*** draft-ietf-ecrit-requirements-10.txt Mon Jun 12 10:54:49 2006 --- draft-ietf-ecrit-requirements-11.txt Tue Aug 1 13:53:19 2006 *************** *** 1,17 **** - ECRIT H. Schulzrinne Internet-Draft Columbia U. ! Expires: December 11, 2006 R. Marshall, Ed. TCS ! June 9, 2006 Requirements for Emergency Context Resolution with Internet Technologies ! draft-ietf-ecrit-requirements-10.txt Status of this Memo --- 1,16 ---- ECRIT H. Schulzrinne Internet-Draft Columbia U. ! Expires: December 3, 2006 R. Marshall, Ed. TCS ! June 2006 Requirements for Emergency Context Resolution with Internet Technologies ! draft-ietf-ecrit-requirements-11 Status of this Memo *************** *** 36,42 **** The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. ! This Internet-Draft will expire on December 11, 2006. Copyright Notice --- 35,41 ---- The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. ! This Internet-Draft will expire on December 3, 2006. Copyright Notice *************** *** 44,86 **** Abstract ! This document enumerates requirements for the context resolution of ! emergency calls placed by the public using voice-over-IP (VoIP) and ! general Internet multimedia systems, where Internet protocols are ! used end-to-end. ! Schulzrinne & Marshall Expires December 11, 2006 [Page 1] Internet-Draft ECRIT Requirements June 2006 Table of Contents ! 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 ! 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 ! 3. Basic Actors . . . . . . . . . . . . . . . . . . . . . . . . . 9 ! 4. High-Level Requirements . . . . . . . . . . . . . . . . . . . 12 ! 5. Identifying the Caller's Location . . . . . . . . . . . . . . 15 ! 6. Emergency Service Identifier . . . . . . . . . . . . . . . . . 18 ! 7. Mapping Protocol . . . . . . . . . . . . . . . . . . . . . . . 21 ! 8. Security Considerations . . . . . . . . . . . . . . . . . . . 25 ! 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26 ! 10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 27 ! 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 28 ! 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 29 ! 12.1. Normative References . . . . . . . . . . . . . . . . . . 29 ! 12.2. Informative References . . . . . . . . . . . . . . . . . 29 ! Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 30 ! Intellectual Property and Copyright Statements . . . . . . . . . . 31 ! ! ! ! ! --- 43,88 ---- Abstract ! This document defines terminology and enumerates requirements for the ! context resolution of emergency calls placed by the public using ! voice-over-IP (VoIP) and general Internet multimedia systems, where ! Internet protocols are used end-to-end. ! Schulzrinne & Marshall Expires December 3, 2006 [Page 1] Internet-Draft ECRIT Requirements June 2006 Table of Contents ! 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 ! 2. Requirements Terminology . . . . . . . . . . . . . . . . . . 5 ! 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 6 ! 3.1 Emergency Services . . . . . . . . . . . . . . . . . . . . 6 ! 3.2 Service Providers . . . . . . . . . . . . . . . . . . . . 6 ! 3.3 Actors . . . . . . . . . . . . . . . . . . . . . . . . . . 7 ! 3.4 Call Routing Entities . . . . . . . . . . . . . . . . . . 7 ! 3.5 Location . . . . . . . . . . . . . . . . . . . . . . . . . 7 ! 3.6 Identifiers, Numbers and Dial Strings . . . . . . . . . . 8 ! 3.7 Mapping . . . . . . . . . . . . . . . . . . . . . . . . . 9 ! 4. Basic Actors . . . . . . . . . . . . . . . . . . . . . . . . 11 ! 5. High-Level Requirements . . . . . . . . . . . . . . . . . . 14 ! 6. Identifying the Caller's Location . . . . . . . . . . . . . 16 ! 7. Emergency Service Identifier . . . . . . . . . . . . . . . . 19 ! 8. Mapping Protocol . . . . . . . . . . . . . . . . . . . . . . 21 ! 9. Security Considerations . . . . . . . . . . . . . . . . . . 26 ! 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . 27 ! 11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 28 ! 12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 29 ! 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 30 ! 13.1 Normative References . . . . . . . . . . . . . . . . . . 30 ! 13.2 Informative References . . . . . . . . . . . . . . . . . 30 ! Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 31 ! Intellectual Property and Copyright Statements . . . . . . . 32 *************** *** 106,180 **** ! ! ! ! Schulzrinne & Marshall Expires December 11, 2006 [Page 2] Internet-Draft ECRIT Requirements June 2006 1. Introduction ! Users of both voice-centric (telephone-like) and non voice type ! services (e.g., text communication for hearing disabled users (RFC ! 3351 [2]) have an expectation to be able to initiate a request for ! help in case of an emergency. Unfortunately, the existing mechanisms to support emergency calls that have evolved within the public circuit-switched telephone network (PSTN) are not appropriate to handle evolving IP-based voice, text and real-time multimedia communications. This document outlines the key requirements that IP-based end systems and network elements, ! such as SIP proxies, need to satisfy in order to provide emergency ! call services, which at a minimum, offer the same functionality as ! existing PSTN services, with the additional overall goal of making ! emergency calling more robust, less costly to implement, and ! multimedia-capable. This document only focuses on end-to-end IP-based calls, i.e., where ! the emergency call originates from an IP end system and terminates ! into an IP-capable PSAP, conveyed entirely over an IP network. ! Outlined within this document are various functional issues which ! relate to placing an IP-based emergency call, including a description ! of baseline requirements (Section 4), identification of the emergency ! caller's location (Section 5), use of an service identifier to ! declare a call to be an emergency call (Section 6), and finally, the ! mapping function required to route the call to the appropriate PSAP ! (Section 7). ! ! The primary intent of the mapping protocol is to produce a PSAP URI ! (from a preferred set of URIs, e.g., SIP:URI, SIPS:URI) based on both ! location information [6] and a service identifier in order to ! facilitate the IP end-to-end completion of an emergency call. Aside ! from obtaining a PSAP URI, the mapping protocol is useful for obtaining other information as well. There may be a case, for ! example, where an appropriate dial string is not known, only location. The mapping protocol can then return a geographically ! appropriate dial string based on the input. ! Since some PSAPs may not immediately support IP, or because some end ! devices (UAs) may not initially support emergency service URNs, it ! may be necessary to also support emergency service identifiers that ! utilize less preferred URI schemes, such as a tel URI in order to ! complete an emergency call via the PSTN. - Identification of the caller, while not incompatible with the - requirements for messaging outlined within this document, is ! Schulzrinne & Marshall Expires December 11, 2006 [Page 3] Internet-Draft ECRIT Requirements June 2006 considered to be outside the scope of this document. Location is required for two separate purposes, first, to support the routing of the emergency call to the appropriate PSAP and second, to ! display the caller's location to the call taker for help in dispatching emergency assistance to the appropriate location. --- 108,181 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 2] Internet-Draft ECRIT Requirements June 2006 1. Introduction ! Users of both voice-centric (telephone-like) and non-voice services ! such as text communication for hearing disabled users (RFC 3351 [3]) ! expect to be able to initiate a request for help in case of an ! emergency. Unfortunately, the existing mechanisms to support emergency calls that have evolved within the public circuit-switched telephone network (PSTN) are not appropriate to handle evolving IP-based voice, text and real-time multimedia communications. This document outlines the key requirements that IP-based end systems and network elements, ! such as Session Initiation Protocol (SIP) [2] proxies, need to ! satisfy in order to provide emergency call services, which at a ! minimum, offer the same functionality as existing PSTN services, with ! the additional overall goal of making emergency calling more robust, ! less costly to implement, and multimedia-capable. This document only focuses on end-to-end IP-based calls, i.e., where ! the emergency call originates from an IP end system and terminates in ! an IP-capable PSAP, conveyed entirely over an IP network. ! We first define terminology in Section 3. The document then outlines ! various functional issues which relate to placing an IP-based ! emergency call, including a description of baseline requirements ! (Section 5), identification of the emergency caller's location ! (Section 6), use of a service identifier to declare a call to be an ! emergency call (Section 7), and finally, the mapping function ! required to route the call to the appropriate PSAP (Section 8). ! ! The primary purpose of the mapping protocol is to produce a PSAP URI ! drawn from a preferred set of URI schemes such as SIP or SIPS URIs, ! based on both location information [9] and a service identifier in ! order to facilitate the IP end-to-end completion of an emergency ! call. ! ! Aside from obtaining a PSAP URI, the mapping protocol is useful for obtaining other information as well. There may be a case, for ! example, where an appropriate emergency number is not known, only location. The mapping protocol can then return a geographically ! appropriate emergency number based on the input. ! Since some PSAPs may not immediately support IP, or because some user ! equipement (UE) may not initially support emergency service ! identifiers, it may be necessary to also support emergency service ! identifiers that utilize less preferred URI schemes, such as a tel ! URI in order to complete an emergency call via the PSTN. ! Schulzrinne & Marshall Expires December 3, 2006 [Page 3] Internet-Draft ECRIT Requirements June 2006 + Identification of the caller, while not incompatible with the + requirements for messaging outlined within this document, is considered to be outside the scope of this document. Location is required for two separate purposes, first, to support the routing of the emergency call to the appropriate PSAP and second, to ! display the caller's location to the call taker to help in dispatching emergency assistance to the appropriate location. *************** *** 219,232 **** ! ! ! Schulzrinne & Marshall Expires December 11, 2006 [Page 4] Internet-Draft ECRIT Requirements June 2006 ! 