draft-ietf-ancp-pon-05.txt		rfc6934.txt
	Network Working Group Nabil Bitar(ed.)		Internet Engineering Task Force (IETF) N. Bitar, Ed.
	Verizon		Request for Comments: 6934 Verizon
	Internet Draft		Category: Informational S. Wadhwa, Ed.
	Intended Status: Informational Sanjay Wadhwa (ed.)		ISSN: 2070-1721 Alcatel-Lucent
	Alcatel-Lucent		T. Haag
	Expires: August 25, 2013		Deutsche Telekom
	Thomas Haag		H. Li
	Deutsche Telekom		Huawei Technologies
			June 2013
	Hongyu Li
	Huawei Technologies
	February 25, 2013
	Applicability of Access Node Control Mechanism to
	PON based Broadband Networks
	draft-ietf-ancp-pon-05.txt		Applicability of the Access Node Control Mechanism to
			Broadband Networks Based on Passive Optical Networks (PONs)
	Abstract		Abstract
	The purpose of this document is to provide applicability of the		The purpose of this document is to provide applicability of the
	Access Node Control mechanism to Passive Optical Network (PON)-based		Access Node Control Mechanism to broadband access based on Passive
	broadband access. The need for an Access Node Control mechanism		Optical Networks (PONs). The need for an Access Node Control
	between a Network Access Server (NAS) and an Access Node Complex (a		Mechanism between a Network Access Server (NAS) and an Access Node
	combination of Optical Line Termination (OLT) and Optical Network		Complex, composed of a combination of Optical Line Termination (OLT)
	Termination (ONT) elements) is described in a multi-service reference		and Optical Network Termination (ONT) elements, is described in a
	architecture in order to perform QoS-related, service-related and		multi-service reference architecture in order to perform QoS-related,
	Subscriber-related operations. The Access Node Control mechanism is		service-related, and subscriber-related operations. The Access Node
	also extended for interaction between components of the Access Node		Control Mechanism is also extended for interaction between components
	Complex (OLT and ONT). The Access Node Control mechanism will ensure		of the Access Node Complex (OLT and ONT). The Access Node Control
	that the transmission of information between the NAS and Access Node		Mechanism will ensure that the transmission of information between
	Complex (ANX) and between the OLT and ONT within an ANX does not need		the NAS and Access Node Complex (ANX) and between the OLT and ONT
	to go through distinct element managers but rather uses a direct		within an ANX does not need to go through distinct element managers
	device-to-device communication and stays on net. This allows for		but rather uses direct device-to-device communication and stays on
	performing access link related operations within those network		net. This allows for performing access-link-related operations
	elements to meet performance objectives.		within those network elements to meet performance objectives.
	Status of this Memo
	This Internet-Draft is submitted in full conformance with the		Status of This Memo
	provisions of BCP 78 and BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		This document is not an Internet Standards Track specification; it is
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	This Internet-Draft will expire on August 25,2013.		Information about the current status of this document, any errata,
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			http://www.rfc-editor.org/info/rfc6934.
	Copyright Notice		Copyright Notice
	Copyright (c) 2013 IETF Trust and the persons identified as the		Copyright (c) 2013 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
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	Table of Contents		Table of Contents
	1. Introduction ..................................................... 3		1. Introduction ....................................................3
	2. Terminology ...................................................... 5		2. Terminology .....................................................4
	3. Motivation for explicit extension of ANCP to FTTx PON ............ 7		3. Motivation for Explicit Extension of ANCP to FTTx PON ...........6
	4. Reference Model for PON Based Broadband Access Network ........... 8		4. Reference Model for PON-Based Broadband Access Network ..........7
	4.1. Functional Blocks ............................................. 10		4.1. Functional Blocks ..........................................9
	4.1.1. Home Gateway ............................................... 10		4.1.1. Home Gateway ........................................9
	4.1.2. PON Access ................................................. 10		4.1.2. PON Access ..........................................9
	4.1.3. Access Node Complex ........................................ 11		4.1.3. Access Node Complex ................................10
	4.1.4. Access Node Complex Uplink to the NAS ....................... 11		4.1.4. Access Node Complex Uplink to the NAS ..............10
	4.1.5. Aggregation Network ......................................... 11		4.1.5. Aggregation Network ................................10
	4.1.6. Network Access Server ....................................... 11		4.1.6. Network Access Server ..............................10
	4.1.7. Regional Network ............................................ 11		4.1.7. Regional Network ...................................10
	4.2. Access Node Complex Control Reference Architecture Options .... 12		4.2. Access Node Complex Control Reference Architecture
	4.2.1. ANCP+OMCI ANX Control ....................................... 12		Options ...................................................11
	4.2.2. All-ANCP ANX Control ........................................ 13		4.2.1. ANCP+OMCI ANX Control ..............................11
	5. Concept of Access Node Control Mechanism for PON Based Access ... 14		4.2.2. All-ANCP ANX Control ...............................12
	6. Multicast ....................................................... 17		5. Concept of Access Node Control Mechanism for PON-Based Access ..13
	6.1. Multicast Conditional Access .................................. 18		6. Multicast ......................................................16
	6.2. Multicast Admission Control ................................... 20		6.1. Multicast Conditional Access ..............................16
	6.3. Multicast Accounting .......................................... 33		6.2. Multicast Admission Control ...............................18
	7. Remote Connectivity Check ....................................... 33		6.3. Multicast Accounting ......................................30
	8. Access Topology Discovery ....................................... 34		7. Remote Connectivity Check ......................................31
	9. Access Loop Configuration ....................................... 36		8. Access Topology Discovery ......................................32
	10. Security Considerations ........................................ 37		9. Access Loop Configuration ......................................34
	11. Differences in ANCP applicability between DSL and PON .......... 38		10. Security Considerations .......................................34
	12. ANCP versus OMCI between the OLT and ONT/ONU ................... 39		11. Differences in ANCP Applicability between DSL and PON .........35
	13. IANA Considerations ............................................ 40		12. ANCP versus OMCI between the OLT and ONT/ONU ..................36
	14. Acknowledgements ............................................... 40		13. Acknowledgements ..............................................37
	15. References ..................................................... 41		14. References ....................................................37
	15.1. Normative References ........................................ 41		14.1. Normative References .....................................37
	15.2. Informative References ....................................... 41		14.2. Informative References ...................................38
	1. Introduction		1. Introduction
	Passive Optical Networks (PONs) based on BPON [G.983.1] and GPON		Passive Optical Networks (PONs) based on Broadband PON (BPON)
	[G.984.1] are being deployed across carrier networks. There are two		[G.983.1] and Gigabit PON (GPON) [G.984.1] are being deployed across
	models for PON deployment: Fiber to the building/curb (FTTB/FTTC),		carrier networks. There are two models for PON deployment: Fiber to
	and Fiber to the Premises (FTTP). In the FTTB/C deployment, the last		the Building/Curb (FTTB/FTTC) and Fiber to the Premises (FTTP). In
	mile connectivity to the subscriber premises is provided over the		the FTTB/C deployment, the last-mile connectivity to the subscriber
	local Copper loop, often using Very High Speed Digital Subscriber		premises is provided over the local copper loop, often using Very
	line (VDSL). In the FTTP case, PON extends to the premises of the		High Speed Digital Subscriber Line (VDSL). In the FTTP case, PON
	subscriber. In addition, there are four main PON technologies: (1)		extends to the premises of the subscriber. In addition, there are
	Broadband PON (BPON), (2) Gigabit PON (GPON), (3) 10-Gigabit PON (XG-		four main PON technologies: (1) BPON, (2) GPON, (3) 10-Gigabit PON
	PON), and (4) Ethernet PON (EPON). This document describes the		(XG-PON), and (4) Ethernet PON (EPON). This document describes the
	applicability of Access Node Control Protocol (ANCP) in the context		applicability of the Access Node Control Protocol (ANCP) in the
	of FTTB/C and FTTP deployments, focusing on BPON, GPON and XG-PON.		context of FTTB/C and FTTP deployments, focusing on BPON, GPON, and
	Architectural considerations lead to different ANCP compositions.		XG-PON. Architectural considerations lead to different ANCP
	Therefore, the composition of ANCP communication between Access Nodes		compositions. Therefore, the composition of ANCP communication
	and Network Access Server (NAS) is described using different models.		between Access Nodes (ANs) and Network Access Servers (NASs) is
			described using different models.
	BPON, GPON and XG-PON in FTTP deployments provide large bandwidth in		BPON, GPON, and XG-PON in FTTP deployments provide large bandwidth in
	the first mile, bandwidth that is an order of magnitude larger than		the first mile, bandwidth that is an order of magnitude larger than
	that provided by xDSL. In the downstream direction, BPON		that provided by xDSL. In the downstream direction, BPON provides
	provides 622 Mbps per PON while GPON provides 2.4 Gbps, and XG-PON		622 Mbit/s per PON, GPON provides 2.4 Gbit/s, and XG-PON provides 10
	provides 10 Gbps.		Gbit/s.
	In residential deployments, the number of homes sharing the same PON		In residential deployments, the number of homes sharing the same PON
	is limited by the technology and the network engineering rules.		is limited by the technology and the network engineering rules.
	Typical deployments have 32-64 homes per PON.		Typical deployments have 32-64 homes per PON.
	The motive behind BPON, GPON and XG-PON deployment is providing		The motive behind BPON, GPON, and XG-PON deployment is to provide
	triple-play services over IP: voice, video and data. Voice is		triple-play services over IP: voice, video, and data. Voice is
	generally low bandwidth but has low-delay, low-jitter, and low		generally low bandwidth but has requirements for low delay, low
	packet-loss requirements. Data services (e.g., Internet services)		jitter, and low packet loss. Data services (e.g., Internet services)
	often require high throughput and can tolerate medium latency. Data		often require high throughput and can tolerate medium latency. Data
	services may include multimedia content download such as video.		services may include multimedia content download such as video.
	However, in that case, the video content is not required to be real-		However, in that case, the video content is not required to be real-
	time and/or it is low quality video. Video services, on the other		time, and/or it is low-quality video. Video services, on the other
	hand, are targeted to deliver Standard Definition or High Definition		hand, are targeted to deliver Standard Definition or High Definition
	video content in real-time or near-real time, depending on the		video content in real time or near real time, depending on the
	service model. Standard Definition content using MPEG2 encoding		service model. Standard Definition content using MPEG2 encoding
	requires on the order of 3.75 Mbps per stream while High definition		requires on the order of 3.75 Mbit/s per stream while High Definition
	content using MPEG2 encoding requires on the order of 15-19 Mbps		content using MPEG2 encoding requires 15-19 Mbit/s depending on the
	depending on the level of compression used. Video services require		level of compression used. Video services require low jitter and low
	low-jitter and low-packet loss with low start-time latency. There are		packet loss with low start-time latency. There are two types of
	two types of video services: on demand and broadcast (known also as		video services: on demand and broadcast (known also as linear
	liner programming content). While linear programming content can be		programming content). While linear programming content can be
	provided over Layer1 on the PON, the focus in this document is on		provided over Layer 1 on the PON, the focus in this document is on
	delivering linear programming content over IP to the subscriber,		delivering linear programming content over IP to the subscriber using
	using IP multicast. Video on demand is also considered for delivery		IP multicast. Video on Demand (VoD) is also considered for delivery
	to the subscriber over IP using a unicast session model.		to the subscriber over IP using a unicast session model.
	Providing simultaneous triple-play services over IP with unicast		Providing simultaneous triple-play services over IP with unicast
	video and multicast video, VoIP and data requires an architecture		video and multicast video, VoIP, and data requires an architecture
	that preserves the quality of service of each service. Fundamental to		that preserves the quality of service of each service. Fundamental
	this architecture is ensuring that the video content (unicast and		to this architecture is ensuring that the video content (unicast and
	multicast) delivered to the subscriber does not exceed the bandwidth		multicast) delivered to the subscriber does not exceed the bandwidth
	allocated to the subscriber for video services. Architecture models		allocated to the subscriber for video services. Architecture models
	often ensure that data is guaranteed a minimum bandwidth and that		often ensure that data is guaranteed a minimum bandwidth and that
	VoIP is guaranteed its own bandwidth. In addition, QoS control across		VoIP is guaranteed its own bandwidth. In addition, QoS control
	services is often performed at a Network Access Server (NAS), often		across services is often performed at a Network Access Server (NAS),
	referred to as Broadband Network Gateway (BNG) for subscriber		often referred to as Broadband Network Gateway (BNG) for subscriber
	management, per subscriber and shared link resources. Efficient		management, per subscriber and shared link resources. Efficient
	multicast video services require enabling multicast services in the		multicast video services require enabling multicast services in the
	access network between the subscriber and the subscriber management		access network between the subscriber and the subscriber management
	platform. In the FTTP/B/C PON environment, this implies enabling IP		platform. In the FTTP/B/C PON environment, this implies enabling IP
	multicast on the Access Node (AN) complex composed of the Optical		multicast on the ANX composed of the Optical Network Terminal (ONT)
	Network Terminal (ONT) or Unit (ONU) and Optical Line Terminal (OLT),		or Unit (ONU) and Optical Line Terminal (OLT), as applicable. This
	as applicable. This is as opposed to Digital Subscriber Line (DSL)		is as opposed to Digital Subscriber Line (DSL) deployments where
	deployments where multicast is enabled on the DSL Access Multiplexer		multicast is enabled on the DSL Access Multiplexer (DSLAM) only. The
	(DSLAM) only. The focus in this document will be on the ANCP		focus in this document will be on the ANCP requirements needed for
	requirements needed for coordinated admission control of unicast and		coordinated admission control of unicast and multicast video in
	multicast video in FTTP/B/C PON environments between the AN complex		FTTP/B/C PON environments between the ANX and the NAS, specifically
	(ANX) and the NAS, specifically focusing on bandwidth dedicated for		focusing on bandwidth dedicated for multicast and shared bandwidth
	multicast and shared bandwidth between multicast and unicast.		between multicast and unicast.
	[RFC5851] provides the framework and requirements for coordinated		[RFC5851] provides the framework and requirements for coordinated
	admission control between a NAS and an AN with special focus on DSL		admission control between a NAS and an AN with special focus on DSL
	deployments. This document extends that framework and the related		deployments. This document extends that framework and the related
	requirements to explicitly address PON deployments.		requirements to explicitly address PON deployments.
