Internet DRAFT - draft-schulzrinne-ecrit-requirements
draft-schulzrinne-ecrit-requirements
ecrit H. Schulzrinne
Internet-Draft Columbia U.
Expires: November 2, 2005 R. Marshall, Ed.
TCS
May 2005
Requirements for Emergency Context Resolution with Internet Technologies
draft-schulzrinne-ecrit-requirements-01
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
other groups may also distribute working documents as Internet-
Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
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 November 2, 2005.
Copyright Notice
Copyright (C) The Internet Society (2005).
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.
Schulzrinne & Marshall Expires November 2, 2005 [Page 1]
Internet-Draft ECRIT requirements May 2005
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 5
3. High-Level Requirements . . . . . . . . . . . . . . . . . . 9
4. Emergency Address . . . . . . . . . . . . . . . . . . . . . 11
5. Identifying the Caller Location . . . . . . . . . . . . . . 12
6. Identifying the Appropriate PSAP . . . . . . . . . . . . . . 13
7. Emergency Address Directory . . . . . . . . . . . . . . . . 16
8. Supplemental Information . . . . . . . . . . . . . . . . . . 17
9. Security Considerations . . . . . . . . . . . . . . . . . . 18
10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 19
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 20
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 21
12.1 Normative References . . . . . . . . . . . . . . . . . . 21
12.2 Informative References . . . . . . . . . . . . . . . . . 21
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 21
Intellectual Property and Copyright Statements . . . . . . . 23
Schulzrinne & Marshall Expires November 2, 2005 [Page 2]
Internet-Draft ECRIT requirements May 2005
1. Introduction
Users of telephone-like services expect to be able to call for
emergency help, such as police, the fire department or an ambulance,
regardless of where they are, what (if any) service provider they are
using and what kind of device they are using. Unfortunately, the
mechanisms for emergency calls that have evolved in the public
circuit-switched telephone network (PSTN) are not quite appropriate
for evolving IP-based voice, text and real-time multimedia
communications. This document outlines the key requirements that end
systems and network elements such as SIP proxies need to satisfy in
order to provide emergency call services that offer at least the same
functionality as existing PSTN services, with the goal of making
emergency calling more robust, cheaper to implement and multimedia-
capable.
In the future, users of other real-time and near real-time services
may also expect to be able to summon emergency help. For example,
instant messaging (IM) users may want to use such services. IM is
particularly helpful for hearing-disabled users (RFC 3351 [4]) and in
cases where bandwidth is scarce.
This document only focuses on end-to-end IP-based calls, i.e., where
the emergency call originates from an IP end system, (Internet
device), and terminates to an IP-capable PSAP, done entirely over an
IP network.
This document identifies functional and security issues for
determining the correct emergency identifier, for identifying the
appropriate PSAP (emergency address) and for identifying the caller
and its current location.
Emergency calls need to be identified (Section 6). Emergency
identifiers are used by the emergency caller to declare a call to be
an emergency call. The device MUST recognize the emergency
identifiers used and convert them to an emergency address to guide
the call to a PSAP. The emergency address MUST be a predefined
"sip", "sips" or "tel" URI scheme.
Emergency calls need to be routed to the appropriate PSAP (ref.
Section 6). Several terms are used for causing the call signaling to
reach the geographically appropriate PSAP. This has been referred to
as call routing, (PSAP) lookup or location mapping, all capturing
aspects of the problem.
Emergency calls need to identify who placed the call (Section 7). In
most jurisdictions, callers do not have a choice as to whether they
want to reveal their location or identity; such disclosure is
Schulzrinne & Marshall Expires November 2, 2005 [Page 3]
Internet-Draft ECRIT requirements May 2005
typically mandated by law.
Emergency calls need to identify the location from which the call is
initiated (Section 5). The caller location needs to be identified
for two purposes, namely to route the call to the appropriate PSAP
and to display the caller location to the call taker to simplify
dispatching emergency assistance to the correct location.
Emergency calls may not be subject to access restrictions placed on
non-emergency calls. Also, some call features may interfere with
emergency calls, particularly if triggered accidentally (Section 7).
