draft-ietf-dime-nat-control-01.txt		draft-ietf-dime-nat-control-02.txt
	Internet Engineering Task Force F. Brockners		Internet Engineering Task Force F. Brockners
	Internet-Draft S. Bhandari		Internet-Draft S. Bhandari
	Intended status: Standards Track Cisco		Intended status: Standards Track Cisco
	Expires: April 26, 2010 V. Singh		Expires: September 8, 2010 V. Singh
	Mavenir Systems		Mavenir Systems
	V. Fajardo		V. Fajardo
	Telcordia Technologies		Telcordia Technologies
	October 23, 2009		March 7, 2010
	Diameter NAT Control Application		Diameter Network Address and Port Translation Control Application
	draft-ietf-dime-nat-control-01		draft-ietf-dime-nat-control-02
			Abstract
			This document describes the framework, messages, and procedures for
			the Diameter Network Address and Port Translation Control Application
			(DNCA), allowing for per-endpoint control of large scale NAT/NAPT
			devices, which are put in place to cope with IPv4-address space
			completion. The DNCA allows external devices to configure and manage
			a NAT device - expanding the existing Diameter-based AAA and policy
			control capabilities with a NAT/NAPT control component. These
			external devices can be network elements in the data plane such as a
			Network Access Server (NAS), or can be more centralized control plane
			devices such as AAA-servers. DNCA establishes a context to commonly
			identify and manage endpoints on a gateway or server, and a large
			scale NAPT/NAT device. This includes, for example, the control of
			the total number of NAT-bindings allowed or the allocation of a
			specific NAT-binding for a particular endpoint. In addition, it
			allows large scale NAT devices to provide information relevant to
			accounting purposes.
	Status of this Memo		Status of this Memo
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	Copyright Notice		Copyright Notice
	Copyright (c) 2009 IETF Trust and the persons identified as the		Copyright (c) 2010 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
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	Abstract		include Simplified BSD License text as described in Section 4.e of
			the Trust Legal Provisions and are provided without warranty as
	This document describes the framework, messages, and procedures for		described in the BSD License.
	the Diameter NAT Control Application (DNCA), allowing for per-
	endpoint control of large scale NAT devices, which are put in place
	to cope with IPv4-address space completion. The Diameter NAT Control
	Application allows external devices to configure and manage a Large
	Scale NAT (LSN) device - expanding the existing Diameter-based AAA
	and policy control capabilities with a NAT control component. These
	external devices can be network elements in the data plane such as a
	Network Access Server (NAS), or can be more centralized control plane
	devices such as AAA-servers. DNCA establishes a context to commonly
	identify and manage endpoints on a gateway or server, and a large
	scale NAT device. This includes, for example, the control of the
	total number of NAT-bindings allowed or the allocation of a specific
	NAT-binding for a particular endpoint. In addition, it allows large
	scale NAT devices to provide information relevant to accounting
	purposes.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5
	2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 6		2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 6
	3. Deployment framework and DNCA capabilities . . . . . . . . . . 6		3. Deployment Framework . . . . . . . . . . . . . . . . . . . . . 7
	3.1. Diameter NAT Control Application capabilities . . . . . . 6		3.1. Deployment Scenario . . . . . . . . . . . . . . . . . . . 7
	3.2. LSN Control Deployment Framework . . . . . . . . . . . . . 7		3.2. Diameter NAPT Control Application Overview . . . . . . . . 8
	3.2.1. LSN Deployment scenario . . . . . . . . . . . . . . . 8		3.3. Deployment Scenarios For The Diameter NAPT Control
	3.2.2. Diameter NAT Control Application overview . . . . . . 9		Application . . . . . . . . . . . . . . . . . . . . . . . 8
	3.2.3. Deployment scenarios for the Diameter NAT Control
	Application . . . . . . . . . . . . . . . . . . . . . 9
	4. Diameter NAT Control Application Session Establishment and		4. Diameter NAT Control Application Session Establishment and
	Management . . . . . . . . . . . . . . . . . . . . . . . . . . 12		Management . . . . . . . . . . . . . . . . . . . . . . . . . . 11
	4.1. Parties involved . . . . . . . . . . . . . . . . . . . . . 12		4.1. Parties Involved . . . . . . . . . . . . . . . . . . . . . 11
	4.2. Session Establishment . . . . . . . . . . . . . . . . . . 12		4.2. Session Establishment . . . . . . . . . . . . . . . . . . 11
	4.3. Session Re-Authorization . . . . . . . . . . . . . . . . . 14		4.3. Session Re-Authorization . . . . . . . . . . . . . . . . . 13
	4.4. Session and Binding Query . . . . . . . . . . . . . . . . 16		4.4. Session And Binding Query . . . . . . . . . . . . . . . . 15
	4.5. Session Termination . . . . . . . . . . . . . . . . . . . 18		4.5. Session Termination . . . . . . . . . . . . . . . . . . . 17
	4.6. DNCA Manager/Agent failures . . . . . . . . . . . . . . . 19		4.6. DNCA Manager/Agent Failures . . . . . . . . . . . . . . . 18
	5. Use of the DIAMETER base protocol . . . . . . . . . . . . . . 20		5. Use Of The Diameter Base Protocol . . . . . . . . . . . . . . 19
	5.1. Securing DIAMETER messages . . . . . . . . . . . . . . . . 20		5.1. Securing Diameter Messages . . . . . . . . . . . . . . . . 19
	5.2. Accounting functionality . . . . . . . . . . . . . . . . . 21		5.2. Accounting Functionality . . . . . . . . . . . . . . . . . 20
	5.3. Use of sessions . . . . . . . . . . . . . . . . . . . . . 21		5.3. Use Of Sessions . . . . . . . . . . . . . . . . . . . . . 20
	5.4. Routing considerations . . . . . . . . . . . . . . . . . . 21		5.4. Routing Considerations . . . . . . . . . . . . . . . . . . 20
	5.5. Advertising Application support . . . . . . . . . . . . . 21		5.5. Advertising Application Support . . . . . . . . . . . . . 20
	6. Diameter NAT Control Application Commands . . . . . . . . . . 22		6. Diameter NAT Control Application Commands . . . . . . . . . . 20
	6.1. NAT-Control Request (NCR) Command . . . . . . . . . . . . 22		6.1. NAT-Control Request (NCR) Command . . . . . . . . . . . . 21
	6.2. NAT-Control Answer (NCA) Command . . . . . . . . . . . . . 22		6.2. NAT-Control Answer (NCA) Command . . . . . . . . . . . . . 21
	7. Diameter NAT Control Application AVPs . . . . . . . . . . . . 23		7. Diameter NAT Control Application AVPs . . . . . . . . . . . . 22
	7.1. Reused Base Protocol AVPs . . . . . . . . . . . . . . . . 23		7.1. Reused Base Protocol AVPs . . . . . . . . . . . . . . . . 22
	7.2. Additional Result-Code AVP values . . . . . . . . . . . . 24		7.2. Additional Result-Code AVP Values . . . . . . . . . . . . 23
	7.2.1. Success . . . . . . . . . . . . . . . . . . . . . . . 24		7.2.1. Success . . . . . . . . . . . . . . . . . . . . . . . 23
	7.2.2. Transient failures . . . . . . . . . . . . . . . . . . 25		7.2.2. Transient Failures . . . . . . . . . . . . . . . . . . 24
	7.2.3. Permanent failures . . . . . . . . . . . . . . . . . . 25		7.2.3. Permanent Failures . . . . . . . . . . . . . . . . . . 24
	7.3. Reused NASREQ Diameter application AVPs . . . . . . . . . 26		7.3. Reused NASREQ Diameter Application AVPs . . . . . . . . . 25
	7.4. Reused from RFC 4675 . . . . . . . . . . . . . . . . . . . 26		7.4. Reused from RFC 4675 . . . . . . . . . . . . . . . . . . . 25
	7.5. Reused from Diameter QoS Application . . . . . . . . . . . 27		7.5. Reused from Diameter QoS Application . . . . . . . . . . . 26
	7.6. Reused from ETSI ES 283 034, e4 Diameter application . . . 27		7.6. Reused From ETSI ES 283 034, e4 Diameter Application . . . 26
	7.7. Diameter NAT Control Application Defined AVPs . . . . . . 28		7.7. Diameter NAT Control Application Defined AVPs . . . . . . 27
	7.7.1. NC-Request-Type AVP . . . . . . . . . . . . . . . . . 28		7.7.1. NC-Request-Type AVP . . . . . . . . . . . . . . . . . 27
	7.7.2. NAT-Control-Install AVP . . . . . . . . . . . . . . . 29		7.7.2. NAT-Control-Install AVP . . . . . . . . . . . . . . . 28
	7.7.3. NAT-Control-Remove AVP . . . . . . . . . . . . . . . . 29		7.7.3. NAT-Control-Remove AVP . . . . . . . . . . . . . . . . 28
	7.7.4. NAT-Control-Definition AVP . . . . . . . . . . . . . . 30		7.7.4. NAT-Control-Definition AVP . . . . . . . . . . . . . . 29
	7.7.5. NAT-Internal-Address AVP . . . . . . . . . . . . . . . 30		7.7.5. NAT-Internal-Address AVP . . . . . . . . . . . . . . . 29
	7.7.6. NAT-External-Address AVP . . . . . . . . . . . . . . . 31		7.7.6. NAT-External-Address AVP . . . . . . . . . . . . . . . 30
	7.7.7. Max-NAT-Bindings . . . . . . . . . . . . . . . . . . . 31		7.7.7. Max-NAT-Bindings . . . . . . . . . . . . . . . . . . . 30
	7.7.8. NAT-Control-Binding-Rule AVP . . . . . . . . . . . . . 31		7.7.8. NAT-Control-Binding-Rule AVP . . . . . . . . . . . . . 30
	7.7.9. Duplicate-Session-Id AVP . . . . . . . . . . . . . . . 31		7.7.9. Duplicate-Session-Id AVP . . . . . . . . . . . . . . . 30
			8. Accounting Commands . . . . . . . . . . . . . . . . . . . . . 30
	8. Accounting Commands . . . . . . . . . . . . . . . . . . . . . 31		8.1. NAT Control Accounting Messages . . . . . . . . . . . . . 31
	8.1. NAT Control Accounting Messages . . . . . . . . . . . . . 32		8.2. NAT Control Accounting AVPs . . . . . . . . . . . . . . . 31
	8.2. NAT Control Accounting AVPs . . . . . . . . . . . . . . . 32		8.2.1. NAT-Control-Record . . . . . . . . . . . . . . . . . . 31
	8.2.1. NAT-Control-Record . . . . . . . . . . . . . . . . . . 32		8.2.2. NAT-Control-Binding-Status . . . . . . . . . . . . . . 31
	8.2.2. NAT-Control-Binding-Status . . . . . . . . . . . . . . 32		8.2.3. Current-NAT-Bindings . . . . . . . . . . . . . . . . . 32
	8.2.3. Current-NAT-Bindings . . . . . . . . . . . . . . . . . 33		9. AVP Occurrence Table . . . . . . . . . . . . . . . . . . . . . 32
	9. AVP Occurrence Table . . . . . . . . . . . . . . . . . . . . . 33
	9.1. DNCA AVP Table for NAT control initial and update		9.1. DNCA AVP Table for NAT control initial and update
	requests . . . . . . . . . . . . . . . . . . . . . . . . . 34		requests . . . . . . . . . . . . . . . . . . . . . . . . . 33
	9.2. DNCA AVP Table for Session Query request . . . . . . . . . 34		9.2. DNCA AVP Table for Session Query request . . . . . . . . . 33
	9.3. DNCA AVP Table for NAT Control Terminate requests . . . . 34		9.3. DNCA AVP Table for NAT Control Terminate requests . . . . 33
	9.4. DNCA AVP Table for accounting message . . . . . . . . . . 35		9.4. DNCA AVP Table For Accounting Message . . . . . . . . . . 34
	10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 35		10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 34
	10.1. Command Codes . . . . . . . . . . . . . . . . . . . . . . 35		10.1. Command Codes . . . . . . . . . . . . . . . . . . . . . . 34
	10.2. AVP Codes . . . . . . . . . . . . . . . . . . . . . . . . 36		10.2. AVP Codes . . . . . . . . . . . . . . . . . . . . . . . . 35
	10.3. AVP Values . . . . . . . . . . . . . . . . . . . . . . . . 36		10.3. AVP Values . . . . . . . . . . . . . . . . . . . . . . . . 35
	10.3.1. Result-Code AVP Values . . . . . . . . . . . . . . . . 36		10.3.1. Result-Code AVP Values . . . . . . . . . . . . . . . . 35
	10.4. Application IDs . . . . . . . . . . . . . . . . . . . . . 37		10.4. Application IDs . . . . . . . . . . . . . . . . . . . . . 36
	11. Security Considerations . . . . . . . . . . . . . . . . . . . 37		11. Security Considerations . . . . . . . . . . . . . . . . . . . 36
	12. Change history (to be removed prior to publication as an		12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 37
	RFC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38		13. Change History (to be removed prior to publication as an
	13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 38		RFC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
	13.1. Normative References . . . . . . . . . . . . . . . . . . . 38		14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 38
	13.2. Informative References . . . . . . . . . . . . . . . . . . 39		14.1. Normative References . . . . . . . . . . . . . . . . . . . 38
			14.2. Informative References . . . . . . . . . . . . . . . . . . 38
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 39		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 39
	1. Introduction		1. Introduction
	With the foreseeable depletion of available IPv4 addresses from the		Internet service providers have started to deploy Network Address
	IANA pool, service providers are starting to consider network designs		Translators (NATs) and Network Address and Port Translators (NAPTs)
	which no longer assign unique global IPv4 addresses to their		at the edge of their networks to deal with the depletion of available
	subscribers. One of the approaches considered, is the deployment of		public IPv4 addresses. This document defines a Diameter application
	a provider-operated large scale NAT device between the end-users and		for providers deploying such NATs and NAPT devices. The use of a
	the Internet. Nishitani et al. [I-D.nishitani-cgn] call this NAT		Diameter application allows for simple integration into the existing
	device a "Large Scale NAT (LSN)".		AAA environment of a provider.