	2. Terminology		2. Terminology
	- PON (Passive Optical Network) [G.983.1][G.984.1]: a point-to-		- PON (Passive Optical Network) [G.983.1][G.984.1]: a point-to-
	multipoint fiber to the premises network architecture in which		multipoint FTTP network architecture in which unpowered splitters
	unpowered splitters are used to enable the splitting of an optical		are used to enable the splitting of an optical signal from a
	signal from a central office on a single optical fiber to multiple		central office on a single optical fiber to multiple premises. Up
	premises. Up to 32-128 may be supported on the same PON. A PON		to 32-128 may be supported on the same PON. A PON configuration
	configuration consists of an Optical Line Terminal (OLT) at the		consists of an Optical Line Terminal (OLT) at the service
	Service Provider's Central Office (CO) and a number of Optical		provider's central office (CO) and a number of Optical Network
	Network Units or Terminals (ONU/ONT) near end users, with an optical		Units or Terminals (ONUs/ONTs) near end users, with an Optical
	distribution network (ODN) composed of fibers and splitters between		Distribution Network (ODN) composed of fibers and splitters
	them. A PON configuration reduces the amount of fiber and CO		between them. A PON configuration reduces the amount of fiber and
	equipment required compared with point-to-point architectures.		CO equipment required compared with point-to-point architectures.
	- Access Node Complex (ANX): The Access Node Complex is composed of		- Access Node Complex (ANX): composed of two geographically
	two geographically separated functional elements OLT and ONU/ONT. The		separated functional elements -- OLT and ONU/ONT. The general
	general term Access Node Complex (ANX) will be used when describing a		term Access Node Complex (ANX) will be used when describing a
	functionality which does not depend on the physical location but		functionality that does not depend on the physical location but
	rather on the "black box" behavior of OLT and ONU/ONT.		rather on the "black box" behavior of OLT and ONU/ONT.
	-Optical Line Terminal (OLT): is located in the Service provider's		- Optical Line Terminal (OLT): is located in the service provider's
	central office (CO). It terminates and aggregates multiple PONs		central office (CO). It terminates and aggregates multiple PONs
	(providing fiber access to multiple premises or neighborhoods) on the		(providing fiber access to multiple premises or neighborhoods) on
	subscriber side, and interfaces with the Network Access server (NAS)		the subscriber side and interfaces with the Network Access Server
	that provides subscriber management.		(NAS) that provides subscriber management.
	- Optical Network Terminal (ONT): terminates PON on the network side		- Optical Network Terminal (ONT): terminates PON on the network side
	and provides PON adaptation. The subscriber side interface and the		and provides PON adaptation. The subscriber side interface and
	location of the ONT are dictated by the type of network deployment.		the location of the ONT are dictated by the type of network
	For a Fiber-to-the-Premise (FTTP) deployment (with Fiber all the way		deployment. For an FTTP deployment (with fiber all the way to the
	to the apartment or living unit), ONT has Ethernet (FE/GE/MoCA)		apartment or living unit), ONT has Ethernet (Fast Ethernet (FE) /
	connectivity with the Home Gateway (HGW)/Customer Premise		Gigabit Ethernet (GE) / Multimedia over Coax Alliance (MoCA))
	Equipment(CPE). In certain cases, one ONT may provide connections to		connectivity with the Home Gateway (HGW) / Customer Premises
	more than one Home Gateway at the same time.		Equipment (CPE). In certain cases, one ONT may provide
			connections to more than one Home Gateway at the same time.
	-Optical Network Unit (ONU): A generic term denoting a device that		- Optical Network Unit (ONU): a generic term denoting a device that
	terminates any one of the distributed (leaf) endpoints of an Optical		terminates any one of the distributed (leaf) endpoints of an
	Distribution Node (ODN), implements a PON protocol, and adapts PON		Optical Distribution Network (ODN), implements a PON protocol, and
	PDUs to subscriber service interfaces. In case of an MDU multi-		adapts PON PDUs to subscriber service interfaces. In the case of
	dwelling or multi-tenant unit, a multi-subscriber ONU typically		a multi-dwelling unit (MDU) or multi-tenant unit (MTU), a multi-
	resides in the basement or a wiring closet (FTTB case), and has		subscriber ONU typically resides in the basement or a wiring
	FE/GE/Ethernet over native Ethernet link or over xDSL (typically		closet (FTTB case) and has FE/GE/Ethernet over native Ethernet
	VDSL) connectivity with each CPE at the subscriber premises. In the		link or over xDSL (typically VDSL) connectivity with each CPE at
	case where fiber is terminated outside the premises (neighborhood or		the subscriber premises. In the case where fiber is terminated
	curb side) on an ONT/ONU, the last-leg-premises connections could be		outside the premises (neighborhood or curb side) on an ONT/ONU,
	via existing or new Copper, with xDSL physical layer (typically		the last-leg-premises connections could be via existing or new
	VDSL). In this case, the ONU effectively is a "PON fed DSLAM".		copper, with xDSL physical layer (typically VDSL). In this case,
			the ONU effectively is a "PON-fed DSLAM".
	-Network Access Server (NAS): Network element which aggregates		- Network Access Server (NAS): network element that aggregates
	subscriber traffic from a number of ANs or ANXs. The NAS is often an		subscriber traffic from a number of ANs or ANXs. The NAS is often
	injection point for policy management and IP QoS in the access		an injection point for policy management and IP QoS in the access
	network. It is also referred to as Broadband Network Gateway (BNG) or		network. It is also referred to as Broadband Network Gateway
	Broadband Remote Access Server (BRAS).		(BNG) or Broadband Remote Access Server (BRAS).
	-Home Gateway (HGW): Network element that connects subscriber devices		- Home Gateway (HGW): network element that connects subscriber
	to the AN or ANX and the access network. In case of xDSL, the Home		devices to the AN or ANX and the access network. In the case of
	Gateway is an xDSL network termination that could either operate as a		xDSL, the Home Gateway is an xDSL network termination that could
	Layer 2 bridge or as a Layer 3 router. In the latter case, such a		either operate as a Layer 2 bridge or as a Layer 3 router. In the
	device is also referred to as a Routing Gateway (RG). In the case of		latter case, such a device is also referred to as a Routing
	PON, it is often a Layer3 routing device with the ONT performing PON		Gateway (RG). In the case of PON, it is often a Layer 3 routing
	termination.		device with the ONT performing PON termination.
	-PON-Customer-ID: This is an identifier which uniquely identifies the		- PON-Customer-ID: identifier that uniquely identifies the ANX and
	ANX and the access loop logical port on the ANX to the subscriber		the access loop logical port on the ANX to the subscriber
	(customer) premises, and is used in any interaction between NAS and		(customer) premises and is used in any interaction between NAS and
	ANX that relates to access-loops. Logically it is composed of		ANX that relates to access loops. Logically, it is composed of
	information containing identification of the OLT (the OLT may be		information containing identification of the OLT (the OLT may be
	physically directly connected to the NAS), the PON port on the OLT,		physically and directly connected to the NAS), the PON port on the
	the ONT/ONU, and the port on the ONT/ONU connecting to the subscriber		OLT, the ONT/ONU, and the port on the ONT/ONU connecting to the
	HGW. When acting as a DHCP relay agent, the OLT can encode PON-		subscriber HGW. When acting as a DHCP relay agent, the OLT can
	Customer-ID in the "Agent-Circuit-Identifier" Sub-option in Option-82		encode PON-Customer-ID in the "Agent Circuit ID" sub-option in
	of the DHCP messages [RFC3046].		Option 82 of the DHCP messages [RFC3046].
	3. Motivation for explicit extension of ANCP to FTTx PON		3. Motivation for Explicit Extension of ANCP to FTTx PON
	The fundamental difference between PON and DSL is that a PON is an		The fundamental difference between PON and DSL is that a PON is an
	optical broadcast network by definition. That is, at the PON level,		optical broadcast network by definition. That is, at the PON level,
	every ONT on the same PON sees the same signal. However, the ONT		every ONT on the same PON sees the same signal. However, the ONT
	filters only those PON frames addressed to it. Encryption is used on		filters only those PON frames addressed to it. Encryption is used on
	the PON to prevent eavesdropping.		the PON to prevent eavesdropping.
	The broadcast PON capability is very suitable to delivering multicast		The broadcast PON capability is very suitable for delivering
	content to connected premises, maximizing bandwidth usage efficiency		multicast content to connected premises, maximizing bandwidth usage
	on the PON. Similar to DSL deployments, enabling multicast on the		efficiency on the PON. Similar to DSL deployments, enabling
	Access Node Complex (ANX) provides for bandwidth use efficiency on		multicast on the Access Node Complex (ANX) provides for bandwidth use
	the path between the Access Node and the NAS as well as improves the		efficiency on the path between the Access Node and the NAS as well as
	scalability of the NAS by reducing the amount of multicast traffic		improves the scalability of the NAS by reducing the amount of
	being replicated at the NAS. However, the broadcast capability on the		multicast traffic being replicated at the NAS. However, the
	PON enables the AN (OLT) to send one copy on the PON as opposed to		broadcast capability on the PON enables the AN (OLT) to send one copy
	one copy to each receiver on the PON. The PON multicast capability		on the PON as opposed to one copy to each receiver on the PON. The
	can be leveraged in the case of GPON and BPON as discussed in this		PON multicast capability can be leveraged in the case of GPON and
	document.		BPON as discussed in this document.
	Fundamental to leveraging the broadcast capability on the PON for		Fundamental to leveraging the broadcast capability on the PON for
	multicast delivery is the ability to assign a single encryption key		multicast delivery is the ability to assign no key, a single
	for all PON frames carrying all multicast channels or a key per set		encryption key for all PON frames carrying all multicast channels, or
	of multicast channels that correspond to service packages, or none.		a key per set of multicast channels that correspond to a service
	When supporting encryption for multicast channels, the encryption key		package. When supporting encryption for multicast channels, the
	is generated by the OLT and sent by the OLT to each targeted ONT via		encryption key is generated by the OLT and sent by the OLT to each
	the ONT Management and Control Interface (OMCI) as described in		targeted ONT via the ONT Management and Control Interface (OMCI) as
	section 15.5.2 of ITU-T G.987.3 [G.987.3] for XG-PON. It should be		described in Section 15.5.2 of ITU-T G.987.3 [G.987.3] for XG-PON.
	noted that the ONT can be a multi-Dwelling Unit (MDU) ONT with		It should be noted that the ONT can be a multi-dwelling unit (MDU)
	multiple Ethernet ports, each connected to a living unit. Thus, the		ONT with multiple Ethernet ports, each connected to a living unit.
	ONT must not only be able to receive a multicast frame, but must also		Thus, the ONT must not only be able to receive a multicast frame but
	be able to forward that frame only to the Ethernet port with		must also be able to forward that frame only to the Ethernet port
	receivers for the corresponding channel.		with receivers for the corresponding channel.
	In order to implement triple-play service delivery with necessary		In order to implement triple-play service delivery with necessary
	"quality-of-experience", including end-to-end bandwidth optimized		"quality-of-experience", including end-to-end bandwidth optimized
	multicast video delivery, there needs to be tight coordination		multicast video delivery, there needs to be tight coordination
	between the NAS and the ANX. This interaction needs to be near real-		between the NAS and the ANX. This interaction needs to be near real-
	time as services are requested via application or network level		time as services are requested via application- or network-level
	signaling by broadband subscribers. ANCP as defined in [RFC5851] for		signaling by broadband subscribers. ANCP, as defined in [RFC5851]
	DSL based networks is very suitable to realize a control protocol		for DSL based networks, is very suitable to realize a control
	(with transactional exchange capabilities), between PON enabled ANX		protocol (with transactional exchange capabilities) between the PON-
	and the NAS, and also between the components comprising the ANX,		enabled ANX and the NAS and also between the components comprising
	i.e., between OLT and the ONT. Typical use cases for ANCP in PON		the ANX, i.e., between the OLT and the ONT. Typical use cases for
	environment include the following:		ANCP in the PON environment include the following:
	- Access topology discovery		- Access topology discovery
	- Access Loop Configuration		- Access loop configuration
	- Multicast		- Multicast
	- Optimized multicast delivery		- Optimized multicast delivery
	- Unified video resource control		- Unified video resource control
	- NAS based provisioning of ANX		- NAS-based provisioning of ANX
	- Remote connectivity check		- Remote connectivity check
	4. Reference Model for PON Based Broadband Access Network		4. Reference Model for PON-Based Broadband Access Network
	An overall end-to-end reference architecture of a PON access network		An overall end-to-end reference architecture of a PON access network
	is depicted in Figure 1 and Figure 2 with ONT serving a single HGW,		is depicted in Figures 1 and 2 with ONT serving a single HGW, and
	and ONT/ONU serving multiples HGWs, respectively. An OLT may provide		ONT/ONU serving multiples HGWs, respectively. An OLT may provide
	FTTP and FTTB/C access at the same time but most likely not on the		FTTP and FTTB/C access at the same time but most likely not on the
	same PON port. Specifically, the following PON cases are addressed in		same PON port. Specifically, the following PON cases are addressed
	the context of this reference architecture:		in the context of this reference architecture:
	- BPON with Ethernet uplink to the NAS and ATM on the PON		- BPON with Ethernet uplink to the NAS and ATM on the PON side
	side.		- GPON/XG-PON with Ethernet uplink to the NAS and Ethernet on the
	- GPON/XG-PON with Ethernet uplink to the NAS and Ethernet on		PON side
	the PON side
	In case of an Ethernet aggregation network that supports new QoS-		In the case of an Ethernet aggregation network that supports new QoS-
	enabled IP services (including Ethernet multicast replication), the		enabled IP services (including Ethernet multicast replication), the
	architecture builds on the reference architecture specified in the		architecture builds on the reference architecture specified in the
	Broadband Forum (BBF) [TR-101]. The Ethernet aggregation network		Broadband Forum (BBF) [TR-101]. The Ethernet aggregation network
	between a NAS and an OLT may be degenerated to one or more direct		between a NAS and an OLT may be degenerated to one or more direct
	physical Ethernet links.		physical Ethernet links.
	Given the industry move towards Ethernet as the new access and		Given the industry move towards Ethernet as the new access and
	aggregation technology for triple play services, the primary focus		aggregation technology for triple-play services, the primary focus
	throughout this document is on GPON/XG-PON and BPON with Ethernet		throughout this document is on GPON/XG-PON and BPON with Ethernet
	between the NAS and the OLT.		between the NAS and the OLT.