Schulzrinne & Marshall Expires November 2, 2005 [Page 4]
Internet-Draft ECRIT requirements May 2005
2. Terminology
In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
and "OPTIONAL" are to be interpreted as described in RFC 2119 [1] and
indicate requirement levels for compliant implementations.
Since a requirements document does not directly specify an implement
able protocol, these compliance labels should be read as indicating
requirements for the protocol or architecture, rather than an
implementation.
For lack of a better term, we will use the term "caller" or
"emergency caller" to refer to the person placing an emergency call
or sending an emergency IM.
Access Infrastructure Provider (AIP): An organization that provides
physical network connectivity to its customers or users, e.g.
through digital subscriber lines, cable TV plants, Ethernet,
leased lines or radio frequencies. This entity may or may not
also provide IP routing, IP addresses, or other Internet protocol
services. Examples of such organizations include
telecommunication carriers, municipal utilities, larger
enterprises with their own network infrastructure, and government
organizations such as the military.
[Ed. AIP vs. IAP vs. ? not yet clear as to general agreement on a
single term.]
address: A description of a location of a person, organization, or
building, most often consisting of numerical and text elements
such as street number, street name, and city arranged in a
particular format.
administrative domain: An area or group of services falling with in a
specific category or jurisdictional boundary.
Application (Voice) Service Provider (ASP, VSP): The organization
that provides voice or other application-layer services, such as
call routing, a SIP URI or PSTN termination. This organization
can be a private individual, an enterprise, a government or a
service provider. We avoid the term voice service provider as
emergency calls are likely to use other media, including text and
video, in the future. For a particular user, the ASP may not be
the same organization as the AIP or ISP.
Schulzrinne & Marshall Expires November 2, 2005 [Page 5]
Internet-Draft ECRIT requirements May 2005
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).
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.)
civic location: A described location based on some defined grid, such
as a jurisdictional, postal, metropolitan, or rural reference
system (e.g. street address).
domain authentication and validation entity: A node that has
authority within a given domain to authenticate and validate user
location information.
Emergency Control Center (ECC): Facilities used by emergency
organizations to accept and handle emergency calls. A PSAP
(below) forwards emergency calls to the emergency control center,
which dispatches police, fire, rescue and other emergency
services. An ECC serves a limited geographic area. A PSAP and
ECC can be combined into one facility (ETSI SR 002 180
definition). We assume that the ECC is reachable by IP-based
protocols, such as SIP for call signaling and RTP for media.
emergency address: The sip:uri, sips:uri, or tel:uri which
represents the network address of the PSAP useful for the
completion of a VoIP emergency call.
emergency caller: The user or user device entity which sends his/her
location to another entity in the network.
emergency identifier: The numerical and/or text identifier which is
supplied by a user or a user device, which identifies the call as
an emergency call and is translated into an emergency address for
call routing and completion.
enhanced emergency service: Enhanced emergency services add the
ability to identify the caller identity and/or caller location to
basic emergency services. (Sometimes, only the caller location
may be known, e.g. from a public access point that is not owned by
an individual.)
Schulzrinne & Marshall Expires November 2, 2005 [Page 6]
Internet-Draft ECRIT requirements May 2005
ESRP (Emergency Services Routing Proxy): An ESRP is a call routing
entity that invokes the location-to-URL mapping, which in turn may
return either the URL for another ESRP or the PSAP. (In a SIP
system, the ESRP would typically be a SIP proxy, but could also be
a Back-to-back user agent (B2BUA).
geocoding: The process of finding the location of a street address on
a map. The location can be an x,y coordinate or a feature such as
a street segment, postal delivery location, or building. In GIS,
geocoding requires a reference dataset that contains address
attributes for the geographic features in the area of interest.
geographic coordinates: A representation (measurement) of a location
on the earth's surface expressed in degrees of latitude and
longitude.
geographic coordinate system: A reference system that uses latitude
and longitude to define the locations of points on the surface of
a sphere or spheroid.
geographic transformation: A method of converting data between two
geographic coordinate systems (datums).
geographic location: A reference to a locatable point described by a
set of defined coordinates within a geographic coordinate system,
(e.g. lat/lon within WGS-84 datum)
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.