	LSNs will be inserted into the existing subscriber access and		The Diameter NAPT Control Application (DNCA) offers the following
	aggregation networks which typically provide for per-endpoint service		capabilities:
	management and control as well as per-endpoint accounting. Per-
	endpoint rules include those which relate to service offerings of the
	SP (e.g. access bandwidth, time or volume based access restrictions)
	as well as rules which follow legal regulations of the "National
	Regulation Authorities (NRA)". The introduction of a LSN impacts the
	per-endpoint service offerings as well as the regulatory requirements
	and gives rise to new control requirements within the service
	provider network: Service providers need to manage the behavior of
	the LSN on a per-endpoint basis.
	The per-endpoint management capabilities of a LSN comprise, for		1. Limit/Define the number of NAPT/NAT-bindings made available to an
	example the control of the number of NAT-address-port pairs (often		individual subscriber or end point.
	called "NAT-bindings" or simply "bindings") allocated to a single
	endpoint. Given that global IPv4 address-port pairs are becoming a
	scarce resource, several service providers intend to restrict the
	number of NAT-bindings on a per endpoint basis and thus increase
	address utilization efficiency. The number of bindings an endpoint
	can consume becomes another parameter within a tiered-service
	offering. In addition, the service provider might offer static
	bindings to endpoints or pre-allocate external IP-address/port-ranges
	to certain endpoints. One of the NRA requirements is that a service
	provider needs to provide the identity of a user (which e.g.
	translates to the public IP address and ports leveraged by the user
	at a given point in time) upon request.
	Dynamic per-endpoint management at the LSN requires an associated		2. Support the allocation of specific NAPT/NAT-bindings. Two types
	interface that has to be tightly integrated with the existing per-		of specific bindings can be distinguished:
	endpoint authentication, authorization, and accounting (AAA)
	environment of the service provider.
	This document describes the framework, messages and procedures for		* Allocation of a pre-defined NAT-binding. Both the internal as
	the Diameter carrier-grade NAT Control Application (DNCA). The DNCA		well as the external IP-address/port pair are specified within
	interacts with the LSN to coordinate per-endpoint configuration and		the request. Some deployment cases, such as access to a web-
	management of subscriber traffic traversing the LSN. Use of a		server within a user's home network with IP-address and port,
	Diameter application allows for simple integration into the existing		benefit from statically configured bindings.
	AAA environment of a service provider.
			* Allocation of an external IP-address for a given internal IP-
			address. The allocated external IP-address will be reported
			back to the requestor. In some deployment scenarios, the
			application requires immediate knowledge of the allocated
			binding for a given internal IP-address but does not control
			the allocation of the external IP-address (e.g. SIP-proxy
			server deployments).
			3. Define the external address-pool(s) to be used for allocating an
			external IP-address. External address-pools can either be pre-
			assigned at the NAPT/NAT, or specified within a request. If pre-
			assigned address-pools are used, a request needs to include a
			reference to identify the pool. Otherwise, the request will
			contain a description of the IP- address pool(s) to be used (e.g.
			list of IP-subnets).
			4. Accounting/Reporting: Report established bindings for a
			particular user. The collected information is used by accounting
			systems, for statistical purposes, etc.
			5. Query functionality to retrieve details about bindings on demand.
			This feature complements the previously mentioned accounting
			functionality mentioned above (see item 4). The query
			functionality complements alternative information query
			mechanisms such as SNMP-based mechanisms, if available.
			6. Common identification of a subscriber or endpoint on multiple
			network devices such as the NAPT/NAT device, the AAA server, or
			the Network Access Server (NAS). Endpoint identification is
			facilitated through a Global Endpoint ID. Endpoints are
			identified through a single or a set of classifiers such as IP
			address, VLAN identifier, or interface identifier which uniquely
			identify the traffic associated with a particular global endpoint
			This document is structured as follows: Section 2 lists terminology,
			while Section 3 provides an introduction to the Diameter NAPT Control
			Application and its overall deployment framework. Sections 4 to 8
			cover the DNCA specifics, with Section 4 describing session
			management, Section 5 the use of the Diameter base protocol, Section
			6 new commands, Section 7 the respective AVPs used, and Section 8
			accounting aspects. Section 9 presents an AVP occurance table. IANA
			and security considerations are addressed in Sections 10 and 11.
	2. Conventions		2. Conventions
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this		"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
	document are to be interpreted as described in [RFC2119].		document are to be interpreted as described in [RFC2119].
	Abbreviations are used in this document:		Abbreviations are used in this document:
	AAA: Authentication, Authorization, Accounting		AAA: Authentication, Authorization, Accounting
	DNCA: Diameter NAT Control Application		DNCA: Diameter NAT Control Application
	LSN: Large Scale NAT device		NAPT: Network Address and Port Translation
	NAT: Network Address Translation
	NAS: Network Access Server		NAT: Network Address Translation (NAT and NAPT are used in this
			document interchangeably)
	NAT-Binding or Binding: Association of two IP-address/port pairs		NAT-Binding or Binding: Association of two IP-address/port pairs
	(with one IP-address typically being private and the other one		(with one IP-address typically being private and the other one
	public) to facilitate NAT		public) to facilitate NAT
	NRA: National Regulatory Authority		NAS: Network Access Server
	3. Deployment framework and DNCA capabilities
	3.1. Diameter NAT Control Application capabilities
	The Diameter NAT control application offers the following
	capabilities:
	1. Limit the number of NAT-bindings per endpoint: Define/restrict
	the maximum number of NAT-bindings on a per-endpoint basis. This
	enables service providers to offer differentiated services based
	on the number of bindings and hence optimize the consumption of
	IP-address/port-ranges.
	2. Request the allocation of specific NAT-bindings: Under normal
	operation the LSN would allocate NAT-bindings based on rules and
	algorithms local to the LSN. Fixed or pre-defined bindings would
	be the exception rather than the rule but are essential for
	certain deployment scenarios. Requests for NAT-binding
	allocation could happen either at or after initial session
	establishment. Two cases could be distinguished:
	* Request the allocation of a pre-defined NAT-binding. Both the
	internal as well as the external IP-address/port pair are
	specified within the request. Some deployment cases, such as
	access to a web-server within a user's home network with IP-
	address and port, benefit from statically configured bindings.
	* Request the allocation of an external IP-address for a given
	internal IP-address and report the allocated external IP-
	address back to the requestor. In some deployment scenarios,
	the application requires immediate knowledge of the allocated
	binding for a given internal IP-address but does not control
	the allocation of the external IP-address (e.g. SIP-proxy
	server deployments).
	3. Define the external address-pool(s) to be used for allocating an
	external IP-address. External address-pools can either be pre-
	defined on the LSN, or specified within a request. If pre-
	defined address-pools are used, a request would just include a
	reference (e.g. name) to an already defined address pool on LSN.
	Otherwise, the request will contain a description of the IP-
	address pool(s) to be used (e.g. list of IP-subnets).
	4. Accounting/Reporting: Report established bindings for a
	particular user. Apart from statistical and charging purposes,
	binding reporting is also required for legal reasons. Most
	National Regulatory Authorities (NRA) require that service
	providers provide the identity of a user upon request. The
	service provider needs to be able to correlate a tuple (public
	IP-address, port, time) to a particular user or endpoint.
	5. Flexible Information Query: Report details and statistics of
	bindings for a single endpoint or a set of endpoints through an
	external interface which integrates with the overall per-endpoint
	management suite. Hence this information query capability of the
	DNCA potentially complements alternative information query
	mechanisms such as SNMP-based mechanisms.
	6. Global Endpoint ID: The global endpoint ID will allow for common		3. Deployment Framework
	identification of an endpoint on a LSN as well as other endpoint-
	or subscriber-aware devices such as a Network Access Server (NAS)
	or an AAA system. Endpoints are identified through a single or a
	set of classifiers such as IP address, VLAN identifier, or
	interface identifier which uniquely identify the traffic
	associated with a particular global endpoint.
	3.2. LSN Control Deployment Framework		3.1. Deployment Scenario
	3.2.1. LSN Deployment scenario
	Figure 1 shows a typical network deployment for internet access. A		Figure 1 shows a typical network deployment for internet access. A
	user's IPv4-host gains access to the internet though a Network Access		user's IPv4-host gains access to the internet though a Network Access
	Server (NAS) which facilitates the authentication of the endpoint and		Server (NAS) which facilitates the authentication of the endpoint and
	configures the user's connection according to the authorization and		configures the user's connection according to the authorization and
	configuration data received from the AAA-server upon successful		configuration data received from the AAA-server upon successful
	authentication. Public IPv4 addresses are used throughout the		authentication. Public IPv4 addresses are used throughout the
	network.		network.
	+---------+
	| |
	| AAA |
	| |
	+---------+
	|
	|
	|
	|
	+---------+ +---------+ +----------+
	| IPv4 | | | | IPv4 |
	| Host |----------| NAS |-------------| Internet |
	| | | | | |
	+---------+ +---------+ +----------+
	<-------------------- Public IPv4 ---------------------->
	Figure 1: Typical network deployment for internet access
	Figure 2 depicts the deployment scenario when a service provider
	introduces a LSN to increase the efficiency of the global IPv4
	address pool utilization. The objective is to provide the customer
	with connectivity to the public IPv4 Internet. The LSN performs
	network address translation between private IPv4 addresses and public
	IPv4 addresses. If the LSN would be put in place without any
	endpoint awareness, the service offerings of the service provider
	would be hampered. Provisioning static NAT-bindings for particular
	endpoints, using different public IP-address pools for different set
	of endpoints (e.g. residential or business customers), as well as
	reporting on the allocated bindings on a per-endpoint basis would be
	burdensome for a service provider if the LSN would not be aware of
	endpoints and allow for per-endpoint control and management which
	easily integrates with the already existing per-endpoint management
	infrastructure of the service provider.