	Access Customer		Access Customer
	<---------Aggregation-------><-Prem->		<---------Aggregation-------><-Prem->
	Network Network		Network Network
	+------------------+		+------------------+
	| Access Node |		| Access Node |
	| Complex (ANX) |		| Complex (ANX) |
	+---------+ +---+ +-----+ |+---+ +---+ | +---+		+---------+ +---+ +-----+ |+---+ +---+ | +---+
	| | +-|NAS|--|Eth |--||OLT|-<PON>-|ONT|-|--|HGW|		| | +-|NAS|--|Eth |--||OLT|-<PON>-|ONT|-|--|HGW|
	NSP---+Regional | | +---+ |Agg | |+---+ +---+ | +---+		NSP---+Regional | | +---+ |Agg | |+---+ +---+ | +---+
	|Broadband| | +---+ +-----+ +------------------+		|Broadband| | +---+ +-----+ +------------------+
	|Network |-+-|NAS| |		|Network |-+-|NAS| |
	ASP---+ | | +---+ |		ASP---+ | | +---+ |
	| | | +---+ |		| | | +---+ |
	+---------+ +-|NAS| | +---+ +---+		+---------+ +-|NAS| | +---+ +---+
	+---| +-<PON>-|ONT|--|HGW|		+---| +-<PON>-|ONT|--|HGW|
	| +---+ +---+		| +---+ +---+
	|		|
	| +---+ +---+		| +---+ +---+
	+---|ONT|--|HGW|		+---|ONT|--|HGW|
	+---+ +---+		+---+ +---+
	HGW : Home Gateway		HGW : Home Gateway
	NAS : Network Access Server		NAS : Network Access Server
	PON : Passive Optical Network		PON : Passive Optical Network
	OLT : Optical Line Terminal		OLT : Optical Line Terminal
	ONT : Optical Network Terminal		ONT : Optical Network Terminal
	Figure 1: Access Network with PON.		Figure 1: Access Network with PON
			FE/GE/VDSL
			+---+ +---+
			+----------------+ | |-|HGW|
			+---------+ +-----+ | +-----+ +----+| | | +---+
			| | +-|NAS |--| |Eth |--|OLT||-<PON>- | |
			NSP---+Regional | | +-----+ | |Agg | | || | |ONT| +---+
			|Broadband| | | | | | || | | or|-|HGW|
			|Network | | +-----+ | +-----+ +----+| | |ONU| +---+
			| |-+-|NAS | +----------------+ | | |
			ASP---+ | | +-----+ | | | +---+
			| | | +-----+ | | |-|HGW|
			+---------+ +-|NAS | | +---+ +---+
			+-----+ |
			| +---+ +---+
			+-|ONT|-|HGW|
			+---+ +---+
	FE/GE/VDSL		Figure 2: FTTP/FTTB/C with Multi-Subscriber ONT/ONU Serving MTUs/MDUs
	+---+ +---+
	+----------------+ | |-|HGW|
	+---------+ +-----+ | +-----+ +----+| | | +---+
	| | +-|NAS |--| |Eth |--|OLT||-<PON>- | |
	NSP---+Regional | | +-----+ | |Agg | | || | |ONT| +---+
	| | | | | | | || | | or|-|HGW|
	|Broadband| | +-----+ | +-----+ +----+| | |ONU| +---+
	|Network |-+-|NAS | +----------------+ | | |
	ASP---+ | | +-----+ | | | +---+
	| | | +-----+ | | |-|HGW|
	+---------+ +-|NAS | | +---+ +---+
	+-----+ |
	| +---+ +---+
	+-|ONT|-|HGW|
	+---+ +---+
	Figure 2: FTTP/FTTB/C with multi-subscriber ONT/ONU serving MTUs/MDUs.		The following sections describe the functional blocks and network
	The following sections describe the functional blocks and network		segments in the PON access reference architecture.
	segments in the PON access reference architecture.
	4.1. Functional Blocks		4.1. Functional Blocks
	4.1.1. Home Gateway		4.1.1. Home Gateway
	The Home Gateway (HGW) connects the different Customer Premises		The Home Gateway (HGW) connects the different CPEs to the ANX and the
	Equipment (CPE) to the ANX and the access network. In case of PON,		access network. In the case of PON, the HGW is a Layer 3 router. In
	the HGW is a layer 3 router. In this case, the HGW performs IP		this case, the HGW performs IP configuration of devices within the
	configuration of devices within the home via DHCP, and performs		home via DHCP and performs Network Address and Port Translation
	Network Address and Port Translation (NAPT) between the LAN and WAN		(NAPT) between the LAN and WAN side. In the case of FTTP/B/C, the
	side. In case of FTTP/B/C, the HGW connects to the ONT/ONU over an		HGW connects to the ONT/ONU over an Ethernet interface. That
	Ethernet interface. That Ethernet interface could be over an Ethernet		Ethernet interface could be over an Ethernet physical port or over
	physical port or over another medium. In case of FTTP, it is possible		another medium. In the case of FTTP, it is possible to have a single
	to have a single box GPON CPE solution, where the ONT encompasses the		box GPON CPE solution where the ONT encompasses the HGW functionality
	HGW functionality as well as the GPON adaptation function.		as well as the GPON adaptation function.
	4.1.2. PON Access		4.1.2. PON Access
	PON access is composed of the ONT/ONU and OLT. PON ensures		PON access is composed of the ONT/ONU and OLT. PON ensures physical
	physical connectivity between the ONT/ONU at the customer		connectivity between the ONT/ONU at the customer premises and the
	premises and the OLT. PON framing can be BPON (in case of BPON)		OLT. PON framing can be BPON or GPON. The protocol encapsulation on
	or GPON (in case of GPON). The protocol encapsulation on BPON is		BPON is based on multi-protocol encapsulation over ATM Adaptation
	based on multi-protocol encapsulation over AAL5, defined in		Layer 5 (AAL5), defined in [RFC2684]. This covers PPP over Ethernet
	[RFC2684]. This covers PPP over Ethernet (PPPoE, defined in		(PPPoE, defined in [RFC2516]) or IP over Ethernet (IPoE). The
	[RFC2516]), or bridged IP (IPoE). The protocol encapsulation on		protocol encapsulation on GPON is always IPoE. In all cases, the
	GPON is always IPoE. In all cases, the connection between the AN		connection between the AN (OLT) and the NAS (or BNG) is assumed to be
	(OLT) and the NAS (or BNG) is assumed to be Ethernet in this		Ethernet in this document.
	document.
	4.1.3. Access Node Complex		4.1.3. Access Node Complex
	This is composed of OLT and ONT/ONU and is defined in section 2.		The Access Node Complex (ANX) is composed of OLT and ONT/ONU and is
			defined in Section 2.
	4.1.4. Access Node Complex Uplink to the NAS		4.1.4. Access Node Complex Uplink to the NAS
	The ANX uplink connects the OLT to the NAS. The fundamental		The ANX uplink connects the OLT to the NAS. The fundamental
	requirements for the ANX uplink are to provide traffic aggregation,		requirements for the ANX uplink are to provide traffic aggregation,
	Class of Service distinction and customer separation and		Class of Service distinction, customer separation, and traceability.
	traceability. This can be achieved using an ATM or an Ethernet based		This can be achieved using an ATM or an Ethernet-based technology.
	technology. The focus in this document is on Ethernet as stated		As stated earlier, the focus in this document is on Ethernet.
	earlier.
	4.1.5. Aggregation Network		4.1.5. Aggregation Network
	The aggregation network provides traffic aggregation towards the NAS.		The aggregation network provides traffic aggregation towards the NAS.
	The Aggregation network is assumed to be Ethernet in this document.		The aggregation network is assumed to be Ethernet in this document.
	4.1.6. Network Access Server		4.1.6. Network Access Server
	The NAS is a network device which aggregates multiplexed Subscriber		The NAS is a network device that aggregates multiplexed subscriber
	traffic from a number of ANXs. The NAS plays a central role in per-		traffic from a number of ANXs. The NAS plays a central role in per-
	subscriber policy enforcement and QoS. It is often referred to as a		subscriber policy enforcement and QoS. It is often referred to as a
	Broadband Network Gateway (BNG) or Broadband Remote Access Server		Broadband Network Gateway (BNG) or Broadband Remote Access Server
	(BRAS). A detailed definition of the NAS is given in [RFC2881]. The		(BRAS). A detailed definition of the NAS is given in [RFC2881]. The
	NAS interfaces to the aggregation network by means of 802.1Q or 802.1		NAS interfaces to the aggregation network by means of 802.1Q or 802.1
	Q-in-Q Ethernet interfaces, and towards the Regional Network by means		Q-in-Q Ethernet interfaces and towards the Regional Network by means
	of transport interfaces (e.g., GigE, PPP over SONET). The NAS		of transport interfaces (e.g., GigE, PPP over Synchronous Optical
	functionality corresponds to the BNG functionality described in		Network (SONET)). The NAS functionality corresponds to the BNG
	BroadBand Forum (BBF) TR-101 [TR-101]. In addition, the NAS supports		functionality described in BBF TR-101 [TR-101]. In addition, the NAS
	the Access Node Control functionality defined for the respective use		supports the Access Node Control functionality defined for the
	cases in this document.		respective use cases in this document.
	4.1.7. Regional Network		4.1.7. Regional Network
	The Regional Network connects one or more NAS and associated Access		The Regional Network connects one or more NASs and associated access
	Networks to Network Service Providers (NSPs) and Application Service		networks to Network Service Providers (NSPs) and Application Service
	Providers (ASPs). The NSP authenticates access and provides and		Providers (ASPs). The NSP authenticates access and provides and
	manages the IP address to Subscribers. It is responsible for overall		manages the IP address to subscribers. It is responsible for overall
	service assurance and includes Internet Service Providers (ISPs). The		service assurance and includes Internet Service Providers (ISPs).
	ASP provides application services to the application Subscriber		The ASP provides application services to the application subscriber
	(gaming, video, content on demand, IP telephony, etc.). The NAS can		(gaming, video, content on demand, IP telephony, etc.). The NAS can
	be part of the NSP network. Similarly, the NSP can be the ASP.		be part of the NSP network. Similarly, the NSP can be the ASP.
	4.2. Access Node Complex Control Reference Architecture Options		4.2. Access Node Complex Control Reference Architecture Options
	Section 3 details the differences between xDSL access and PON access		Section 3 details the differences between xDSL access and PON access
	and the implication of these differences on DSLAM control vs. OLT and		and the implication of these differences on DSLAM control versus OLT
	ONT/ONU (access node complex (ANX)) control. The following sections		and ONT/ONU (ANX) control. The following sections describe two
	describe two reference models: (1) ANCP+OMCI ANX control, and (2)		reference models: (1) ANCP+OMCI ANX control and (2) All-ANCP ANX
	all-ANCP ANX control. That is, the two models differ in the ONT/ONU		control. That is, the two models differ in the ONT/ONU control
	control within the ANX. Implementations, out of the scope of this		within the ANX. Choosing which model to implement may be based on
	document, may choose to implement one or the other based on the		the ONT/ONU type and the capabilities of the ONT/ONU and OLT; this is
	ONT/ONU type and the capabilities of the ONT/ONU and OLT. It is		an implementation-specific decision that is outside the scope of this
	possible for an OLT or an OLT PON port to connect to ONTs/ONUs with		document. It is possible for an OLT or an OLT PON port to connect to
	different capabilities and for these two models to co-exist on the		ONTs/ONUs with different capabilities and for these two models to co-
	same OLT and same PON. Section 12 describes the differences between		exist on the same OLT and same PON. Section 12 describes the
	OMCI and ANCP in controlling the ONU/ONT.		differences between OMCI and ANCP in controlling the ONU/ONT.
	OMCI is designed as a protocol between the OLT and ONT/ONU. It		OMCI is designed as a protocol between the OLT and ONT/ONU. It
	enables the OLT to configure and administer capabilities on the		enables the OLT to configure and administer capabilities on the
	ONT/ONU in BPON, GPON and XG-PON. ANCP is designed as a protocol		ONT/ONU in BPON, GPON, and XG-PON. ANCP is designed as a protocol
	between the NAS and access node. It enables the NAS to enforce		between the NAS and Access Node. Among other functions, it enables
	dynamic policies on the access node, and the access node to report		the NAS to enforce dynamic policies on the Access Node and the Access
	events to the NAS among other functions.		Node to report events to the NAS.
	4.2.1. ANCP+OMCI ANX Control		4.2.1. ANCP+OMCI ANX Control
	Figure 3 depicts the reference model for ANCP+OMCI ANX control. In		Figure 3 depicts the reference model for ANCP+OMCI ANX control. In
	this model, ANCP is enabled between the NAS and a connected OLT, and		this model, ANCP is enabled between the NAS and a connected OLT, and
	OMCI is enabled between the OLT and an attached ONT/ONU. NAS		OMCI is enabled between the OLT and an attached ONT/ONU. NAS
	communicates with the ANX via ANCP. The OLT acts as an ANCP/OMCI		communicates with the ANX via ANCP. The OLT acts as an ANCP/OMCI
	gateway for communicating necessary events and policies between the		gateway for communicating necessary events and policies between the
	OLT and ONT/ONU within the ANX and for communicating relevant		OLT and ONT/ONU within the ANX and for communicating relevant
	policies and events between the ONT/ONU and the NAS. The		policies and events between the ONT/ONU and the NAS. The
	functionality performed by the OLT as ANCP/OMCI gateway will be		functionality performed by the OLT as an ANCP/OMCI gateway will be
	application dependent (e.g., multicast control, topology discovery)		application dependent (e.g., multicast control, topology discovery)
	and should be specified in a related specification. It should be		and should be specified in a related specification. It should be
	noted that some applications are expected to require ANCP and/or OMCI		noted that some applications are expected to require ANCP and/or OMCI
	extensions to map messages between OMCI and ANCP. OMCI extensions are		extensions to map messages between OMCI and ANCP. OMCI extensions
	likely to be defined by the ITU-T. It should also be noted that OMCI,		are likely to be defined by the ITU-T. It should also be noted that
	in addition to configuration and administration, provides the		in addition to configuration and administration, OMCI provides the
	capability to report status changes on an ONT/ONU with AVC (Attribute		capability to report status changes on an ONT/ONU with AVC (Attribute
	Value Change) notifications. When ONT/ONU's DSL or Ethernet UNI		Value Change) notifications. When the ONT/ONU's DSL or Ethernet
	attributes change, a related ME (management Entity) will send a		User-Network Interface (UNI) attributes change, a related Management
	corresponding notification (AVC) to the OLT. The OLT interworks such		Entity will send a corresponding notification (AVC) to the OLT. The
	notification into an ANCP report and sends it to the connected NAS		OLT interworks such a notification into an ANCP report and sends it
	via the ANCP session between the OLT and the NAS. As the ANCP report		to the connected NAS via the ANCP session between the OLT and the
	contains information of ONT/ONU's UNI and OLT's PON port, NAS can		NAS. As the ANCP report contains information of ONT/ONU's UNI and
	obtain accurate information of access topology.		OLT's PON port, NAS can obtain accurate information of access
	+----------------------+		topology.