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 address. 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 Key (LK): A key identifier used to query a location server
in order to retrieve a specific end user or end user device
location.
location validation: A caller location is considered valid if the
civic or geographic location is recognizable within an acceptable
location reference systems (e.g. USPS, WGS84, etc.), and can be
mapped to one or more PSAPs. Location validation ensures that a
location is reference able, but makes no assumption about the
Schulzrinne & Marshall Expires November 2, 2005 [Page 7]
Internet-Draft ECRIT requirements May 2005
association between the caller and the caller's location.
PSAP (Public Safety Answering Point): 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.
x,y coordinates: A pair of values that represents the distance from
an origin (0,0) along two axes, a horizontal axis (x) representing
east-west, and a vertical axis (y) representing north-south. On a
map, x,y coordinates are used to represent features at the
location they are found on the earth's spherical surface.
Schulzrinne & Marshall Expires November 2, 2005 [Page 8]
Internet-Draft ECRIT requirements May 2005
3. High-Level Requirements
Below, we summarize high-level architectural requirements that guide
some of the component requirements detailed later in the document.
R1. Application Service Provider: The existence of a Application
Service Provider (ASP) MUST NOT be assumed.
Motivation: The caller may not have a voice service provider,
i.e., a corporate entity that provides voice services as a
business. 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.
R2. International: The protocols and protocol extensions developed
MUST support regional, political and organizational differences.
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.
R3. Distributed Administration: Deployment of emergency services
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, AIPs or other participants.
R4. Multiple Modes: Multiple communication modes, including
Multimedia data and services MUST be supported.
Motivation: Emergency calling must support a variety of media, not
just voice and TDD (telecommunication device for the deaf) beyond
the capabilities of current limitations. Such additional media
should include conversational text, instant messaging and video.
In addition, it should be possible to convey telemetry data, such
as data from automobile crash sensors.
Schulzrinne & Marshall Expires November 2, 2005 [Page 9]
Internet-Draft ECRIT requirements May 2005
R5. Minimum Connectivity: An emergency call should succeed as long
as there is a working network path between the caller and the
PSAP. In particular, reliance during call set-up and calls on
entities and network paths that are located elsewhere should be
minimized.
Example: A caller in New York who needs to contact a PSAP in the
same city shouldn't have to get information from some entity in
Texas to make that call, as the call would then fail if the New
York to Texas path is unavailable. (To avoid this, the caller
could, for example, have cached mapping information, use a local
server that has the necessary information, or use other mechanisms
to avoid such off-path dependencies.)
[Ed. No resolution yet agreed to for the above requirement.]
R6. Incremental Deployment The output of the ECRIT mapping protocol
will be one or more URIs that can be used as the target of an
emergency communication. These must be usable by an appropriately
capable device even if that device has no knowledge of the mapping
protocol. As an example, if the mapping protocol returns a SIP
URI any SIP-capable phone should be able to use it as a target of
the call; no special extension to SIP should be required.
Schulzrinne & Marshall Expires November 2, 2005 [Page 10]
Internet-Draft ECRIT requirements May 2005
4. Emergency Address
A1. Universal: Each device and all network elements MUST recognize
one or more universal (global) emergency identifiers, regardless
of the location of the device, the service provider used (if any)
or other factors. Examples of these might include: 911, 112, and
sos.*
Motivation: SIP and other call signaling protocols are not
specific to one country or service provider and devices are likely
to be used across national or service provider boundaries. Since
services such as disabling mandatory authentication for emergency
calls requires the cooperation of outbound proxies, the outbound
proxy has to be able to recognize the emergency address and be
assured that it will be routed as an emergency call. Thus, a
simple declaration on a random URI that it is an emergency call
will likely lead to fraud and possibly attacks on the network
infrastructure. A universal address also makes it possible to
create user interface elements that are correctly configured
without user intervention. UA features could be made to work
without such an identifier, but the user interface would then have
to provide an unambiguous way to declare a particular call an
emergency call.
