< draft-ietf-ecrit-unauthenticated-access-06.txt		draft-ietf-ecrit-unauthenticated-access-07.txt >
	ECRIT H. Schulzrinne		ECRIT H. Schulzrinne
	Internet-Draft Columbia University		Internet-Draft Columbia University
	Intended status: Standards Track S. McCann		Intended status: Standards Track S. McCann
	Expires: November 01, 2013 Research in Motion UK Ltd		Expires: January 14, 2014 Research in Motion UK Ltd
	G. Bajko		G. Bajko
	Nokia		Nokia
	H. Tschofenig		H. Tschofenig
	Nokia Siemens Networks		Nokia Siemens Networks
	D. Kroeselberg		D. Kroeselberg
	Siemens		Siemens
	April 30, 2013		July 13, 2013
	Extensions to the Emergency Services Architecture for dealing with		Extensions to the Emergency Services Architecture for dealing with
	Unauthenticated and Unauthorized Devices		Unauthenticated and Unauthorized Devices
	draft-ietf-ecrit-unauthenticated-access-06.txt		draft-ietf-ecrit-unauthenticated-access-07.txt
	Abstract		Abstract
	The IETF emergency services architecture assumes that the calling		The IETF emergency services architecture assumes that the calling
	device has acquired rights to use the access network or that no		device has acquired rights to use the access network or that no
	authentication is required for the access network, such as for public		authentication is required for the access network, such as for public
	wireless access points. Subsequent protocol interactions, such as		wireless access points. Subsequent protocol interactions, such as
	obtaining location information, learning the address of the Public		obtaining location information, learning the address of the Public
	Safety Answering Point (PSAP) and the emergency call itself are		Safety Answering Point (PSAP) and the emergency call itself are
	largely decoupled from the underlying network access procedures.		largely decoupled from the underlying network access procedures.
	skipping to change at page 2, line 7 ¶		skipping to change at page 2, line 7 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on November 01, 2013.		This Internet-Draft will expire on January 14, 2014.
	Copyright Notice		Copyright Notice
	Copyright (c) 2013 IETF Trust and the persons identified as the		Copyright (c) 2013 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 2, line 30 ¶		skipping to change at page 2, line 30 ¶
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
	2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5		2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
	3. Use Case Categories . . . . . . . . . . . . . . . . . . . . . 5		3. Use Case Categories . . . . . . . . . . . . . . . . . . . . . 5
	4. ZBP Considerations . . . . . . . . . . . . . . . . . . . . . 7		4. ZBP Considerations . . . . . . . . . . . . . . . . . . . . . 7
	5. NASP Considerations . . . . . . . . . . . . . . . . . . . . . 7		5. NASP Considerations . . . . . . . . . . . . . . . . . . . . . 8
	5.1. End Host Profile . . . . . . . . . . . . . . . . . . . . 9		5.1. End Host Profile . . . . . . . . . . . . . . . . . . . . 10
	5.1.1. LoST Server Discovery . . . . . . . . . . . . . . . . 9		5.1.1. LoST Server Discovery . . . . . . . . . . . . . . . . 10
	5.1.2. ESRP Discovery . . . . . . . . . . . . . . . . . . . 9		5.1.2. ESRP Discovery . . . . . . . . . . . . . . . . . . . 10
	5.1.3. Location Determination and Location Configuration . . 9		5.1.3. Location Determination and Location Configuration . . 10
	5.1.4. Emergency Call Identification . . . . . . . . . . . . 10		5.1.4. Emergency Call Identification . . . . . . . . . . . . 10
	5.1.5. SIP Emergency Call Signaling . . . . . . . . . . . . 10		5.1.5. SIP Emergency Call Signaling . . . . . . . . . . . . 10
	5.1.6. Media . . . . . . . . . . . . . . . . . . . . . . . . 10		5.1.6. Media . . . . . . . . . . . . . . . . . . . . . . . . 11
	5.1.7. Testing . . . . . . . . . . . . . . . . . . . . . . . 10		5.1.7. Testing . . . . . . . . . . . . . . . . . . . . . . . 11
	5.2. IAP/ISP Profile . . . . . . . . . . . . . . . . . . . . . 11		5.2. IAP/ISP Profile . . . . . . . . . . . . . . . . . . . . . 11
	5.2.1. ESRP Discovery . . . . . . . . . . . . . . . . . . . 11		5.2.1. ESRP Discovery . . . . . . . . . . . . . . . . . . . 11
	5.2.2. Location Determination and Location Configuration . . 11		5.2.2. Location Determination and Location Configuration . . 11
	5.3. ESRP Profile . . . . . . . . . . . . . . . . . . . . . . 11		5.3. ESRP Profile . . . . . . . . . . . . . . . . . . . . . . 11
	5.3.1. Emergency Call Routing . . . . . . . . . . . . . . . 11		5.3.1. Emergency Call Routing . . . . . . . . . . . . . . . 11
	5.3.2. Emergency Call Identification . . . . . . . . . . . . 11		5.3.2. Emergency Call Identification . . . . . . . . . . . . 12
	5.3.3. SIP Emergency Call Signaling . . . . . . . . . . . . 11		5.3.3. SIP Emergency Call Signaling . . . . . . . . . . . . 12