	| ANX |
	+---------+ +---+ +---+ |+---+ +-------+ | +---+
	| | +-|NAS|--|Eth|--||OLT|-<PON>-|ONU/ONT|-|-|HGW|
	NSP---+Regional | | +---+ |Agg| |+---+ +-------+ | +---+
	|Broadband| | +---+ +---+ +----------------------+
	|Network |-+-|NAS| |
	ASP---+ | | +---+ |
	| | | +---+ |
	+---------+ +-|NAS| | +-------+ +---+
	+---| +-<PON>-|ONU/ONT|-|HGW|
	| +-------+ +---+
	| +---+ +---+
	+--|ONT|-----|HGW|
	+---+ +---+
	ANCP OMCI
	+<--------------->+<----------->+
	HGW: Home Gateway		+----------------------+
	NAS: Network Access Server		| ANX |
	PON: Passive Optical Network		+---------+ +---+ +---+ |+---+ +-------+ | +---+
	OLT: Optical Line Terminal		| | +-|NAS|--|Eth|--||OLT|-<PON>-|ONU/ONT|-|-|HGW|
	ONT: Optical Network Terminal		NSP---+Regional | | +---+ |Agg| |+---+ +-------+ | +---+
	ONU: Optical Network Unit		|Broadband| | +---+ +---+ +----------------------+
			|Network |-+-|NAS| |
			ASP---+ | | +---+ |
			| | | +---+ |
			+---------+ +-|NAS| | +-------+ +---+
			+---| +-<PON>-|ONU/ONT|-|HGW|
			| +-------+ +---+
			| +---+ +---+
			+--|ONT|-----|HGW|
			+---+ +---+
			ANCP OMCI
			+<--------------->+<----------->+
	Figure 3: Access Network with single ANCP+OMCI access control		HGW: Home Gateway
			NAS: Network Access Server
			PON: Passive Optical Network
			OLT: Optical Line Terminal
			ONT: Optical Network Terminal
			ONU: Optical Network Unit
	4.2.2. All-ANCP ANX Control		Figure 3: Access Network with Single ANCP+OMCI Control
	Figure 4 depicts the All-ANCP ANX control reference model. In this		4.2.2. All-ANCP ANX Control
	model, an ANCP session is enabled between a NAS and a connected OLT,
	and another ANCP session is enabled between the OLT and a connected
	ONT/ONU. ANCP enables communication of policies and events between
	the OLT and the ANX. The OLT acts as a gateway to relay policies and
	events between the NAS and ONT/ONU within the ANX in addition to
	communicating policies and events between the OLT and ONT/ONU. It
	should be noted that in this model, OMCI(not shown) is expected to be
	simultaneously enabled between the ONT and OLT, supporting existing
	OMCI capabilities and applications on the PON, independent of ANCP or
	applications intended to be supported by ANCP.
	+----------------------+		Figure 4 depicts the All-ANCP ANX control reference model. In this
	| Access Node Complex |		model, an ANCP session is enabled between a NAS and a connected OLT,
	| (ANX) |		and another ANCP session is enabled between the OLT and a connected
	+---------+ +---+ +---+ |+---+ +-------+ | +---+		ONT/ONU. ANCP enables communication of policies and events between
	| | +-|NAS|--|Eth|--||OLT|-<PON>-|ONU/ONT| |--|HGW|		the OLT and the ANX. The OLT acts as a gateway to relay policies and
	NSP---+Regional | | +---+ |Agg| |+---+ +-------+ | +---+		events between the NAS and ONT/ONU within the ANX in addition to
	|Broadband| | +---+ +---+ +----------------------+		communicating policies and events between the OLT and ONT/ONU. It
	|Network |-+-|NAS| |		should be noted that in this model, OMCI (not shown) is expected to
	ASP---+ | | +---+ |		be simultaneously enabled between the ONT and OLT, supporting
	| | | +---+ |		existing OMCI capabilities and applications on the PON, independent
	+---------+ +-|NAS| | +-------+ +---+		of ANCP or applications intended to be supported by ANCP.
	+---| +-<PON>-|ONU/ONT|--|HGW|
	| +-------+ +---+
	|
	| +-------+ +---+
	+---|ONU/ONT|--|HGW|
	+-------+ +---+
	ANCP ANCP		+----------------------+
	+<----------------->+<---------->+		| Access Node Complex |
			| (ANX) |
			+---------+ +---+ +---+ |+---+ +-------+ | +---+
			| | +-|NAS|--|Eth|--||OLT|-<PON>-|ONU/ONT| |--|HGW|
			NSP---+Regional | | +---+ |Agg| |+---+ +-------+ | +---+
			|Broadband| | +---+ +---+ +----------------------+
			|Network |-+-|NAS| |
			ASP---+ | | +---+ |
			| | | +---+ |
			+---------+ +-|NAS| | +-------+ +---+
			+---| +-<PON>-|ONU/ONT|--|HGW|
			| +-------+ +---+
			|
			| +-------+ +---+
			+---|ONU/ONT|--|HGW|
			+-------+ +---+
	HGW: Home Gateway		ANCP ANCP
	NAS: Network Access Server		+<----------------->+<---------->+
	PON: Passive Optical Network
	OLT: Optical Line Terminal
	ONT: Optical Network Terminal
	ONU: Optical Network Unit
	Figure 4: All-ANCP ANX Reference Model		HGW: Home Gateway
			NAS: Network Access Server
			PON: Passive Optical Network
			OLT: Optical Line Terminal
			ONT: Optical Network Terminal
			ONU: Optical Network Unit
	5. Concept of Access Node Control Mechanism for PON Based Access		Figure 4: All-ANCP ANX Control Reference Model
	The high-level communication framework for an Access Node Control		5. Concept of Access Node Control Mechanism for PON-Based Access
	mechanism is shown in Figure 5 for the ALL-ANCP ANX control model.
	The Access Node Control mechanism defines a quasi real-time, general-
	purpose method for multiple network scenarios with an extensible
	communication scheme, addressing the different use cases that are
	described in the sections that follow. The access node control
	mechanism is also extended to run between OLT and ONT/ONU. The
	mechanism consists of control function, and reporting and/or
	enforcement function. Controller function is used to receive status
	information or admission requests from the reporting function. It is
	also used to trigger a certain behavior in the network element where
	the reporting and/or enforcement function resides.
	The reporting function is used to convey status information to the		The high-level communication framework for an Access Node Control
	controller function that requires the information for executing local		Mechanism is shown in Figure 5 for the All-ANCP ANX control model.
	functions. The enforcement function can be contacted by the		The Access Node Control Mechanism defines a quasi-real-time, general-
	controller function to enforce a specific policy or trigger a local		purpose method for multiple network scenarios with an extensible
	action. The messages shown in Figure 5 show the conceptual message		communication scheme, addressing the different use cases that are
	flow. The actual use of these flows, and the times or frequencies		described in the sections that follow. The Access Node Control
	when these messages are generated depend on the actual use cases,		Mechanism is also extended to run between OLT and ONT/ONU. The
	which are described in later sections.		mechanism consists of a controller function and a reporting and/or
			enforcement function. The controller function is used to receive
			status information or admission requests from the reporting function.
			It is also used to trigger a certain behavior in the network element
			where the reporting and/or enforcement function resides.
	+--------+		The reporting function is used to convey status information to the
	| Policy | +----+		controller function that requires the information for executing local
	| Server | +--<PON>---|ONT |------- HGW		functions. The enforcement function can be contacted by the
	+--------+ + +----+ +---+		controller function to enforce a specific policy or trigger a local
	| + +----------|ONT|----HGW		action. The messages shown in Figure 5 show the conceptual message
	| + | +---+		flow. The actual use of these flows, and the times or frequencies
	| +----------------|-------------+		when these messages are generated, depend on the actual use cases,
	+----+ | +----+ | +-----+ | +---+		which are described in later sections.
	|NAS |---------------| | | | |-|----|HGW|
	| |<------------->| | | | ONU | | +---+
	+----+ ANCP | |OLT |------<PON>----| | |
	| | | | | | | +---+
	| | | |<------------->| |------|HGW|
	| | +----+ ANCP +-----+ | +---+
	| +------------------------------+
	| | Access Node |
	| Control Request | |
	| ------------------>| Control Request |
	| |-------------------->|
	| | Control Response |
	| Control Response |<------------------- |
	|<-------------------| |
	| |Admission Request |
	| Admission Request |<--------------------|
	|<-------------------| |
	|Admission Response | |
	|------------------->|Admission Response |
	| |-------------------->|
	|Information Report | |
	|<-------------------| |
	Access Node Control Access Node Control
	Mechanism Mechanism
	<--------------------><-------------------->
	PPP, DHCP, IP
	<------------------------------------------------------>
	Figure 5: Conceptual message flow for Access Node Control mechanism		+--------+
	in all-ANCP ANX control model.		| Policy | +----+
			| Server | +--<PON>---|ONT |------- HGW
			+--------+ + +----+ +---+
			| + +----------|ONT|----HGW
			| + | +---+
			| +----------------|-------------+
			+----+ | +----+ | +-----+ | +---+
			|NAS |---------------| | | | |-|----|HGW|
			| |<------------->| | | | ONU | | +---+
			+----+ ANCP | |OLT |------<PON>----| | |
			| | | | | | | +---+
			| | | |<------------->| |------|HGW|
			| | +----+ ANCP +-----+ | +---+
			| +------------------------------+
			| | Access Node |
			| Control Request | |
			| ------------------>| Control Request |
			| |-------------------->|
			| | Control Response |
			| Control Response |<------------------- |
			|<-------------------| |
			| |Admission Request |
			| Admission Request |<--------------------|
			|<-------------------| |
			|Admission Response | |
			|------------------->|Admission Response |
			| |-------------------->|
			|Information Report | |
			|<-------------------| |
			Access Node Control Access Node Control
			Mechanism Mechanism
			<--------------------><-------------------->
			PPP, DHCP, IP
			<------------------------------------------------------>
	As discussed previously, in different PON deployment scenarios, ANCP		Figure 5: Conceptual Message Flow for Access Node Control Mechanism
	may be used in variant ways and may interwork with other protocols,		in All-ANCP ANX Control Model
	e.g., OMCI. In the ANCP+OMCI model described earlier, the NAS
	maintains ANCP adjacency with the OLT while the OLT controls the
	ONT/ONU via OMCI. The messages shown in Figure 6 show the conceptual
	message flow for this model. The actual use of these flows, and the
	times or frequencies when these messages are generated depend on the
	actual use cases.
	+--------+		As discussed previously, in different PON deployment scenarios, ANCP
	| Policy |		may be used in variant ways and may interwork with other protocols,
	| Server |		e.g., OMCI. In the ANCP+OMCI control model described earlier, the
	+--------+ +---+ +---+		NAS maintains ANCP adjacency with the OLT while the OLT controls the
	| +---- |ONT|--------|HGW|		ONT/ONU via OMCI. The messages shown in Figure 6 show the conceptual
	| | +---+ +---+		message flow for this model. The actual use of these flows, and the
	| +--------------- |-------------+		times or frequencies when these messages are generated, depend on the
	+----+ | +----+ | +-----+ | +---+		actual use cases.
	|NAS |---------------| | | | |-|----|HGW|
	| |<------------->| | | | ONU | | +---+
	+----+ ANCP | |OLT |------<PON>----| | |
	| | | | | | | +---+
	| | | |<------------->| |------|HGW|
	| | +----+ OMCI +-----+ | +---+
	| +-----------------------------+
	| | Access Node |
	| Control Request | |
	| ------------------>| Control Request |
	| |-------------------->|
	| | Control Response |
	| Control Response |<------------------- |
	|<-------------------| |
	| |Admission Request |
	| Admission Request |<--------------------|
	|<-------------------| |
	|Admission Response | |
	|------------------->|Admission Response |
	| |-------------------->|
	|Information Report | |
	|<-------------------| |
	Access Node Control Operating Maintenance
	Mechanism Control Interface (OMCI)
	<--------------------><-------------------->
	PPP, DHCP, IP		+--------+
	<------------------------------------------------------->		| Policy |
			| Server |
			+--------+ +---+ +---+
			| +---- |ONT|--------|HGW|
			| | +---+ +---+
			| +--------------- |-------------+
			+----+ | +----+ | +-----+ | +---+
			|NAS |---------------| | | | |-|----|HGW|
			| |<------------->| | | | ONU | | +---+
			+----+ ANCP | |OLT |------<PON>----| | |
			| | | | | | | +---+
			| | | |<------------->| |------|HGW|
			| | +----+ OMCI +-----+ | +---+
			| +-----------------------------+
			| | Access Node |
			| Control Request | |
			| ------------------>| Control Request |
			| |-------------------->|
			| | Control Response |
			| Control Response |<------------------- |
			|<-------------------| |
			| |Admission Request |
			| Admission Request |<--------------------|
			|<-------------------| |
			|Admission Response | |
			|------------------->|Admission Response |
			| |-------------------->|
			|Information Report | |
			|<-------------------| |
			Access Node Control Operating Maintenance
			Mechanism Control Interface (OMCI)
			<--------------------><-------------------->
	Figure 6: Conceptual Message Flow for ANCP+OMCI ANX control model.		PPP, DHCP, IP
			<------------------------------------------------------->
	6. Multicast		Figure 6: Conceptual Message Flow for ANCP+OMCI ANX Control Model
	With the rise of supporting IPTV services in a resource-efficient		6. Multicast
	way, multicast services are becoming increasingly important.
	In order to gain bandwidth optimization with multicast, the		With the rise of supporting IPTV services in a resource-efficient
	replication of multicast content per access-loop needs to be		way, multicast services are becoming increasingly important.
	distributed to the ANX. This can be done by ANX (OLT and ONT/ONU)
	becoming multicast aware by implementing an IGMP [RFC3376]
	snooping and/or proxy function [RFC4605]. The replication thus needs
	to be distributed between NAS, aggregation nodes, and ANX. In case of
	GPON, and in case of BPON with Ethernet uplink, this is very viable.
	By introducing IGMP processing on the ANX and aggregation nodes, the
	multicast replication process is now divided between the NAS, the
	aggregation node(s) and ANX. This is in contrast to the ATM-based
	model where NAS is the single element responsible for all multicast
	control and replication. In order to ensure backward compatibility
	with the ATM-based model, the NAS, aggregation node and ANX need to
	behave as a single logical device. This logical device must have
	exactly the same functionality as the NAS in the ATM
	access/aggregation network. The Access Node Control Mechanism can be
	used to make sure that this logical/functional equivalence is
	achieved by exchanging the necessary information between the ANX and
	the NAS.