2. Terminology In this document, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", --- 220,231 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 4] Internet-Draft ECRIT Requirements June 2006 ! 2. Requirements Terminology In this document, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", *************** *** 235,264 **** to the design of the mapping protocol, not its implementation or application. ! Basic emergency service: Basic Emergency Service allows a user to reach a PSAP serving its current location, but the PSAP may not be able to determine the identity or geographic location of the ! caller, except by having the call taker ask the caller. ! Enhanced emergency service: Enhanced emergency services add the ! ability to identify the caller's identity or location to basic ! emergency services. (Sometimes, only the caller location may be ! known, e.g., when a call is placed from a public access point that ! is not owned by an individual.) Internet Attachment Provider (IAP): An organization that provides ! physical and layer 2 network connectivity to its customers or ! users, e.g., through digital subscriber lines, cable TV plants, ! Ethernet, leased lines or radio frequencies. Examples of such ! organizations include telecommunication carriers, municipal ! utilities, larger enterprises with their own network infrastructure, and government organizations such as the military. Internet Service Provider (ISP): An organization that provides IP network-layer services to its customers or users. This entity may ! or may not provide the physical-layer and layer-2 connectivity, ! such as fiber or Ethernet, i.e., it may or may not be the role of ! an IAP. Application Service Provider (ASP): The organization or entity that provides application-layer services, which may include voice (see --- 234,314 ---- to the design of the mapping protocol, not its implementation or application. ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! Schulzrinne & Marshall Expires December 3, 2006 [Page 5] ! ! Internet-Draft ECRIT Requirements June 2006 ! ! ! 3. Terminology ! ! 3.1 Emergency Services ! ! Basic emergency service: Basic emergency service allows a caller to reach a PSAP serving its current location, but the PSAP may not be able to determine the identity or geographic location of the ! caller, except by the call taker asking the caller. ! ! Enhanced emergency service: In enhanced emergency service, the PSAP ! call taker can determine the caller's current location. ! ! 3.2 Service Providers Internet Attachment Provider (IAP): An organization that provides ! physical and data link (layer 2) network connectivity to its ! customers or users, e.g., through digital subscriber lines, cable ! TV plants, Ethernet, leased lines or radio frequencies. Examples ! of such organizations include telecommunication carriers, ! municipal utilities, larger enterprises with their own network infrastructure, and government organizations such as the military. Internet Service Provider (ISP): An organization that provides IP network-layer services to its customers or users. This entity may ! or may not provide the physical-layer and data link (layer-2) ! connectivity, such as fiber or Ethernet, i.e., it may or may not ! play the role of an IAP. Application Service Provider (ASP): The organization or entity that provides application-layer services, which may include voice (see *************** *** 274,387 **** as call routing, a SIP URI, or PSTN termination. In this document, unless noted otherwise, any reference to "Voice Service Provider" or "VSP" may be used interchangeably with "Application/ ! Schulzrinne & Marshall Expires December 11, 2006 [Page 5] Internet-Draft ECRIT Requirements June 2006 ! Voice Service Provider" or "ASP/VSP". Emergency Service Routing Proxy (ESRP): An ESRP is an emergency call routing support entity that invokes the location-to-PSAP URI mapping, to return either the URI for the appropriate PSAP, or the URI for another ESRP. (In a SIP system, the ESRP would typically ! be a SIP proxy, but may also be a Back-to-back user agent (B2BUA)). - Emergency Call Routing Support (ECRS): An intermediary function which - assists in the routing of an emergency call via IP. An ESRP is an - example of an emergency call routing support entity. - Public Safety Answering Point (PSAP): Physical location where emergency calls are received under the responsibility of a public authority. (This terminology is used by both ETSI, in ETSI SR 002 180, and NENA.) In the United Kingdom, PSAPs are called Operator Assistance Centres, in New Zealand, Communications Centres. Within this document, it is assumed, unless stated otherwise, that ! PSAP is that which supports the receipt of emergency calls over ! IP. It is also assumed that the PSAP is reachable by IP-based ! protocols, such as SIP for call signaling and RTP for media. Location: A geographic identification assigned to a region or feature based on a specific coordinate system, or by other precise information such as a street number and name. It can be either a civic or geographic location. ! Civic location: A described location based on some defined grid, such ! as a jurisdictional, postal, metropolitan, or rural reference ! system, (e.g., street address). Geographic location: A reference to a point which is able to be located as described by a set of defined coordinates within a ! geographic coordinate system, (e.g., lat/lon within the WGS-84 ! datum). For example, (2-D) geographic location is defined as an ! x,y coordinate value pair according to the distance North or South ! of the equator and East or West of the prime meridian. Location validation: A caller location is considered valid if the civic or geographic location is recognizable within an acceptable ! location reference system (e.g., USPS, WGS-84, etc.), and can be ! mapped to one or more PSAPs. While it is desirable to determine ! that a location exists, validation may not ensure that such a ! location exists, but rather may only ensure that the location ! falls within some range of known values. Location validation ! ensures that a location is able to be referenced for mapping, but ! makes no assumption about the association between the caller and ! Schulzrinne & Marshall Expires December 11, 2006 [Page 6] Internet-Draft ECRIT Requirements June 2006 ! the caller's location. - (Location-dependent) emergency dial string: A location-dependent - emergency dial string should be thought of as the digit sequence - that is dialed in order to reach emergency services. There are - two dial strings described within this document, namely a "home - emergency dial string", and a "visited emergency dial string". - Home emergency dial string: A home emergency dial string represents a - (e.g., dialed) sequence of digits, that is used to initiate an - emergency call within a geographically correct location of a - caller if it is considered to be a user's "home" location or - vicinity. - Visited emergency dial string: A visited emergency dial string - represents a sequence of digits that is used to initiate an - emergency call within a geographically correct location of the - caller if outside the caller's "home" location or vicinity. - Service identifier: A general identifier that has applicability to - both emergency and non-emergency contexts (specifically referred - to within this document as "emergency service identifier"). - Service URN: An implementation of a service identifier, which has - applicability to both emergency and non-emergency contexts (e.g., - urn:service:sos, urn:service:info, etc.) Within this document, - service URN is specifically referred to as 'emergency service URN' - [8]. - Emergency service identifier (ESI): A specific service identifier - that is used to request a PSAP URI in order to initiate an - emergency call, and may be used to mark any call as an emergency - call. An ESI is a more general term than 'emergency service URN', - since it could also refer to an alternate identifier, such as a - tel URI (Section 6). - Emergency service URN: An emergency-context specific service URN that - is an implementation of an emergency service identifier (e.g., - urn:service:sos). Is often referred to as, and is equivalent with - 'sos service URN'. - PSAP URI: The URI (e.g., SIP:URI, SIPS:URI, XMPP:URI, etc.) at which - the PSAP may be contacted with an emergency call. This contact - could be done directly, or via an intermediary, (e.g., ESRP). --- 324,522 ---- as call routing, a SIP URI, or PSTN termination. In this document, unless noted otherwise, any reference to "Voice Service Provider" or "VSP" may be used interchangeably with "Application/ + Voice Service Provider" or "ASP/VSP". + + ! ! ! Schulzrinne & Marshall Expires December 3, 2006 [Page 6] Internet-Draft ECRIT Requirements June 2006 ! 3.3 Actors ! ! (Emergency) caller: The term "caller" or "emergency caller" refer to ! the person placing an emergency call or sending an emergency ! instant message (IM). ! ! User Equipment (UE): User equipment is the device or software ! operated by the caller to place an emergency call. A SIP user ! agent (UA) is an example of a UE. ! ! Call taker: A call taker is an agent at the PSAP that accepts calls ! and may dispatch emergency help. Sometimes the functions of call ! taking and dispatching are handled by different groups of people, ! but these divisions of labor are not generally visible to the ! caller and thus do not concern us here. ! ! ! 