	6. Lower Layer Considerations for NAA Case . . . . . . . . . . . 11		6. Lower Layer Considerations for NAA Case . . . . . . . . . . . 12
	6.1. Link Layer Emergency Indication . . . . . . . . . . . . . 12		6.1. Link Layer Emergency Indication . . . . . . . . . . . . . 13
	6.2. Securing Network Attachment in NAA Cases . . . . . . . . 13		6.2. Securing Network Attachment in NAA Cases . . . . . . . . 14
	7. Security Considerations . . . . . . . . . . . . . . . . . . . 15		7. Security Considerations . . . . . . . . . . . . . . . . . . . 15
	8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16		8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16
	9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16		9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
	10. References . . . . . . . . . . . . . . . . . . . . . . . . . 16		10. References . . . . . . . . . . . . . . . . . . . . . . . . . 16
	10.1. Normative References . . . . . . . . . . . . . . . . . . 16		10.1. Normative References . . . . . . . . . . . . . . . . . . 16
	10.2. Informative References . . . . . . . . . . . . . . . . . 17		10.2. Informative References . . . . . . . . . . . . . . . . . 17
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18
	1. Introduction		1. Introduction
	skipping to change at page 3, line 22 ¶		skipping to change at page 3, line 22 ¶
	is one of the fundamental and most-valued functions of the telephone.		is one of the fundamental and most-valued functions of the telephone.
	As telephone functionality moves from circuit-switched telephony to		As telephone functionality moves from circuit-switched telephony to
	Internet telephony, its users rightfully expect that this core		Internet telephony, its users rightfully expect that this core
	functionality will continue to work at least as well as it has for		functionality will continue to work at least as well as it has for
	the older technology. New devices and services are being made		the older technology. New devices and services are being made
	available that could be used to make a request for help, which are		available that could be used to make a request for help, which are
	not traditional telephones, and users are increasingly expecting them		not traditional telephones, and users are increasingly expecting them
	to be used to place emergency calls.		to be used to place emergency calls.
	Roughly speaking, the IETF emergency services architecture (see		Roughly speaking, the IETF emergency services architecture (see
	[I-D.ietf-ecrit-phonebcp] and [RFC6443]) divides responsibility for		[RFC6881] and [RFC6443]) divides responsibility for handling
	handling emergency calls between the access network (ISP), the		emergency calls between the access network (ISP), the application
	application service provider (ASP) that may be a VoIP service		service provider (ASP) that may be a VoIP service provider and the
	provider and the provider of emergency signaling services, the		provider of emergency signaling services, the emergency service
	emergency service network (ESN). The access network may provide		network (ESN). The access network may provide location information
	location information to end systems, but does not have to provide any		to end systems, but does not have to provide any ASP signaling
	ASP signaling functionality. The emergency caller can reach the ESN		functionality. The emergency caller can reach the ESN either
	either directly or through the ASP's outbound proxy. Any of the		directly or through the ASP's outbound proxy. Any of the three
	three parties can provide the mapping from location to PSAP URI by		parties can provide the mapping from location to PSAP URI by offering
	offering LoST [RFC5222] services.		LoST [RFC5222] services.
	In general, a set of automated configuration mechanisms allows a		In general, a set of automated configuration mechanisms allows a
	device to function in a variety of architectures, without the user		device to function in a variety of architectures, without the user
	being aware of the details on who provides location, mapping services		being aware of the details on who provides location, mapping services
	or call routing services. However, if emergency calling is to be		or call routing services. However, if emergency calling is to be
	supported when the calling device lacks access network authorization		supported when the calling device lacks access network authorization
	or does not have an ASP, one or more of the providers may need to		or does not have an ASP, one or more of the providers may need to
	provide additional services and functions.		provide additional services and functions.
	In all cases, the end device has to be able to perform a LoST lookup		In all cases, the end device has to be able to perform a LoST lookup
	skipping to change at page 5, line 13 ¶		skipping to change at page 5, line 13 ¶
	environments.		environments.
