--- 1/draft-ietf-ecrit-requirements-03.txt 2006-02-22 20:12:24.000000000 +0100 +++ 2/draft-ietf-ecrit-requirements-04.txt 2006-02-22 20:12:25.000000000 +0100 @@ -1,19 +1,20 @@ ECRIT H. Schulzrinne Internet-Draft Columbia U. -Expires: August 6, 2006 R. Marshall, Ed. +Expires: August 23, 2006 R. Marshall, Ed. TCS - February 2, 2006 + February 19, 2006 -Requirements for Emergency Context Resolution with Internet Technologies - draft-ietf-ecrit-requirements-03.txt + Requirements for Emergency Context Resolution with Internet + Technologies + draft-ietf-ecrit-requirements-04.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that @@ -24,21 +25,21 @@ and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. - This Internet-Draft will expire on August 6, 2006. + This Internet-Draft will expire on August 23, 2006. Copyright Notice Copyright (C) The Internet Society (2006). Abstract This document enumerates requirements for emergency calls placed by the public using voice-over-IP (VoIP) and general Internet multimedia systems, where Internet protocols are used end-to-end. @@ -198,20 +199,25 @@ or may not provide the physical-layer and layer-2 connectivity, such as fiber or Ethernet. 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. In the geocoding process, the location is defined with an x,y coordinate value according to the distance north or south of the equator and east or west of the prime meridian. + Location Context Mapping System (LCMS): A system defined as a set of + mechanisms and services working together to perform a mapping, + (or, direct association), between a location and a PSAP uri + designated as responsibleto to serve that location. + Location-dependent emergency identifier: Location-dependent emergency identifiers, also referred to as "emergency dial-strings" within this document, should be thought of as the digit sequence that is dialed in order to reach emergency services. There are two dial- strings, namely either a "home emergency dial-string", or a "visited emergency dial-string", and is something separate from a universal emergency identifier, since each represents specific emergency identifiers which are recognized within a local geographic area or jurisdiction. @@ -245,22 +251,22 @@ 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. PSAP URI: PSAP URI is a general term, used to refer to the output of the mapping protocol, and represents either the actual PSAP IP - address, or some other intermediary's IP address, which points to - the actual PSAP. + address, or the IP address of some other intermediary, e.g. an + ESRP, which points to the actual PSAP. Universal identifier: An emergency identifier which is recognized by any compatible endpoint, from any geographic location as useful for initiating an emergency request. A general approach to using universal identifiers is outlined in the service URN draft (I-D.schulzrinne-sipping-service [5]). Visited emergency dial-string: A visited emergency dial-string (ref. Location-dependent emergency identifier) represents a sequence of digits that is used to initiate an emergency call within a @@ -372,30 +378,31 @@ o (8) Location Information is used by emergency call routing entities to determine appropriate PSAP mapping. 4. High-Level Requirements Below, we summarize high-level architectural requirements that guide some of the component requirements detailed later in the document. Re1. Application Service Provider: The existence of an Application - Service Provider (ASP) MUST NOT be assumed. + Service Provider (ASP) SHOULD NOT be assumed. 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 and staff, but not be a telecommunication provider. - Re2. International: The protocols and protocol extensions developed - MUST support regional, political and organizational differences. + Re2. International: Regional, political and organizational aspects + MUST be considered during the design of protocols and protocol + extensions. Motivation: It must be possible for a device or software developed or purchased in one country to place emergency calls in another country. System components should not be biased towards a particular set of emergency numbers or languages. Also, different countries have evolved different ways of organizing emergency services, e.g. either centralizing them or having smaller regional subdivisions such as United States counties or municipalities handle emergency calls. @@ -403,66 +410,67 @@ MUST NOT depend on a sole central administration authority. Motivation: Once common standards are established, it must be possible to deploy and administer emergency calling features on a regional or national basis without requiring coordination with other regions or nations. The system cannot assume, for example, that there is a single global entity issuing certificates for PSAPs, ASPs, IAPs or other participants. Re4. Multiple Modes: Multiple communication modes, such as audio, - video and text messaging MUST be supported. + video and text messaging MUST be supported (i.e. implemented in + the protocol, though not necessarily used). Motivation: In PSTN, voice and text telephony (often called TTY or textphone in North America) are the only commonly supported media. Emergency calling must support a variety of media. Such media should include