	An alternative to multicast awareness in the ANX is for the		In order to gain bandwidth optimization with multicast, the
	subscriber to communicate the IGMP "join/leave" messages with the		replication of multicast content per access loop needs to be
	NAS, while the ANX is being transparent to these messages. In this		distributed to the ANX. This can be done by ANX (OLT and ONT/ONU)
	scenario, the NAS can use ANCP to create replication state in the ANX		becoming multicast aware by implementing an IGMP [RFC3376] snooping
	for efficient multicast replication. The NAS sends a single copy of		and/or proxy function [RFC4605]. The replication thus needs to be
	the multicast stream towards the ANX. The NAS can perform network-		distributed between NAS, aggregation nodes, and ANX. In the case of
	based conditional access and multicast admission control on multicast		GPON and in the case of BPON with Ethernet uplink, this is very
	joins, and create replication state in the ANX if the request is		viable. By introducing IGMP processing on the ANX and aggregation
	admitted by the NAS.		nodes, the multicast replication process is now divided between the
			NAS, the aggregation node(s), and ANX. This is in contrast to the
			ATM-based model where NAS is the single element responsible for all
			multicast control and replication. In order to ensure backward
			compatibility with the ATM-based model, the NAS, aggregation node,
			and ANX need to behave as a single logical device. This logical
			device must have exactly the same functionality as the NAS in the ATM
			access/aggregation network. The Access Node Control Mechanism can be
			used to make sure that this logical/functional equivalence is
			achieved by exchanging the necessary information between the ANX and
			the NAS.
	The following sections describe various use cases related to		An alternative to multicast awareness in the ANX is for the
	multicast.		subscriber to communicate the IGMP "join/leave" messages with the
			NAS, while the ANX is being transparent to these messages. In this
			scenario, the NAS can use ANCP to create replication state in the ANX
			for efficient multicast replication. The NAS sends a single copy of
			the multicast stream towards the ANX. The NAS can perform network-
			based conditional access and multicast admission control on multicast
			joins and create replication state in the ANX if the request is
			admitted by the NAS.
	6.1. Multicast Conditional Access		The following sections describe various use cases related to
			multicast.
	In a Broadband FTTP/B/C access scenario, Service Providers may want		6.1. Multicast Conditional Access
	to dynamically control, at the network level, access to some
	multicast flows on a per user basis. This may be used in order to
	differentiate among multiple Service Offers or to realize/reinforce
	conditional access based on customer subscription. Note that, in some
	environments, application layer conditional access by means of
	Digital Rights Management (DRM) for instance may provide sufficient
	control so that network-based Multicast conditional access may not be
	needed. However, network level access control may add to the service
	security by preventing the subscriber from receiving a non-subscribed
	channel. In addition, it enhances network security by preventing a
	multicast stream from being sent on a link or a PON based on a non-
	subscriber request.
	Where network-based channel conditional access is desired, there are		In a broadband FTTP/B/C access scenario, service providers may want
	two approaches. It can be done on the NAS along with bandwidth-based		to dynamically control, at the network level, access to some
	admission control. The NAS can control the replication state on the		multicast flows on a per user basis. This may be used in order to
	ANX based on the outcome of access and bandwidth based admission		differentiate among multiple Service Offers or to realize/reinforce
	control. This is covered in a later section. The other approach is to		conditional access based on customer subscription. Note that, in
	provision the necessary conditional access information on the ANX		some environments, application-layer conditional access by means of
	(ONT/ONU and/or OLT) so the ANX can perform the conditional access		Digital Rights Management (DRM), for instance, may provide sufficient
	decisions autonomously. For these cases, the NAS can use ANCP to		control so that network-based multicast conditional access may not be
	provision black and white lists as defined in [RFC5851] on the ANX so		needed. However, network-level access control may add to the service
	that the ANX can decide locally to honor a join or not. It should be		security by preventing the subscriber from receiving a non-subscribed
	noted that in the PON case, the ANX is composed of the ONT/ONU and		channel. In addition, it enhances network security by preventing a
	OLT. Thus, this information can be programmed on the ONT/ONU and/or		multicast stream from being sent on a link or a PON based on a non-
	OLT. Programming this information on the ONT/ONU prevents		subscriber request.
	illegitimate joins from propagating further into the network. A third
	approach, outside of the scope, may be to program the HGW with the
	access list. A White list associated with an Access Port identifies
	the multicast channels that are allowed to be replicated to that
	port. A Black list associated with an Access Port identifies the
	multicast channels that are not allowed to be replicated to that
	port. It should be noted that the black list if not explicitly
	programmed is the complement of the white list and vice versa.
	If the ONT/ONU performs IGMP snooping and it is programmed with a		Where network-based channel conditional access is desired, there are
	channel access list, the ONT/ONU will first check if the requested		two approaches. First, it can be done on the NAS along with
	multicast channel is part of a White list or a Black list associated		bandwidth-based admission control. The NAS can control the
	with the access port on which the IGMP join is received. If the		replication state on the ANX based on the outcome of access and
	channel is part of a White list, the ONT/ONU will pass the join		bandwidth-based admission control. This is covered in a later
	request upstream towards the NAS. The ONT/ONU must not start		section. A second approach is to provision the necessary conditional
	replicating the associated multicast stream to the access port if		access information on the ANX (ONT/ONU and/or OLT) so the ANX can
	such a stream is received until it gets confirmation that it can do		perform the conditional access decisions autonomously. For these
	so from the upstream node (NAS or OLT). Passing the channel access		cases, the NAS can use ANCP to provision black and white lists as
	list is one of the admission control criteria whereas bandwidth-based		defined in [RFC5851] on the ANX so that the ANX can decide locally to
	admission control is another. If the channel is part of a Black list,		honor a join or not. It should be noted that in the PON case, the
	the ONT/ONU can autonomously discard the message because the channel		ANX is composed of the ONT/ONU and OLT. Thus, this information can
	is not authorized for that subscriber.		be programmed on the ONT/ONU and/or OLT. Programming this
			information on the ONT/ONU prevents illegitimate joins from
			propagating further into the network. A third approach, outside of
			the scope of this document, may be to program the HGW with the access
			list. A white list associated with an Access Port identifies the
			multicast channels that are allowed to be replicated to that port. A
			black list associated with an Access Port identifies the multicast
			channels that are not allowed to be replicated to that port. It
			should be noted that the black list, if not explicitly programmed, is
			the complement of the white list and vice versa.
	The ONT/ONU, in addition to forwarding the IGMP join, sends an ANCP		If the ONT/ONU performs IGMP snooping and is programmed with a
	admission request to the OLT identifying the channel to be joined and		channel access list, the ONT/ONU will first check if the requested
	the premises. Premises identification to the OLT can be based on a		multicast channel is part of a white list or a black list associated
	Customer-Port-ID that maps to the access port on the ONT/ONU and		with the Access Port on which the IGMP join is received. If the
	known at the ONT/ONU and OLT. If the ONT/ONU has a white list and/or		channel is part of a white list, the ONT/ONU will pass the join
	a black list per premises, the OLT need not have such a list. If the		request upstream towards the NAS. The ONT/ONU must not start
	ONT/ONU does not have such a list, the OLT may be programmed with		replicating the associated multicast stream to the Access Port if
	such a list for each premises. In this latter case, the OLT would		such a stream is received until it gets confirmation that it can do
	perform the actions described earlier on the ONT/ONU. Once the		so from the upstream node (NAS or OLT). Passing the channel access
	outcome of admission control (conditional access and bandwidth based		list is one of the admission control criteria whereas bandwidth-based
	admission control) is determined by the OLT (either by interacting		admission control is another. If the channel is part of a black
	with the NAS or locally), it is informed to the ONT/ONU. OLT		list, the ONT/ONU can autonomously discard the message because the
	Bandwidth based admission control scenarios are defined in a later		channel is not authorized for that subscriber.
	section.
	The White List and Black List can contain entries allowing:		The ONT/ONU, in addition to forwarding the IGMP join, sends an ANCP
			admission request to the OLT identifying the channel to be joined and
			the premises. Premises identification to the OLT can be based on a
			Customer-Port-ID that maps to the Access Port on the ONT/ONU and is
			known at the ONT/ONU and OLT. If the ONT/ONU has a white list and/or
			a black list per premises, the OLT need not have such a list. If the
			ONT/ONU does not have such a list, the OLT may be programmed with
			such a list for each premises. In the latter case, the OLT would
			perform the actions described earlier on the ONT/ONU. Once the
			outcome of admission control (conditional access and bandwidth-based
			admission control) is determined by the OLT (either by interacting
			with the NAS or locally), it is informed to the ONT/ONU. OLT
			bandwidth-based admission control scenarios are defined in a later
			section.
	- An exact match for a (*,G) Any Source Multicast (ASM) group		The white list and black list can contain entries allowing:
	(e.g., <G=g.h.i.l>);
	- An exact match for a (S,G) Source Specific Multicast		- An exact match for a (*,G) Any-Source Multicast (ASM) group (e.g.,
	(SSM)channel (e.g., <S=s.t.u.v,G=g.h.i.l>);		<G=g.h.i.l>)
	- A mask-based range match for a (*,G) ASM group (e.g.,		- An exact match for a (S,G) Source-Specific Multicast (SSM) channel
	<G=g.h.i.l/Mask>);		(e.g., <S=s.t.u.v,G=g.h.i.l>)
	- A mask-based range match for a (S,G) SSM channel (e.g.,		- A mask-based range match for a (*,G) ASM group (e.g.,
	<S=s.t.u.v,G=g.h.i.l/Mask>);		<G=g.h.i.l/Mask>)
	The use of a White list and Black list may be applicable, for		- A mask-based range match for a (S,G) SSM channel (e.g.,
	instance, to regular IPTV services (i.e., Broadcast TV) offered by an		<S=s.t.u.v,G=g.h.i.l/Mask>)
	Access Provider to broadband (e.g., FTTP) subscribers. For this
	application, the IPTV subscription is typically bound to a specific
	FTTP home, and the multicast channels that are part of the
	subscription are well-known beforehand. Furthermore, changes to the
	conditional access information are infrequent, since they are bound
	to the subscription. Hence the ANX can be provisioned with the
	conditional access information related to the IPTV service.
	Instead of including the channel list(s) at the ONT/ONU, the OLT or		The use of a white list and black list may be applicable, for
	NAS can be programmed with these access lists. Having these access		instance, to regular IPTV services (i.e., Broadcast TV) offered by an
	lists on the ONT/ONU prevents forwarding of unauthorized joins to the		Access Provider to broadband (e.g., FTTP) subscribers. For this
	OLT or NAS, reducing unnecessary control load on these network		application, the IPTV subscription is typically bound to a specific
	elements. Similarly, performing the access control at the OLT instead		FTTP home, and the multicast channels that are part of the
	of the NAS, if not performed on the ONT/ONU, will reduce unnecessary		subscription are well-known beforehand. Furthermore, changes to the
	control load on the NAS.		conditional access information are infrequent, since they are bound
			to the subscription. Hence, the ANX can be provisioned with the
			conditional access information related to the IPTV service.
	6.2. Multicast Admission Control		Instead of including the channel list(s) at the ONT/ONU, the OLT or
			NAS can be programmed with these access lists. Having these access
			lists on the ONT/ONU prevents forwarding of unauthorized joins to the
			OLT or NAS, reducing unnecessary control load on these network
			elements. Similarly, performing the access control at the OLT
			instead of the NAS, if not performed on the ONT/ONU, will reduce
			unnecessary control load on the NAS.
	The successful delivery of Triple Play Broadband services is quickly		6.2. Multicast Admission Control
	becoming a big capacity planning challenge for most of the Service
	Providers nowadays. Solely increasing available bandwidth is not
	always practical, cost-economical and/or sufficient to satisfy end-
	user experience given not only the strict QoS requirements of unicast
	applications like VoIP and Video on Demand, but also the fast growth
	of multicast interactive applications such as "video conferencing",
	digital TV, and digital audio. These applications typically require
	low delay, low jitter, low packet loss and high bandwidth. These
	applications are also typically "non-elastic", which means that they
	operate at a fixed bandwidth, which cannot be dynamically adjusted to
	the currently available bandwidth.
	An Admission Control (AC) mechanism covering admission of multicast		The successful delivery of triple-play broadband services is quickly
	traffic for the FTTP/B/C access is required in order to avoid over-		becoming a big capacity-planning challenge for most of the service
	subscribing the available bandwidth and negatively impacting the end-		providers nowadays. Solely increasing available bandwidth is not
	user experience. Before honoring a user request to join a new		always practical, cost-economical, and/or sufficient to satisfy end-
	multicast flow, the combination of ANX and NAS must ensure admission		user experience given not only the strict QoS requirements of unicast
	control is performed to validate that there is enough video bandwidth		applications like VoIP and Video on Demand but also the fast growth
	remaining on the PON, and on the uplink between the OLT and NAS to		of multicast interactive applications such as "video conferencing",
	carry the new flow (in addition to all other existing multicast and		digital TV, and digital audio. These applications typically require
	unicast video traffic) and that there is enough video bandwidth for		low delay, low jitter, low packet loss, and high bandwidth. These
	the subscriber to carry that flow. The solution needs to cope with		applications are also typically "non-elastic", which means that they
	multiple flows per premises and needs to allow bandwidth to be		operate at a fixed bandwidth that cannot be dynamically adjusted to
	dynamically shared across multicast and unicast video traffic per		the currently available bandwidth.
	subscriber, PON, and uplink (irrespective of whether unicast AC is
	performed by the NAS, or by some off-path Policy Server). It should
	be noted that the shared bandwidth between multicast and unicast
	video is under operator control. That is, in addition to the shared
	bandwidth, some video bandwidth could be dedicated to Video on
	Demand, while other video bandwidth could be dedicated for multicast.
	The focus in this document will be on multicast-allocated bandwidth		An Admission Control (AC) Mechanism covering admission of multicast
	including the shared unicast and multicast bandwidth. Thus,		traffic for the FTTP/B/C access is required in order to avoid over-
	supporting admission control requires some form of synchronization		subscribing the available bandwidth and negatively impacting the end-
	between the entities performing multicast AC (e.g., the ANX and/or		user experience. Before honoring a user request to join a new
	NAS), the entity performing unicast AC (e.g., the NAS or a Policy		multicast flow, the combination of ANX and NAS must ensure admission
	Server), and the entity actually enforcing the multicast replication		control is performed to validate that there is enough video bandwidth
	(i.e., the NAS and the ANX). This synchronization can be achieved in		remaining on the PON and on the uplink between the OLT and NAS to
	a number of ways:		carry the new flow (in addition to all other existing multicast and
			unicast video traffic) and that there is enough video bandwidth for
			the subscriber to carry that flow. The solution needs to cope with
			multiple flows per premises and needs to allow bandwidth to be
			dynamically shared across multicast and unicast video traffic per
			subscriber, PON, and uplink (irrespective of whether unicast AC is
			performed by the NAS or by some off-path policy server). It should
			be noted that the shared bandwidth between multicast and unicast
			video is under operator control. That is, in addition to the shared
			bandwidth, some video bandwidth could be dedicated to Video on
			Demand, while other video bandwidth could be dedicated for multicast.