	There are also indications that the functionality of unauthenticated		There are also indications that the functionality of unauthenticated
	emergency calls (called SIM-less calls) in today's cellular system in		emergency calls (called SIM-less calls) in today's cellular system in
	certain countries leads to a fair amount of hoax or test calls. This		certain countries leads to a fair amount of hoax or test calls. This
	causes overload situations at PSAPs which is considered harmful to		causes overload situations at PSAPs which is considered harmful to
	the overall availability and reliability of emergency services.		the overall availability and reliability of emergency services.
	As an example, Federal Office of Communications (OFCOM, Switzerland)		As an example, Federal Office of Communications (OFCOM, Switzerland)
	provided statistics about emergency (112) calls in Switzerland from		provided statistics about emergency (112) calls in Switzerland from
	Jan. 1997 to Nov. 2001. Switzerland did not offer SIM-less		Jan. 1997 to Nov. 2001. Switzerland did not offer SIM-less
	emergency calls except for almost a month in July 2000 where a		emergency calls except for almost a month in July 2000 where a
	significant increase in hoax and test calls was reported. As a		significant increase in hoax and test calls was reported. As a
	consequence, the functionality was disabled again. More details can		consequence, the functionality was disabled again. More details can
	be found in the panel presentations of the 3rd SDO Emergency Services		be found in the panel presentations of the 3rd SDO Emergency Services
	Workshop [esw07].		Workshop [esw07].
	2. Terminology		2. Terminology
	In this document, the key words "MUST", "MUST NOT", "REQUIRED",		In this document, the key words "MUST", "MUST NOT", "REQUIRED",
	"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",		"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
	skipping to change at page 6, line 49 ¶		skipping to change at page 6, line 49 ¶
	network +--->| End | | +---------------+		network +--->| End | | +---------------+
	attachment| `...../ | YES | | NO		attachment| `...../ | YES | | NO
	possible? | | | |		possible? | | | |
	v | v v		v | v v
	+------------+ | +------------+ +------------+		+------------+ | +------------+ +------------+
	| Execute | | | Execute | | Execute |		| Execute | | | Execute | | Execute |
	| NAA |--------+ | Phone BCP | | NASP |		| NAA |--------+ | Phone BCP | | NASP |
	| Procedures | | Procedures | | Procedures |		| Procedures | | Procedures | | Procedures |
	+------------+ +------------+ +------------+		+------------+ +------------+ +------------+
	Authorization for| |		Authorization for| |
	Emergency Call? | |		making an | |
			emergency call | |
			with the ASP/VSP?| |
	+--------------+ v		+--------------+ v
	| NO | YES +-----Y		| NO | YES +-----Y
	| | | Done|		| | | Done|
	v v `...../		v v `...../
	+------------+ +------------+		+------------+ +------------+
	| Execute | | Execute |		| Execute | | Execute |
	| ZBP | | Phone BCP |		| ZBP | | Phone BCP |
	| Procedures | | Procedures |		| Procedures | | Procedures |
	+------------+ +------------+		+------------+ +------------+
	| |		| |
	skipping to change at page 7, line 26 ¶		skipping to change at page 7, line 29 ¶
	+-----Y +-----Y		+-----Y +-----Y
	| Done| | Done|		| Done| | Done|
	`...../ `...../		`...../ `...../
	Abbreviations:		Abbreviations:
	LLA: Link Layer Attachment		LLA: Link Layer Attachment
	ES: Emergency Services		ES: Emergency Services
	Figure 1: Flow Diagram		Figure 1: Flow Diagram
			The "No Access Authentication (NAA)" procedures are described in
			Section 6. The "Zero-balance ASP (ZBP)" procedures are described in
			Section 4. The "No ASP (NASP)" procedures are described in
			Section 5. The Phone BCP procedures are described in [RFC6881]. The
			"Link Layer Attachment (LLA)" procedures are not described in this
			document since they are specific to the link layer technology in use.
	4. ZBP Considerations		4. ZBP Considerations
	ZBP includes all cases where a subscriber is known to an ASP, but		ZBP includes all cases where a subscriber is known to an ASP, but
	lacks the necessary authorization to access regular ASP services.		lacks the necessary authorization to access regular ASP services.
	Example ZBP cases include empty prepaid accounts, barred accounts,		Example ZBP cases include empty prepaid accounts, barred accounts,
	roaming and mobility restrictions, or any other conditions set by ASP		roaming and mobility restrictions, or any other conditions set by ASP
	policy.		policy.