3.4 Call Routing Entities Emergency Service Routing Proxy (ESRP): An ESRP is an emergency call routing support entity that invokes the location-to-PSAP URI mapping, to return either the URI for the appropriate PSAP, or the URI for another ESRP. (In a SIP system, the ESRP would typically ! be a SIP proxy, but may also be a back-to-back user agent (B2BUA)). Public Safety Answering Point (PSAP): Physical location where emergency calls are received under the responsibility of a public authority. (This terminology is used by both ETSI, in ETSI SR 002 180, and NENA.) In the United Kingdom, PSAPs are called Operator Assistance Centres, in New Zealand, Communications Centres. Within this document, it is assumed, unless stated otherwise, that ! PSAPs support the receipt of emergency calls over IP, using ! appropriate application layer protocols such as SIP for call ! signaling and RTP for media. ! ! ! 3.5 Location Location: A geographic identification assigned to a region or feature based on a specific coordinate system, or by other precise information such as a street number and name. It can be either a civic or geographic location. ! Civic location: A described location based on some reference system, ! such a jurisdictions or postal delivery. A street address is a ! common example. ! ! ! ! ! Schulzrinne & Marshall Expires December 3, 2006 [Page 7] ! ! Internet-Draft ECRIT Requirements June 2006 ! Geographic location: A reference to a point which is able to be located as described by a set of defined coordinates within a ! geographic coordinate system, such as latitude and longitude ! within the WGS-84 datum. For example, 2-D geographic location is ! defined as an (x,y) coordinate value pair according to the ! distance north or south of the equator and east or west of the ! prime meridian. Location validation: A caller location is considered valid if the civic or geographic location is recognizable within an acceptable ! location reference system (e.g., United States Postal Address or ! the WGS-84 datum) and can be mapped to one or more PSAPs. While ! it is desirable to determine that a location exists, validation ! may not ensure that such a location exists, but rather may only ! ensure that the location falls within some range of known values. ! Location validation ensures that a location is able to be ! referenced for mapping, but makes no assumption about the ! association between the caller and the caller's location. ! ! ! 3.6 Identifiers, Numbers and Dial Strings ! ! (Emergency) service number: The (emergency) service number is a ! string of digits used to reach the (emergency) service. The ! emergency service number is often just called the emergency ! number. It is the number typically dialed on devices directly ! connected to the PSTN and the number reserved for emergency calls ! by national or regional numbering authorities. The service number ! may depend on the location of the caller. For example, the ! general emergency service number in the United States is 112 and ! the poison control service number is 18002221222. In most cases, ! the service number and dial string are the same; they may differ ! in some private phone networks. A service number may be carried ! in tel URLs [7], along with a context identifier. In the North ! American numbering plan, some service numbers are also three-digit ! N11 or service codes, but not all emergency numbers have three ! digits. ! ! (Emergency) service dial string: The service dial string identifies ! the string of digits that a caller must dial to reach a particular ! (emergency) service. In devices directly connected to the PSTN, ! the service dial string is the same as the service number and may ! thus depend on the location of the caller. However, in private ! phone networks, such as in PBXs, the service dial string may ! contain a prefix to reach an outside line. For example, in a ! hotel, the dial string for emergency services in the United States ! might be 9911. Service dial strings are outside the scope of this ! document. ! ! ! ! Schulzrinne & Marshall Expires December 3, 2006 [Page 8] ! ! Internet-Draft ECRIT Requirements June 2006 ! ! ! (Emergency) service identifier: The (emergency) service identifier ! describes the emergency service independent of the user interface ! mechanism, the signaling protocol that is used to reach the ! service or the caller's geographic location. It is a protocol ! constant and used within the mapping and signaling protocols. An ! example is the service URN [12]. ! ! (Emergency) service URL: The service URL is a protocol-specific ! (e.g., SIP) or protocol-agnostic (e.g., im: [6]) contains the ! address of the PSAP or other emergency service. It depends on the ! specific signaling or data transport protocol used to reach the ! emergency service. ! ! Service URN: A service URN is an implementation of a service ! identifier, which can be applied to both emergency and non- ! emergency contexts, e.g., urn:service:sos or ! urn:service:counseling. Within this document, service URNs are ! referred to as 'emergency service URNs' [12]. ! ! Home emergency number: A home emergency number is the emergency ! number valid at the caller's customary home location, e.g., his ! permanent residence. The home location may or may not coincide ! with the service area of the caller's VSP. ! ! Visited emergency number: A visited emergency number is the emergency ! number valid at the caller's current physical location. We ! distinguish the visited emergency number if the caller is ! traveling outside his home region. ! ! ! 3.7 Mapping ! ! Mapping: Mapping is the process of resolving a location to one or ! more PSAP URIs which directly identify a PSAP, or point to an ! intermediary which knows about a PSAP and that is designated as ! responsible for serving that location. ! ! Mapping client: A mapping client interacts with the mapping server to ! learn one or more PSAP URIs for a given location. ! ! Mapping protocol: A protocol used to convey the mapping request and ! response. ! ! Mapping server: The mapping server holds information about the ! location-to-PSAP URI mapping. ! ! ! ! Schulzrinne & Marshall Expires December 3, 2006 [Page 9] Internet-Draft ECRIT Requirements June 2006 ! Mapping service: A network service which uses a distributed mapping ! protocol to perform a mapping between a location and a PSAP, or ! intermediary which knows about the PSAP, and is used to assist in ! routing an emergency call. *************** *** 389,427 **** - Schulzrinne & Marshall Expires December 11, 2006 [Page 7] - - Internet-Draft ECRIT Requirements June 2006 - Mapping: The process of resolving a location to one or more PSAP URIs - which directly identify a PSAP, or point to an intermediary which - knows about a PSAP and that is designated as responsible to serve - that location. - Mapping client: A mapping client interacts with the mapping server to - learn one or more PSAP URIs for a given location. - Mapping protocol: A protocol used to convey the mapping request and - response. - Mapping server: The mapping server holds information about the - location-to-PSAP URI mapping. - Mapping service: A network service which uses a distributed mapping - protocol to perform a mapping between a location and a PSAP, or - intermediary which knows about the PSAP, and is used to assist in - routing an emergency call. - (Emergency) caller: The term "caller" or "emergency caller" refer to - the person placing an emergency call or sending an emergency - instant message (IM). - Call taker: A call taker is an agent at the PSAP that accepts calls - and may dispatch emergency help. Sometimes the functions of call - taking and dispatching are handled by different groups of people, - but these divisions of labor are not generally visible to the - outside and thus do not concern us here. --- 524,537 ---- *************** *** 445,456 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 8] Internet-Draft ECRIT Requirements June 2006 ! 3. Basic Actors In order to support emergency services covering a large physical area, various infrastructure elements are necessary, including: --- 555,567 ---- ! ! Schulzrinne & Marshall Expires December 3, 2006 [Page 10] Internet-Draft ECRIT Requirements June 2006 ! 