	- One approach is for the NAS to perform bandwidth based		The focus in this document is on multicast-allocated bandwidth
	admission control on all multicast video traffic and unicast		including the shared unicast and multicast bandwidth. Thus,
	video traffic that requires using the shared bandwidth with		supporting admission control requires some form of synchronization
	multicast. Based on the outcome of admission control, NAS then		between the entities performing multicast AC (e.g., the ANX and/or
	controls the replication state on the ANX. The subscriber		NAS), the entity performing unicast AC (e.g., the NAS or a policy
	generates an IGMP join for the desired stream on its logical		server), and the entity actually enforcing the multicast replication
	connection to the NAS. The NAS terminates the IGMP message, and		(i.e., the NAS and the ANX). This synchronization can be achieved in
	performs conditional access and bandwidth based admission		a number of ways.
	control on the IGMP request. The bandwidth admission control is
	performed against the following:
	1. Available video bandwidth on the link to OLT		One approach is for the NAS to perform bandwidth-based admission
			control on all multicast video traffic and unicast video traffic that
			requires using the shared bandwidth with multicast. Based on the
			outcome of admission control, NAS then controls the replication state
			on the ANX. The subscriber generates an IGMP join for the desired
			stream on its logical connection to the NAS. The NAS terminates the
			IGMP message and performs conditional access and bandwidth-based
			admission control on the IGMP request. The bandwidth admission
			control is performed against the following:
	2. Available video bandwidth on the PON interface		1. Available video bandwidth on the link to OLT
	3. Available video bandwidth on the last mile (access-port on		2. Available video bandwidth on the PON interface
	the ONT/ONU).
	The NAS can locally maintain and track video bandwidth it manages for		3. Available video bandwidth on the last mile (Access Port on the
	all the three levels mentioned above. The NAS can maintain		ONT/ONU)
	identifiers corresponding to the PON interface and the last mile
	(customer interface). It also maintains a channel map, associating
	every channel (or a group of channels sharing the same bandwidth
	requirement) with a data rate. For instance, in case of 1:1 VLAN
	representation of the premises, the outer tag (S-VLAN) could be
	inserted by the ANX to correspond to the PON interface on the OLT,
	and the inner-tag could be inserted by the ANX to correspond to the
	access-line towards the customer. Bandwidth tracking and maintenance
	for the PON interface and the last-mile could be done on these VLAN
	identifiers. In case of N:1 representation, the single VLAN inserted
	by ANX could correspond to the PON interface on the OLT. The access
	loop is represented via Customer-Port-ID received in "Agent Circuit
	Identifier" sub-option in DHCP messages.
	The NAS can perform bandwidth accounting on received IGMP messages.		The NAS can locally maintain and track video bandwidth it manages for
	The video bandwidth is also consumed by any unicast video being		all the three levels mentioned above. The NAS can maintain
	delivered to the CPE. NAS can perform video bandwidth accounting and		identifiers corresponding to the PON interface and the last mile
	control on both IGMP messages and on requests for unicast video		(customer interface). It also maintains a channel map, associating
	streams when either all unicast admission control is done by the NAS		every channel (or a group of channels sharing the same bandwidth
	or an external policy server makes a request to the NAS for using		requirement) with a data rate. For instance, in the case of 1:1 VLAN
	shared bandwidth with multicast as described later in the document.		representation of the premises, the outer tag (S-VLAN) could be
			inserted by the ANX to correspond to the PON interface on the OLT,
			and the inner-tag could be inserted by the ANX to correspond to the
			access-line towards the customer. Bandwidth tracking and maintenance
			for the PON interface and the last mile could be done on these VLAN
			identifiers. In the case of N:1 representation, the single VLAN
			inserted by ANX could correspond to the PON interface on the OLT.
			The access loop is represented via Customer-Port-ID received in the
			"Agent Circuit ID" sub-option in DHCP messages.
	This particular scenario assumes the NAS is aware of the bandwidth on		The NAS can perform bandwidth accounting on received IGMP messages.
	the PON, and under all conditions can track the changes in available		The video bandwidth is also consumed by any unicast video being
	bandwidth on the PON. On receiving an IGMP Join message, NAS will		delivered to the CPE. NAS can perform video bandwidth accounting and
	perform bandwidth check on the subscriber bandwidth. If this passes,		control on both IGMP messages and on requests for unicast video
	and the stream is already being forwarded on the PON by the OLT		streams when either all unicast admission control is done by the NAS
	(which also means that it is already forwarded by the NAS to the		or an external policy server makes a request to the NAS for using
	OLT), NAS will admit the JOIN, update the available subscriber		shared bandwidth with multicast as described later in the document.
	bandwidth, and transmit an ANCP message to the OLT and in turn to the
	ONT/ONU to start replication on the customer port. If the stream is
	not already being replicated to the PON by the OLT, the NAS will also
	check the available bandwidth on the PON, and if it is not already
	being replicated to the OLT it will check the bandwidth on the link
	towards the OLT. If this passes, the available PON bandwidth and the
	bandwidth on the link towards the OLT are updated. The NAS adds the
	OLT as a leaf to the multicast tree for that stream. On receiving the
	message to start replication, the OLT will add the PON interface to
	its replication state if the stream is not already being forwarded on
	that PON. Also, the OLT will send an ANCP message to direct the
	ONT/ONU to add or update its replication state with the customer port
	for that channel. The interaction between ANX and NAS is shown in
	Figures 7 and 8. For unicast video streams, application level
	signaling from the CPE typically triggers an application server to
	request bandwidth based admission control from a policy server. The
	policy server can in turn interact with the NAS to request the
	bandwidth for the unicast video flow if it needs to use shared
	bandwidth with multicast. If the bandwidth is available, NAS will
	reserve the bandwidth, update the bandwidth pools for subscriber
	bandwidth, the PON bandwidth, and the bandwidth on the link towards
	the OLT, and send a response to the policy server, which is
	propagated back to the application server to start streaming.
	Otherwise, the request is rejected.
	+----+		This particular scenario assumes the NAS is aware of the bandwidth on
	+---<PON>---------- |ONT |------ HGW		the PON and can track the changes in available bandwidth on the PON
	+ +----+		under all conditions. On receiving an IGMP join message, NAS will
	+ +----+		perform bandwidth check on the subscriber bandwidth. If this passes
	+ +--------- |ONT |------ HGW		and the stream is already being forwarded on the PON by the OLT
	+----+ +----+ + +----+		(which also means that it is already forwarded by the NAS to the
	|NAS |---------------| |------<PON>		OLT), NAS will admit the join, update the available subscriber
	| |<------------->| | + +-----+		bandwidth, and transmit an ANCP message to the OLT and in turn to the
	+----+ ANCP |OLT | +--------- | |----- HGW		ONT/ONU to start replication on the customer port. If the stream is
	| | | | |		not already being replicated to the PON by the OLT, the NAS will also
	| | |<------------------>| ONU |------HGW		check the available bandwidth on the PON, and if it is not already
	| +----+ ANCP | | +---+		being replicated to the OLT, it will check the bandwidth on the link
	| | | |-----|HGW|		towards the OLT. If this passes, the available PON bandwidth and the
	| | +-----+ +---+		bandwidth on the link towards the OLT are updated. The NAS adds the
	| 1.IGMP JOIN(S/*,G) | |		OLT as a leaf to the multicast tree for that stream. On receiving
	|<---------------------------------------------------------- |		the message to start replication, the OLT will add the PON interface
	2.| | | |		to its replication state if the stream is not already being forwarded
	+=======================+ | |		on that PON. Also, the OLT will send an ANCP message to direct the
	[Access Control & ] | |		ONT/ONU to add or update its replication state with the customer port
	[Subscriber B/W ] | |		for that channel. The interaction between ANX and NAS is shown in
	[PON B/W & OLT link B/W ] | |		Figures 7 and 8. For unicast video streams, application-level
	[based Admission Control] | |		signaling from the CPE typically triggers an application server to
	+=======================+ | |		request bandwidth-based admission control from a policy server. The
	| | | |		policy server can, in turn, interact with the NAS to request the
	|-------------------> | | |		bandwidth for the unicast video flow if it needs to use shared
	3.ANCP Replication-Start| | |		bandwidth with multicast. If the bandwidth is available, NAS will
	(<S/*,G> or Multicast | | |		reserve the bandwidth; update the bandwidth pools for subscriber
	|MAC,Customer-Port-ID>| --------------------> | |		bandwidth, the PON bandwidth, and the bandwidth on the link towards
	| |4.ANCP Replication-Start |		the OLT; and send a response to the policy server, which is
	| (<S/*,G> or Multicast MAC,Customer-Port-ID)		propagated back to the application server to start streaming.
	|-------------------> | | |		Otherwise, the request is rejected.
	|5.Multicast Flow(S,G)| | |
	|On Multicast VLAN |---------------------> | |
	| |6.Multicast Flow (S,G) | |
	| |forwarded on | |
	| |Unidirectional | |
	| |<Multicast GEM-PORT> | |
	| |on the PON by OLT |------------->|
	7. Multicast Flow
	orwarded on |
	Customer-Port by|
	|ONT/OLT. |
	| |
	Figure 7: Interactions for NAS based Multicast Admission Control (no		+----+
	IGMP processing on ANX, and NAS maintains available video bandwidth		+---<PON>---------- |ONT |------ HGW
	for PON) upon channel join.		+ +----+
			+ +----+
			+ +--------- |ONT |------ HGW
			+----+ +----+ + +----+
			|NAS |---------------| |------<PON>
			| |<------------->| | + +-----+
			+----+ ANCP |OLT | +--------- | |----- HGW
			| | | | |
			| | |<------------------>| ONU |------HGW
			| +----+ ANCP | | +---+
			| | | |-----|HGW|
			| | +-----+ +---+
			| 1.IGMP join (S/*,G) | |
			|<---------------------------------------------------------- |
			2.| | | |
			+=======================+ | |
			[Access Control & ] | |
			[Subscriber B/W ] | |
			[PON B/W & OLT link B/W ] | |
			[based Admission Control] | |
			+=======================+ | |
			| | | |
			|-------------------> | | |
			3.ANCP Replication-Start| | |
			(<S/*,G> or Multicast | | |
			|MAC,Customer-Port-ID)| --------------------> | |
			| |4.ANCP Replication-Start |
			| (<S/*,G> or Multicast MAC,Customer-Port-ID)
			|-------------------> | | |
			|5.Multicast Flow(S,G)| | |
			|on Multicast VLAN |---------------------> | |
			| |6.Multicast Flow (S,G) | |
			| |forwarded on | |
			| |Unidirectional | |
			| |<Multicast GEM-PORT> | |
			| |on the PON by OLT |------------->|
			7.Multicast Flow
			forwarded on |
			Customer-Port by|
			|ONT/OLT. |
			| |
	+----+		Figure 7: Interactions for NAS-Based Multicast Admission Control
	+---<PON>---------- |ONT |----- HGW		(No IGMP Processing on ANX and NAS Maintains Available Video
	+ +----+		Bandwidth for PON) upon Channel Join
	+ +----+		+----+
	+ +--------- |ONT |----- HGW		+---<PON>---------- |ONT |----- HGW
	+----+ +----+ + +----+		+ +----+
	|NAS |---------------| |------<PON>		+ +----+
	| |<------------->| | + +-----+		+ +--------- |ONT |----- HGW
	+----+ ANCP |OLT | +--------- | |---- HGW		+----+ +----+ + +----+
	| | | | |		|NAS |---------------| |------<PON>
	| | |<------------------>| ONU |-----HGW		| |<------------->| | + +-----+
	| +----+ ANCP | | +---+		+----+ ANCP |OLT | +--------- | |---- HGW
	| | | |-----|HGW|		| | | | |
	| | +-----+ +---+		| | |<------------------>| ONU |-----HGW
	| | | |		| +----+ ANCP | | +---+
	| IGMP LEAVE(S/*,G) | |		| | | |-----|HGW|
	|<-----------------------------------------------------------|		| | +-----+ +---+
	| | | |		| | | |
	+====================+ | | |		| IGMP leave (S/*,G) | |
	[Admission Control ] | | |		|<-----------------------------------------------------------|
	[<Resource Released> ] | | |		| | | |
	+====================+ | | |		+====================+ | | |
	| | | |		[Admission Control ] | | |
	| | | |		[<Resource Released> ] | | |
	| | | |		+====================+ | | |
	|-------------------> | | |		| | | |
	ANCP Replication-Stop | | |		| | | |
	(<S/*,G> or Multicast MAC,Customer-Port-ID) | |		| | | |
	| | | |		|-------------------> | | |
	| |---------------------> | |		ANCP Replication-Stop | | |
	| | ANCP Replication-Stop | |		(<S/*,G> or Multicast MAC,Customer-Port-ID) | |
	(<S/*,G> or Multicast MAC,Customer-Port-ID)		| | | |
			| |---------------------> | |
			| | ANCP Replication-Stop | |
			(<S/*,G> or Multicast MAC,Customer-Port-ID)
	Figure 8: Interactions for NAS based Multicast Admission Control (no		Figure 8: Interactions for NAS-Based Multicast Admission Control
	IGMP processing on ANX, and NAS maintains available video bandwidth		(No IGMP Processing on ANX and NAS Maintains Available Video
	for PON) upon channel leave.		Bandwidth for PON) upon Channel Leave
	- An alternate approach is required if the NAS is not aware of		An alternate approach is required if the NAS is not aware of the
	the bandwidth on the PON. In this case the OLT does the PON bandwidth		bandwidth on the PON. In this case, the OLT does the PON bandwidth
	management, and requests NAS to perform bandwidth admission control		management and requests NAS to perform bandwidth admission control on
	on subscriber bandwidth and the bandwidth on the link to the OLT.		subscriber bandwidth and the bandwidth on the link to the OLT.
	Following are operations of various elements:		Following are operations of various elements:
	ANX operation:		ANX operation:
	- ONT/ONU can snoop IGMP messages. If conditional access is		- ONT/ONU can snoop IGMP messages. If conditional access is
	configured and the channel is in the Black list (or it is not on the		configured and the channel is in the black list (or it is not on
	White list), ONT will drop the IGMP Join. If the channel passes the		the white list), ONT will drop the IGMP join. If the channel
	conditional access check, the ONT will forward the IGMP Join, and		passes the conditional access check, the ONT will forward the IGMP
	will send a bandwidth admission control request to the OLT. In case		join and will send a bandwidth admission control request to the
	the multicast stream is already being received on the PON, the		OLT. If the multicast stream is already being received on the
	ONT/ONU does not forward the stream to the access port where IGMP is		PON, the ONT/ONU does not forward the stream to the Access Port
	received till it has received a positive admission control response		where IGMP is received until it has received a positive admission
	from the OLT.		control response from the OLT.