	Local regulation might demand that emergency calls are always		Local regulation might demand that emergency calls cannot proceed
	authorized. An ASP can identify emergency sessions by identifying		without successful service authorization. In regulatory regimes,
	the service URN [RFC5031] used in call setup. Emergency calls can		however, it may be possible to allow emergency calls to continue
	then be authorized accordingly. The ZBP case therefore only affects		despite authorization failures. To distinguish an emergency call
	the ASP.		from a regular call an ASP can identify emergency sessions by
			inspecting the service URN [RFC5031] used in call setup. The ZBP
			case therefore only affects the ASP.
	Permitting a call with limited authorization could present an		Permitting a call despite authorization failures could present an
	opportunity for abuse. The ASP MAY choose to validate session		opportunity for abuse. The ASP may choose to verify the destination
	initiation messages for valid destinations, see Section 7.		of the emergency calls and to only permit calls to certain, pre-
			configured entities (e.g., to local PSAPs). Section 7 discusses this
			topic in more detail.
	An ASP without a regulatory requirement to authorize emergency calls		An ASP without a regulatory requirement to authorize emergency calls
	can deny emergency call setup. Where an ASP does not authorize an		can deny emergency call setup. Where an ASP does not authorize an
	emergency call, the caller can fall back to NASP procedures.		emergency call, the caller may be able to fall back to NASP
			procedures.
	5. NASP Considerations		5. NASP Considerations
	To start the description we consider the sequence of steps that are		To start the description we consider the sequence of steps that are
	executed in an emergency call based on Figure 2.		executed in an emergency call based on Figure 2.
	o As an initial step the devices attaches to the network as shown in		o As an initial step the devices attaches to the network as shown in
	step (1). This step is outside the scope of this section.		step (1). This step is outside the scope of this section.
	o When the link layer network attachment procedure is completed the		o When the link layer network attachment procedure is completed the
	end host learns basic configuration information using DHCP from		end host learns basic IP configuration information using DHCP from
	the ISP, as shown in step (2).		the ISP, as shown in step (2).
	o When the IP address configuration is completed then the end host		o When the IP address configuration is completed then the end host
	starts an interaction with the discovered Location Configuration		starts an interaction with the discovered Location Configuration
	Server at the ISP, as shown in step (3). The ISP may in certain		Server at the ISP, as shown in step (3). The ISP may in certain
	deployments need to interact with the IAP. This protocol exchange		deployments need to interact with the IAP. This protocol exchange
	is shown in step (4).		is shown in step (4).
	o Once location information is obtained the end host triggers the		o Once location information is obtained the end host triggers the
	LoST protocol to obtain the address of the ESRP/PSAP. This step		LoST protocol to obtain the address of the ESRP/PSAP. This step
	skipping to change at page 10, line 4 ¶		skipping to change at page 10, line 18 ¶
	The end host MUST discover a LoST server [RFC5222] using DHCP		The end host MUST discover a LoST server [RFC5222] using DHCP
	[RFC5223].		[RFC5223].
	5.1.2. ESRP Discovery		5.1.2. ESRP Discovery
	The end host MUST discover the ESRP using the LoST protocol		The end host MUST discover the ESRP using the LoST protocol
	[RFC5222].		[RFC5222].
	5.1.3. Location Determination and Location Configuration		5.1.3. Location Determination and Location Configuration
	The end host MUST support location acquisition and the LCPs described		The end host MUST support location acquisition and the LCPs described
	in Section 6.5 of [I-D.ietf-ecrit-phonebcp]. The description in		in Section 6.5 of [RFC6881]. The description in Section 6.5 and 6.6
	Section 6.5 and 6.6 of [I-D.ietf-ecrit-phonebcp] regarding the		of [RFC6881] regarding the interaction between the device and the LIS
	interaction between the device and the LIS applies to this document.		applies to this document.
	The SIP UA in the end host MUST attach available location information		The SIP UA in the end host MUST attach available location information
	in a PIDF-LO [RFC4119] when making an emergency call. When		in a PIDF-LO [RFC4119] when making an emergency call. When
	constructing the PIDF-LO the guidelines in PIDF-LO profile [RFC5491]		constructing the PIDF-LO the guidelines in PIDF-LO profile [RFC5491]
	MUST be followed. For civic location information the format defined		MUST be followed. For civic location information the format defined
	in [RFC5139] MUST be supported.		in [RFC5139] MUST be supported.
	5.1.4. Emergency Call Identification		5.1.4. Emergency Call Identification
	To determine which calls are emergency calls, some entity needs to		To determine which calls are emergency calls, some entity needs to
	map a user entered dialstring into this URN scheme. A user may		map a user entered dialstring into this URN scheme. A user may
	"dial" 1-1-2, but the call would be sent to urn:service:sos. This		"dial" 1-1-2, 9-1-1, etc., but the call would be sent to
	mapping SHOULD be performed at the endpoint device.		urn:service:sos. This mapping SHOULD be performed at the endpoint
			device.