4. Basic Actors In order to support emergency services covering a large physical area, various infrastructure elements are necessary, including: *************** *** 492,498 **** |Provider | +---------------------+ ! Figure 1: Framework for emergency call routing Figure 1 shows the interaction between the entities involved in the call. There are a number of different deployment choices, as can be --- 603,609 ---- |Provider | +---------------------+ ! Figure 1: Framework for emergency call routing Figure 1 shows the interaction between the entities involved in the call. There are a number of different deployment choices, as can be *************** *** 501,522 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 9] Internet-Draft ECRIT Requirements June 2006 ! o How is location information provided to the end host? It might either be known to the end host itself via manual configuration, ! provided via GPS, made available via DHCP (RFC 3825 [4]) or some ! other mechanisms. Alternatively, location information is used as ! part of call routing and inserted by intermediaries. ! o Is the Internet Attachment Provider also the Application/Voice Service Provider? In the Internet today these roles are typically provided by different entities. As a consequence, the Application/ ! Voice Service Provider is typically not able to learn the physical ! location of the emergency caller. The overlapping squares in the figure indicate that some functions can be collapsed into a single entity. As an example, the --- 612,633 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 11] Internet-Draft ECRIT Requirements June 2006 ! How is location information provided to the end host? It might either be known to the end host itself via manual configuration, ! provided via GPS, made available via DHCP ([5], [14]) or some other ! mechanism. Alternatively, location information is inserted by ! intermediaries. ! Is the Internet Attachment Provider also the Application/Voice Service Provider? In the Internet today these roles are typically provided by different entities. As a consequence, the Application/ ! Voice Service Provider is typically not able to directly determine ! the physical location of the emergency caller. The overlapping squares in the figure indicate that some functions can be collapsed into a single entity. As an example, the *************** *** 527,573 **** residential users. Various potential interactions between the entities depicted in ! Figure 1, are described in the following: ! (1) Location information might be available to the end host itself. ! (2) Location information might, however, also be obtained from the ! Internet Attachment Provider (e.g., using DHCP or application layer ! signaling protocols). ! (3) The emergency caller might need to consult a mapping service to ! determine the PSAP (or other relevant information) that is ! appropriate for the physical location of the emergency caller, ! possibly considering other attributes such as appropriate language ! support by the emergency call taker. ! (4) The emergency caller might get assistance for emergency call ! routing by infrastructure elements that are emergency call routing ! support entities, (e.g., an Emergency Service Routing Proxy (ESRP), ! in SIP). ! (5) Location information is used by emergency call routing support ! entities for subsequent mapping requests. ! (6) Emergency call routing support entities might need to consult a ! mapping service to determine where to route the emergency call. ! (7) For infrastructure-based emergency call routing (in contrast to ! UE-based emergency call routing), the emergency call routing support ! Schulzrinne & Marshall Expires December 11, 2006 [Page 10] Internet-Draft ECRIT Requirements June 2006 ! entity needs to forward the call to the PSAP. ! ! (8) The emergency caller (UE) may interact directly with the PSAP ! (e.g., UE invokes mapping, and initiates a connection), without ! relying on any intermediary emergency call routing support entities. --- 638,684 ---- residential users. Various potential interactions between the entities depicted in ! Figure 1 are described below: ! 1. Location information might be available to the end host itself. ! 2. Location information might, however, also be obtained from the ! Internet Attachment Provider (e.g., using DHCP or application ! layer signaling protocols). ! 3. The emergency caller might need to consult a mapping service to ! determine the PSAP (or other relevant information) that is ! appropriate for the physical location of the emergency caller, ! possibly considering other attributes such as appropriate ! language support by the emergency call taker. ! 4. The emergency caller might get assistance for emergency call ! routing by infrastructure elements that are emergency call ! routing support entities, such as an Emergency Service Routing ! Proxy (ESRP) in SIP. ! 5. Location information is used by emergency call routing support ! entities for subsequent mapping requests. ! 6. Emergency call routing support entities might need to consult a ! mapping service to determine where to route the emergency call. ! 7. For infrastructure-based emergency call routing (in contrast to ! UE-based emergency call routing), the emergency call routing ! Schulzrinne & Marshall Expires December 3, 2006 [Page 12] Internet-Draft ECRIT Requirements June 2006 ! support entity needs to forward the call to the PSAP. + 8. The emergency caller may interact directly with the PSAP, where + the UE invokes mapping, and initiates a connection, without + relying on any intermediary emergency call routing support + entities. *************** *** 613,624 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 11] Internet-Draft ECRIT Requirements June 2006 ! 4. High-Level Requirements Below, we summarize high-level architectural requirements that guide some of the component requirements detailed later in the document. --- 724,735 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 13] Internet-Draft ECRIT Requirements June 2006 ! 5. High-Level Requirements Below, we summarize high-level architectural requirements that guide some of the component requirements detailed later in the document. *************** *** 627,633 **** an IP-based emergency call SHOULD NOT assume the existence of an Application/Voice Service Provider (ASP/VSP). ! Motivation: The caller may not have an application/voice service provider. For example, a residence may have its own DNS domain and run its own SIP proxy server for that domain. On a larger scale, a university might provide voice services to its students --- 738,744 ---- an IP-based emergency call SHOULD NOT assume the existence of an Application/Voice Service Provider (ASP/VSP). ! Motivation: The caller may not have an application/voice service provider. For example, a residence may have its own DNS domain and run its own SIP proxy server for that domain. On a larger scale, a university might provide voice services to its students *************** *** 648,654 **** municipalities which handle emergency calls. Re3. Distributed administration: Deployment of IP-based emergency ! services MUST NOT depend on a sole central administration authority. Motivation: The design of the mapping protocol must make it --- 759,765 ---- municipalities which handle emergency calls. Re3. Distributed administration: Deployment of IP-based emergency ! services MUST NOT depend on a single central administrative authority. Motivation: The design of the mapping protocol must make it *************** *** 669,710 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 12] Internet-Draft ECRIT Requirements June 2006 ! 4103 [5]), instant messaging and video. ! ! Re5. Alternate mapping sources: The mapping protocol MUST implement ! a mechanism that allows for the retrieval of mapping information ! from different sources. ! ! Motivation: This provides the possibility of having available ! alternative sources of mapping information when the normal source ! is unavailable or unreachable. ! ! Re6. Currency indication: The mapping protocol SHOULD support an ! indicator describing how current the information provided by the ! mapping source is. ! ! Motivation: This is especially useful when an alternate mapping is ! requested, and alternative sources of mapping data may not have ! been created or updated with the same set of information or within ! the same timeframe. Differences in currency between mapping data ! contained within mapping sources should be minimized. ! Re7. Mapping result usability: The mapping protocol MUST return one or more URIs that are usable within a standard signaling protocol (i.e., without special emergency extensions). ! Motivation: For example, a SIP specific URI which is returned by ! the mapping protocol needs to be usable by any SIP capable phone within a SIP initiated emergency call. This is in contrast to a "special purpose" URI, which may not be recognizable by a legacy SIP device. ! Re8. PSAP URI accessibility: The mapping protocol MUST support interaction between the client and server where no enrollment to a mapping service exists or is required. --- 780,803 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 14] Internet-Draft ECRIT Requirements June 2006 ! 4103 [8]), instant messaging and video. ! Re5. Mapping result usability: The mapping protocol MUST return one or more URIs that are usable within a standard signaling protocol (i.e., without special emergency extensions). ! Motivation: For example, a SIP URI which is returned by the ! mapping protocol needs to be usable by any SIP capable phone within a SIP initiated emergency call. This is in contrast to a "special purpose" URI, which may not be recognizable by a legacy SIP device. ! Re6. PSAP URI accessibility: The mapping protocol MUST support interaction between the client and server where no enrollment to a mapping service exists or is required. *************** *** 712,756 **** provider, but access to the server offering the mapping must not require use of a specific ISP or ASP/VSP. ! Re9. Common data structures and formats: The mapping protocol SHOULD ! support common data structures and formats from the mapping ! server. ! Motivation: Location databases should not need to be transformed or modified in any unusual or unreasonable way in order for the mapping protocol to use the data. For example, a database which contains civic addresses used by location servers may be used for multiple purposes and applications beyond emergency service location-to-PSAP URI mapping. ! ! ! Schulzrinne & Marshall Expires December 11, 2006 [Page 13] ! ! Internet-Draft ECRIT Requirements June 2006 ! ! ! Re10. Anonymous mapping: The mapping protocol MUST NOT require the true identity of the target for which the location information is attributed. Motivation: Ideally, no identity information is provided via the mapping protocol. Where identity information is provided, it may ! be in the form of an unlinked pseudonym (RFC 3693 [3]). ! ! ! ! ! ! ! ! ! ! ! ! ! ! --- 805,827 ---- provider, but access to the server offering the mapping must not require use of a specific ISP or ASP/VSP. ! Re7. Common data structures and formats: The mapping protocol SHOULD ! support common formats for location data. ! Motivation: Location databases should not need to be transformed or modified in any unusual or unreasonable way in order for the mapping protocol to use the data. For example, a database which contains civic addresses used by location servers may be used for multiple purposes and applications beyond emergency service location-to-PSAP URI mapping. ! Re8. Anonymous mapping: The mapping protocol MUST NOT require the true identity of the target for which the location information is attributed. Motivation: Ideally, no identity information is provided via the mapping protocol. Where identity information is provided, it may ! be in the form of an unlinked pseudonym (RFC 3693 [4]). *************** *** 765,870 **** ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! Schulzrinne & Marshall Expires December 11, 2006 [Page 14] Internet-Draft ECRIT Requirements June 2006 ! 