	- OLT can snoop IGMP messages. It also receives a bandwidth		- OLT can snoop IGMP messages. It also receives a bandwidth
	admission control request from the ONT/ONU for the requested channel.		admission control request from the ONT/ONU for the requested
	It can be programmed with a channel bandwidth map. If the multicast		channel. It can be programmed with a channel bandwidth map. If
	channel is already being streamed on the PON, or the channel		the multicast channel is already being streamed on the PON or the
	bandwidth is less than the multicast available bandwidth on the PON,		channel bandwidth is less than the available multicast bandwidth
	the OLT forwards the IGMP request to the NAS and keeps track of the		on the PON, the OLT forwards the IGMP request to the NAS and keeps
	subscriber (identified by customer-Port-ID) as a receiver. If the		track of the subscriber (identified by Customer-Port-ID) as a
	channel is not already being streamed on the PON, but the PON has		receiver. If the channel is not already being streamed on the PON
	sufficient bandwidth for that channel, the OLT reduces the PON		but the PON has sufficient bandwidth for that channel, the OLT
	multicast video bandwidth by the channel bandwidth and may optionally		reduces the PON multicast video bandwidth by the channel bandwidth
	add the PON to the multicast tree without activation for that		and may optionally add the PON to the multicast tree without
	channel. This is biased towards a forward expectation that the		activation for that channel. This is biased towards a forward
	request will be accepted at the NAS. The OLT forwards the IGMP join		expectation that the request will be accepted at the NAS. The OLT
	to the NAS. It also sends a bandwidth admission request to the NAS		forwards the IGMP join to the NAS. It also sends a bandwidth
	identifying the channel, and the premises for which the request is		admission request to the NAS identifying the channel and the
	made. It sets a timer for the subscriber multicast entry within which		premises for which the request is made. It sets a timer for the
	it expects to receive a request from the NAS that relates to this		subscriber multicast entry within which it expects to receive a
	request. If the PON available bandwidth is less than the bandwidth		request from the NAS that relates to this request. If the
	of the requested channel, the OLT sends an admission response (with a		available PON bandwidth is less than the bandwidth of the
	reject) to the ONT/ONU, and does not forward the IGMP join to the		requested channel, the OLT sends an admission response (with a
	NAS.		reject) to the ONT/ONU and does not forward the IGMP join to the
			NAS.
	NAS operation:		NAS operation:
	The NAS receives the IGMP join from the subscriber on the subscriber		The NAS receives the IGMP join from the subscriber on the subscriber
	connection. When NAS receives the admission control request from ANX		connection. When NAS receives the admission control request from ANX
	(also signifying the bandwidth on the PON is available), it performs		(also signifying the bandwidth on the PON is available), it performs
	admission control against the subscriber available multicast		admission control against the subscriber's available multicast
	bandwidth. If this check passes, and the NAS is already transmitting		bandwidth. If this check passes, and the NAS is already transmitting
	that channel to the OLT, the request is accepted. If the check passes		that channel to the OLT, the request is accepted. If the check
	and the NAS is not transmitting the channel to the OLT yet, it		passes and the NAS is not transmitting the channel to the OLT yet, it
	performs admission control against the multicast video available		performs admission control against the available multicast video
	bandwidth (this includes the dedicated multicast bandwidth and the		bandwidth (this includes the dedicated multicast bandwidth and the
	shared bandwidth between multicast and video on demand) on the		shared bandwidth between multicast and Video on Demand) on the
	link(s) to the OLT. If the check passes, the request is accepted, the		link(s) to the OLT. If the check passes, the request is accepted,
	available video bandwidth for the subscriber and downlink to the OLT		the available video bandwidth for the subscriber and downlink to the
	are reduced by the channel bandwidth, and the NAS sends an ANCP		OLT are reduced by the channel bandwidth, and the NAS sends an ANCP
	admission control response (indicating accept) to the OLT, requesting		admission control response (indicating accept) to the OLT, requesting
	the addition of the subscriber to the multicast tree for that		the addition of the subscriber to the multicast tree for that
	channel. The OLT activates the corresponding multicast entry if not		channel. The OLT activates the corresponding multicast entry if not
	active and maintains state of the subscriber in the list of receivers		active and maintains state of the subscriber in the list of receivers
	for that channel. The OLT also sends an ANCP request to the ONT/ONU		for that channel. The OLT also sends an ANCP request to the ONT/ONU
	to enable reception of the multicast channel and forwarding to the		to enable reception of the multicast channel and forwarding to the
	subscriber access port. Otherwise, if the request is rejected, the		subscriber Access Port. Otherwise, if the request is rejected, the
	NAS will send an admission reject to the OLT, which in turn removes		NAS will send an admission reject to the OLT, which, in turn, removes
	the subscriber as a receiver for that channel (if it were added), and		the subscriber as a receiver for that channel (if it was added) and
	credits back the channel bandwidth to the PON video bandwidth if		credits back the channel bandwidth to the PON video bandwidth if
	there is no other receiver on the PON for that channel. The		there is no other receiver on the PON for that channel. The
	interactions between ANX and NAS are shown in Figures 9 and 10.		interactions between ANX and NAS are shown in Figures 9 and 10.
	If the OLT does not receive a response from the NAS within a set		If the OLT does not receive a response from the NAS within a set
	timer, the OLT removes the subscriber from the potential list of		timer, the OLT removes the subscriber from the potential list of
	receivers for the indicated channel. It also returns the allocated		receivers for the indicated channel. It also returns the allocated
	bandwidth to the PON available bandwidth if there are no other		bandwidth to the available PON bandwidth if there are no other
	receivers. In this case, the NAS may send a response to the OLT with		receivers. In this case, the NAS may send a response to the OLT with
	no matching entry as the entry has been deleted. The OLT must perform		no matching entry as the entry has been deleted. The OLT must
	admission control against the PON available bandwidth and may accept		perform admission control against the available PON bandwidth and may
	the request and send an ANCP request to the ONT/ONU to activate the		accept the request and send an ANCP request to the ONT/ONU to
	corresponding multicast entry as described earlier. If it does not		activate the corresponding multicast entry as described earlier. If
	accept the request, it will respond back to the NAS with a reject.		it does not accept the request, it will respond back to the NAS with
	The NAS shall credit back the channel bandwidth to the subscriber. It		a reject. The NAS shall credit back the channel bandwidth to the
	shall also stop sending the channel to the OLT if that subscriber was		subscriber. It shall also stop sending the channel to the OLT if
	the last leaf on the multicast tree towards the OLT.		that subscriber was the last leaf on the multicast tree towards the
			OLT.
	On processing an IGMP leave, the OLT will send an ANCP request to NAS		On processing an IGMP leave, the OLT will send an ANCP request to NAS
	to release resources. NAS will release the subscriber bandwidth. If		to release resources. NAS will release the subscriber bandwidth. If
	this leave causes the stream to be no longer required by the OLT, the		this leave causes the stream to be no longer required by the OLT, the
	NAS will update its replication state and release the bandwidth on		NAS will update its replication state and release the bandwidth on
	the NAS to OLT link.		the NAS to OLT link.
	If the subscriber makes a request for a unicast video stream (i.e.,		If the subscriber makes a request for a unicast video stream (i.e.,
	Video on Demand), the request results in appropriate application		Video on Demand), the request results in appropriate application-
	level signaling, which typically results in an application server		level signaling, which typically results in an application server
	requesting a policy server for bandwidth-based admission control for		requesting a policy server for bandwidth-based admission control for
	the VoD stream. The policy server after authorizing the request, can		the VoD stream. After authorizing the request, the policy server can
	send a request to the NAS for the required bandwidth if it needs to		send a request to the NAS for the required bandwidth if it needs to
	use bandwidth that is shared with multicast. This request may be		use bandwidth that is shared with multicast. This request may be
	based on a protocol outside of the scope of this document. The NAS		based on a protocol outside of the scope of this document. The NAS
	checks if the available video bandwidth (accounting for both		checks if the available video bandwidth (accounting for both
	multicast and unicast) per subscriber and for the link to the OLT is		multicast and unicast) per subscriber and for the link to the OLT is
	sufficient for the request. If it is, it temporarily reserves the		sufficient for the request. If it is, it temporarily reserves the
	bandwidth and sends an ANCP admission request to the OLT for the		bandwidth and sends an ANCP admission request to the OLT for the
	subscriber, indicating the desired VoD bandwidth. If the OLT has		subscriber, indicating the desired VoD bandwidth. If the OLT has
	sufficient bandwidth on the corresponding PON, it reserves that		sufficient bandwidth on the corresponding PON, it reserves that
	bandwidth and returns an accept response to the NAS. If not, it		bandwidth and returns an accept response to the NAS. If not, it
	returns a reject to the NAS. If the NAS receives an accept, it		returns a reject to the NAS. If the NAS receives an accept, it
	returns an accept to the policy server which in turn returns an		returns an accept to the policy server, which, in turn, returns an
	accept to the application server, and the video stream is streamed to		accept to the application server, and the video stream is streamed to
	the subscriber. This interaction is shown in Figure 11. If the NAS		the subscriber. This interaction is shown in Figure 11. If the NAS
	does not accept the request from the policy server, it returns a		does not accept the request from the policy server, it returns a
	reject. If the NAS receives a reject from the OLT, it returns the		reject. If the NAS receives a reject from the OLT, it returns the
	allocated bandwidth to the subscriber and the downlink to the OLT.		allocated bandwidth to the subscriber and the downlink to the OLT.
	+----+		It should be noted that similar functionality to that described in
	+-------- |ONT |-------- HGW		this section and depicted in Figures 9, 10, and 11 will be required
	+----+ +----+ + +----+		when OMCI is enabled between the OLT and ONT/ONU in the ANCP+OMCI ANX
	|NAS |---------------| |------<PON>		control model. In the latter case, the OLT will act as an ANCP-OMCI
	| |<------------->|OLT | + +-----+		gateway.
	+----+ ANCP | | ANCP +--------- | ONU |------ HGW
	| +----+<------------------>+-----+-------HGW
	| | | |
	|1.IGMP Join(s/*,G) +=============+ +=============+ |
	|<------------------[IGMP Snooping]---------[IGMP snooping]--|
	| +=============+ +=============+ |
	| |2.Admission-Request | |
	| |(Flow,Customer-Port-ID) | |
	| |<---------------------- | |
	| 3.+===============+ | |
	| [ Access Ctrl ] | |
	| [ & PON B/W ] | |
	| [ Admission Ctrl] | |
	| +===============+ PASS | |
	|4.Admission-Request | | |
	| <Flow, | | |
	| Customer-Port-ID> | | |
	|<--------------------| | |
	5.| | | |
	+=================+ | | |
	[Subscriber B/W ] | | |
	[& OLT link B/W ] | | |
	[Admission Ctrl ] | | |
	+=================+PASS | | |
	|6.Admission-Reply-Pass | |
	|<Flow,Customer-Port-ID> | |
	|-------------------->| | |
	| 7.+========================+ | |
	| [Update Replication State] | |
	| +========================+ | |
	| | 8.Admission-Reply-Pass | |
	| |(<Flow,Cust-Port-ID> | |
	| |----------------------> | |
	| | 9.+============+ |
	| | [Update Repl.] |
	| | [ State ] |
	| | +============+ |
	Figure 9: Interaction between NAS & ANX for Multicast Bandwidth		+----+
	Admission Control in the All-ANCP ANX control model upon success.		+-------- |ONT |-------- HGW
	Similar functionality will be required when OMCI is enabled between the		+----+ +----+ + +----+
	OLT and ONT/ONU in the ANCP+OMCI ANX control model. In this latter case,		|NAS |---------------| |------<PON>
	the OLT will act as ANCP-OMCI gateway.		| |<------------->|OLT | + +-----+
			+----+ ANCP | | ANCP +--------- | ONU |------ HGW
			| +----+<------------------>+-----+-------HGW
			| | | |
			|1.IGMP join(S/*,G) +=============+ +=============+ |
			|<------------------[IGMP Snooping]---------[IGMP snooping]--|
			| +=============+ +=============+ |
			| |2.Admission-Request | |
			| |(Flow,Customer-Port-ID) | |
			| |<---------------------- | |
			| 3.+===============+ | |
			| [ Access Ctrl ] | |
			| [ & PON B/W ] | |
			| [ Admission Ctrl] | |
			| +===============+ PASS | |
			|4.Admission-Request | | |
			| <Flow, | | |
			| Customer-Port-ID> | | |
			|<--------------------| | |
			5.| | | |
			+=================+ | | |
			[Subscriber B/W ] | | |
			[& OLT link B/W ] | | |
			[Admission Ctrl ] | | |
			+=================+PASS | | |
			|6.Admission-Reply-Pass | |
			|<Flow,Customer-Port-ID> | |
			|-------------------->| | |
			| 7.+========================+ | |
			| [Update Replication State] | |
			| +========================+ | |
			| | 8.Admission-Reply-Pass | |
			| |(<Flow,Cust-Port-ID> | |
			| |----------------------> | |
			| | 9.+============+ |
			| | [Update Repl.] |
			| | [ State ] |
			| | +============+ |
	+----+		Figure 9: Interaction between NAS & ANX for Multicast Bandwidth
	+--------- |ONT |------ HGW		Admission Control in the All-ANCP ANX Control Model upon Success
	+----+ +----+ + +----+		+----+
	|NAS |---------------| |------<PON>		+--------- |ONT |------ HGW
	| |<------------->|OLT | + +-----+		+----+ +----+ + +----+
	+----+ ANCP | | ANCP +----------| ONU |----- HGW		|NAS |---------------| |------<PON>
	| +----+<----------------->+-----+------HGW		| |<------------->|OLT | + +-----+
	| | | |		+----+ ANCP | | ANCP +----------| ONU |----- HGW
	|1.IGMP Join(s/*,G) +=============+ +=============+ |		| +----+<----------------->+-----+------HGW
	|<------------------[IGMP Snooping]--------[IGMP snooping]-- |		| | | |
	| +=============+ +=============+ |		|1.IGMP join(S/*,G) +=============+ +=============+ |
	| |2.Admission-Request | |		|<------------------[IGMP Snooping]--------[IGMP snooping]-- |
	| |(Flow,Customer-Port-ID) | |		| +=============+ +=============+ |
	| |<---------------------- | |		| |2.Admission-Request | |
	| 2.+===============+ | |		| |(Flow,Customer-Port-ID) | |
	| [ Access Ctrl ] | |		| |<---------------------- | |
	| [ & PON B/W ] | |		| 2.+===============+ | |
	| [ Admission Ctrl] | |		| [ Access Ctrl ] | |
	| +===============+ PASS | |		| [ & PON B/W ] | |
	|3.Admission-Request | | |		| [ Admission Ctrl] | |
	| <Flow,Customer-Port-ID> | |		| +===============+ PASS | |
	|<--------------------| | |		|3.Admission-Request | | |
	4.| | | |		| <Flow,Customer-Port-ID> | |
	+==================+ | | |		|<--------------------| | |
	[Subscriber B/W ] | | |		4.| | | |
	[& OLT link B/W ] | | |		+==================+ | | |
	[Admission Ctrl ] | | |		[Subscriber B/W ] | | |
	+==================+FAIL | |		[& OLT link B/W ] | | |
	| | | |		[Admission Ctrl ] | | |
	|5.Admission-Reply-Fail | |		+==================+FAIL | |
	|<Flow,Cust-Port-ID> | | |		| | | |
	|-------------------->| | |		|5.Admission-Reply-Fail | |
	| 6.+==================+ | |		|<Flow,Cust-Port-ID> | | |
	| [Release PON B/W ] | |		|-------------------->| | |
	| [Remove Repl.State ] | |		| 6.+==================+ | |
	| +==================+ | |		| [Release PON B/W ] | |
	| | 7.Admission-Reply-Fail | |		| [Remove Repl.State ] | |
	| |<Flow,Cust-Port-ID> | |		| +==================+ | |
	| |----------------------> | |		| | 7.Admission-Reply-Fail | |
	| | 8.+============+ |		| |<Flow,Cust-Port-ID> | |
	| | [Remove Repl.] |		| |----------------------> | |
	| | [ State ] |		| | 8.+============+ |
	| | +============+ |		| | [Remove Repl.] |
	Figure 10: Interaction between NAS and ANX for Multicast Bandwidth		| | [ State ] |
	Admission Control in the All-ANCP ANX control model upon failure.		| | +============+ |
	Similar functionality will be required when OMCI is enabled between the
	OLT and ONT/ONU in the ANCP+OMCI ANX control model. In this latter case,
	the OLT will act as ANCP-OMCI gateway.
