号码数字或本地号码数字（请参见[RFC3966]）部分。
For a non-ported geographical telephone number, the network node MUST convert the phone number in the ISUP Called Party Number parameter to a phone number in either the "global-number" or "local-number" format and put it in the global-number-digits or local-number-digits (see [RFC3966]) part of the "tel" URI that is used for routing. The "rn" parameter MUST NOT appear in the "tel" URI unless the local policies require the network node to include it. It is outside the scope of this document how to include the "rn" parameter if the local policies require the network node to do so.
对于非移植的地理电话号码，网络节点必须将ISUP被叫方号码参数中的电话号码转换为“全局号码”或“本地号码”格式的电话号码，并将其放入用于路由的“tel”URI的全局号码数字或本地号码数字（请参阅[RFC3966]）部分。“rn”参数不得出现在“tel”URI中，除非本地策略要求网络节点包含它。如果本地策略要求网络节点这样做，那么如何包含“rn”参数超出了本文档的范围。
The network node MUST include the "npdi" parameter in the "tel" URI that is used for routing when the Ported Number Translation Indicator (PNTI) bit in the Forward Call Indicator (FCI) parameter is set to "1".
当前向呼叫指示符（FCI）参数中的端口号码转换指示符（PNTI）位设置为“1”时，网络节点必须在用于路由的“tel”URI中包含“npdi”参数。
The network node MUST include the "cic" parameter in either the "global-cic" or "local-cic" format in the "tel" URI that is used for routing when the ISUP Carrier Identification Parameter (CIP) is present.
网络节点必须在“tel”URI中包含“全局cic”或“本地cic”格式的“cic”参数，该URI在ISUP载波标识参数（CIP）存在时用于路由。
The network node MAY include the "rn" parameter in the "tel" URI associated with the caller information when the ISUP JIP is present. This may be subject to the network node's local policy and/or the signaling protocol that carries the "tel" URI.
当ISUP JIP存在时，网络节点可以在与呼叫者信息相关联的“tel”URI中包括“rn”参数。这可能受制于网络节点的本地策略和/或承载“tel”URI的信令协议。
Mapping NP-related parameters in a "tel" URI to the NP-related information in the ISUP message depends on the national ISUP implementation and is outside the scope of this document.
将“tel”URI中的NP相关参数映射到ISUP消息中的NP相关信息取决于国家ISUP实施，不在本文档范围内。
A. A "tel" URI, tel:+1-800-123-4567, contains a freephone number "+1-800-123-4567". Assume that this freephone number is served by a freephone service provider with a CIC "+1-6789". After retrieving the NP-related information, the "tel" URI would be set to
A.一个“电话”URI，电话：+1-800-123-4567，包含一个免费电话号码“+1-800-123-4567”。假设此免费电话号码由免费电话服务提供商提供，CIC为“+1-6789”。检索NP相关信息后，“tel”URI将设置为
tel:+1-800-123-4567;cic=+1-6789
tel:+1-800-123-4567;cic=+1-6789
B. A "tel" URI, tel:+1-800-123-4567;cic=+1-6789, is handled by a network node in the serving freephone service provider's network. Assume that the freephone number is mapped to a geographical telephone number "+1-202-533-1234". After retrieving the NP-related information, the "tel" URI would be set to
B.一个“电话”URI，电话：+1-800-123-4567；cic=+1-6789，由服务免费电话服务提供商网络中的网络节点处理。假设免费电话号码映射到地理电话号码“+1-202-533-1234”。检索NP相关信息后，“tel”URI将设置为
tel:+1-202-533-1234
电话：+1-202-533-1234
C. A "tel" URI, tel:+1-202-533-1234, contains a geographical telephone number "+1-202-533-1234". Assume that this geographical telephone number is ported and is associated with a routing number "1-202-544-0000". After retrieving the NP-related information, the "tel" URI would be set to
C.“电话”URI，电话：+1-202-533-1234，包含地理电话号码“+1-202-533-1234”。假设此地理电话号码已移植，并与路由号码“1-202-544-0000”关联。检索NP相关信息后，“tel”URI将设置为
tel:+1-202-533-1234;npdi;rn=+1-202-544-0000
tel:+1-202-533-1234;npdi;rn=+1-202-544-0000
D. A "tel" URI, tel:+1-202-533-6789, contains a geographical telephone number "+1-202-533-6789". Assume that this geographical telephone number is not ported. After accessing the NP database, the "tel" URI would be set to
D.一个“电话”URI，电话：+1-202-533-6789，包含一个地理电话号码“+1-202-533-6789”。假设此地理电话号码未移植。访问NP数据库后，“tel”URI将设置为
tel:+1-202-533-6789;npdi
tel:+1-202-533-6789;npdi
E. A "tel" URI, tel:+1-202-533-1234;npdi;rn=+1-202-000-0000, contains an invalid routing number (e.g., no routing information on "+1- 202-000-0000"); the network node may drop the "rn" parameter and access the NP database again.