	+---------+		+---------+
	| |		| |
	| AAA |		| AAA |
	| |		| |
	+---------+		+---------+
	|		|
	|		|
	|		|
	|		|
	+--------+ +---------+ +---------+ +----------+		+---------+ +---------+ +----------+
	| IPv4 | | | | | | IPv4 |		| IPv4 | | | | IPv4 |
	| Host |----| NAS |----| LSN |----| Internet |		| Host |----------| NAS |-------------| Internet |
	| | | | | | | |		| | | | | |
	+--------+ +---------+ +---------+ +----------+		+---------+ +---------+ +----------+
	<-------- Private IPv4 -----------><--- Public IPv4 --->		<-------------------- Public IPv4 ---------------------->
			Figure 1: Typical network deployment for internet access
			Figure 2 depicts the deployment scenario when a service provider
			introduces a NAT device to increase the efficiency of the global IPv4
			address pool utilization. The objective is to provide the customer
			with connectivity to the public IPv4 Internet. The NAT device
			performs network address (and optionally protocol) translation,
			depending on whether the access network uses private IPv4 addresses
			or public IPv6 addresses, to public IPv4 addresses. If the NAT
			device would be put in place without any endpoint awareness, the
			service offerings of the service provider would be hampered.
			Provisioning static NAT-bindings for particular endpoints, using
			different public IP-address pools for different set of endpoints
			(e.g. residential or business customers), as well as reporting on the
			allocated bindings on a per-endpoint basis would be burdensome for a
			service provider if the NAT device would not be aware of endpoints
			and allow for per-endpoint control and management which easily
			integrates with the already existing per-endpoint management
			infrastructure of the service provider.
			+---------+
			| |
			| AAA |
			| |
			+---------+
			|
			|
			|
			|
			+--------+ +---------+ +---------+ +----------+
			| IPv4 | | | | | | IPv4 |
			| Host |----| NAS |----| NAT |----| Internet |
			| | | | | | | |
			+--------+ +---------+ +---------+ +----------+
			<-------- Private IPv4 -----------><--- Public IPv4 --->
			<-------- Public IPv6 -----------><--- Public IPv4 --->
	Figure 2: Access network deployment with LSN		Figure 2: Access network deployment with LSN
	3.2.2. Diameter NAT Control Application overview		3.2. Diameter NAPT Control Application Overview
	The Diameter NAT Control Application runs between a Diameter NAT		The Diameter NAT Control Application runs between a Diameter NAT
	Control Application Agent on the LSN and the Diameter NAT Control		Control Application Agent on the NAT and the Diameter NAT Control
	Application Manager. DNCA allows for per-endpoint control and		Application Manager. DNCA allows for per-endpoint control and
	management of a LSN. Being based on Diameter, DNCA integrates well		management of a NAT. Being based on Diameter, DNCA integrates well
	with the suite of Diameter applications deployed for per-endpoint		with the suite of Diameter applications deployed for per-endpoint
	authentication, authorization, accounting, and policy control in		authentication, authorization, accounting, and policy control in
	service provider networks.		service provider networks.
	DNCA offers request and answer commands to control the allowed number		DNCA offers request and answer commands to control the allowed number
	of NAT-bindings per endpoint, to request the allocation of specific		of NAT-bindings per endpoint, to request the allocation of specific
	bindings for an endpoint, to define the address pool to be used for		bindings for an endpoint, to define the address pool to be used for
	an endpoint, to provide per endpoint reporting on the allocated NAT-		an endpoint, to provide per endpoint reporting on the allocated NAT-
	bindings, as well as to provide for unique identification of an		bindings, as well as to provide for unique identification of an
	endpoint on both LSN, AAA-server and NAS, thus simplifying the		endpoint on both NAT, AAA-server and NAS, thus simplifying the
	correlation of accounting data streams.		correlation of accounting data streams.
	DNCA allows for controlling the behavior of a LSN on a per-endpoint		DNCA allows for controlling the behavior of a NAT device on a per-
	basis during initial session establishment as well as at later stages		endpoint basis during initial session establishment as well as at
	by providing an update procedure for already established sessions.		later stages by providing an update procedure for already established
	Using DNCA, per-endpoint NAT-binding information can be retrieved		sessions. Using DNCA, per-endpoint NAT-binding information can be
	either using accounting mechanisms or through an explicit session		retrieved either using accounting mechanisms or through an explicit
	query to the LSN.		session query to the NAT.
	3.2.3. Deployment scenarios for the Diameter NAT Control Application		3.3. Deployment Scenarios For The Diameter NAPT Control Application
	Deployment dependent, the role of the Diameter NAT Control Manager		Deployment dependent, the role of the Diameter NAT Control Manager
	can be fulfilled by either the NAS or by an external server such as		can be fulfilled by either the NAS or by an external server such as
	an AAA-server. The two deployment scenarios are outlined in Figure 3		an AAA-server. The two deployment scenarios are outlined in Figure 3
	("integrated deployment") and Figure 4 ("autonomous deployment").		("integrated deployment") and Figure 4 ("autonomous deployment").
	Within the figures (M) denotes the network element which takes on the		Within the figures (M) denotes the network element which takes on the
	DNCA manager role. Similarly, (A) identifies the network element		DNCA manager role. Similarly, (A) identifies the network element
	which performs the DNCA agent role.		which performs the DNCA agent role.
	The integrated deployment approach hides the existence of the LSN		The integrated deployment approach hides the existence of the NAT
	from external servers such as the AAA-server as much as possible. It		device from external servers such as the AAA-server as much as
	is suited for environments where minimal changes to the existing AAA		possible. It is suited for environments where minimal changes to the
	deployment are desired. The NAS, taking the role of the DNCA		existing AAA deployment are desired. The NAS, taking the role of the
	manager, is in charge of initiating and managing the session to the		DNCA manager, is in charge of initiating and managing the session to
	LSN, exchanging LSN specific configuration information as well as		the NAT device, exchanging NAT specific configuration information as
	handling reporting and accounting information. The NAS receives		well as handling reporting and accounting information. The NAS
	reporting and accounting information from LSN. This way the NAS can		receives reporting and accounting information from NAT device. This
	provide for a single accounting record for the user, offloading		way the NAS can provide for a single accounting record for the user,
	external accounting systems from correlating accounting information		offloading external accounting systems from correlating accounting
	received from multiple sources.		information received from multiple sources.
	An example network attachment for an integrated LSN deployment could		An example network attachment for an integrated NAT deployment could
	be described as follows: An endpoint connects to the network, with		be described as follows: An endpoint connects to the network, with
	the NAS being the point of attachment. After successful		the NAS being the point of attachment. After successful
	authentication, NAS receives endpoint related authorization data from		authentication, NAS receives endpoint related authorization data from
	the AAA-server. A portion of the authorization data applies to per-		the AAA-server. A portion of the authorization data applies to per-
	endpoint configuration on the NAS itself, another portion describes		endpoint configuration on the NAS itself, another portion describes
	authorization and configuration information for NAT control aimed at		authorization and configuration information for NAT control aimed at
	the LSN. NAS will initiate a DNCA session to the LSN and send the		the NAT. NAS will initiate a DNCA session to the NAT and send the
	relevant authorization and configuration information for the		relevant authorization and configuration information for the
	particular endpoint to the LSN. This could comprise e.g. NAT-		particular endpoint to the NAT device. This could comprise e.g.
	bindings which have to be pre-established for the endpoint, or		NAT-bindings which have to be pre-established for the endpoint, or
	management related configuration, such as the maximum number of NAT-		management related configuration, such as the maximum number of NAT-
	bindings allowed for the endpoint or accounting requirements. The		bindings allowed for the endpoint or accounting requirements. The
	LSN will send its per-endpoint accounting information to the NAS		NAT device will send its per-endpoint accounting information to the
	which aggregates the accounting information received from the LSN		NAS which aggregates the accounting information received form the NAT
	with its local accounting information for the endpoint into a single		with its local accounting information for the endpoint into a single
	accounting stream towards the AAA-server.		accounting stream towards the AAA-server.
	+---------+		+---------+
	| |		| |
	| AAA |		| AAA |
	| |		| |
	+---------+		+---------+
	|		|
	|		|
	|		|
	+--------+ +---------+ +---------+ +----------+		+--------+ +---------+ +---------+ +----------+
	| IPv4 | | (M) | | (A) | | IPv4 |		| IPv4 | | (M) | | (A) | | IPv4 |
	| Host |----| NAS |----| LSN |----| Internet |		| Host |----| NAS |----| NAT |----| Internet |
	| | | | | | | |		| | | | | | | |
	+--------+ +---------+ +---------+ +----------+		+--------+ +---------+ +---------+ +----------+
			<-------- Public IPv6 ----------><--- Public IPv4 ---->
	<-------- Private IPv4 ----------><--- Public IPv4 ---->		<-------- Private IPv4 ----------><--- Public IPv4 ---->
	Figure 3: LSN Control deployment: Integrated deployment		Figure 3: LSN Control deployment: Integrated deployment
	The autonomous deployment approach decouples user management on NAS		The autonomous deployment approach decouples user management on NAS
	and LSN. The AAA system performing the role of the DNCA manager		and NAT device. The AAA system performing the role of the DNCA
	manages the connection to the LSN, controls the per-endpoint		manager manages the connection to the NAT device, controls the per-
	configuration, and also receives accounting and reporting information		endpoint configuration, and also receives accounting and reporting
	from LSN. Different from the integrated deployment scenario, the		information from the NAT device. Different from the integrated
	autonomous deployment scenario does not "hide" the existence of the		deployment scenario, the autonomous deployment scenario does not
	LSN from the AAA infrastructure. Here two accounting streams are		"hide" the existence of the NAT device from the AAA infrastructure.
	received by the AAA-server for one particular endpoint, one from the		Here two accounting streams are received by the AAA-server for one
	NAS, and one from the LSN.		particular endpoint, one from the NAS, and one from the NAT device.
			+---------+
	+---------+		| (M) |
	| (M) |		| AAA |
	| AAA |		| |
	| |		+---------+
	+---------+		|
	|		|
	|		|
	|		+--------+ +---------+ +---------+ +----------+
	+--------+ +---------+ +---------+ +----------+		| IPv4 | | | | (A) | | IPv4 |
	| IPv4 | | | | (A) | | IPv4 |		| Host |----| NAS |----| NAT |----| Internet |
	| Host |----| NAS |----| LSN |----| Internet |		| | | | | | | |
	| | | | | | | |		+--------+ +---------+ +---------+ +----------+
	+--------+ +---------+ +---------+ +----------+		<-------- Public IPv6 ----------><---- Public IPv4 --->
			<-------- Private IPv4 ----------><---- Public IPv4 --->
	<-------- Private IPv4 ----------><---- Public IPv4 --->
	Figure 4: LSN Control deployment: Autonomous deployment		Figure 4: LSN Control deployment: Autonomous deployment
	4. Diameter NAT Control Application Session Establishment and		4. Diameter NAT Control Application Session Establishment and
	Management		Management
	Note that this section forward references some of the commands and		Note that this section forward references some of the commands and
	AVPs defined for the DNCA. Please refer to Section 6 and Section 7		AVPs defined for the DNCA. Please refer to Section 6 and Section 7
	for details.		for details.