voice, conversational text (RFC 4103 [9]), instant messaging and video. - Re5. Alternate Mapping Sources: The mapping protocol SHOULD allow - for alternative redundant sources of mapping information, possibly - of different degrees of currency. + Re5. Alternate Mapping Sources: The mapping protocol SHOULD + implement a mechanism that allows for the retrieval of mapping + information, possibly of different degrees of currency. Motivation: This provides the possibility of having available alternative sources of mapping information when the normal source is unavailable or unreachable, without specifying the means by which the alternative source is created or updated. Re6. Incremental Deployment: The ECRIT mapping protocol MUST return URIs that are usable by a standard signaling protocol (i.e., without special emergency extensions) unless an error is returned. Motivation: The format of the output returned by the mapping protocol is in a standard format for communication protocol. For example, it should return something SIP specific (e.g. URI), that any SIP capable phone would be able to use if used in a SIP context. Special purpose URIs would not be understood by "legacy" SIP devices since they do not have knowledge about the mapping protocol, and therefore are not to be used. - Re7. Ubiquitous Triggering: It MUST be possible to invoke the - mapping protocol at any time, from any location, by any client - which supports the mapping protocol. + Re7. Ubiquitous Triggering: The mapping protocol MUST implement, + (not necessarily use), the ability to be invoked at any time, from + any location, by any client which supports the mapping protocol. Motivation: While end devices are the typical initiators of mapping service requests, it is also expected that other mapping clients, such as relays, 3rd party devices, PSAPs, etc. may also trigger a mapping request. Re8. PSAP Identification: The mapping information MUST be available without having to enroll with a service provider. Motivation: The mapping server may well be operated by a service provider, but access to the server offering the mapping must not require use of a specific ISP or VSP. - Re9X. No Modification of Location Databases: The mapping protocol + Re9. No Modification of Location Databases: The mapping protocol SHOULD NOT require that data within location databases be transformed or modified in any unusual or unreasonable way in order for the mapping protocol to use the data. Motivation: Databases which contain civic addresses (used within location information servers), may be used for multiple purposes and applications, (in addition to being used for emergency service mapping only). 5. Identifying the Caller Location @@ -479,64 +487,84 @@ Discovery Protocol (LLDP) [see IEEE8021AB]. UA-referenced: The caller's user agent provides a reference, via a permanent or temporary identifier, to the location which is stored by a location service somewhere else and then retrieved by the PSAP. Proxy-inserted: A proxy along the call path inserts the location or location reference. - Lo1. Validation of Civic Location: It MUST be possible to validate a - civic location prior to its use in an actual emergency call. + Lo1. Validation of Civic Location: The mapping protocol MUST + implement a method that makes it possible for a mappng server to + validate a civic location prior to that location's use in an + actual emergency call. Motivation: Location validation provides an opportunity to help assure ahead of time, whether 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. - Lo1X. Validation Resolution: The mapping protocol MUST support the - return of additional information which can be used to determine - the precision or resolution of the data elements used to determine - a PSAP URI, for example. + Lo2. Validation Resolution: The mapping protocol MUST support (i.e. + required to implement, though not required for use) the return of + additional information which can be used to determine the + precision or resolution of the data elements used to determine a + PSAP URI, for example. - Lo1XX. Indication of non-existent location: The protocol MUST - support a mechanism to indicate that a location or a part of a - location is known to not exist, even if a valid location-to-PSAP - uri mapping can be provided. + Motivation: The mapping server may not use all the data elements + in the provided location information to determine a match, or may + be able to find a match based on all of the information except for + some specific data elements. The uniqueness of this information + set may be used to differentiate among emergency jurisdictions. + Precision or resolution in the context of this requirement might + mean, for example, explicit identification of the data elements + that were used successfully in the mapping. - Lo2. Limits to Validation: Validation of a civic location MUST NOT - be required to enable any feature that is part of the emergency - call process. + Lo3. Indication of non-existent location: The protocol MUST support + (i.e. must implement in the protocol, though not necessarily use) + a mechanism to indicate that a location or a part of a location is + known to not exist, even if a valid location-to-PSAP uri mapping + can be provided. This mechanism