E.一个“电话”URI，电话：+1-202-533-1234；npdi；rn=+1-202-000-0000，包含无效的路由编号（例如，“+1-202-000-0000”上没有路由信息）；网络节点可以删除“rn”参数并再次访问NP数据库。
F. A "tel" URI, tel:+1-800-123-456, contains a freephone number "+1-800-123-456" that is one digit short. When accessing the freephone database, there will not be any "cic" information for this freephone number. The call would be released.
F.“电话”URI，电话：+1-800-123-456，包含一个短一位数的免费电话号码“+1-800-123-456”。访问免费电话数据库时，此免费电话号码将不会有任何“cic”信息。电话将被释放。
G. A "tel" URI, tel:+1-800-123-4567;cic=+1-56789, is handled by a network node in an originating or a transit network. The "cic" information is invalid. The network node may drop the "cic" parameter and access the freephone database again. If the same wrong CIC information is received, the network node would release the call because it does not know how to route the call with an invalid CIC. If valid information is received, the network node will use the received CIC in the "cic" and route the call based on the "cic".
G.A“电话”URI，电话：+1-800-123-4567；cic=+1-56789，由发起网络或传输网络中的网络节点处理。“cic”信息无效。网络节点可以删除“cic”参数并再次访问freephone数据库。如果接收到相同的错误CIC信息，网络节点将释放呼叫，因为它不知道如何使用无效CIC路由呼叫。如果接收到有效信息，网络节点将使用“CIC”中接收到的CIC，并基于“CIC”路由呼叫。
In addition to those security implications discussed in the revised "tel" URI [RFC3966], there are new security implications associated with the parameters defined in this document.
除了修订后的“tel”URI[RFC3966]中讨论的安全含义外，还有与本文档中定义的参数相关的新安全含义。
If the value of the "rn" or "cic" in the "tel" URI is changed illegally when the signaling message carrying the "tel" URI is en route to the destination entity, the signaling message or call may be routed to the wrong network or network node causing the call setup to be rejected.
如果当承载“tel”URI的信令消息正在路由到目的地实体时，“tel”URI中的“rn”或“cic”的值被非法更改，则信令消息或呼叫可能被路由到错误的网络或网络节点，从而导致呼叫设置被拒绝。
If the "npdi" is illegally inserted into the "tel" URI when the signaling message carrying the "tel" URI is en route to the destination entity, the call may be routed to the wrong network or network node causing the call setup to be rejected. It is less a problem if the "npdi" is illegally removed. An additional NPDB query may be performed to retrieve the routing number information and have the "npdi" included again.
如果当承载“tel”URI的信令消息正在路由到目的地实体时，“npdi”被非法插入到“tel”URI中，则呼叫可能被路由到错误的网络或网络节点，从而导致呼叫设置被拒绝。如果“npdi”被非法删除，问题就不那么严重了。可执行额外的NPDB查询以检索路由号码信息，并再次包括“npdi”。
If the "rn" in the "tel" URI that is associated with the caller is illegally changed or inserted, the call charge based on that "rn" would be incorrect.