	4.1. Parties involved		4.1. Parties Involved
	Authorization and control models supported by this application		Authorization and control models supported by this application
	include the following parties:		include the following parties:
	o Diameter NAT Control Application (DNCA) agent: The DNCA agent is		o Diameter NAT Control Application (DNCA) agent: The DNCA agent is
	part of the Large scale NAT (LSN) device		part of the Large scale NAT (NAT) device
	o Diameter NAT Control Application (DNCA) manager		o Diameter NAT Control Application (DNCA) manager
	The current version of the draft assumes that the NAT control		The NAT control requesting entity is always the DNCA manager.
	requesting entity is always the DNCA manager. Sessions will always		Sessions will always be initiated, updated, or terminated by the DNCA
	be initiated, updated, or terminated by the DNCA manager. This mode		manager. This mode of operation is sometimes also referred to as
	of operation is sometimes also referred to as "push mode". Session		"push mode".
	initiation by the DNCA agent (sometimes referred to as "pull mode")
	will be covered in a future version of this draft.		DNCA manager can be NAS or AAA Server. DNCA manager will initiate a
			session with DNCA agent when it learns about the subscriber. DNCA
			manager may learn about a subscriber when it receives authentication,
			authorization or accounting request for that subscriber or by some
			other means such as on the box configuration to identify subscriber
			w.r.t IP packets.
	4.2. Session Establishment		4.2. Session Establishment
	The DNCA manager establishes a session to the DNCA agent to control		The DNCA manager establishes a session to the DNCA agent to control
	the behavior of the NAT device. During session establishment, the		the behavior of the NAT device. During session establishment, the
	DNCA manager will pass along configuration information to the DNCA		DNCA manager will pass along configuration information to the DNCA
	agent. Session configuration information could for example comprise		agent. Session configuration information could for example comprise
	the maximum number of bindings allowed for the endpoint associated		the maximum number of bindings allowed for the endpoint associated
	with this session, a set of pre-defined NAT-bindings to be		with this session, a set of pre-defined NAT-bindings to be
	established for this endpoint, or a description of the address pool,		established for this endpoint, or a description of the address pool,
	skipping to change at page 12, line 52		skipping to change at page 12, line 8
	message to the DNCA agent with NC-Request-Type AVP set to		message to the DNCA agent with NC-Request-Type AVP set to
	INITIAL_REQUEST. On receipt of the NCR the DNCA agent will setup a		INITIAL_REQUEST. On receipt of the NCR the DNCA agent will setup a
	new session for the endpoint associated with the endpoint		new session for the endpoint associated with the endpoint
	classifier(s) contained in the NCR. The DNCA agent notifies the DNCA		classifier(s) contained in the NCR. The DNCA agent notifies the DNCA
	manager about successful session setup using a NAT-Control Answer		manager about successful session setup using a NAT-Control Answer
	(NCA) message with Result-Code set to DIAMETER_SUCCESS. Figure 5		(NCA) message with Result-Code set to DIAMETER_SUCCESS. Figure 5
	shows the protocol interaction between the DNCA manager and the DNCA		shows the protocol interaction between the DNCA manager and the DNCA
	agent.		agent.
	The initial NAT-Control-Request can contain configuration information		The initial NAT-Control-Request can contain configuration information
	for the session which specifies the behavior of the LSN for the		for the session which specifies the behavior of the NAT for the
	session. Configuration information which can be included comprises:		session. Configuration information which can be included comprises:
	o A list of NAT-bindings which should be pre-allocated for the		o A list of NAT-bindings which should be pre-allocated for the
	session (e.g. in case a subscriber requires a fixed external IP-		session (e.g. in case a subscriber requires a fixed external IP-
	address/port pair for one of his applications).		address/port pair for one of his applications).
	o The maximum number of NAT bindings allowed for an endpoint.		o The maximum number of NAT bindings allowed for an endpoint.
	o A description of the external address pool(s) to be used for the		o A description of the external address pool(s) to be used for the
	session.		session.
	o A reference to a predefined binding rule on DNCA agent that will		o A reference to a predefined binding rule on DNCA agent that will
	be applied to the session. Such a predefined binding rule on DNCA		be applied to the session. Such a predefined binding rule on DNCA
	agent may contain, for example, the name of the IP-address pool		agent may contain, for example, the name of the IP-address pool
	that the external IP-addresses should be allocated from, the		that external IP-addresses should be allocated from, maximum
	maximum number of bindings permitted for the endpoint etc.		number of bindings permitted for the endpoint etc.
	In certain cases, the DNCA agent may not be able to perform the tasks		In certain cases, the DNCA agent may not be able to perform the tasks
	requested within the NCR. These include the following:		requested within the NCR. These include the following:
	o If a DNCA agent receives a NCR from a DNCA manager with NC-		o If a DNCA agent receives a NCR from a DNCA manager with NC-
	Request-Type AVP set to INITIAL_REQUEST that identifies an already		Request-Type AVP set to INITIAL_REQUEST that identifies an already
	existing session (i.e. DNCA manager and endpoint identifier match		existing session (i.e. DNCA manager and endpoint identifier match
	an already existing session), the DNCA agent will return NCA with		an already existing session), the DNCA agent will return NCA with
	Result-Code set to SESSION_EXISTS, and provides Session-Id of the		Result-Code set to SESSION_EXISTS, and provides Session-Id of the
	existing session in Duplicate-Session-Id AVP.		existing session in Duplicate-Session-Id AVP.
	o If a DNCA agent receives an NCR from a DNCA manager with NC-		o If a DNCA agent receives an NCR from a DNCA manager with NC-
	Request-Type AVP set to INITIAL_REQUEST that matches more than one		Request-Type AVP set to INITIAL_REQUEST that matches more than one
	of the already existing sessions (i.e. DNCA manager and endpoint		of the already existing sessions (i.e. DNCA manager and endpoint
	identifier match already existing sessions), the DNCA agent will		identifier match already existing sessions), the DNCA agent will
	return a NCA with Result-Code set to Insufficient- Classifiers.		return a NCA with Result-Code set to Insufficient-Classifiers. In
	In case a DNCA manager receives a NCA that reports Insufficient-		case a DNCA manager receives a NCA that reports Insufficient-
	Classifiers, it may choose to retry establishing a new session		Classifiers, it may choose to retry establishing a new session
	using additional/more specific classifiers.		using additional/more specific classifiers.
	o If the NCR contains a binding rule not defined on the LSN, the		o If the NCR contains a binding rule not defined on the NAT, the
	DNCA agent will return a NCA with Result-Code AVP set to		DNCA agent will return a NCA with Result-Code AVP set to
	UNKNOWN_BINDING_RULE.		UNKNOWN_BINDING_RULE.
	o In case the DNCA agent is unable to establish all of the bindings		o In case the DNCA agent is unable to establish all of the bindings
	requested in the NCR, it will return a NCA with Result-Code set to		requested in the NCR, it will return a NCA with Result-Code set to
	BINDING_FAILURE. The DNCA agent (i.e. LSN) treats a NCR as an		BINDING_FAILURE. The DNCA agent (i.e. NAT) treats a NCR as an
	atomic operation; hence none of the requested bindings will be		atomic operation; hence none of the requested bindings will be
	established by LSN. Either all requested actions within a NCR are		established by NAT. Either all requested actions within a NCR are
	completed successfully, or the entire request fails.		completed successfully, or the entire request fails.
	o If DNCA agent does not have sufficient resources to process a		o If DNCA agent does not have sufficient resources to process a
	request, it will return NCA with Result-Code set to		request, it will return NCA with Result-Code set to
	RESOURCE_FAILURE.		RESOURCE_FAILURE.
	o In case Max-NAT-Binding and Nat-Control-Definition are included in		o In case Max-NAT-Binding and Nat-Control-Definition are included in
	the NCR along with a reference to a binding rule (i.e. a		the NCR along with a reference to a binding rule (i.e. a
	predefined template on LSN) and the values in Max-NAT-Binding and		predefined template on NAT) and the values in Max-NAT-Binding and
	NAT-Control-Definition contradict those specified in the pre-		NAT-Control-Definition contradict those specified in the pre-
	defined binding rule, Max-NAT-Binding and NAT-Control-Definition		defined binding rule, Max-NAT-Binding and NAT-Control-Definition
	override the values specified in the binding rule.		override the values specified in the binding rule.
	DNCA Manager DNCA Agent		DNCA Manager DNCA Agent
	| |		| |
	| |		| |
	| |		| |
	Trigger |		Trigger |
	| |		| |
	skipping to change at page 14, line 42		skipping to change at page 13, line 45
	|<------------------------------------------|		|<------------------------------------------|
	| (result code) |		| (result code) |
	| |		| |
	| |		| |
	Figure 5: Initial NAT Control request and session establishment		Figure 5: Initial NAT Control request and session establishment
	4.3. Session Re-Authorization		4.3. Session Re-Authorization
	Session re-authorization is performed if the DNCA manager desires to		Session re-authorization is performed if the DNCA manager desires to
	change the behavior of the LSN for an existing session. Re-		change the behavior of the NAT for an existing session. Re-
	authorization could be used, for example, to change the number of		authorization could be used, for example, to change the number of
	allowed bindings for a particular session, or establish or remove a		allowed bindings for a particular session, or establish or remove a
	pre-defined binding.		pre-defined binding.
	The DNCA manager generates a NAT-Control Request (NCR) message to the		The DNCA manager generates a NAT-Control Request (NCR) message to the
	DNCA agent with NC-Request-Type AVP set to UPDATE_REQUEST upon		DNCA agent with NC-Request-Type AVP set to UPDATE_REQUEST upon
	receiving a trigger signal. In case the session is updated		receiving a trigger signal. In case the session is updated
	successfully, the DNCA agent notifies the DNCA manager about		successfully, the DNCA agent notifies the DNCA manager about
	successful session update using a NAT-Control Answer (NCA) message		successful session update using a NAT-Control Answer (NCA) message
	with Result-Code set to DIAMETER_SUCCESS. Figure 6 shows the		with Result-Code set to DIAMETER_SUCCESS. Figure 6 shows the
	protocol interaction between the DNCA manager and the DNCA agent.		protocol interaction between the DNCA manager and the DNCA agent.
	In certain cases, the DNCA agent may not be able to perform the tasks		In certain cases, the DNCA agent may not be able to perform the tasks
	requested within the NCR. These include the following:		requested within the NCR. These include the following:
	o If DNCA agent receives a NCR update/query request for non-existent		o If DNCA agent receives a NCR update/query request for non-existent
	session it will set error code in answer, to		session it will set error code in answer, to
	DIAMETER_UNKNOWN_SESSION_ID.		DIAMETER_UNKNOWN_SESSION_ID.
	o If the NCR contains a binding rule not defined on the LSN, the		o If the NCR contains a binding rule not defined on the NAT, the
	DNCA agent will return a NCA with Result-Code AVP set to		DNCA agent will return a NCA with Result-Code AVP set to
	UNKNOWN_BINDING_RULE.		UNKNOWN_BINDING_RULE.
	o If the DNCA agent cannot establish the requested binding because		o If the DNCA agent cannot establish the requested binding because
	the maximum number of allowed bindings has been reached for the		the maximum number of allowed bindings has been reached for the
	Endpoint Classifier, it will return NCA with Result-Code AVP set		Endpoint Classifier, it will return NCA with Result-Code AVP set
	to MAXIMUM_BINDINGS_REACHED_FOR_ENDPOINT.		to MAXIMUM_BINDINGS_REACHED_FOR_ENDPOINT.
	o In case the DNCA agent cannot establish some or all of the		o In case the DNCA agent cannot establish some or all of the
	bindings requested in a NCR, but has not yet reached the maximum		bindings requested in a NCR, but has not yet reached the maximum
	number of allowed bindings for the subscriber, it will return a		number of allowed bindings for the subscriber, it will return a
	NCA with Result-Code set to BINDING_FAILURE. The DNCA agent (i.e.		NCA with Result-Code set to BINDING_FAILURE. The DNCA agent (i.e.