5. Identifying the Caller's Location ! Location can either be provided directly, or by reference, and ! represents either a civic location, or a geographic location. An important question is how and when to attach location information to ! the VoIP emergency signaling. In general, we can distinguish three ! modes of operation of how a location is associated with an emergency ! call: UA-inserted: The caller's user agent inserts the location information into the call signaling message. The location information is ! derived from sources such as GPS, DHCP (see [4] for geographic ! location information and [10]) for civic location information or ! utilizing the Link Layer Discovery Protocol (LLDP) [see ! IEEE8021AB]. UA-referenced: The caller's user agent provides a pointer (i.e., a location reference), via a permanent or temporary identifier, to ! the location which is stored by a location server somewhere else ! and then retrieved by the PSAP, ESRP, or other authorized service ! entity. Proxy-inserted: A proxy along the call path inserts the location or location reference. Lo1. Reference datum: The mapping protocol MUST support the WGS-84 coordinate reference system and MAY support other coordinate reference systems. ! Motivation: Though many different datums exist around the world, ! the WGS-84 datum is recommended here since it is designed to ! describe the whole earth, rather than a single continent, etc. ! ! Lo2. Location object/info preservation: The mapping protocol MUST ! retain any location information which is provided to it, even ! after mapping is performed. ! ! Motivation: The ESRP and the PSAP use the same location ! information object, but for a different purpose. Therefore, it is ! imperative that the mapping protocol does not remove the location ! information from the messaging, so that it can be provided to the ! PSAP. ! Lo3. Location delivery by-value: The mapping protocol MUST support the delivery of location information using a by-value method, though it MAY also support de-referencing a URL that references a location object. - Schulzrinne & Marshall Expires December 11, 2006 [Page 15] - - Internet-Draft ECRIT Requirements June 2006 ! Motivation: The mapping protocol is not required to support the ! ability to de-reference specific location references. - Lo4. Alternate community names: The mapping protocol MUST support - both the jurisdictional community name and the postal community - name fields within the PIDF-LO data. ! Motivation: A mapping query must be accepted with either or both ! community name fields, and provide appropriate responses. If a ! mapping query is made with only one field present, and if the ! database contains both jurisdictional and postal, the mapping ! protocol response should return both. ! Lo5. Validation of civic location: The mapping protocol MUST support ! location validation for civic location (street addresses). ! Motivation: Location validation provides an opportunity to help ! assure ahead of time, whether or not a successful mapping to the appropriate PSAP will likely occur when it is required. Validation may also help to avoid delays during emergency call ! setup due to invalid locations. ! Lo6. Validation resolution: The mapping protocol MUST support the ability to provide ancillary information about the resolution of location data used to retrieve a PSAP URI. --- 836,918 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 15] Internet-Draft ECRIT Requirements June 2006 ! 6. Identifying the Caller's Location ! Location can either be provided directly (by value), or by reference, ! and represents either a civic location, or a geographic location. An important question is how and when to attach location information to ! the VoIP emergency signaling messages. In general, we can ! distinguish three modes of operation of how a location is associated ! with an emergency call: UA-inserted: The caller's user agent inserts the location information into the call signaling message. The location information is ! derived from sources such as GPS, DHCP (see [5] for geographic ! location information and [14] for civic location information) or ! utilizing the Link Layer Discovery Protocol (LLDP) [16]. UA-referenced: The caller's user agent provides a pointer (i.e., a location reference), via a permanent or temporary identifier, to ! the location information, which is stored by a location server ! somewhere else and then retrieved by the PSAP, ESRP, or other ! authorized entity. Proxy-inserted: A proxy along the call path inserts the location or location reference. + The following requirements apply: + Lo1. Reference datum: The mapping protocol MUST support the WGS-84 coordinate reference system and MAY support other coordinate reference systems. ! Motivation: Though many different datums exist around the world, ! this document recommends the WGS-84 datum since it is designed to ! describe the whole earth, rather than a single continent or other ! region, and is commonly used to represent Global Positioning ! System coordinates. ! Lo2. Location delivery by-value: The mapping protocol MUST support the delivery of location information using a by-value method, though it MAY also support de-referencing a URL that references a location object. + Motivation: The mapping protocol is not required to support the + ability to de-reference specific location references. + Lo3. Alternate community names: The mapping protocol MUST support + both the jurisdictional community name and the postal community + name fields within the PIDF-LO [9] data. ! Schulzrinne & Marshall Expires December 3, 2006 [Page 16] ! ! Internet-Draft ECRIT Requirements June 2006 ! Motivation: The mapping protocol must accept queries with either ! community name field and provide appropriate responses. If a ! mapping query contains only one community name and the database ! contains both jurisdictional and postal community names, the ! mapping protocol response SHOULD return both community names. ! Lo4. Validation of civic location: The mapping protocol MUST support ! location validation for civic locations (street addresses). ! Motivation: Location validation provides an opportunity to help ! ascertain ahead of time whether or not a successful mapping to the appropriate PSAP will likely occur when it is required. Validation may also help to avoid delays during emergency call ! setup due to invalid location data. ! Lo5. Validation resolution: The mapping protocol MUST support the ability to provide ancillary information about the resolution of location data used to retrieve a PSAP URI. *************** *** 877,899 **** mean, for example, explicit identification of the data elements that were used successfully in the mapping. ! Lo7. Indication of non-existent location: The mapping protocol MUST ! support a mechanism to indicate and resolve any associated issues ! attributed to a location or a part of a location that is known to ! not exist, despite the receipt of a successful mapping response. ! ! Motivation: The emergency authority for a given jurisdiction may ! provide a means to resolve addressing problems, e.g., a URI for a ! web service that can be used to report problems with an address. ! Lo8. Limits to validation: Successful validation of a civic location MUST NOT be required to place an emergency call. ! Schulzrinne & Marshall Expires December 11, 2006 [Page 16] Internet-Draft ECRIT Requirements June 2006 --- 925,954 ---- mean, for example, explicit identification of the data elements that were used successfully in the mapping. ! Lo6. Contact for location problems: The mapping protocol MUST ! support a mechanism to contact an appropriate authority to resolve ! mapping-related issues for the queried location. For example, the ! querier may want to report problems with the response values or ! indicate that the mapping database is mistaken on declaring a ! civic location as non-existent. ! ! Motivation: Initially, authorities may provide URLs where a human ! user can report problems with an address or location. In ! addition, web services may be defined to automate such reporting. ! For example, the querier may wish to report that the mapping ! database may be missing a newly-built or renamed street or house ! number. ! Lo7. Limits to validation: Successful validation of a civic location MUST NOT be required to place an emergency call. ! ! ! Schulzrinne & Marshall Expires December 3, 2006 [Page 17] Internet-Draft ECRIT Requirements June 2006 *************** *** 903,927 **** rejected by any entity along the call setup signaling path to the PSAP. ! Lo9. 3D sensitive mapping: The mapping protocol MUST implement support for both 2D and 3D location information, and may accept either a 2D or 3D mapping request as input. ! Motivation: It is expected that end devices or location servers ! will provide either 2D or 3D data. When a 3D request is presented ! within an area only defined by 2D data within the mapping server, ! the mapping result would be the same as if the height/altitude ! dimension was omitted in the request. ! ! Lo10. Database type indicator: The mapping protocol MAY support a ! mechanism which provides an indication describing a specific ! "type" of location database used. Motivation: It is useful to know the source of the data stored in ! the database used for location validation. This is applicable for ! either civic or geographic location matching (e.g., USPS, MSAG, ! GDT, etc.). ! --- 958,982 ---- rejected by any entity along the call setup signaling path to the PSAP. ! Lo8. 