如果与呼叫者关联的“tel”URI中的“rn”被非法更改或插入，则基于该“rn”的呼叫费用将不正确。
Because of these considerations, these "tel" URI extensions are only applicable within a set of network nodes among which there is mutual trust. If a node receives a call signaling request from an upstream node that it does not trust, it SHOULD remove these parameters. This will generally cause it to redo any DB queries.
由于这些考虑，这些“tel”URI扩展仅适用于一组相互信任的网络节点。如果一个节点从它不信任的上游节点接收到呼叫信令请求，它应该删除这些参数。这通常会导致它重做任何数据库查询。
To verify that an upstream neighbor is trusted, and to prevent man-in-the-middle attacks whereby an attacker inserts or modifies these parameters, call signaling protocols carrying these parameters SHOULD provide hop-by-hop message integrity. In the case of SIP, this is accomplished with the Session Initiation Protocol Secure (SIPS) URI mechanism.
为了验证上游邻居是否可信，并防止攻击者插入或修改这些参数的中间人攻击，携带这些参数的呼叫信令协议应提供逐跳消息完整性。对于SIP，这是通过会话启动协议安全（SIPS）URI机制实现的。
The author would like to thank Penn Pfautz, Jon Peterson, Jonathan Rosenberg, Henning Schulzrinne, Antti Vaha-Sipila, Flemming Andreasen, and Mike Hammer for their discussions and comments.
作者要感谢Penn Pfautz、Jon Peterson、Jonathan Rosenberg、Henning Schulzrinne、Antti Vaha Sipila、Flemming Andreasen和Mike Hammer的讨论和评论。
This document defines five parameters for the "tel" URI. Further information on a registry for those parameters is covered in [TELREG]. This document requires no IANA actions.
本文档为“tel”URI定义了五个参数。有关这些参数的注册表的更多信息，请参见[TELREG]。本文件无需IANA操作。
[E164] ITU-T Recommendation E.164, "The international public telecommunication numbering plan," May 1997.
[E164]ITU-T建议E.164，“国际公共电信编号计划”，1997年5月。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[RFC3966] Schulzrinne, H., "The tel URI for Telephone Numbers", RFC 3966, December 2004.
[RFC3966]Schulzrinne，H.，“电话号码的电话URI”，RFC 3966，2004年12月。
[RFC4234] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 4234, October 2005.
[RFC4234]Crocker，D.和P.Overell，“语法规范的扩充BNF:ABNF”，RFC 4234，2005年10月。
[H323] ITU-T Recommendation H.323, "Packet-Based Multimedia Communications Systems," November 2000.
[H323]ITU-T建议H.323，“基于分组的多媒体通信系统”，2000年11月。
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, June 2002.
[RFC3261]Rosenberg，J.，Schulzrinne，H.，Camarillo，G.，Johnston，A.，Peterson，J.，Sparks，R.，Handley，M.，和E.Schooler，“SIP：会话启动协议”，RFC 3261，2002年6月。
[RFC3482] Foster, M., McGarry, T., and J. Yu, "Number Portability in the Global Switched Telephone Network (GSTN): An Overview", RFC 3482, February 2003.
[RFC3482]Foster，M.，McGarry，T.，和J.Yu，“全球交换电话网络（GSTN）中的号码可移植性：概述”，RFC 3482，2003年2月。
[TELREG] Jennings, C. and V. Gurbani, "The Internet Assigned Numbers Authority (IANA) tel Uniform Resource Identifier (URI) Parameter Registry", Work in Progress, May 2006.
[TELREG]Jennings，C.和V.Gurbani，“互联网分配号码管理局（IANA）电话统一资源标识符（URI）参数注册表”，正在进行的工作，2006年5月。
Author's Address
作者地址
James Yu NeuStar, Inc. 46000 Center Oak Plaza Sterling, VA 20166 U.S.A.
James Yu NeuStar，Inc.美国弗吉尼亚州斯特林中心橡木广场46000号，邮编20166。
Phone: +1-571-434-5572
EMail: james.yu@neustar.biz
Phone: +1-571-434-5572
EMail: james.yu@neustar.biz
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