	LSN) treats a NCR as an atomic operation; hence none of the		NAT) treats a NCR as an atomic operation; hence none of the
	requested bindings will be established by LSN. Either all		requested bindings will be established by NAT. Either all
	requested actions within a NCR are completed successfully, or the		requested actions within a NCR are completed successfully, or the
	entire request fails.		entire request fails.
	o If DNCA agent does not have sufficient resources to process a		o If DNCA agent does not have sufficient resources to process a
	request, it will return a NCA with Result-Code set to		request, it will return a NCA with Result-Code set to
	RESOURCE_FAILURE.		RESOURCE_FAILURE.
	o If a NCR redefines the maximum number of NAT bindings allowed for		o If a NCR redefines the maximum number of NAT bindings allowed for
	the endpoint, the new value will override any previously defined		the endpoint, the new value will override any previously defined
	limit on NAT-bindings. It depends on the implementation of the		limit on NAT-bindings. It depends on the implementation of the
	LSN how LSN would cope with a case where the new value is lower		NAT how NAT would cope with a case where the new value is lower
	than the actual number of allocated bindings. Typically the LSN		than the actual number of allocated bindings. Typically the NAT
	would refrain from enforcing the new limit immediately (i.e.		would refrain from enforcing the new limit immediately (i.e.
	actively remove bindings) but rather disallow the establishment of		actively remove bindings) but rather disallow the establishment of
	new bindings until the current number of bindings is lower than		new bindings until the current number of bindings is lower than
	the newly established maximum number of allowed bindings.		the newly established maximum number of allowed bindings.
	o If a NCR specifies a new binding rule, predefined on the DNCA		o If a NCR specifies a new binding rule, predefined on the DNCA
	agent, the binding rule will override any previously defined rules		agent, the binding rule will override any previously defined rules
	for the session.		for the session.
	o In case Max-NAT-Binding and Nat-Control-Definition are included in		o In case Max-NAT-Binding and Nat-Control-Definition AVPs are
	the NCR along with a reference to a binding rule (i.e. a		included in the NCR along with a reference to a binding rule (i.e.
	predefined template on LSN) and the values in Max-NAT-Binding and		a predefined template on NAT) and the values in Max-NAT-Binding
	Nat-Control-Definition contradict those specified in the pre-		and Nat-Control-Definition AVPs contradict those specified in the
	defined binding rule, Max-NAT-Binding and NAT-Control-Definition		pre-defined binding rule, Max-NAT-Binding and NAT-Control-
	override the values specified in the binding rule.		Definition AVPs override the values specified in the binding rule.
	DNCA Manager DNCA Agent		DNCA Manager DNCA Agent
	| |		| |
	| |		| |
	| |		| |
	Change of session |		Change of session |
	attributes |		attributes |
	| |		| |
	| NCR |		| NCR |
	|------------------------------------------>|		|------------------------------------------>|
	skipping to change at page 16, line 33		skipping to change at page 15, line 36
	| |		| |
	| |		| |
	| NCA |		| NCA |
	|<------------------------------------------|		|<------------------------------------------|
	| (result code) |		| (result code) |
	| |		| |
	| |		| |
	Figure 6: NAT Control request for session update		Figure 6: NAT Control request for session update
	4.4. Session and Binding Query		4.4. Session And Binding Query
	Session query can be used by the DNCA manager to either retrieve		Session query can be used by the DNCA manager to either retrieve
	information on the current bindings for a particular session at the		information on the current bindings for a particular session at the
	LSN or discover the session identifier for a particular external IP-		NAT or discover the session identifier for a particular external IP-
	address/port pair.		address/port pair.
	The DNCA manager initiates a session query by sending a NAT-Control		The DNCA manager initiates a session query by sending a NAT-Control
	Request (NCR) message to the DNCA agent with NC-Request-Type AVP set		Request (NCR) message to the DNCA agent with NC-Request-Type AVP set
	to QUERY_REQUEST. Figure 7 shows the protocol interaction between		to QUERY_REQUEST. Figure 7 shows the protocol interaction between
	the DNCA manager and the DNCA agent.		the DNCA manager and the DNCA agent.
	Two types of query requests exist. The first type of query request		Two types of query requests exist. The first type of query request
	uses the session ID as input parameter to the query. It is to allow		uses the session ID as input parameter to the query. It is to allow
	the DNCA manager retrieve the current set of bindings for a specific		the DNCA manager retrieve the current set of bindings for a specific
	skipping to change at page 18, line 31		skipping to change at page 17, line 31
	|<------------------------------------------|		|<------------------------------------------|
	| (result code) |		| (result code) |
	| |		| |
	| |		| |
	Figure 7: Session Query		Figure 7: Session Query
	4.5. Session Termination		4.5. Session Termination
	The DNCA manager generates a NAT-Control Request (NCR) message to the		The DNCA manager generates a NAT-Control Request (NCR) message to the
	DNCA agent with NC-Request-Type AVP set to TERMINATE REQUEST upon		DNCA agent with NC-Request-Type AVP set to TERMINATE_REQUEST upon
	receiving a trigger signal. The DNCA agent sends accounting stop		receiving a trigger signal. The DNCA agent sends accounting stop
	record reporting all the bindings and notifies the DNCA manager about		record reporting all the bindings and notifies the DNCA manager about
	successful session termination using a NAT-Control Answer (NCA)		successful session termination using a NAT-Control Answer (NCA)
	message with Result-Code set to DIAMETER_SUCCESS. Figure 8 shows the		message with Result-Code set to DIAMETER_SUCCESS. Figure 8 shows the
	protocol interaction between the DNCA manager and the DNCA agent.		protocol interaction between the DNCA manager and the DNCA agent.
	If a DNCA agent receives a NCR from a DNCA manager with NC-Request-		If a DNCA agent receives a NCR from a DNCA manager with NC-Request-
	Type AVP set to Terminate REQUEST and fails to find a matching		Type AVP set to TERMINATE_REQUEST and fails to find a matching
	session, the DNCA agent returns DIAMETER_UNKNOWN_SESSION_ID error.		session, the DNCA agent returns DIAMETER_UNKNOWN_SESSION_ID error.
	DNCA Manager DNCA Agent		DNCA Manager DNCA Agent
	| |		| |
	| |		| |
	Trigger |		Trigger |
	| |		| |
	| NCR |		| NCR |
	|------------------------------------------->|		|------------------------------------------->|
	| (TERMINATE_REQUEST, session id) |		| (TERMINATE_REQUEST, session id) |
	skipping to change at page 19, line 35		skipping to change at page 18, line 35
	| |		| |
	| |		| |
	| |		| |
	| NCA |		| NCA |
	|<-------------------------------------------|		|<-------------------------------------------|
	| (result code) |		| (result code) |
	| |		| |
	Figure 8: Terminate NAT Control session		Figure 8: Terminate NAT Control session
	4.6. DNCA Manager/Agent failures		4.6. DNCA Manager/Agent Failures
	Disclaimer: This version of the draft does not cover details in case		This document does not cover details in case DNCA manager and DNCA
	DNCA manager and DNCA agent go out of sync, which could happen for		agent go out of sync, which could happen for example due to DNCA
	example due to DNCA manager or DNCA agent restart, (temporary) loss		manager or DNCA agent restart, (temporary) loss of network
	of network connectivity etc. Future versions of this draft will		connectivity etc. DNCA application will rely on DNCA Manager and
	cover failure cases and corresponding behavior of DNCA manager and		DNCA Agent to have builtin redundancy support to recover state in
	DNCA agent in detail.		case of failure.
	Example failure cases include the following:		Example failure cases include the following:
	o The DNCA manager loses session state (e.g. due to a restart). In		o The DNCA manager loses session state (e.g. due to a restart). In
	this case,		this case,
	* the DNCA agent may receive a NCR with NC-Request-Type AVP set		* the DNCA agent may receive a NCR with NC-Request-Type AVP set
	to INITIAL_REQUEST that matches an existing session of DNCA		to INITIAL_REQUEST that matches an existing session of DNCA
	agent. The DNCA agent will return an error that contains		agent. The DNCA agent will return an error that contains
	Duplicate-Session-Id AVP to report Session-Id of existing		Duplicate-Session-Id AVP to report Session-Id of existing
	skipping to change at page 20, line 22		skipping to change at page 19, line 22
	o The DNCA agent loses session state. In such a case, the DNCA		o The DNCA agent loses session state. In such a case, the DNCA
	agent could receive a NCR with NC-Request-Type AVP set to		agent could receive a NCR with NC-Request-Type AVP set to
	UPDATE_REQUEST for a non-existent session. The DNCA agent will		UPDATE_REQUEST for a non-existent session. The DNCA agent will
	return NCA with error code set to DIAMETER_UNKNOWN_SESSION_ID.		return NCA with error code set to DIAMETER_UNKNOWN_SESSION_ID.
	State recovery procedures of the DNCA agent will be covered in a		State recovery procedures of the DNCA agent will be covered in a
	future version of this document.		future version of this document.
	o The DNCA manager is unreachable (as e.g. detected by Diameter		o The DNCA manager is unreachable (as e.g. detected by Diameter
	watchdog) or down and accounting requests from the DNCA agent fail		watchdog) or down and accounting requests from the DNCA agent fail
	to get a response. The current version of the draft does not		to get a response. The mechanism to ensure that a DNCA manager no
	specify procedures for DNCA agent session state clean up or		longer has associated state for a session being cleared at the
	recovery. The mechanism to ensure that a DNCA manager no longer		DNCA agent is beyond the scope of this document.
	has associated state for a session being cleared at the DNCA agent
	is beyond the scope of this document.
	o The DNCA agent is unreachable or down and NCR requests fail to get		o The DNCA agent is unreachable or down and NCR requests fail to get
	a response. Handling of this case depends on the actual service		a response. Handling of this case depends on the actual service
	offering of the service provider. The service provider could, for		offering of the service provider. The service provider could, for
	example, choose to terminate the access session to the endpoint.		example, choose to terminate the access session to the endpoint.
	5. Use of the DIAMETER base protocol		5. Use Of The Diameter Base Protocol
	The DIAMETER Base Protocol defined by [RFC3588] shall apply, with the		The Diameter Base Protocol defined by [RFC3588] shall apply, with the
	clarifications listed in the present specification.		clarifications listed in the present specification.
	5.1. Securing DIAMETER messages		5.1. Securing Diameter Messages
	For secure transport of DIAMETER messages, IPSec may be used.		For secure transport of Diameter messages, IPSec MAY be used.
	The DNCA agent may verify the identity of the DNCA Manager during the		The DNCA agent MAY verify the identity of the DNCA Manager during the
	Capabilities Exchange Request procedure.		Capabilities Exchange Request procedure.
	The DNCA agent may verify if the DNCA Manager that issues a NCR		The DNCA agent MAY verify if the DNCA Manager that issues a NCR
	command is allowed to do so, based on:		command is allowed to do so, based on:
	o The Identity of the DNCA Manager		o The Identity of the DNCA Manager
	o The Type of NCR Command
			o The Type of NCR Command
	o The content of the NCR Command		o The content of the NCR Command
	o Any combination of the above		o Any combination of the above
	5.2. Accounting functionality		5.2. Accounting Functionality
	Accounting functionality (Accounting Session State Machine, related		Accounting functionality (Accounting Session State Machine, related
	command codes and AVPs) is defined in Section 8 below.		command codes and AVPs) is defined in Section 8 below.