3D sensitive mapping: The mapping protocol MUST implement support for both 2D and 3D location information, and may accept either a 2D or 3D mapping request as input. ! Motivation: It is expected that queriers may provide either 2D or ! 3D data. When a 3D request is presented within an area only ! defined by 2D data within the mapping server, the mapping result ! would be the same as if the height or altitude coordinate had been ! omitted from the mapping request. ! ! Lo9. Database type indicator: The mapping protocol MAY support a ! mechanism which provides an indication describing a specific type ! of location database used. Motivation: It is useful to know the source of the data stored in ! the database used for location validation, either for civic or ! geographic location matching. In the United States, sources of ! data could include the United States Postal Service, the Master ! Street Address Guide (MSAG) or commercial map data providers. *************** *** 949,1134 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 17] Internet-Draft ECRIT Requirements June 2006 ! 6. Emergency Service Identifier ! ! The term, service identifier, is a general term that incorporates all ! service URNs [8], but which may also refer to other identifiers which ! are not service URNs, for example, a tel URI. In protocol exchanges, ! any request to invoke an emergency service along with the specific ! type of emergency service desired, such as fire department or police, ! is indicated by the service URN. ! Since this document addresses only emergency service context specific ! requirements for mapping, the terms service identifier and service ! URN, which have a more general applicability than that of only ! emergency services, are replaced by the terms "emergency service ! identifier" (ESI) and "emergency service URN", respectively, ! throughout this document. The term "sos service URN" is used ! interchangeably with "emergency service URN". ! Id1. Emergency service identifier support: The mapping protocol MUST ! be able to return one or multiple emergency service identifiers in ! response to a query. ! Motivation: Since there is a need for any device or network ! element to recognize an emergency call throughout the call setup, ! there is also a need to have the mapping protocol provide support ! for such an identifier. This is regardless of the device location ! or the ASP/VSP used. An example of this kind of identifier might ! be the emergency service URN, 'urn:service:sos'. ! Id2. Emergency service identifier resolution: Where multiple ! emergency service identifiers exist, the mapping protocol MUST be ! able to differentiate between ESIs based on the specific type of ! emergency help requested. ! Motivation: Some jurisdictions may have multiple types of ! emergency services available, (e.g., fire, police, ambulance), in ! which case, it is important that any one could be selected ! directly. ! ! Id3. Extensible emergency service identifiers: The mapping protocol MUST support an extensible list of emergency identifiers, though ! it is not required to provide mapping for every possible service. ! Motivation: The use of an emergency service identifier is locally ! determined. ! Schulzrinne & Marshall Expires December 11, 2006 [Page 18] Internet-Draft ECRIT Requirements June 2006 ! Id4. Discovery of emergency dial string: There MUST be support for a ! mechanism to discover an existing location-dependent emergency ! dial string, (e.g., "9-1-1", "1-1-2"), contextually appropriate ! for the location of the caller. ! ! Motivation: Users are trained to dial the appropriate emergency ! dial string to reach emergency services. There needs to be a way ! to figure out what the dial string is within the local environment ! of the caller. ! ! Id5. Home emergency dial string translation: There MUST be support ! for end device translation (e.g., SIP UA) of a home emergency dial ! string into an emergency service identifier. ! ! Motivation: The UA would most likely be pre-provisioned with the ! appropriate information in order to make such a translation. The ! mapping protocol would be able to support either type for those ! clients which may not support dial string translation. ! ! Id6. Emergency dial string replacement: There SHOULD be support for ! replacement of the original dial string with a reserved emergency ! service identifier for each signaling protocol used for an ! emergency call. This replacement of the original dial string ! should be based on local conventions, regulations, or preference ! (e.g., as in the case of an enterprise). Motivation: Any signaling protocol requires the use of some ! identifier to indicate the called party, and the user terminal may ! lack the capability to determine the actual emergency address (PSAP URI). The use of local conventions may be required as a ! transition mechanism. Note: Such use complicates international ! movement of the user terminal. Evolution to a standardized ! emergency service identifier or set of identifiers is preferred. ! ! Id7. Emergency service identifier marking: There MUST be support for ! an emergency service identifier to be used for marking the call as ! an emergency call. Motivation: Marking ensures proper handling as an emergency call by downstream elements that may not recognize, for example, a ! local variant of a logical emergency address, etc. This marking ! mechanism is assumed to be different than a QoS marking mechanism. ! ! Id8. Emergency service identifier not recognized: There MUST be ! support for calls which are initiated as emergency calls even if ! the specific emergency service requested is not recognized, based ! on the emergency service identifier used. ! ! ! ! ! Schulzrinne & Marshall Expires December 11, 2006 [Page 19] ! ! Internet-Draft ECRIT Requirements June 2006 ! Motivation: In order to have a robust system that supports ! incremental service deployment while still maintaining a fallback ! capability. ! Id9. Discovery of visited emergency dial strings: There MUST be ! support for a mechanism to allow the end device to learn visited ! emergency dial strings. ! Motivation: Scenarios exist where a user dials a visited emergency ! dial string that is different from the home emergency dial string: ! If a user (i.e., UA operator) visits a foreign country, observes a ! fire truck with 999 on the side, the expectation is one of being ! able to dial that same number to summon a fire truck. Another use ! case cited is where a tourist collapses, and a "good Samaritan" ! uses the tourist's cell phone to enter a home emergency dial ! string appropriate for that foreign country. ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! Schulzrinne & Marshall Expires December 11, 2006 [Page 20] Internet-Draft ECRIT Requirements June 2006 ! 7. Mapping Protocol There are two basic approaches to invoke the mapping protocol. We refer to these as caller-based and mediated. In each case, the mapping client initiates a request to a mapping server via a mapping ! protocol. A proposed mapping protocol is outlined in the document ! I-D.hardie-ecrit-lost [9]. For caller-based resolution, the caller's user agent invokes the mapping protocol to determine the appropriate PSAP based on the --- 1004,1132 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 18] Internet-Draft ECRIT Requirements June 2006 ! 7. Emergency Service Identifier ! Emergency service identifiers are protocol constants that allow ! protocol entities such as SIP proxy servers to distinguish emergency ! calls from non-emergency calls and to identify the specific emergency ! service desired. Emergency service identifiers are a subclass of ! service identifiers that more generally identify services reachable ! by callers. An example of a service identifier is the service URN ! [12], but other identifiers, such as tel URIs [7], may also serve ! this role during a transition period. ! Since this document only addresses emergency services, we use the ! terms "emergency service identifier" and "service identifier" ! interchangeably. Requirements for these identifiers include: ! Id1. Multiple emergency services: The mapping protocol MUST be able ! to distinguish between different emergency services, ! differentiated by different service identifiers. ! Motivation: Some jurisdictions may offer multiple types of ! emergency services that operate independently and can be contacted ! directly, for example, fire, police and ambulance services. ! Id2. Extensible emergency service identifiers: The mapping protocol MUST support an extensible list of emergency identifiers, though ! it is not required to provide mappings for every possible service. ! Motivation: The use of a particular emergency service identifier ! varies between locations. For example, a separate fire emergency ! service is typically not available in the United States. + Id3. Discovery of emergency number: The mapping protocol MUST be + able to return the location-dependent emergency number for the + location indicated in the query. + Motivation: Users are trained to dial the appropriate emergency + number to reach emergency services. There needs to be a way to + figure out the emergency number at the current location of the + caller. + Id4. Home emergency number recognition: User equipment MUST be able + to translate a home emergency number into an emergency service + identifier. + Motivation: The UE could be pre-provisioned with the appropriate + information in order to perform such a translation or could + discover the