includes a means to identify a + separate mechanism that could be used to resolve the discrepancy. + + 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. + The mapping response would allow this service to be identified. + + Lo4. Limits to Validation: Successful validation of a civic location + MUST NOT be required to enable any feature that is part of the + emergency call process. Motivation: In some cases, (based on a variety of factors), a civic location may not be considered valid. This fact should not result in the call being dropped or rejected by any entity along the signaling path to the PSAP. - Lo3. Reference Datum: The mapping server MUST understand WGS-84 - coordinate reference system and may understand other reference - systems. + Lo5. Reference Datum: The mapping server MUST implement support for + the WGS-84 coordinate reference system and may implement support + for use of other reference systems. - Lo4. Location Provided: An Emergency Services Routing Proxy (ESRP) + Lo6. Location Provided: An Emergency Services Routing Proxy (ESRP) MUST NOT remove location information after performing location based routing. Motivation: The ESRP and the PSAP use the same location information object but for a different purpose. Therefore, the PSAP still requires the receipt of information which represents the end device's location. - Lo5. 3D Sensitive Mapping: The mapping protocol MUST accept either a - 2D or 3D mapping request, and return an appropriate result, based - on which type of input is used. + Lo7. 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, so to return an + appropriate result, based on which type of input is used. Motivation: It is expected that provisioning systems will accept both 2D and 3D data. When a 3D request is presented to an area only defined by 2D data, the mapping result would be the same as if the height/altitude dimension was omitted on the request." 6. Emergency Identifier Id1. Universal Identifier Setup: One or more universal emergency identifiers MUST be recognized by any device or network element @@ -546,110 +574,119 @@ recognize an emergency call throughout the call setup. This is regardless of the device location, the application (voice) service provider used (if any at all), or of any other factor. Examples of these might include: 911, 112, and sos.*. Id2. Universal Identifier Resolution: Where multiple emergency service types exist, it MUST be possible to treat each emergency identifier separately, based on the specific type of emergency help requested. + Id2. Universal Identifier Resolution: Where multiple emergency + service types exist, the mapping protocol MUST support the + individual treatment of each emergency identifier used, based on + the specific type of emergency help requested. + Motivation: Some jurisdictions may have multiple types of emergency services available at the same level, (e.g. fire, police, ambulance), in which case it is important that any one could be selected directly. Id3. Emergency Marking: Any device in the signaling path that recognizes by some means that the signaling is associated with an - emergency call MUST add the emergency indication called for in Id1 - to the signaling before forwarding it. This marking mechanism - must be different than QoS marking. + emergency call MUST add a specific emergency indication, if it + doesn't already exist, to the signaling before forwarding it. + This marking mechanism must be different than QoS marking. 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. Id4. Emergency Identifier-based Marking: User agents, proxies, and other network elements that process signaling associated with emergency calls SHOULD be configured to recognize a reasonable selection of logical emergency identifiers as a means to initiate emergency marking. Motivation: Since user devices roam, emergency identifiers may vary from region to region. It is therefore important that a network entity be able to perform mapping and/or call routing within the context of its own point of origin rather than relying on non-local logical emergency identifiers as the only basis for emergency marking of calls. - Id5. Prevention of Fraud: A call identified as an emergency call or - marked as such in accordance with the above requirements for - marking MUST be routed to a PSAP. + Id5. Prevention of Fraud: A call MUST be routed to a PSAP if it is + identified as an emergency call or is marked as such in accordance + with the above emergency marking requirements. Motivation: this prevents use of the emergency call indication to gain access to call features or authentication override for non- emergency purposes. Id6. Extensibility of emergency service types: The list of emergency service types MUST be extensible, and it is not necessary to provide mapping for every possible service type. Motivation: The use of a service type is locally determined. - Id6X. Discovery of emergency dial-string: The mapping protocol MUST - support a mechanism to discover existing location-dependent - emergency identifiers, known as emergency dial-strings, (e.g. - 9-1-1, 1-1-2), appropriate for the location of the caller. + Id7. Discovery of emergency dial-string: The mapping protocol MUST + support (i.e. implement, though not necessarily use) a mechanism + to