	5.3. Use of sessions		5.3. Use Of Sessions
	Each DNCA session MUST have a globally unique Session-Id as defined		Each DNCA session MUST have a globally unique Session-Id as defined
	in [RFC3588], which MUST NOT be changed during the lifetime of a DNCA		in [RFC3588], which MUST NOT be changed during the lifetime of a DNCA
	session. The Diameter Session-Id serves as the global endpoint		session. The Diameter Session-Id serves as the global endpoint
	identifier (see also capabilities Section 3.1). The DNCA agent and		identifier. The DNCA agent and DNCA manager maintain state
	DNCA manager maintain state associated with the Session-Id. This		associated with the Session-Id. This globally unique Session-Id is
	globally unique Session-Id is used for updating, accounting for and		used for updating, accounting for and terminating the session. DNCA
	terminating the session. DNCA session MUST NOT have more than one		session MUST NOT have more than one outstanding request at any given
	outstanding request at any given instant. The DNCA agent sends an		instant. The DNCA agent sends an Abort-Session-Request as defined in
	Abort-Session-Request as defined in [RFC3588] if it is unable to		[RFC3588] if it is unable to maintain sessions due to resource
	maintain sessions due to resource limitation.		limitation.
	5.4. Routing considerations		5.4. Routing Considerations
	It is assumed that the DNCA manager knows the address/name of the		It is assumed that the DNCA manager knows the DiameterIdentity of the
	DNCA agent for a given endpoint. Both the Destination-Realm and		DNCA agent for a given endpoint. Both the Destination-Realm and
	Destination-Host AVPs are present in the Request from the DNCA		Destination-Host AVPs are present in the Request from the DNCA
	manager to the DNCA agent.		manager to the DNCA agent.
	5.5. Advertising Application support		5.5. Advertising Application Support
	Diameter applications conforming to this specification MUST advertise		Diameter applications conforming to this specification MUST advertise
	support by including the value of TBD in:		support by including the value of TBD in:
	o Auth-Application-Id and Acct-Application-Id of Capabilities-		o Auth-Application-Id and Acct-Application-Id of Capabilities-
	Exchange-Request (CER)		Exchange-Request (CER)
	o Auth-Application-Id of NC-request (NCR), NC-Answer (NCA), Abort-		o Auth-Application-Id of NC-request (NCR), NC-Answer (NCA), Abort-
	Session-Request(ASR), Abort-Session-Answer (AAA) messages		Session-Request(ASR), Abort-Session-Answer (AAA) messages
	o Acct-Application-Id in Accounting-Request (ACR) and Accounting-		o Acct-Application-Id in Accounting-Request (ACR) and Accounting-
	Answer (AAA) messages.		Answer (AAA) messages.
	6. Diameter NAT Control Application Commands		6. Diameter NAT Control Application Commands
	The following commands are used to establish, maintain and clear LSN		The following commands are used to establish, maintain and clear NAT
	bindings.		bindings.
	6.1. NAT-Control Request (NCR) Command		6.1. NAT-Control Request (NCR) Command
	The NAT-Control Request (NCR) command, indicated by the command field		The NAT-Control Request (NCR) command, indicated by the command field
	set to TBD and the "R" bit set in the Command Flags field, is sent		set to TBD and the "R" bit set in the Command Flags field, is sent
	from the DNCA manager to the DNCA agent in order to install NAT		from the DNCA manager to the DNCA agent in order to install NAT
	bindings.		bindings.
	Message Format:		User-Name, Logical-Access-Id, Physical-Access-ID, Framed-IP-Address,
			Framed-IPv6-Prefix , Framed-Interface-Id, EGRESS-VLANID, NAS-Port-ID,
			Address-Realm, Calling-Station-ID AVPs serve as identifiers for the
			subscriber.
			Message Format:
	< NC-Request > ::= < Diameter Header: TBD, REQ, PXY>		< NC-Request > ::= < Diameter Header: TBD, REQ, PXY>
	< Session-Id >		< Session-Id >
	{ Auth-Application-Id }		{ Auth-Application-Id }
	{ Origin-Host }		{ Origin-Host }
	{ Origin-Realm }		{ Origin-Realm }
	{ Destination-Realm }		{ Destination-Realm }
	{ Destination-Host }		{ Destination-Host }
	{ NC-Request-Type }		{ NC-Request-Type }
	[ Origin-State-Id ]		[ Origin-State-Id ]
	[ Auth-Session-State ]		[ Auth-Session-State ]
	* [ NAT-Control-Remove ]		* [ NAT-Control-Remove ]
	* [ NAT-Control-Install ]		* [ NAT-Control-Install ]
	[ User-Name ]		[ User-Name ]
	[ Logical-Access-Id ]		[ Logical-Access-Id ]
	[ Physical-Access-ID ]		[ Physical-Access-ID ]
	[ Framed-IP-Address ]		[ Framed-IP-Address ]
			[ Framed-IPv6-Prefix ]
	[ Framed-Interface-Id ]		[ Framed-Interface-Id ]
	[ EGRESS-VLANID]		[ EGRESS-VLANID]
	[ NAS-Port-ID]		[ NAS-Port-ID]
	[ Address-Realm ]		[ Address-Realm ]
	[ Called-Station-ID ]		[ Calling-Station-ID ]
	* [ Proxy-Info ]		* [ Proxy-Info ]
	* [ Route-Record ]		* [ Route-Record ]
	* [ AVP ]		* [ AVP ]
	6.2. NAT-Control Answer (NCA) Command		6.2. NAT-Control Answer (NCA) Command
	The NAT-Control-Answer (NCA) command, indicated by the Command-Code		The NAT-Control-Answer (NCA) command, indicated by the Command-Code
	field set to TBD and the "R" bit cleared in the Command Flags field,		field set to TBD and the "R" bit cleared in the Command Flags field,
	is sent by the DNCA agent in response to NAT-Control-Request command.		is sent by the DNCA agent in response to NAT-Control-Request command.
	skipping to change at page 23, line 19		skipping to change at page 22, line 19
	{ NC-Request-Type }		{ NC-Request-Type }
	[ Result-Code ]		[ Result-Code ]
	* [ NAT-Control-Definition ]		* [ NAT-Control-Definition ]
	[ Current-NAT-Bindings ]		[ Current-NAT-Bindings ]
	[ Origin-State-Id ]		[ Origin-State-Id ]
	[ Error-Message ]		[ Error-Message ]
	[ Error-Reporting-Host ]		[ Error-Reporting-Host ]
	* [ Failed-AVP ]		* [ Failed-AVP ]
	* [ Proxy-Info ]		* [ Proxy-Info ]
	[ Duplicate-Session-ID ]		[ Duplicate-Session-ID ]
			* [ Redirect-Host]
			[ Redirect-Host-Usage ]
			[ Redirect-Max-Cache-Time ]
			* [ Proxy-Info ]
			* [ Route-Record ]
			* [ Failed-AVP ]
			* [ AVP ]
	* [ AVP ]		* [ AVP ]
	7. Diameter NAT Control Application AVPs		7. Diameter NAT Control Application AVPs
	7.1. Reused Base Protocol AVPs		7.1. Reused Base Protocol AVPs
	AVPs reused from Diameter Base Protocol [RFC3588] are listed below.		AVPs reused from Diameter Base Protocol [RFC3588] are listed below.
	+-------------------+		+-------------------+
	| AVP Flag rules |		| AVP Flag rules |
	skipping to change at page 24, line 40		skipping to change at page 23, line 40
	| message, which carries this AVP, to be accepted. |		| message, which carries this AVP, to be accepted. |
	|P - Indicates the need for encryption for end-to-end security. |		|P - Indicates the need for encryption for end-to-end security. |
	+-------------------------------------------------------------------+		+-------------------------------------------------------------------+
	Figure 9: DIAMETER AVPs used from Diameter base		Figure 9: DIAMETER AVPs used from Diameter base
	The Auth-Application-Id AVP (AVP Code 258) is assigned by IANA to		The Auth-Application-Id AVP (AVP Code 258) is assigned by IANA to
	Diameter applications. The value of the Auth-Application-Id for the		Diameter applications. The value of the Auth-Application-Id for the
	Diameter NAT Control Application is TBD.		Diameter NAT Control Application is TBD.
	7.2. Additional Result-Code AVP values		7.2. Additional Result-Code AVP Values
	This section defines new values for the Result-Code AVP which SHALL		This section defines new values for the Result-Code AVP which SHALL
	be supported by all DIAMETER implementations that conform to the		be supported by all Diameter implementations that conform to the
	present document.		present document.
	7.2.1. Success		7.2.1. Success
	No new Result-Code AVP value is defined within this category.		No new Result-Code AVP value is defined within this category.
	7.2.2. Transient failures		7.2.2. Transient Failures
	Result-Code AVP values that fall within the transient failures		Result-Code AVP values that fall within the transient failures
	category are those used to inform a peer that the request could not		category are those used to inform a peer that the request could not
	be satisfied at the time that it was received. The request may be		be satisfied at the time that it was received. The request may be
	able to be satisfied in the future.		able to be satisfied in the future.
	The following new values of the Result-Code AVP are defined:		The following new values of the Result-Code AVP are defined:
	RESOURCE_FAILURE (TBD)		RESOURCE_FAILURE (TBD)
	The DNCA agent indicates that the binding could not be		The DNCA agent indicates that the binding could not be
	installed or a new session could not be created due to resource		installed or a new session could not be created due to resource
	shortage.		shortage.
	7.2.3. Permanent failures		7.2.3. Permanent Failures
	Result-Code AVP values that fall within the permanent failures		Result-Code AVP values that fall within the permanent failures
	category are used to inform the peer that the request failed, and		category are used to inform the peer that the request failed, and
	should not be attempted again. The request may be able to be		should not be attempted again. The request may be able to be
	satisfied in the future.		satisfied in the future.
	The following new values of the Result-Code AVP are defined:		The following new values of the Result-Code AVP are defined:
	UNKNOWN_BINDING_RULE_NAME (TBD)		UNKNOWN_BINDING_RULE_NAME (TBD)
	skipping to change at page 26, line 11		skipping to change at page 25, line 11
	it already has a DNCA session that uses the same set of		it already has a DNCA session that uses the same set of
	classifiers as indicated by DNCA manager in the new session		classifiers as indicated by DNCA manager in the new session
	init request.		init request.
	INSUFFICIENT_CLASSIFIERS (TBD)		INSUFFICIENT_CLASSIFIERS (TBD)
	The DNCA agent defines request to initialize a new session, if		The DNCA agent defines request to initialize a new session, if
	the classifiers in the request match more than one of the		the classifiers in the request match more than one of the
	existing sessions on DNCA agent.		existing sessions on DNCA agent.
	7.3. Reused NASREQ Diameter application AVPs		7.3. Reused NASREQ Diameter Application AVPs
	The following AVPs are reused from Diameter Network Access Server		The following AVPs are reused from Diameter Network Access Server
	Application [RFC4005].		Application [RFC4005].
	+---------------------+		+---------------------+
	| AVP Flag rules |		| AVP Flag rules |
	+------------------+------+------------|----+-----+----+-----|----+		+------------------+------+------------|----+-----+----+-----|----+
	| | AVP | | | |SHLD| MUST| |		| | AVP | | | |SHLD| MUST| |
	| Attribute Name | Code | Value Type|MUST| MAY | NOT| NOT|Encr|		| Attribute Name | Code | Value Type|MUST| MAY | NOT| NOT|Encr|
	|------------------|------|------------|----+-----+----+-----|----|		|------------------|------|------------|----+-----+----+-----|----|
	| NAS-Port | 5 | Unsigned32 | M | P | | V | Y |		| NAS-Port | 5 | Unsigned32 | M | P | | V | Y |
	| NAS-Port-Id | 87 | UTF8String | M | P | | V | Y |		| NAS-Port-Id | 87 | UTF8String | M | P | | V | Y |
	| Called-Station-Id| 30 | UTF8String | M | P | | V | Y |
	| Calling-Station- | 31 | UTF8String | M | P | | V | Y |		| Calling-Station- | 31 | UTF8String | M | P | | V | Y |
	| Id | | | | | | | |		| Id | | | | | | | |
	| Framed-IP-Address| 8 | OctetString| M | P | | V | Y |		| Framed-IP-Address| 8 | OctetString| M | P | | V | Y |
	| Framed-Interface-| 96 | Unsigned64 | M | P | | V | Y |		| Framed-Interface-| 96 | Unsigned64 | M | P | | V | Y |
	| ID | | | | | | | |		| ID | | | | | | | |
			| Framed-IPv6- | 97 | OctetString| M | P | | V | Y |
			| Prefix | | | | | | | |
	+------------------+------+------------|----+-----+----+-----|----+		+------------------+------+------------|----+-----+----+-----|----+
	Figure 10: Reused NASREQ Diameter application AVPs		Figure 10: Reused NASREQ Diameter application AVPs
	7.4. Reused from RFC 4675		7.4. Reused from RFC 4675
	The following AVPs are reused from "RADIUS Attributes for Virtual LAN		The following AVPs are reused from "RADIUS Attributes for Virtual LAN
	and Priority Support" specification [RFC4675].		and Priority Support" specification [RFC4675].