	End hosts MUST use the Service URN mechanism [RFC5031] to mark calls		End hosts MUST use the Service URN mechanism [RFC5031] to mark calls
	as emergency calls for their home emergency dial string.		as emergency calls for their home emergency dial string.
	5.1.5. SIP Emergency Call Signaling		5.1.5. SIP Emergency Call Signaling
	SIP signaling capabilities [RFC3261] are mandated for end hosts.		SIP signaling capabilities [RFC3261] are mandated for end hosts.
	The initial SIP signaling method is an INVITE. The SIP INVITE		The initial SIP signaling method is an INVITE. The SIP INVITE
	request MUST be constructed according to the requirements in		request MUST be constructed according to the requirements in
	Section 9.2 [I-D.ietf-ecrit-phonebcp].		Section 9.2 [RFC6881].
	Regarding callback behavior SIP UAs SHOULD place a globally routable		Regarding callback behavior SIP UAs SHOULD place a globally routable
	URI in a Contact: header.		URI in a Contact: header.
	5.1.6. Media		5.1.6. Media
	End points MUST comply with the media requirements for end points		End points MUST comply with the media requirements for end points
	placing an emergency call found in Section 14 of		placing an emergency call found in Section 14 of [RFC6881].
	[I-D.ietf-ecrit-phonebcp].
	5.1.7. Testing		5.1.7. Testing
	The description in Section 15 of [I-D.ietf-ecrit-phonebcp] is fully		The description in Section 15 of [RFC6881] is fully applicable to
	applicable to this document.		this document.
	5.2. IAP/ISP Profile		5.2. IAP/ISP Profile
	5.2.1. ESRP Discovery		5.2.1. ESRP Discovery
	An ISP MUST provision a DHCP server with information about LoST		An ISP MUST provision a DHCP server with information about LoST
	servers [RFC5223]. An ISP operator may choose to deploy a LoST		servers [RFC5223]. An ISP operator may choose to deploy a LoST
	server or to outsource it to other parties.		server or to outsource it to other parties.
	5.2.2. Location Determination and Location Configuration		5.2.2. Location Determination and Location Configuration
	The ISP is responsible for location determination and exposes this		The ISP is responsible for location determination and exposes this
	information to the end points via location configuration protocols.		information to the end points via location configuration protocols.
	The considerations described in [RFC6444] are applicable to this		The considerations described in [RFC6444] are applicable to this
	document.		document.
	The ISP MUST support one of the LCPs described in Section 6.5 of		The ISP MUST support one of the LCPs described in Section 6.5 of
	[I-D.ietf-ecrit-phonebcp]. The description in Section 6.5 and 6.6 of		[RFC6881]. The description in Section 6.5 and 6.6 of [RFC6881]
	[I-D.ietf-ecrit-phonebcp] regarding the interaction between the end		regarding the interaction between the end device and the LIS applies
	device and the LIS applies to this document.		to this document.
	The interaction between the LIS at the ISP and the IAP is often		The interaction between the LIS at the ISP and the IAP is often
	priorietary but the description in		priorietary but the description in
	[I-D.winterbottom-geopriv-lis2lis-req] may be relevant to the reader.		[I-D.winterbottom-geopriv-lis2lis-req] may be relevant to the reader.
	5.3. ESRP Profile		5.3. ESRP Profile
	5.3.1. Emergency Call Routing		5.3.1. Emergency Call Routing
	The ESRP continues to route the emergency call to the PSAP		The ESRP continues to route the emergency call to the PSAP
	skipping to change at page 12, line 23 ¶		skipping to change at page 12, line 39 ¶
	To perform network attachment and get access to the resources		To perform network attachment and get access to the resources
	provided by an IAP/ISP, the end host uses access technology specific		provided by an IAP/ISP, the end host uses access technology specific
	network attachment procedures, including for example network		network attachment procedures, including for example network
	detection and selection, authentication, and authorization. For		detection and selection, authentication, and authorization. For
	initial network attachment of an emergency service requester, the		initial network attachment of an emergency service requester, the
	method of how the emergency indication is given to the IAP/ISP is		method of how the emergency indication is given to the IAP/ISP is
	specific to the access technology. However, a number of general		specific to the access technology. However, a number of general
	approaches can be identified:		approaches can be identified:
	Link layer emergency indication: The end host provides an		Link layer emergency indication: The end host provides an
	indication, e.g. an emergency parameter or flag, as part of the		indication, e.g., an emergency parameter or flag, as part of the
	link layer signaling for initial network attachment. Examples		link layer signaling for initial network attachment. Examples
	include an emergency bit signalled in the IEEE 802.16-2009		include an emergency bit signalled in the IEEE 802.16-2009
	wireless link. In IEEE 802.11 WLAN, an emergency support		wireless link. In IEEE 802.11 WLAN, an emergency support
	indicator allows the STA to download before association an NAI		indicator allows the STA to download before association an NAI
	which it can use to request server side authentication only for an		which it can use to request server side authentication only for an
	802.1x network.		802.1x network.