discover existing location-dependent emergency identifiers, + known as emergency dial-strings, (e.g. 9-1-1, 1-1-2), 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. - Id6XX. XXX: The SIP UA SHOULD translate home emergency dial-strings - to universal emergency identifiers. The UA is most likely pre- - provisioned with this information to be able to make such a - translation. A mechanism to provide the user's home emergency - dial-strings MUST be available. + Id8. Local Identifier Translation: The SIP UA SHOULD translate home + emergency dial-strings to universal emergency identifiers. The UA + would most likely be pre-provisioned with the appropriate + information in order to make such a translation. This assumes + that a mechanism to provide the user's home emergency dial-strings + be available. - Id7. Emergency Identifier Replacement: For each signaling protocol + Id9. Emergency Identifier Replacement: For each signaling protocol that can be used in an emergency call, reserved identifiers SHOULD be allowed to replace the original emergency identifier, 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, and evolution to a standardized universal emergency identifier or set of identifiers is preferred. - Id8. Universal Identifier Recognition: Universal identifier(s), MUST - be universally recognizable by any network element which supports - the ECRIT protocol." - Id9. Universal Identifier Unrecognized: A call MUST be recognized as - emergency call even if the specific emergency service requested is - not recognized." + Id10. Universal Identifier Recognition: Universal identifier(s), + MUST be universally recognizable (as the label suggests), by any + network element which supports the (ECRIT) mapping protocol. + + Id11. Universal Identifier Unrecognized: A call MUST be recognized + as emergency call even if the specific emergency service requested + is not recognized. "Motivation: In order to have a robust system that supports - incremental Service deployment while still maintaining a fallback + incremental service deployment while still maintaining a fallback capability." - Id10X. Translation of emergency dial-strings: The SIP UA SHOULD + Id12. Translation of emergency dial-strings: The SIP UA SHOULD translate both home and visited emergency dial-strings into a universal emergency identifier. - Id11X. Detection of visited emergency dial-strings: The mapping - protocol MUST support a mechanism to allow the end device to learn - visited emergency dial-strings. + Id13. Detection of visited emergency dial-strings: The mapping + protocol MUST support (i.e. implement, though not necessarily + use), 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 of a UA visits a foreign country, observes a fire truck with 999 on the side, the expectation is to be 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 dial a local emergency number. 7. Mapping Protocol @@ -699,191 +736,215 @@ for this particular geographic area. In particular, the location determination should not be fooled by the location of IP telephony gateways or dial-in lines into a corporate LAN (and dispatch emergency help to the gateway or campus, rather than the caller), multi-site LANs and similar arrangements. Motivation: Routing to the wrong PSAP will result in delays in handling emergencies as calls are redirected, and result in inefficient use of PSAP resources at the initial point of contact. - Ma2. Mapping redirection: The mapping protocol MUST support - redirection functionality, since in some cases, an initial mapping - may provide a single URL for a large geographic area. Redirection - is needed to then re-invokes the mapping protocol on a different - database to obtain another URL for a more resolute ESRP or PSAP, - which covers a smaller area. + Ma2. Mapping redirection: The mapping protocol MUST support (i.e. + implement for use) redirection functionality, since in some cases, + an initial mapping may provide a single URL for a large geographic + area. Redirection is needed to then re-invokes the mapping + protocol on a different database to obtain another URL for a more + resolute ESRP or PSAP, which covers a smaller area. Motivation: The more local the mapping output is, the more favorable (in most cases) the likely outcome will be for the emergency caller. Ma3. Minimal additional delay: The execution of the mapping protocol SHOULD minimize the amount of additional delay to 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. - Ma4. Referral: The mapping client MUST be able to contact any server - and be referred to another server that is more qualified to answer - the query. + Ma4. Referral: The mapping protocol MUST support (i.e. Implement + for use), a mechanism for the mapping client to be able to contact + any mapping server and be referred to another server that is more + qualified to answer the query. Motivation: This requirement alleviates the potential for incorrect configurations to cause calls to fail, particularly for caller-based queries. Ma5. Multiple Response URIs: The mapping protocol response MUST - allow the return of multiple URIs. + support (i.e. implement, though not necessarily use), the + inclusion of multiple URIs in the response. Motivation: In response to a mapping request, a server will normally