A3. Recognizable: Emergency calls MUST be recognizable by user
agents, proxies and other network elements. To prevent fraud, an
address identified as an emergency number for call features or
authentication override MUST also cause routing to a PSAP.
A4. Minimal configuration: Any local emergency identifiers SHOULD be
configured automatically, without user intervention.
Motivation: A new UA "unofficially imported" into an organization
from elsewhere should have the same emergency capabilities as one
officially installed.
A6. Backwards-compatible: Existing devices that predate the
specification of emergency call-related protocols and conventions
MUST be able reach a PSAP.
Schulzrinne & Marshall Expires November 2, 2005 [Page 11]
Internet-Draft ECRIT requirements May 2005
5. Identifying the Caller Location
This section supplements the requirements outlined in RFC 3693 [5].
Thus, the requirements enumerated there are not repeated here. In
general, we can distinguish three modes of operation:
UA-inserted: The caller's user agent inserts the location
information, derived from sources such as GPS, DHCP or link-layer
announcements (LLDP).
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.
L6. Validation of civic location: It MUST be possible to validate an
address prior to its use in an actual emergency call.
Motivation: Location validation refers to a process to determine
whether or not a given civic location is valid or not. A location
is said to be valid if it can be mapped exactly to a unique
emergency address for a PSAP, known to the emergency services
directory/mapping database.
L10. Preferred datum: The preferred geographic coordinate system for
emergency calls SHALL be WGS-84.
L28. Location Provided: If location is provided to the routing
proxy, it MUST be provided to the PSAP.
Motivation: Transmission of the current location of the
contacting device to the PSAP.
Schulzrinne & Marshall Expires November 2, 2005 [Page 12]
Internet-Draft ECRIT requirements May 2005
6. Identifying the Appropriate PSAP
From the previous section, we take the requirement of a single (or
small number of) emergency addresses which are independent of the
caller's location. However, since for reasons of robustness,
jurisdiction and local knowledge, PSAPs only serve a limited
geographic region, having the call reach the correct PSAP is crucial.
While a PSAP may be able to transfer an errant call, any such
transfer is likely to add tens of seconds to call setup latency and
is prone to errors. (In the United States, there are about 6,100
PSAPs.)
There appears to be two basic architectures for translating an
emergency identifier into the correct PSAP emergency address. We
refer to these as caller-based and mediated. In caller-based
resolution, the caller's user agent consults a directory and
determines the correct PSAP based on its location. We assume that
the user agent can determine its own location, either by knowing it
locally or asking some third party for it. A UA could conceivably
store a complete list of all PSAPs across the world, but that would
require frequent synchronization with a master database as PSAPs
merge or jurisdictional boundaries change.
For mediated resolution, a call signaling server, such as a SIP
(outbound) proxy or redirect server performs this function. Note
that the latter case includes the architecture where the call is
effectively routed to a copy of the database, rather than having some
non-SIP protocol query the database. Since servers may be used as
outbound proxy servers by clients that are not in the same geographic
area as the proxy server, any proxy server has to be able to
translate any caller location to the appropriate PSAP. (A traveler
may, for example, accidentally or intentionally configure its home
proxy server as its outbound proxy server, even while far away from
home.)
The resolution may take place well before the actual emergency call
is placed, or at the time of the call.
The problem is harder than for traditional web or email services.
There, the originator knows which entity it wants to reach,
identified by the email address or HTTP URL. However, the emergency
caller only dialed an emergency identifier. Depending on the
location, any of several ten thousand PSAPs around the world could be
valid. In addition, the caller probably does not care which specific
PSAP answers the call, but rather that it be an accredited PSAP, e.g.
one run by the local government authorities. (Many PSAPs are run by
private entities. For example, universities and corporations with
large campuses often have their own emergency response centers.)