	Higher-layer emergency indication: Typically emergency indication in		Higher-layer emergency indication: Typically emergency indication in
	access authentication. The emergency caller's end host provides		access authentication. The emergency caller's end host provides
	an indication as part of the access authentication exchanges. EAP		an indication as part of the access authentication exchanges. EAP
	based authentication is of particular relevance here. Examples		based authentication is of particular relevance here. Examples
	are the EAP NAI decoration used in WiMAX networks and modification		are the EAP NAI decoration used in WiMAX networks and modification
	of the authentication exchange in IEEE 802.11. [nwgstg3].		of the authentication exchange in IEEE 802.11. [nwgstg3].
	6.1. Link Layer Emergency Indication		6.1. Link Layer Emergency Indication
	In general, link layer emergency indications provide good integration		In general, link layer emergency indications provide good integration
	into the actual network access procedure regarding the enabling of		into the actual network access procedure regarding the enabling of
	means to recognize and prioritize an emergency service request from		means to recognize and prioritize an emergency service request from
	an end host at a very early stage of the network attachment		an end host at a very early stage of the network attachment
	procedure. However, support in end hosts for such methods cannot be		procedure. However, support in end hosts for such methods cannot be
	considered to be commonly available.		considered to be commonly available.
	skipping to change at page 13, line 30 ¶		skipping to change at page 13, line 49 ¶
	authorization server that owns the policy for granting access to		authorization server that owns the policy for granting access to
	the network resources. As a result, there is no direct dependency		the network resources. As a result, there is no direct dependency
	on the access network architecture that otherwise would need to		on the access network architecture that otherwise would need to
	take care of merging link-layer indications into the AA and policy		take care of merging link-layer indications into the AA and policy
	decision process.		decision process.
	o EAP signaling happens at a relatively early stage of network		o EAP signaling happens at a relatively early stage of network
	attachment, so it is likely to match most requirements for		attachment, so it is likely to match most requirements for
	prioritization of emergency signaling. However, it does not cover		prioritization of emergency signaling. However, it does not cover
	early stages of link layer activity in the network attachment		early stages of link layer activity in the network attachment
	process. Possible conflicts may arise e.g. in case of MAC-based		process. Possible conflicts may arise e.g. in case of MAC-based
	filtering in entities terminating the link-layer signaling in the		filtering in entities terminating the link-layer signaling in the
	network (like a base station). In normal operation, EAP related		network (like a base station). In normal operation, EAP related
	information will only be recognized in the NAS. Any entity		information will only be recognized in the NAS. Any entity
	residing between end host and NAS should not be expected to		residing between end host and NAS should not be expected to
	understand/parse EAP messages.		understand/parse EAP messages.
	o An emergency indication can be given by forming a specific NAI		o An emergency indication can be given by forming a specific NAI
	that is used as the identity in EAP based authentication for		that is used as the identity in EAP based authentication for
	network entry.		network entry.
	skipping to change at page 14, line 26 ¶		skipping to change at page 14, line 46 ¶
	appropriate trusted root certificates to be able to verify the		appropriate trusted root certificates to be able to verify the
	server certificate of the EAP server (unless this step is		server certificate of the EAP server (unless this step is
	explicitly skipped in the device in case of an emergency service		explicitly skipped in the device in case of an emergency service
	request). This method is used to provide access of devices		request). This method is used to provide access of devices
	without existing credentials to an 802.1x network. The details		without existing credentials to an 802.1x network. The details
	are incorporated into the not yet published 802.11-2011		are incorporated into the not yet published 802.11-2011
	specification.		specification.