	+---------------------+		+---------------------+
	| AVP Flag rules |		| AVP Flag rules |
	+------------------+------+------------|----+-----+----+-----|----+		+------------------+------+------------|----+-----+----+-----|----+
	| | AVP | | | |SHLD| MUST| |		| | AVP | | | |SHLD| MUST| |
	| Attribute Name | Code | Value Type|MUST| MAY | NOT| NOT|Encr|		| Attribute Name | Code | Value Type|MUST| MAY | NOT| NOT|Encr|
	|------------------|------|------------|----+-----+----+-----|----|		|------------------|------|------------|----+-----+----+-----|----|
	| Egress-VLANID | 56 | OctetString| M | P | | V | Y |		| Egress-VLANID | 56 | OctetString| M | P | | V | Y |
	+------------------+------+------------|----+-----+----+-----|----+		+------------------+------+------------|----+-----+----+-----|----+
	Figure 11: Reused attributes from RFC 4675		Figure 11: Reused attributes from RFC 4675
	skipping to change at page 27, line 28		skipping to change at page 26, line 28
	|Direction TBD Enumerated | M | P | Y |		|Direction TBD Enumerated | M | P | Y |
	+-----------------------------------------------+-----+---+---------+		+-----------------------------------------------+-----+---+---------+
	|M - Mandatory bit. An AVP with "M" bit set and its value MUST be |		|M - Mandatory bit. An AVP with "M" bit set and its value MUST be |
	| supported and recognized by a Diameter entity in order the |		| supported and recognized by a Diameter entity in order the |
	| message, which carries this AVP, to be accepted. |		| message, which carries this AVP, to be accepted. |
	|P - Indicates the need for encryption for end-to-end security. |		|P - Indicates the need for encryption for end-to-end security. |
	+-------------------------------------------------------------------+		+-------------------------------------------------------------------+
	Figure 12: Reused QoS-attributes		Figure 12: Reused QoS-attributes
	7.6. Reused from ETSI ES 283 034, e4 Diameter application		7.6. Reused From ETSI ES 283 034, e4 Diameter Application
	The following AVPs are reused from the Diameter e4 Application		The following AVPs are reused from the Diameter e4 Application
	[ETSIES283034].		[ETSIES283034].
	+-------------------+		+-------------------+
	| AVP Flag rules |		| AVP Flag rules |
	+-----------------------------------------------|-----+---+---------+		+-----------------------------------------------|-----+---+---------+
	| AVP | | | May |		| AVP | | | May |
	| Attribute Name Code Data Type |MUST |MAY| encrypt |		| Attribute Name Code Data Type |MUST |MAY| encrypt |
	+-----------------------------------------------+-----+---+---------+		+-----------------------------------------------+-----+---+---------+
	|Address-Realm 301 OctetString | M,V | | Y |		|Address-Realm 301 OctetString | M,V | | Y |
	|Logical-Access-Id 302 OctetString | V | M | Y |		|Logical-Access-Id 302 OctetString | V | M | Y |
	|Physical-Access-ID 313 UTF8String | V | M | Y |		|Physical-Access-ID 313 UTF8String | V | M | Y |
	+-----------------------------------------------+-----+---+---------+		+-----------------------------------------------+-----+---+---------+
	skipping to change at page 30, line 45		skipping to change at page 29, line 42
	{ NAT-Internal-Address }		{ NAT-Internal-Address }
	[ Protocol ]		[ Protocol ]
	[ Direction ]		[ Direction ]
	[ NAT-External-Address ]		[ NAT-External-Address ]
	[ Session-Id ]		[ Session-Id ]
	* [ AVP ]		* [ AVP ]
	7.7.5. NAT-Internal-Address AVP		7.7.5. NAT-Internal-Address AVP
	The NAT-Internal-Address AVP (AVP code TBD) is of type Grouped, and		The NAT-Internal-Address AVP (AVP code TBD) is of type Grouped, and
	it describes the internal IP address and port for a binding.		it describes the internal IP address and port for a binding. Framed-
			IPV6-Prefix and Framed-IP-Address AVPs are mutually exclusive.
	AVP format:		AVP format:
	NAT-Internal-Address ::= < AVP Header: TBD >		NAT-Internal-Address ::= < AVP Header: TBD >
	[ Framed-IP-Address ]		[ Framed-IP-Address ]
			[ Framed-IPv6-Prefix ]
	[ Port]		[ Port]
	[ AVP ]		* [ AVP ]
	7.7.6. NAT-External-Address AVP		7.7.6. NAT-External-Address AVP
	The NAT-External-Address AVP (AVP code TBD) is of type Grouped, and		The NAT-External-Address AVP (AVP code TBD) is of type Grouped, and
	it describes the external IP address and port for a binding. IP-		it describes the external IP address and port for a binding. IP-
	Address-Mask AVP can only be specified when Framed-IP-Address AVP is		Address-Mask AVP can only be specified when Framed-IP-Address AVP is
	present.		present.
	AVP format:		AVP format:
	NAT-External-Address ::= < AVP Header: TBD >		NAT-External-Address ::= < AVP Header: TBD >
	[ Framed-IP-Address ]		[ Framed-IP-Address ]
	[ IP-Address-Mask ]		[ IP-Address-Mask ]
	[ Port ]		[ Port ]
	[ AVP ]		* [ AVP ]
	7.7.7. Max-NAT-Bindings		7.7.7. Max-NAT-Bindings
	The Max-NAT-Bindings AVP (AVP code TBD) is of type Unsigned32, and it		The Max-NAT-Bindings AVP (AVP code TBD) is of type Unsigned32, and it
	indicates the maximum number of NAT bindings allowed.		indicates the maximum number of NAT bindings allowed.
	7.7.8. NAT-Control-Binding-Rule AVP		7.7.8. NAT-Control-Binding-Rule AVP
	The NAT-Control-Binding-Rule AVP (AVP code TBD) is of type is of type		The NAT-Control-Binding-Rule AVP (AVP code TBD) is of type is of type
	OctetString, and it defines a name for a policy template that will be		OctetString, and it defines a name for a policy template that will be
	predefined at LSN. Details on the contents and structure of the		predefined at NAT. Details on the contents and structure of the
	template as well as how it would be configured are outside the scope		template as well as how it would be configured are outside the scope
	of this document. The policy to which this AVP refers to may contain		of this document. The policy to which this AVP refers to may contain
	NAT Bindings, address pool for external address allocation of NAT		NAT Bindings, address pool for external address allocation of NAT
	binding, maximum allowed NAT bindings etc.		binding, maximum allowed NAT bindings etc.
	7.7.9. Duplicate-Session-Id AVP		7.7.9. Duplicate-Session-Id AVP
	The Duplicate-Session-Id AVP (AVP Code TBD) is of is of type		The Duplicate-Session-Id AVP (AVP Code TBD) is of is of type
	UTF8String. It is used to report error and contains the Session-Id		UTF8String. It is used to report error and contains the Session-Id
	of an existing session.		of an existing session.
	skipping to change at page 32, line 21		skipping to change at page 31, line 20
	The function of correlating the multiple bindings used by an endpoint		The function of correlating the multiple bindings used by an endpoint
	at any given time is relegated to the post processor.		at any given time is relegated to the post processor.
	The DNCA agent may trigger an interim accounting record when maximum		The DNCA agent may trigger an interim accounting record when maximum
	number of bindings, if received in NCR, is reached.		number of bindings, if received in NCR, is reached.
	8.1. NAT Control Accounting Messages		8.1. NAT Control Accounting Messages
	The ACR and ACA messages are reused as defined in Diameter Base		The ACR and ACA messages are reused as defined in Diameter Base
	Protocol [RFC3588] for exchanging endpoint NAT binding details		Protocol [RFC3588] for exchanging endpoint NAT binding details
	between the DNCA agent and the CDF. ACR will contain one or more		between the DNCA agent and the CDF. DNCA Application ID is used in
	optional NAT-Control-Record AVP to report the bindings. The DNCA		the accounting commands. ACR will contain one or more optional NAT-
	agent indicates the number of the currently allocated NAT bindings to		Control-Record AVP to report the bindings. The DNCA agent indicates
	the DNCA manager using the Current-NAT-Bindings AVP. This number		the number of the currently allocated NAT bindings to the DNCA
	needs to match the number of bindings identified as active within the		manager using the Current-NAT-Bindings AVP. This number needs to
	NAT-Control-Record AVP.		match the number of bindings identified as active within the NAT-
			Control-Record AVP.
	8.2. NAT Control Accounting AVPs		8.2. NAT Control Accounting AVPs
	In addition to AVPs for ACR specified in [RFC3588], the DNCA agent		In addition to AVPs for ACR specified in [RFC3588], the DNCA agent
	must add the NAT-Control-Record AVP.		must add the NAT-Control-Record AVP.
	8.2.1. NAT-Control-Record		8.2.1. NAT-Control-Record
	The NAT-Control-Record AVP (AVP code TBD) is of type Grouped, and it		The NAT-Control-Record AVP (AVP code TBD) is of type Grouped, and it
	describes a binding and its status. Event-Timestamp indicates the		describes a binding and its status. Event-Timestamp indicates the
	skipping to change at page 33, line 23		skipping to change at page 32, line 22
	Indicates that NAT binding is active.		Indicates that NAT binding is active.
	Removed (3)		Removed (3)
	Indicates that the NAT binding was removed.		Indicates that the NAT binding was removed.
	8.2.3. Current-NAT-Bindings		8.2.3. Current-NAT-Bindings
	The Current-NAT-Bindings AVP (AVP code TBD) is of type Unsigned32,		The Current-NAT-Bindings AVP (AVP code TBD) is of type Unsigned32,
	and it indicates number of NAT bindings active on LSN.		and it indicates number of NAT bindings active on NAT.
	9. AVP Occurrence Table		9. AVP Occurrence Table
	The following sections presents the AVPs defined in this document and		The following sections presents the AVPs defined in this document and
	specifies in which Diameter messages they MAY be present. Note that		specifies in which Diameter messages they MAY be present. Note that
	AVPs that can only be present within a Grouped AVP are not		AVPs that can only be present within a Grouped AVP are not
	represented in this table.		represented in this table.
	The table uses the following symbols:		The table uses the following symbols:
	skipping to change at page 35, line 19		skipping to change at page 34, line 19
	+-------------------------------------------------------+		+-------------------------------------------------------+
	|NC-Request-Type 1 1 |		|NC-Request-Type 1 1 |
	|NAT-Control-Install 0 0 |		|NAT-Control-Install 0 0 |
	|NAT-Control-Remove 0 0 |		|NAT-Control-Remove 0 0 |
	|NAT-Control-Definition 0 0 |		|NAT-Control-Definition 0 0 |
	|NAT-Control-Record 0 0 |		|NAT-Control-Record 0 0 |
	|Current-NAT-Bindings 0 0 |		|Current-NAT-Bindings 0 0 |
	|Duplicate-Session-Id 0 0 |		|Duplicate-Session-Id 0 0 |
	+-------------------------------------------------------+		+-------------------------------------------------------+
	9.4. DNCA AVP Table for accounting message		9.4. DNCA AVP Table For Accounting Message
	Following table presents which NAT control application specific AVPs		Following table presents which NAT control application specific AVPs
	May or May Not be present in ACR/ACA messages.		May or May Not be present in ACR/ACA messages.