emergency number by querying the mapping protocol + with its home location. ! Schulzrinne & Marshall Expires December 3, 2006 [Page 19] Internet-Draft ECRIT Requirements June 2006 ! Id5. Emergency dial string replacement: There SHOULD be support for ! replacement of the emergency dial string with the appropriate ! emergency service identifier for each signaling protocol used for ! an emergency call, based on local conventions, regulations, or ! preference (e.g., as in the case of an enterprise). Motivation: Any signaling protocol requires the use of some ! identifier to indicate the called party, and the user equipment ! may lack the capability to determine the actual emergency address (PSAP URI). The use of local conventions may be required as a ! transition mechanism. Since relying on recognizing local ! numbering conventions makes it difficult for devices to be used ! outside their home context and for external devices to be ! introduced into a network, protocols should use standardized ! emergency service identifiers. ! ! Id6. Emergency service identifier marking: Signaling protocols MUST ! support emergency service identifiers to mark a call as an ! emergency call. Motivation: Marking ensures proper handling as an emergency call by downstream elements that may not recognize, for example, a ! local variant of a logical emergency address. This marking ! mechanism is related to, but independent of, marking calls for ! prioritized call handling [10]. + Id7. Handling unrecognized emergency service identifiers: There MUST + be support for calls which are initiated as emergency calls even + if the specific emergency service requested is not recognized by + the ESRP. Such calls will then be routed to a generic emergency + service. ! Motivation: Fallback routing allows new emergency services to be ! introduced without incrementally, while avoiding non-routable ! emergency calls. For example, a call for marine rescue services ! would be routed to a general PSAP if the caller's location does ! not offer marine rescue services. ! Id8. Discovery of visited emergency dial strings: There MUST be a ! mechanism to allow the end device to learn visited emergency ! numbers. ! Motivation: Travelers visiting a foreign country may observe the ! local emergency number, e.g., seeing it painted on the side of a ! fire truck, and then rightfully expect to be able to dial that ! emergency number. Similarly, a local "good Samaritan" may use a ! tourist's cell phone to summon help. ! Schulzrinne & Marshall Expires December 3, 2006 [Page 20] Internet-Draft ECRIT Requirements June 2006 ! 8. Mapping Protocol There are two basic approaches to invoke the mapping protocol. We refer to these as caller-based and mediated. In each case, the mapping client initiates a request to a mapping server via a mapping ! protocol. A proposed mapping protocol, LoST, is outlined in [13]. For caller-based resolution, the caller's user agent invokes the mapping protocol to determine the appropriate PSAP based on the *************** *** 1158,1168 **** Motivation: This is needed, for example, to accommodate future extensions to location information that might be included in the ! PIDF-LO ([6]). Ma3. Incrementally deployable: The mapping protocol MUST be designed ! in such a way that supports the incremental deployment of mapping ! services. Motivation: It must not be necessary, for example, to have a global street level database before deploying the system. It is --- 1156,1165 ---- Motivation: This is needed, for example, to accommodate future extensions to location information that might be included in the ! PIDF-LO ([9]). Ma3. Incrementally deployable: The mapping protocol MUST be designed ! to support its incremental deployment. Motivation: It must not be necessary, for example, to have a global street level database before deploying the system. It is *************** *** 1173,1179 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 21] Internet-Draft ECRIT Requirements June 2006 --- 1170,1178 ---- ! ! ! Schulzrinne & Marshall Expires December 3, 2006 [Page 21] Internet-Draft ECRIT Requirements June 2006 *************** *** 1214,1225 **** Ma7. Multiple PSAP URIs: The mapping protocol MUST support a method to return multiple PSAP URIs which cover the same geographic area. ! Motivation: Two different mapping servers may cover the same ! geographic area, and therefore have the same set of coverage ! information. Ma8. Single primary URI per contact protocol: Though the mapping ! protocol supports multiple URIs being returned, it SHOULD return only one primary URI per contact protocol used, so that clients are not required to select among different targets for the same contact protocol. --- 1213,1224 ---- Ma7. Multiple PSAP URIs: The mapping protocol MUST support a method to return multiple PSAP URIs which cover the same geographic area. ! Motivation: Different contact protocols (e.g., PSTN via tel URIs ! and IP via SIP URIs) may be routed to different PSAPs. Less ! likely, two PSAPs may overlap in their coverage region. Ma8. Single primary URI per contact protocol: Though the mapping ! protocol can supports returning multiple URIs, it SHOULD return only one primary URI per contact protocol used, so that clients are not required to select among different targets for the same contact protocol. *************** *** 1229,1240 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 22] Internet-Draft ECRIT Requirements June 2006 ! Motivation: There may be two or more URIs returned when multiple contact protocols are available (e.g., SIP and SMS). The client may select among multiple contact protocols based on its capabilities, preference settings, or availability. --- 1228,1239 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 22] Internet-Draft ECRIT Requirements June 2006 ! Motivation: There may be two or more URIs returned when multiple contact protocols are available (e.g., SIP and SMS). The client may select among multiple contact protocols based on its capabilities, preference settings, or availability. *************** *** 1244,1257 **** URI or contact method explicitly marked as an alternate contact for use when a fallback contact is needed. ! Motivation: In response to a mapping request, the mapping server ! will also return an alternate URI. Implementation details to be ! described within an operational document. Ma10. Non-preferred URI schemes: The mapping protocol MAY support ! the return of a less preferred URI scheme, (e.g., TEL URI). ! Motivation: In order to provide incremental support to non-IP PSAPs it may be necessary to be able to complete an emergency call via the PSTN. --- 1243,1256 ---- URI or contact method explicitly marked as an alternate contact for use when a fallback contact is needed. ! Motivation: There may be multiple ways to provide addresses of ! backup PSAPs, including the mapping protocol, DNS lookup via NAPTR ! and SRV, or call routing by SIP proxies. Ma10. Non-preferred URI schemes: The mapping protocol MAY support ! the return of a less preferred URI scheme, such as tel URIs. ! Motivation: In order to provide incremental support to non-IP PSAPs it may be necessary to be able to complete an emergency call via the PSTN. *************** *** 1259,1265 **** to provide ancillary information about a contact that allows the mapping client to determine relevant properties of the PSAP URI. ! Motivation: In some cases, the same geographic area is served by several PSAPs, for example, a corporate campus might be served by both a corporate security department and the municipal PSAP. The mapping protocol should then return URIs for both, with --- 1258,1264 ---- to provide ancillary information about a contact that allows the mapping client to determine relevant properties of the PSAP URI. ! Motivation: In some cases, the same geographic area is served by several PSAPs, for example, a corporate campus might be served by both a corporate security department and the municipal PSAP. The mapping protocol should then return URIs for both, with *************** *** 1273,1281 **** be referred to another mapping server that is more qualified to answer the query. ! Motivation: To help avoid the case of relying on incorrect ! configuration data which may cause calls to fail, particularly for ! caller-based mapping queries. Ma13. Split responsibility: The mapping protocol MUST support the division of data subset handling between multiple mapping servers --- 1272,1280 ---- be referred to another mapping server that is more qualified to answer the query. ! Motivation: Referrals help mitigate the impact of incorrect ! configuration that directs a client to the wrong initial mapping ! server. Ma13. Split responsibility: The mapping protocol MUST support the division of data subset handling between multiple mapping servers *************** *** 1285,1291 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 23] Internet-Draft ECRIT Requirements June 2006 --- 1284,1290 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 23] Internet-Draft ECRIT Requirements June 2006 *************** *** 1302,1329 **** potentially help resolve the error. Ma15. Resiliance to failure: The mapping protocol MUST support a ! mechanism which enables fail over to different (replica) mapping ! server in order to obtain and return a successful mapping to the ! mapping client. ! ! Motivation: It is important that the failure of a single mapping ! server does not preclude the mapping client's ability to receive ! mapping from a different mapping server. Ma16. Traceable resolution: The mapping protocol SHOULD support the ability of the mapping client to be able to determine the entity or entities that provided the emergency address resolution information. ! Motivation: It is important for public safety reasons, that there ! is a method to provide operational traceability in case of errors. Ma17. Minimal additional delay: Mapping protocol execution SHOULD minimize the