provide a URI or set of URIs for contacting the appropriate PSAP. - Ma6. URI - Alternate Contact: The mapping protocol MUST be able to - return a URI or contact method explicitly marked as an alternate - contact. + Ma6. URI - Alternate Contact: The mapping protocol MUST support + (i.e. implement, though not necessarily use), the return of a URI + or contact method explicitly marked as an alternate contact. Motivation: In response to a mapping request, if an expected URI is unable to be returned, then mapping server may return an alternate URI. When and how this would be used will be described in an operational document. - Ma7. Multiple PSAP URI's: The mapping protocol MUST be able to + Ma7. Multiple PSAP URIs: The mapping protocol MUST be able to return + multiple URIs for different PSAPs that cover the same area. + + Ma7. Multiple PSAP URIs: The mapping protocol MUST support (i.e. + implement, though not necessarily use), a method to be able to return multiple URIs for different PSAPs that cover the same area. Ma8. URL properties: The mapping protocol must provide additional information that allows the querying entity to determine relevant properties of the URL. + Ma8. URL properties: The mapping protocol MUST support (i.e. + implement, thought not necessarily use), the ability to provide + additional information that allows the querying entity to + determine relevant properties of the URL. + 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 URLs for both, with information allowing the querying entity to choose one or the other. This determination could be made by either an ESRP, based on local policy, or by direct user choice, in the case of caller- based trigger methods. - Ma9. Traceable resolution: The entity requesting mapping SHOULD be - able to determine the entity or entities which provided the - emergency address resolution information. + Ma9. Traceable resolution: The mapping protocol SHOULD support the + ability of the mapping client to be able to determine the entity + or entities which provided the emergency address resolution + information. Motivation: To provide operational traceability in case of errors. - Ma9X. URI for error reporting: The mapping protocol MUST have a - mechanism to return a urii that can be used to report a suspected - or known error within the mapping database. + Ma10. URI for error reporting: The mapping protocol MUST support + (i.e. implement for use) a mechanism to return a URI that can be + used to report a suspected or known error within the mapping + database. - Ma10. Resilience against server failure: A client MUST be able to - fail over to another replica of the mapping server, so that a - failure of a server does not endanger the ability to perform the - mapping. + Ma11. Resilience against server failure: The mapping protocol MUST + support (i.e. implement for use) a mechanism to enable the mapping + client to be able to fail over to another replica of the mapping + server, so that a failure of a server does not endanger the + ability to perform the mapping. - Ma11. Incrementally deployable: The mapping function MUST be capable - of being deployed incrementally. + Ma12. 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 acceptable to have some misrouting of calls when the database does not (yet) contain accurate boundary information. - Ma12X. URI for error resolution: The mapping protocol MUST have a - mechanism to return a reference URI which can be used to report a - suspected error in the mapping database. - - Ma13. Mapping requested from anywhere: The mapping protocol MUST be - able to provide the mapping regardless of where the mapping client - is located, either geographically or by network location. + Ma13. Mapping requested from anywhere: The mapping protocol MUST + support (i.e. implement, though not necessarily use) the ability + to provide mapping information in response to queries from any + (earthly) location, regardless of where the mapping client is + located, either geographically or by network location. Motivation: The mapping client, (such as the ESRP), may not necessarily be anywhere close to the caller or the appropriate PSAP, but must still be able to obtain a mapping. - Ma14. Location Updates: It SHOULD be possible to have updates of - location. + Ma14. Location Updates: The mapping protocol MUST support (i.e. + implement, though not necessarily use) the ability to provide + location updates. Mapping services should implement the + mechanisms to provide updated location. Motivation: Updated location information may have an impact on PSAP routing. In some cases it may be possible to redirect that call to a more appropriate PSAP (some device measurement techniques provide quick (i.e. early), but imprecise "first fix" location). - Ma15. Extensible Protocol: The mapping protocol MUST be extensible - to allow for the inclusion of new location fields. + Ma15. Extensible Protocol: The mapping protocol MUST be designed to + support the extensibility of location data elements, both for new + and existing fields. Motivation: This is needed, for example, to accommodate future extensions to location information that might be included in the PIDF-LO (RFC 4119 [3]). - Ma16. Split responsibility: The mapping protocol MUST allow that - within a single