	+-------------------+		+-------------------+
	| Command Code |		| Command Code |
	+-----------------------------------+-------------------+		+-----------------------------------+-------------------+
	| Attribute Name ACR ACA |		| Attribute Name ACR ACA |
	+-------------------------------------------------------+		+-------------------------------------------------------+
	|NC-Request-Type 0 0 |		|NC-Request-Type 0 0 |
	|NAT-Control-Install 0 0 |		|NAT-Control-Install 0 0 |
	|NAT-Control-Remove 0 0 |		|NAT-Control-Remove 0 0 |
	|NAT-Control-Definition 0 0 |		|NAT-Control-Definition 0 0 |
	|NAT-Control-Record 0+ 0 |		|NAT-Control-Record 0+ 0 |
	skipping to change at page 36, line 47		skipping to change at page 35, line 47
	Table 2: AVP codes		Table 2: AVP codes
	10.3. AVP Values		10.3. AVP Values
	10.3.1. Result-Code AVP Values		10.3.1. Result-Code AVP Values
	Section 7.2 defines several new values for the Result-Code AVP for		Section 7.2 defines several new values for the Result-Code AVP for
	transient failures and permanent failures. IANA is requested to		transient failures and permanent failures. IANA is requested to
	allocate the corresponding values from the ranges for transient		allocate the corresponding values from the ranges for transient
	(4xxx) and permanent (5xxx) failures.		(4xxx) and permantent (5xxx) failures.
	+-----------+---------------------------------------+---------------+		+-----------+---------------------------------------+---------------+
	| Code | Name | Reference |		| Code | Name | Reference |
	| Value | | |		| Value | | |
	+-----------+---------------------------------------+---------------+		+-----------+---------------------------------------+---------------+
	| to be | RESOURCE_FAILURE | Section 7.2.2 |		| to be | RESOURCE_FAILURE | Section 7.2.2 |
	| assigned | | |		| assigned | | |
			| (4xxx) | | |
	| to be | UNKNOWN_BINDING_RULE_NAME | Section 7.2.3 |		| to be | UNKNOWN_BINDING_RULE_NAME | Section 7.2.3 |
	| assigned | | |		| assigned | | |
			| (5xxx) | | |
	| to be | BINDING_FAILURE | Section 7.2.3 |		| to be | BINDING_FAILURE | Section 7.2.3 |
	| assigned | | |		| assigned | | |
			| (5xxx) | | |
	| to be | MAXIMUM_BINDINGS_REACHED_FOR_ENDPOINT | Section 7.2.3 |		| to be | MAXIMUM_BINDINGS_REACHED_FOR_ENDPOINT | Section 7.2.3 |
	| assigned | | |		| assigned | | |
			| (5xxx) | | |
	| to be | SESSION_EXISTS | Section 7.2.3 |		| to be | SESSION_EXISTS | Section 7.2.3 |
	| assigned | | |		| assigned | | |
			| (5xxx) | | |
	| to be | INSUFFICIENT_CLASSIFIERS | Section 7.2.3 |		| to be | INSUFFICIENT_CLASSIFIERS | Section 7.2.3 |
	| assigned | | |		| assigned | | |
			| (5xxx) | | |
	+-----------+---------------------------------------+---------------+		+-----------+---------------------------------------+---------------+
	Table 3: Result Code AVP Values		Table 3: Result Code AVP Values
	10.4. Application IDs		10.4. Application IDs
	IANA is requested to allocate the following application ID using the		IANA is requested to allocate the following application ID using the
	next value from the 7-16777215 range.		next value from the 7-16777215 range.
	Registry:		Registry:
	skipping to change at page 38, line 8		skipping to change at page 37, line 14
	entity which is non-local to the device performing network address		entity which is non-local to the device performing network address
	translation. The security considerations for the Diameter QoS		translation. The security considerations for the Diameter QoS
	application (see [I-D.ietf-dime-diameter-qos] section 11) apply in a		application (see [I-D.ietf-dime-diameter-qos] section 11) apply in a
	similar way to the DNCA. Securing the information exchange between		similar way to the DNCA. Securing the information exchange between
	the authorizing entity (the DNCA manager) as well as the NAT device		the authorizing entity (the DNCA manager) as well as the NAT device
	requires bilateral authentication of the involved parties,		requires bilateral authentication of the involved parties,
	authorization of the involved parties to perform the required		authorization of the involved parties to perform the required
	procedures and functions, as well as procedures to ensure integrity		procedures and functions, as well as procedures to ensure integrity
	and confidentiality of the information exchange. DNCA makes use of		and confidentiality of the information exchange. DNCA makes use of
	the capabilities offered by Diameter as well as the underlying		the capabilities offered by Diameter as well as the underlying
	transport protocols to deliver on these requirements (see		transport protocols to deliver on these requirements (see Section 5.1
	Section 5.1).		).
	It is assumed that the DNCA agent and DNCA manager are in the same		It is assumed that the DNCA agent and DNCA manager are in the same
	domain and have a mutual trust set up. Authorization between the		domain and have a mutual trust set up. Authorization between the
	DNCA agent and DNCA manager is beyond the scope of this document.		DNCA agent and DNCA manager is beyond the scope of this document.
	12. Change history (to be removed prior to publication as an RFC)		12. Acknowledgements
			The authors would like to thank Jouni Korhonen, Avi Lior, Chris Metz,
			Hannes Tschofenig, Greg Weber, and Glen Zorn for their input on this
			document.
			13. Change History (to be removed prior to publication as an RFC)
	Changes from -00 to -01		Changes from -00 to -01
	a. new values for Result-Code AVP used - instead of Experimental-		a. new values for Result-Code AVP used - instead of Experimental-
	Result AVP		Result AVP
	b. added support for transport specific binding (UDP/TCP)		b. added support for transport specific binding (UDP/TCP)
	c. added support for twice-NAT		c. added support for twice-NAT
	d. clarified the use of the two different types of query-requests		d. clarified the use of the two different types of query-requests
	13. References		Changes from -01 to -02
	13.1. Normative References		a. Reference to pull mode removed, session initiation event
			clarified in section 4.1
			b. added Redirect-* AVPs in NCA command
			c. Removed reference to Called-Station-Id AVP in NCR command
			d. Editorial changes (shorted intro section
			e. added support for bindings providing AFT (NAT64)
			14. References
			14.1. Normative References
	[ETSIES283034]		[ETSIES283034]
	ETSI, "Telecommunications and Internet Converged Services		ETSI, "Telecommunications and Internet Converged Services
	and Protocols for Advanced Networks (TISPAN),Network		and Protocols for Advanced Networks (TISPAN),Network
	Attachment Sub-System (NASS),e4 interface based on the		Attachment Sub-System (NASS),e4 interface based on the
	Diameter protocol.", September 2008.		Diameter protocol.", September 2008.
	[I-D.ietf-dime-qos-attributes]
	Korhonen, J., Tschofenig, H., Arumaithurai, M., Jones, M.,
	and A. Lior, "Quality of Service Attributes for Diameter",
	draft-ietf-dime-qos-attributes-13 (work in progress),
	July 2009.
	[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.
	[RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J.		[RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J.
	Arkko, "Diameter Base Protocol", RFC 3588, September 2003.		Arkko, "Diameter Base Protocol", RFC 3588, September 2003.
	[RFC4675] Congdon, P., Sanchez, M., and B. Aboba, "RADIUS Attributes		[RFC4675] Congdon, P., Sanchez, M., and B. Aboba, "RADIUS Attributes
	for Virtual LAN and Priority Support", RFC 4675,		for Virtual LAN and Priority Support", RFC 4675,
	September 2006.		September 2006.
	13.2. Informative References		[RFC5777] Korhonen, J., Tschofenig, H., Arumaithurai, M., Jones, M.,
			and A. Lior, "Traffic Classification and Quality of
			Service (QoS) Attributes for Diameter", RFC 5777,
			February 2010.
			14.2. Informative References
	[I-D.ietf-dime-diameter-qos]		[I-D.ietf-dime-diameter-qos]
	Sun, D., McCann, P., Tschofenig, H., ZOU), T., Doria, A.,		Sun, D., McCann, P., Tschofenig, H., ZOU), T., Doria, A.,
	and G. Zorn, "Diameter Quality of Service Application",		and G. Zorn, "Diameter Quality of Service Application",
	draft-ietf-dime-diameter-qos-11 (work in progress),		draft-ietf-dime-diameter-qos-14 (work in progress),
	August 2009.		February 2010.
	[I-D.ietf-dime-qos-parameters]		[I-D.narten-iana-considerations-rfc2434bis]
	Korhonen, J., Tschofenig, H., and E. Davies, "Quality of		Narten, T. and H. Alvestrand, "Guidelines for Writing an
	Service Parameters for Usage with Diameter",		IANA Considerations Section in RFCs",
	draft-ietf-dime-qos-parameters-11 (work in progress),		draft-narten-iana-considerations-rfc2434bis-09 (work in
	May 2009.		progress), March 2008.
	[I-D.nishitani-cgn]		[I-D.nishitani-cgn]
	Nishitani, T., Miyakawa, S., Nakagawa, A., and H. Ashida,		Nishitani, T., Yamagata, I., Miyakawa, S., Nakagawa, A.,
	"Common Functions of Large Scale NAT (LSN)",		and H. Ashida, "Common Functions of Large Scale NAT
	draft-nishitani-cgn-02 (work in progress), June 2009.		(LSN)", draft-nishitani-cgn-03 (work in progress),
			November 2009.
	[RFC4005] Calhoun, P., Zorn, G., Spence, D., and D. Mitton,		[RFC4005] Calhoun, P., Zorn, G., Spence, D., and D. Mitton,
	"Diameter Network Access Server Application", RFC 4005,		"Diameter Network Access Server Application", RFC 4005,
	August 2005.		August 2005.
			[RFC5624] Korhonen, J., Tschofenig, H., and E. Davies, "Quality of
			Service Parameters for Usage with Diameter", RFC 5624,
			August 2009.
	[TS32299] "3rd Generation Partnership Project; Technical		[TS32299] "3rd Generation Partnership Project; Technical
	Specification Group Service and System Aspects;		Specification Group Service and System Aspects;
	Telecommunication management; Charging management;		Telecommunication management; Charging management;
	"Diameter charging applications", 3GPP TS 32.299 Version		"Diameter charging applications", 3GPP TS 32.299 Version
	6.3.0.2", 2008.		6.3.0.2", 2008.
	Authors' Addresses		Authors' Addresses
	Frank Brockners		Frank Brockners
	Cisco		Cisco
	skipping to change at page 40, line 19		skipping to change at page 40, line 4
	Email: shwethab@cisco.com		Email: shwethab@cisco.com
	Vaneeta Singh		Vaneeta Singh
	Mavenir Systems		Mavenir Systems
	Sharda Towers, 56/13 Nandidurga Road		Sharda Towers, 56/13 Nandidurga Road
	Bangalore 560046		Bangalore 560046
	India		India
	Email: vaneeta@mavenir.com		Email: vaneeta@mavenir.com
	Victor Fajardo		Victor Fajardo
	Telcordia Technologies		Telcordia Technologies
	1 Telcordia Drive #1S-222		1 Telcordia Drive #1S-222
	Piscataway, NJ 08854		Piscataway, NJ 08854
	USA		USA
	Email: vfajardo@research.telcordia.com		Email: vf0213@gmail.com
End of changes. 118 change blocks.
	435 lines changed or deleted		430 lines changed or added
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