	2) Null Authentication:		2) Null Authentication:
	In one case (e.g. WiMAX) an EAP method is performed. However, no		In one case (e.g., WiMAX) an EAP method is performed. However, no
	credentials specific to either the server or the device or		credentials specific to either the server or the device or
	subscription are used as part of the authentication exchange. An		subscription are used as part of the authentication exchange. An
	example for this would be an EAP-TLS exchange with using the		example for this would be an EAP-TLS exchange with using the
	TLS_DH_anon (anonymous) ciphersuite. Alternatively, a publicly		TLS_DH_anon (anonymous) ciphersuite. Alternatively, a publicly
	available static key for emergency access could be used. In the		available static key for emergency access could be used. In the
	latter case, the device would need to be provisioned with the		latter case, the device would need to be provisioned with the
	appropriate emergency key for the IAP/ISP in advance. In another		appropriate emergency key for the IAP/ISP in advance. In another
	case (e.g. IEEE 802.11), no EAP method is used, so that empty		case (e.g., IEEE 802.11), no EAP method is used, so that empty
	frames are transported during the over the air IEEE 802.1X		frames are transported during the over the air IEEE 802.1X
	exchange. In this case the authentication state machine completes		exchange. In this case the authentication state machine completes
	with no cryptographic keys being exchanged.		with no cryptographic keys being exchanged.
	3) Device Authentication:		3) Device Authentication:
	This case extends the server-only authentication case. If the		This case extends the server-only authentication case. If the
	device is configured with a device certificate and the IAP/ISP EAP		device is configured with a device certificate and the IAP/ISP EAP
	server can rely on a trusted root allowing the EAP server to		server can rely on a trusted root allowing the EAP server to
	verify the device certificate, at least the device identity (e.g.,		verify the device certificate, at least the device identity (e.g.,
	skipping to change at page 15, line 26 ¶		skipping to change at page 15, line 45 ¶
	functionality is used for GSM networks today this has lead to a		functionality is used for GSM networks today this has lead to a
	significant amount of misuse.		significant amount of misuse.
	In the context of NAA, the IAP and the ISP will probably want to make		In the context of NAA, the IAP and the ISP will probably want to make
	sure that the claimed emergency caller indeed performs an emergency		sure that the claimed emergency caller indeed performs an emergency
	call rather than using the network for other purposes, and thereby		call rather than using the network for other purposes, and thereby
	acting fraudulent by skipping any authentication, authorization and		acting fraudulent by skipping any authentication, authorization and
	accounting procedures. By restricting access of the unauthenticated		accounting procedures. By restricting access of the unauthenticated
	emergency caller to the LoST server and the PSAP URI, traffic can be		emergency caller to the LoST server and the PSAP URI, traffic can be
	restricted only to emergency calls. This can be accomplished with		restricted only to emergency calls. This can be accomplished with
	traffic separation. The details, however, e.g. for using filtering,		traffic separation. The details, however, e.g. for using filtering,
	depend on the deployed ISP architecture and are beyond the scope of		depend on the deployed ISP architecture and are beyond the scope of
	this document.		this document.
	We only illustrate a possible model. If the ISP runs its own LoST		We only illustrate a possible model. If the ISP runs its own LoST
	server, it would maintain an access control list including all IP		server, it would maintain an access control list including all IP
	addresses contained in responses returned by the LoST server, as well		addresses contained in responses returned by the LoST server, as well
	as the LoST server itself. (It may need to translate the domain		as the LoST server itself. (It may need to translate the domain
	names returned to IP addresses and hope that the resolution captures		names returned to IP addresses and hope that the resolution captures
	all possible DNS responses.) Since the media destination addresses		all possible DNS responses.) Since the media destination addresses
	are not predictable, the ISP also has to provide a SIP outbound proxy		are not predictable, the ISP also has to provide a SIP outbound proxy
	skipping to change at page 16, line 13 ¶		skipping to change at page 16, line 28 ¶
	change.		change.
	Finally, a number of security vulnerabilities discussed in [RFC6280]		Finally, a number of security vulnerabilities discussed in [RFC6280]
	around faked location information are less problematic in the context		around faked location information are less problematic in the context
	of unauthenticated emergency since location information does not need		of unauthenticated emergency since location information does not need
	to be provided by the end host itself or it can be verified to fall		to be provided by the end host itself or it can be verified to fall
	within a specific geographical area.		within a specific geographical area.
	8. Acknowledgments		8. Acknowledgments
	Parts of this document are derived from [I-D.ietf-ecrit-phonebcp].		Parts of this document are derived from [RFC6881]. Participants of
	Participants of the 2nd and 3rd SDO Emergency Services Workshop		the 2nd and 3rd SDO Emergency Services Workshop provided helpful
	provided helpful input.		input.
	We would like to thank Richard Barnes, Brian Rosen, James Polk, Marc		We would like to thank Richard Barnes, Brian Rosen, James Polk, Marc
	Linsner, and Martin Thomson for their feedback at the IETF#80 ECRIT		Linsner, and Martin Thomson for their feedback at the IETF#80 ECRIT
	meeting.		meeting.