Schulzrinne & Marshall Expires November 2, 2005 [Page 13]
Internet-Draft ECRIT requirements May 2005
I1. Correct PSAP: Calls Must be routed to the PSAP responsible for
this particular geographic area.
Motivation: 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.
I3. Multi-stage resolution: A mapping server for a large geographic
area SHOULD be able to refer clients to mapping servers
responsible for subsets of the geographic area.
Motivation: In some cases, an initial mapping may provide a single
URL for a large geographic area. The ESRP identified by that URL
then re-invokes the mapping protocol on a different database to
obtain another URL for an ESRP or PSAP covering a smaller area.
I4. Return multiple PSAPs: The mapping protocol MUST be able to
return multiple URLs for different PSAPs that cover the same area.
The mapping protocol MUST 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. The choice would typically be made by an ESRP based on
local policy, not by a human user.
I7. Traceable resolution: The entity requesting mapping SHOULD be
able to definitively and securely determine the entity or entities
who provided the emergency address resolution information.
I8. 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.
I10. Incrementally deployable: The mapping function MUST be capable
of being deployed incrementally. 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.
Schulzrinne & Marshall Expires November 2, 2005 [Page 14]
Internet-Draft ECRIT requirements May 2005
I13. Existing infrastructure support: It SHOULD be possible for the
mapping function to provide information that allows the requesting
entity to determine if ecrit compatible emergency call support is
available in the jurisdiction where the location is proferred for
mapping. Where ecrit compatible emergency calling is NOT
available, the mapping function MAY yield information which could
be used to route emergency calls using existing, country specific
methods. For example, a tel URI may be provided for a PSTN routed
call, or a routing code which has meaning only within a country
specific routing mechanism.
I25. Mapping can be requested from anywhere: The mapping protocol
MUST be able to provide the mapping regardless of where the
querier is located, either geographically or by network location.
Motivation: The querier, 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.
I31: In response to a mapping request, a server will normally provide
a URI or set of URIs for contacting the appropriate PSAP. The
protocol must also be to return a URI or contact method explicitly
marked as an alternate contact. When this is used will be
described in an operational document.
I39: It SHOULD be possible to have updates of location (which may
occur when measuring devices provider early, but imprecise "first
fix" location) which can change routing of calls.
I40. The mapping protocol MUST be extensible to allow for the
inclusion of new location fields.
Motivation: This is needed, for example, to accommodate future
extensions to location information that might be included in the
PIDF-LO.
I41. Split responsibility: The mapping protocol MUST allow that
within a single level of the civic address hierarchy, multiple
mapping servers handle subsets of the data elements.
Motivation: For example, two directories for the same city or
county may handle different streets within that city or county.
I42. The mapping function MUST be able to be invoked at any time,
including while an emergency call is in process.
Schulzrinne & Marshall Expires November 2, 2005 [Page 15]
Internet-Draft ECRIT requirements May 2005
7. Emergency Address Directory
D1. 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.
D5. Call setup latency: The directory lookup SHOULD minimize any
added delay to the call setup.
Motivation: Since outbound proxies will likely be asked to
resolve the same geographic coordinates repeatedly, a suitable
time-limited caching mechanism should be supported.
D7. Referral: The querier MUST be able to contact any server and be
referred to another server that is more qualified to answer the
query.
Motivation: This requirement alleviates the potential for
misconfigurations to cause calls to fail, particularly for caller-
based queries.
D9. Baseline query protocol: A mandatory-to-implement protocol MUST
be specified.
Motivation: An over-abundance of similarly-capable choices
appears undesirable for interoperability.
Schulzrinne & Marshall Expires November 2, 2005 [Page 16]
Internet-Draft ECRIT requirements May 2005
8. Supplemental Information
SD1 The format both of the query and of the result returned by the
protocol must be extensible to accommodate new types of
information.
Motivation: In addition to information sent with the call,
additional information may be available, supplemental to the call,
which is retrieved from internal or external databases using a key
to the information included with the call. This key may also
include information to identify/address the database.
SD2 Additional information MAY be available to the call taker based
on the location of the caller.