level of the civic location hierarchy, multiple - mapping servers handle subsets of the data elements. + Ma16. Split responsibility: The mapping protocol MUST support (i.e. + implement for use) the division of data subset handling between + multiple mapping servers within a single level of a civic location + hierarchy. Motivation: For example, two directories for the same city or county may handle different streets within that city or county. - Ma17. Pervasive Mapping: The mapping function MUST be able to be + Ma17. Pervasive Mapping: The mapping protocol MUST support (i.e. + implement for use) the ability of the mapping function to be invoked at any time, including while an emergency call is in process. Ma18. Baseline query protocol: A mandatory-to-implement protocol MUST be specified. Motivation: An over-abundance of similarly-capable choices appears undesirable for interoperability. Ma19. Single URI Scheme: The mapping protocol MAY return multiple URIs, though it SHOULD return only one URI per scheme, so that clients are not required to select among different targets for the same contact protocol. 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. - Ma20X. Separation of Identity from mapping: The mapping function MUST + Ma20. Separation of Identity from mapping: The mapping protocol MUST NOT require the true identity of the target for which the location information is attributed. Ideally, no identity information is - provided to the mapping function. Where identity information is + provided via the mapping protocol. Where identity information is provided, it may be in the form of an unlinked pseudonym as defined in RFC 3963. - Ma21X. Location delivery by-value: The mapping protocol MUST support - the delivery of location information by-value and MAY support de- - referencing of location references. Location by-reference is not - one of the evaluation criteria. The mapping protocol is not - required to support the ability to de-reference location - references. + Ma21. Location delivery by-value: The mapping protocol MUST support + (i.e. implement, though not necessarily use) the delivery of + location information by-value, though may alternatively support + de-referencing of specific location references. - Ma22X. Alternate community names: The mapping protocol MUST support - both the jurisdiction community name and the postal community name - fields in the PIDF-LO. + Motivation: Location by-reference is not one of the evaluation + criteria for a mapping protocol presented here. (i.e. the mapping + protocol is not required to support the ability to de-reference + specific location references.) + + Ma22. Alternate community names: The mapping protocol MUST support + (i.e. implement, though not necessarily use) both the jurisdiction + 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, given that the database has both fields populated, the mapping protocol response should return both available fields. - Ma23X. Support for alias locations: The mapping protocol MUST support - one or more aliases for a specific location entry. + Ma23. Support for alias locations: The mapping protocol MUST support + (i.e. implement, though not necessarily use) one or more aliases + for a specific location entry. Motivation: It should be possible to relate one entry to another and be able to determine which is the "primary" entry and which is the alias. The result of aliasing is always that mapping from the primary or any of the aliases is the same. - Ma24X. Pre-call mapping for fallback: The mapping protocol MUST - support LCMS queries prior to making an emergency call. + Ma24. Pre-call mapping for fallback: The mapping protocol MUST + support (i.e. implement, though not necessarily use) LCMS queries + prior to making an emergency call. Motivation: Used as a fallback mechanism only, if a LCMS query fails at emergency call time, it may be advantageous to have prior knowledge of the PSAP URI. This prior knowledge would be obtained by performing an LCMS query at any time prior to an emergency call. 8. Security Considerations Note: Security Considerations are referenced in the ECRIT security @@ -910,23 +971,29 @@ Brian Rosen br@brianrosen.net Richard Stastny Richard.Stastny@oefeg.at Martin Thomson Martin.Thomson@andrew.com James Winterbottom James.Winterbottom@andrew.com 10. Acknowledgments - We would like to thank Michael Hammer, Ted Hardie, Marc Linsner, - Andrew Newton, James Polk, Tom Taylor, and Hannes Tschofenig for - their input. + In addition to thanking those listed above, we would like to also + thank Michael Hammer, Ted Hardie, Marc Linsner, Barbara Stark, Clive + D.W. Feather, Keith Drage, Raymond Forbes, Tim Dunn, Steve Norreys, + Patti McCalmont, Rohan Mahy, Nate Wilcox, Michael Haberler, Jonathan + Rosenberg, Shida Schubert, John Schnizlein, Benny Rodrig, John + Rosenberg, Patrik Faeltstroem, Barry Dingle, Gunnar Hellstrom, James + Seng, Byron Smith, Cullen Jennings, Don Mitchell, John Morris, Jon + Peterson, Randall Gellens, Guy Caron, Andrew Newton, James Polk, Tom + Taylor, and Hannes Tschofenig for their invaluable input. 11. References 11.1. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Polk, J., Schnizlein, J., and M. Linsner, "Dynamic Host Configuration Protocol Option for Coordinate-based Location