	Furthermore, we would like to thank Martin Thomson and Bernard Aboba		Furthermore, we would like to thank Martin Thomson and Bernard Aboba
	for their detailed document review in preparation of the 81st IETF		for their detailed document review in preparation of the 81st IETF
	meeting.		meeting.
	9. IANA Considerations		9. IANA Considerations
	skipping to change at page 17, line 8 ¶		skipping to change at page 17, line 25 ¶
	Object (PIDF-LO)", RFC 5139, February 2008.		Object (PIDF-LO)", RFC 5139, February 2008.
	[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,		[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
	A., Peterson, J., Sparks, R., Handley, M., and E.		A., Peterson, J., Sparks, R., Handley, M., and E.
	Schooler, "SIP: Session Initiation Protocol", RFC 3261,		Schooler, "SIP: Session Initiation Protocol", RFC 3261,
	June 2002.		June 2002.
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119, March 1997.		Requirement Levels", BCP 14, RFC 2119, March 1997.
	[I-D.ietf-ecrit-phonebcp]		[RFC6881] Rosen, B. and J. Polk, "Best Current Practice for
	Rosen, B. and J. Polk, "Best Current Practice for		Communications Services in Support of Emergency Calling",
	Communications Services in support of Emergency Calling",		BCP 181, RFC 6881, March 2013.
	draft-ietf-ecrit-phonebcp-20 (work in progress), September
	2011.
	[RFC5222] Hardie, T., Newton, A., Schulzrinne, H., and H.		[RFC5222] Hardie, T., Newton, A., Schulzrinne, H., and H.
	Tschofenig, "LoST: A Location-to-Service Translation		Tschofenig, "LoST: A Location-to-Service Translation
	Protocol", RFC 5222, August 2008.		Protocol", RFC 5222, August 2008.
	[RFC5223] Schulzrinne, H., Polk, J., and H. Tschofenig, "Discovering		[RFC5223] Schulzrinne, H., Polk, J., and H. Tschofenig, "Discovering
	Location-to-Service Translation (LoST) Servers Using the		Location-to-Service Translation (LoST) Servers Using the
	Dynamic Host Configuration Protocol (DHCP)", RFC 5223,		Dynamic Host Configuration Protocol (DHCP)", RFC 5223,
	August 2008.		August 2008.
	10.2. Informative References		10.2. Informative References
	[RFC5687] Tschofenig, H. and H. Schulzrinne, "GEOPRIV Layer 7		[RFC5687] Tschofenig, H. and H. Schulzrinne, "GEOPRIV Layer 7
	Location Configuration Protocol: Problem Statement and		Location Configuration Protocol: Problem Statement and
	Requirements", RFC 5687, March 2010.		Requirements", RFC 5687, March 2010.
	[RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton,		[RFC6443] Rosen, B., Schulzrinne, H., Polk, J., and A. Newton,
	"Framework for Emergency Calling Using Internet		"Framework for Emergency Calling Using Internet
	Multimedia", RFC 6443, December 2011.		Multimedia", RFC 6443, December 2011.
	[I-D.ietf-geopriv-res-gw-lis-discovery]
	Thomson, M. and R. Bellis, "Location Information Server
	(LIS) Discovery using IP address and Reverse DNS", draft-
	ietf-geopriv-res-gw-lis-discovery-05 (work in progress),
	April 2013.
	[RFC5985] Barnes, M., "HTTP-Enabled Location Delivery (HELD)", RFC
	5985, September 2010.
	[RFC5012] Schulzrinne, H. and R. Marshall, "Requirements for		[RFC5012] Schulzrinne, H. and R. Marshall, "Requirements for
	Emergency Context Resolution with Internet Technologies",		Emergency Context Resolution with Internet Technologies",
	RFC 5012, January 2008.		RFC 5012, January 2008.
	[RFC6444] Schulzrinne, H., Liess, L., Tschofenig, H., Stark, B., and		[RFC6444] Schulzrinne, H., Liess, L., Tschofenig, H., Stark, B., and
	A. Kuett, "Location Hiding: Problem Statement and		A. Kuett, "Location Hiding: Problem Statement and
	Requirements", RFC 6444, January 2012.		Requirements", RFC 6444, January 2012.
	[I-D.winterbottom-geopriv-lis2lis-req]		[I-D.winterbottom-geopriv-lis2lis-req]
	Winterbottom, J. and S. Norreys, "LIS to LIS Protocol		Winterbottom, J. and S. Norreys, "LIS to LIS Protocol
End of changes. 31 change blocks.
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