SD3 Additional information MAY be available to the call taker based
on the owner of the structure.
SD4 Additional information MAY be available to the call taker based
on the tenant of the structure.
SD5 Where a vehicle is involved, additional information MAY be
available.
SD6 Additional information MAY be available based on the Address of
Record (AoR) of the caller. In this context, AoR equates to the
caller.
SD7 Consideration SHOULD be given to permitting users to have domain
independent mechanisms to supply information related to the
caller, for example, another datum related to user.
SD8. Additional Data: Transfer of additional data SHOULD be
supported.
Motivation: Capabilities to contact PSAP by automatic means and
for the transfer of additional information (alarm equipment, cars,
buses, trucks with dangerous loads, ...)
SD9 Mechanism MUST be provided to automatically generate and provide
misroute and location error reports.
Schulzrinne & Marshall Expires November 2, 2005 [Page 17]
Internet-Draft ECRIT requirements May 2005
9. Security Considerations
Note: Security Considerations are referenced in the ECRIT security
document [3].
Schulzrinne & Marshall Expires November 2, 2005 [Page 18]
Internet-Draft ECRIT requirements May 2005
10. Contributors
The information contained in this document is a result of a joint
effort based on individual contributions by those involved in the
ECRIT WG. The contributors include Nadine Abbott, Hideki Arai,
Martin Dawson, Motoharu Kawanishi, Brian Rosen, Richard Stastny,
Martin Thomson, James Winterbottom.
The contributors can be reached at:
Nadine Abbott nabbott@telcordia.com
Hideki Arai arai859@oki.com
Martin Dawson mdawson@nortelnetworks.com
Motoharu Kawanishi kawanishi381@oki.com
Brian Rosen br@brianrosen.net
Richard Stastny Richard.Stastny@oefeg.at
Martin Thomson marthom@nortelnetworks.com
James Winterbottom winterb@nortelnetworks.com
Schulzrinne & Marshall Expires November 2, 2005 [Page 19]
Internet-Draft ECRIT requirements May 2005
11. Acknowledgments
Schulzrinne & Marshall Expires November 2, 2005 [Page 20]
Internet-Draft ECRIT requirements May 2005
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.
[2] Polk, J., "Requirements for Session Initiation Protocol Location
Conveyance", draft-ietf-sipping-location-requirements-02 (work
in progress), October 2004.
[3] Tschofenig, H., "Security Threats and Requirements for Emergency
Calling", draft-tschofenig-ecrit-security-threats-00 (work in
progress), May 2005.
12.2 Informative References
[4] 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.
[5] Cuellar, J., Morris, J., Mulligan, D., Peterson, J., and J.
Polk, "Geopriv Requirements", RFC 3693, February 2004.
[6] National Emergency Number Assocation, "NENA technical
information document on the interface between the E9-1-1 service
providers network and the Internet protocol (IP) PSAP",
NENA NENA-08-501, February 2003.
Authors' Addresses
Henning Schulzrinne
Columbia University
Department of Computer Science
450 Computer Science Building
New York, NY 10027
US
Phone: +1 212 939 7004
Email: hgs+ecrit@cs.columbia.edu
URI: http://www.cs.columbia.edu
Schulzrinne & Marshall Expires November 2, 2005 [Page 21]
Internet-Draft ECRIT requirements May 2005
Roger Marshall (editor)
TeleCommunication Systems
2401 Elliott Avenue
2nd Floor
Seattle, WA 98121
US
Phone: +1 206 792 2424
Email: rmarshall@telecomsys.com
URI: http://www.telecomsys.com
Schulzrinne & Marshall Expires November 2, 2005 [Page 22]
Internet-Draft ECRIT requirements May 2005
Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available, or the result of an
attempt made to obtain a general license or permission for the use of
such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org.
Disclaimer of Validity
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement
Copyright (C) The Internet Society (2005). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
Acknowledgment
Funding for the RFC Editor function is currently provided by the
Internet Society.
Schulzrinne & Marshall Expires November 2, 2005 [Page 23]