amount of delay within the overall call-setup time. ! Motivation: Since outbound proxies will likely be asked to resolve ! the same geographic coordinates repeatedly, a suitable time- ! limited caching mechanism should be supported. --- 1301,1378 ---- potentially help resolve the error. Ma15. Resiliance to failure: The mapping protocol MUST support a ! mechanism which enables the client to fail over to different ! (replica) mapping server. ! ! Motivation: The failure of a mapping server should not preclude ! the mapping client from receiving an answer to its query. Ma16. Traceable resolution: The mapping protocol SHOULD support the ability of the mapping client to be able to determine the entity or entities that provided the emergency address resolution information. ! Motivation: To improve reliability and performance, it is ! important to be able to trace which servers contributed to the ! resolution of a query. Ma17. Minimal additional delay: Mapping protocol execution SHOULD minimize the amount of delay within the overall call-setup time. ! Motivation: Since outbound proxies will likely be asked to ! resolve the same geographic coordinates repeatedly, a suitable ! time-limited caching mechanism should be supported. ! ! Ma18. Alternate mapping sources: The mapping protocol MUST implement ! a mechanism that allows for the retrieval of mapping information ! from different sources. ! ! Motivation: This provides the possibility of having available ! alternative sources of mapping information when the normal source ! is unavailable or unreachable. ! ! Ma19. Freshness indication: The mapping protocol SHOULD support an ! indicator describing how current the information provided by the ! mapping source is. ! ! ! ! ! ! ! Schulzrinne & Marshall Expires December 3, 2006 [Page 24] ! ! Internet-Draft ECRIT Requirements June 2006 ! ! ! Motivation: This is especially useful when an alternate mapping is ! requested, and alternative sources of mapping data may not have ! been created or updated with the same set of information or within ! the same timeframe. Differences in currency between mapping data ! contained within mapping sources should be minimized. ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! *************** *** 1341,1355 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 24] Internet-Draft ECRIT Requirements June 2006 ! 8. Security Considerations Threats and security requirements are discussed in a separate ! document, see I-D.ietf-ecrit-security-threats [7] . --- 1390,1410 ---- ! ! ! ! ! ! ! Schulzrinne & Marshall Expires December 3, 2006 [Page 25] Internet-Draft ECRIT Requirements June 2006 ! 9. Security Considerations Threats and security requirements are discussed in a separate ! document document [11]. *************** *** 1397,1408 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 25] Internet-Draft ECRIT Requirements June 2006 ! 9. IANA Considerations This document does not require actions by the IANA. --- 1452,1463 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 26] Internet-Draft ECRIT Requirements June 2006 ! 10. IANA Considerations This document does not require actions by the IANA. *************** *** 1453,1464 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 26] Internet-Draft ECRIT Requirements June 2006 ! 10. Contributors The information contained in this document is a result of a several original joint contributions of text, which was then discussed and --- 1508,1519 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 27] Internet-Draft ECRIT Requirements June 2006 ! 11. Contributors The information contained in this document is a result of a several original joint contributions of text, which was then discussed and *************** *** 1509,1530 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 27] Internet-Draft ECRIT Requirements June 2006 ! 11. Acknowledgments In addition to thanking those listed above, we would like to also thank Guy Caron, Barry Dingle, Keith Drage, Tim Dunn, Patrik ! Faeltstroem, Clive D.W. Feather, Raymond Forbes, Randall Gellens, Michael Haberler, Michael Hammer, Ted Hardie, Gunnar Hellstrom, Cullen Jennings, Marc Linsner, Rohan Mahy, Patti McCalmont, Don Mitchell, John Morris, Andrew Newton, Steve Norreys, Jon Peterson, James Polk, Benny Rodrig, John Rosenberg, Jonathan Rosenberg, John Schnizlein, Shida Schubert, James Seng, Byron Smith, Tom Taylor, ! Barbara Stark, Hannes Tschofenig, and Nate Wilcox, for their invaluable input. --- 1564,1585 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 28] Internet-Draft ECRIT Requirements June 2006 ! 12. Acknowledgments In addition to thanking those listed above, we would like to also thank Guy Caron, Barry Dingle, Keith Drage, Tim Dunn, Patrik ! Faltstrom, Clive D.W. Feather, Raymond Forbes, Randall Gellens, Michael Haberler, Michael Hammer, Ted Hardie, Gunnar Hellstrom, Cullen Jennings, Marc Linsner, Rohan Mahy, Patti McCalmont, Don Mitchell, John Morris, Andrew Newton, Steve Norreys, Jon Peterson, James Polk, Benny Rodrig, John Rosenberg, Jonathan Rosenberg, John Schnizlein, Shida Schubert, James Seng, Byron Smith, Tom Taylor, ! Barbara Stark, Hannes Tschofenig, and Nate Wilcox for their invaluable input. *************** *** 1565,1629 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 28] Internet-Draft ECRIT Requirements June 2006 ! 12. References ! 12.1. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. ! 12.2. Informative References ! [2] Charlton, N., Gasson, M., Gybels, G., Spanner, M., and A. van Wijk, "User Requirements for the Session Initiation Protocol (SIP) in Support of Deaf, Hard of Hearing and Speech-impaired Individuals", RFC 3351, August 2002. ! [3] Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and J. Polk, "Geopriv Requirements", RFC 3693, February 2004. ! [4] Polk, J., Schnizlein, J., and M. Linsner, "Dynamic Host Configuration Protocol Option for Coordinate-based Location Configuration Information", RFC 3825, July 2004. ! [5] Hellstrom, G. and P. Jones, "RTP Payload for Text Conversation", RFC 4103, June 2005. ! [6] Peterson, J., "A Presence-based GEOPRIV Location Object Format", RFC 4119, December 2005. ! [7] Taylor, T., "Security Threats and Requirements for Emergency ! Call Marking and Mapping", draft-ietf-ecrit-security-threats-01 ! (work in progress), April 2006. ! [8] Schulzrinne, H., "A Uniform Resource Name (URN) for Services", draft-ietf-ecrit-service-urn-03 (work in progress), May 2006. - [9] Hardie, T., "LoST: A Location-to-Service Translation Protocol", - draft-hardie-ecrit-lost-00 (work in progress), March 2006. - [10] Schulzrinne, H., "Dynamic Host Configuration Protocol (DHCPv4 - and DHCPv6) Option for Civic Addresses Configuration - Information", draft-ietf-geopriv-dhcp-civil-09 (work in - progress), January 2006. - [11] Wijk, A., "Framework for real-time text over IP using SIP", - draft-ietf-sipping-toip-04 (work in progress), March 2006. ! ! ! Schulzrinne & Marshall Expires December 11, 2006 [Page 29] ! ! Internet-Draft ECRIT Requirements June 2006 Authors' Addresses --- 1620,1701 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 29] Internet-Draft ECRIT Requirements June 2006 ! 13. References ! 13.1 Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. ! 13.2 Informative References ! [2] 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. ! ! [3] Charlton, N., Gasson, M., Gybels, G., Spanner, M., and A. van Wijk, "User Requirements for the Session Initiation Protocol (SIP) in Support of Deaf, Hard of Hearing and Speech-impaired Individuals", RFC 3351, August 2002. ! [4] Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and J. Polk, "Geopriv Requirements", RFC 3693, February 2004. ! [5] Polk, J., Schnizlein, J., and M. Linsner, "Dynamic Host Configuration Protocol Option for Coordinate-based Location Configuration Information", RFC 3825, July 2004. ! [6] Peterson, J., "Common Profile for Instant Messaging (CPIM)", ! RFC 3860, August 2004. ! ! [7] Schulzrinne, H., "The tel URI for Telephone Numbers", RFC 3966, ! December 2004. ! ! [8] Hellstrom, G. and P. Jones, "RTP Payload for Text Conversation", RFC 4103, June 2005. ! [9] Peterson, J., "A Presence-based GEOPRIV Location Object Format", RFC 4119, December 2005. ! [10] Schulzrinne, H. and J. Polk, "Communications Resource Priority ! for the Session Initiation Protocol (SIP)", RFC 4412, ! February 2006. ! ! [11] Taylor, T., "Security Threats and Requirements for Emergency ! Call Marking and Mapping", draft-ietf-ecrit-security-threats-03 ! (work in progress), July 2006. ! [12] Schulzrinne, H., "A Uniform Resource Name (URN) for Services", draft-ietf-ecrit-service-urn-03 (work in progress), May 2006. + Schulzrinne & Marshall Expires December 3, 2006 [Page 30] + + Internet-Draft ECRIT Requirements June 2006 + [13] Hardie, T., "LoST: A Location-to-Service Translation Protocol", + draft-hardie-ecrit-lost-00 (work in progress), March 2006. + [14] Schulzrinne, H., "Dynamic Host Configuration Protocol (DHCPv4 + and DHCPv6) Option for Civic Addresses Configuration + Information", draft-ietf-geopriv-dhcp-civil-09 (work in + progress), January 2006. ! [15] Wijk, A. and G. Gybels, "Framework for real-time text over IP ! using the Session Initiation Protocol (SIP)", ! draft-ietf-sipping-toip-05 (work in progress), June 2006. ! ! [16] Institute of Electrical and Electronics Engineers, "Station and ! Media Access Control Connectivity Discovery", IEEE Standard ! 802.1 AB, April 2005. Authors' Addresses *************** *** 1660,1683 **** ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! Schulzrinne & Marshall Expires December 11, 2006 [Page 30] Internet-Draft ECRIT Requirements June 2006 --- 1732,1738 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 31] Internet-Draft ECRIT Requirements June 2006 *************** *** 1733,1738 **** ! Schulzrinne & Marshall Expires December 11, 2006 [Page 31] - --- 1788,1792 ---- ! Schulzrinne & Marshall Expires December 3, 2006 [Page 32]