	+------------+ 1. VoD Request		Figure 10: Interaction between NAS and ANX for Multicast Bandwidth
	| App. Server|<-----------------------------------------------		Admission Control in the All-ANCP ANX Control Model upon Failure
	| Server |		+------------+ 1. VoD Request
	+------------+		| App. Server|<-----------------------------------------------
	| 2. Admission-Request (VoD-Flow)		| Server |
	+-------+		+------------+
	|Policy |		| 2. Admission-Request (VoD-Flow)
	|Server |		+-------+
	+-------+		|Policy |
	| +		|Server |
	|<-|---3. Admission-Request		+-------+
	| |		| +
	+ | 8. Admission-Reply		|<-|---3. Admission-Request
	+----+ + +----+ +-----+		| |
	|NAS |---------------|OLT |------<PON>-------|ONT |---HGW--CPE		+ | 8. Admission-Reply
	| |<------------->| | +-----+ |		+----+ + +----+ +-----+
	+----+ ANCP +----+ | |		|NAS |---------------|OLT |------<PON>-------|ONT |---HGW--CPE
	| | | |		| |<------------->| | +-----+ |
	4.| | | |		+----+ ANCP +----+ | |
	+=================+ | | |		| | | |
	[Subscriber B/W ] | | |		4.| | | |
	[& OLT link B/W ] | | |		+=================+ | | |
	[Admission Ctrl ] | | |		[Subscriber B/W ] | | |
	+=================+PASS | | |		[& OLT link B/W ] | | |
	| | | |		[Admission Ctrl ] | | |
	| 5.Admission-Request | | |		+=================+PASS | | |
	|(Bandwidth,PON-Port-ID) | |		| | | |
	|-------------------> | | |		| 5.Admission-Request | | |
	| | | |		|(Bandwidth,PON-Port-ID) | |
	| 6.+===============+ | |		|-------------------> | | |
	| [ PON B/W ] | |		| | | |
	| [ Admission Ctrl] | |		| 6.+===============+ | |
	| +===============+ PASS | |		| [ PON B/W ] | |
	|7.Admission-Reply | | |		| [ Admission Ctrl] | |
	| <PON-Port-ID> | | |		| +===============+ PASS | |
	|<------------------- | | |		|7.Admission-Reply | | |
	| | | |		| <PON-Port-ID> | | |
			|<------------------- | | |
			| | | |
	Figure 11: Interactions for VoD Bandwidth Admission Control in the		Figure 11: Interactions for VoD Bandwidth Admission Control
	All-ANCP ANX control model. Similar functionality will be required		in the All-ANCP ANX Control Model
	when OMCI is enabled between the OLT and ONT in the ANCP+OMCI ANX
	control model. In this latter case, the OLT will act as ANCP-OMCI
	gateway.
	-A third possible approach is where the ANX is assumed to have a full		A third possible approach is where the ANX is assumed to have full
	knowledge to make an autonomous decision on admitting or rejecting a		knowledge to make an autonomous decision on admitting or rejecting a
	multicast and a unicast join. With respect to the interaction between		multicast and a unicast join. With respect to the interaction
	ONT/ONU and OLT, the procedure is similar to the first approach		between ONT/ONU and OLT, the procedure is similar to the first
	(i.e., NAS controlled replication). However, when the OLT receives an		approach (i.e., NAS-controlled replication). However, when the OLT
	IGMP request from a subscriber, it performs admission control against		receives an IGMP request from a subscriber, it performs admission
	that subscriber multicast video bandwidth (dedicated and shared with		control against that subscriber multicast video bandwidth (dedicated
	Video on Demand), the PON and uplink to the NAS. It should be noted		and shared with Video on Demand), the PON, and uplink to the NAS. It
	in this case that if there are multiple NAS-OLT links, either the		should be noted in this case that if there are multiple NAS-OLT
	link on which the multicast stream must be sent is pre-determined,		links, either the link on which the multicast stream must be sent is
	needs to be selected by the OLT based on downstream bandwidth from		pre-determined, needs to be selected by the OLT based on downstream
	NAS to OLT and the selection is communicated to the NAS, or the OLT		bandwidth from NAS to OLT and the selection is communicated to the
	has to be ready to receive the stream on any link. If the check		NAS, or the OLT has to be ready to receive the stream on any link.
	passes, the OLT updates the video available bandwidth per PON and		If the check passes, the OLT updates the available video bandwidth
	subscriber. The OLT adds the subscriber to the list of receivers and		per PON and subscriber. The OLT adds the subscriber to the list of
	the PON to the multicast tree, if it is not already on it. It also		receivers and the PON to the multicast tree if it is not already on
	sends an ANCP request to the ONT/ONU to add the subscriber access		it. It also sends an ANCP request to the ONT/ONU to add the
	port to that channel multicast tree, and sends an ANCP message to the		subscriber Access Port to that channel multicast tree and sends an
	NAS informing it of the subscriber and link available video bandwidth		ANCP message to the NAS informing it of the subscriber and link
	and the channel the subscriber joined. The NAS upon receiving the		available video bandwidth and the channel the subscriber joined. The
	ANCP information message, updates the necessary information,		NAS, upon receiving the ANCP information message, updates the
	including the OLT to the multicast tree if it is not already on it.		necessary information, including the OLT to the multicast tree if it
	It should be noted in this case that the ANCP message from the OLT to		is not already on it. It should be noted in this case that the ANCP
	the NAS is being used to add the OLT to a multicast tree as opposed		message from the OLT to the NAS is being used to add the OLT to a
	to an IGMP message. The IGMP message can also be sent by the OLT with		multicast tree as opposed to an IGMP message. The IGMP message can
	the OLT acting as an IGMP proxy at the expense of added messages. In		also be sent by the OLT with the OLT acting as an IGMP proxy at the
	this option, the OLT acts as the network IGMP router for the		expense of added messages. In this option, the OLT acts as the
	subscriber.		network IGMP router for the subscriber.
	For unicast video streams, the policy server receiving an admission		For unicast video streams, the policy server receiving an admission
	request from an application server, as described before, may query		request from an application server, as described before, may query
	the OLT for admission control as it has all information. If the OLT		the OLT for admission control as it has all information. If the OLT
	has sufficient bandwidth for the stream it reserves that bandwidth		has sufficient bandwidth for the stream, it reserves that bandwidth
	for the subscriber, PON and OLT uplink to the NAS and returns an		for the subscriber, the PON, and OLT uplink to the NAS and returns an
	accept to the policy server. It also updates the NAS via an ANCP		accept to the policy server. It also updates the NAS (via an ANCP
	message of the subscriber available video bandwidth. If the OLT		message) of the subscriber's available video bandwidth. If the OLT
	rejects the policy server request, it will return a reject to the		rejects the policy server request, it will return a reject to the
	policy server.		policy server.
	It should be noted that if the policy server adjacency is with the		It should be noted that if the policy server adjacency is with the
	NAS, the policy server may make the admission request to the NAS. The		NAS, the policy server may make the admission request to the NAS.
	NAS then sends an ANCP admission request to the OLT on behalf of the		The NAS then sends an ANCP admission request to the OLT on behalf of
	policy server. The NAS returns an accept or reject to the policy server		the policy server. The NAS returns an accept or reject to the policy
	if it gets a reject or accept, respectively, from the OLT.		server if it gets a reject or accept, respectively, from the OLT.
	6.3. Multicast Accounting		6.3. Multicast Accounting
	It may be desirable to perform accurate per-user or per Access Loop		It may be desirable to perform accurate time- or volume-based
	time or volume based accounting. In case the ANX is performing the		accounting per user or per access loop. If the ANX is performing the
	traffic replication process, it knows when replication of a multicast		traffic replication process, it knows when replication of a multicast
	flow to a particular Access Port or user starts and stops. Multicast		flow to a particular Access Port or user starts and stops. Multicast
	accounting can be addressed in two ways:		accounting can be addressed in two ways:
	- ANX keeps track of when replication starts or stops, and reports		- ANX keeps track of when replication starts or stops and reports
	this information to the NAS for further processing. In this case,		this information to the NAS for further processing. In this case,
	ANCP can be used to send the information from the ANX to the NAS.		ANCP can be used to send the information from the ANX to the NAS.
	This can be done with the Information Report message. The NAS can		This can be done with the Information Report message. The NAS can
	then generate the appropriate time and/or volume accounting		then generate the appropriate time and/or volume accounting
	information per Access Loop and per multicast flow, to be sent to the		information per access loop and per multicast flow to be sent to
	accounting system. The ANCP requirements to support this approach are		the accounting system. The ANCP requirements to support this
	specified in [RFC5851]. If the replication function is distributed		approach are specified in [RFC5851]. If the replication function
	between the OLT and ONT/ONU, a query from the NAS will result in OLT		is distributed between the OLT and ONT/ONU, a query from the NAS
	generating a query to the ONT/ONU.		will result in OLT generating a query to the ONT/ONU.
	- ANX keeps track of when replication starts or stops, and generates		- ANX keeps track of when replication starts or stops and generates
	the time and/or volume based accounting information per Access Loop		the time- and/or volume-based accounting information per access
	and per multicast flow, before sending it to a central accounting		loop and per multicast flow, before sending it to a central
	system for logging. Since ANX communicates with this accounting		accounting system for logging. Since ANX communicates with this
	system directly, the approach does not require the use of ANCP. It is		accounting system directly, the approach does not require the use
	therefore beyond the scope of this document. It may also be desirable		of ANCP. It is therefore beyond the scope of this document. It
	for the NAS to have the capability to asynchronously query the ANX to		may also be desirable for the NAS to have the capability to
	obtain an instantaneous status report related to multicast flows		asynchronously query the ANX to obtain an instantaneous status
	currently replicated by the ANX. Such a reporting functionality could		report related to multicast flows currently replicated by the ANX.
	be useful for troubleshooting and monitoring purposes. If the		Such a reporting functionality could be useful for troubleshooting
	replication function in the ANX is distributed between the OLT and		and monitoring purposes. If the replication function in the ANX
	the ONT/ONU, then for some of the information required by the NAS		is distributed between the OLT and the ONT/ONU, then for some of
	(such as the list of access-ports on which a flow is being forwarded		the information required by the NAS (such as the list of Access
	or list of flows being forwarded on an access-port), a query to the		Ports on which a flow is being forwarded or list of flows being
	OLT from the NAS will result in a query from OLT to ONT/ONU. The OLT		forwarded on an Access Port), a query to the OLT from the NAS will
	responds back to the NAS when it receives the response from the		result in a query from the OLT to the ONT/ONU. The OLT responds
	ONT/ONU. Also, if the list of PONs on which replication is happening		back to the NAS when it receives the response from the ONT/ONU.
	for a multicast channel or the list of channels being replicated on a		Also, if the list of PONs on which replication is happening for a
	PON is what is desired, the OLT can return this information.		multicast channel or the list of channels being replicated on a
			PON is what is desired, the OLT can return this information.
	7. Remote Connectivity Check		7. Remote Connectivity Check
	In an end-to-end Ethernet aggregation network, end-to-end Ethernet		In an end-to-end Ethernet aggregation network, end-to-end Ethernet
	OAM as specified in IEEE 802.1ag and ITU-T Recommendation Y.1730/1731		Operations, Administration, and Maintenance (OAM), as specified in
	can provide Access Loop connectivity testing and fault isolation.		IEEE 802.1ag [802.1ag] and ITU-T Recommendation Y.1730/1731 [Y.1731],
			can provide access loop connectivity testing and fault isolation.
			However, most HGWs do not yet support these standard Ethernet OAM
			procedures. Also, in a mixed Ethernet and ATM access network (e.g.,
			Ethernet-based aggregation upstream from the OLT and BPON
			downstream), interworking functions for end-to-end OAM are not yet
			standardized or widely available. Until such mechanisms become
			standardized and widely available, the Access Node Control Mechanism
			between NAS and ANX can be used to provide a simple mechanism to test
			connectivity of an access loop from the NAS.
	However, most HGWs do not yet support these standard Ethernet OAM		Triggered by a local management interface, the NAS can use the Access
	procedures. Also, in a mixed Ethernet and ATM access network (e.g.,		Node Control Mechanism (Control Request message) to initiate an
	Ethernet based aggregation upstream from the OLT, and BPON		access loop test between an Access Node and a HGW or ONT/ONU. On
	downstream), interworking functions for end-to-end OAM are not yet		reception of the ANCP message, the OLT can trigger native OAM
	standardized or widely available. Until such mechanisms become		procedures defined for BPON in [G.983.1] and for GPON in [G.984.1].
	standardized and widely available, Access Node Control mechanism		The Access Node can send the result of the test to the NAS via a
	between NAS and ANX can be used to provide a simple mechanism to test		Control Response message.
	connectivity of an access-loop from the NAS.
	Triggered by a local management interface, the NAS can use the Access		8. Access Topology Discovery
	Node Control Mechanism (Control Request Message) to initiate an
	Access Loop test between Access Node and HGW or ONT/ONU. On reception
	of the ANCP message, the OLT can trigger native OAM procedures
	defined for BPON in [G.983.1] and for GPON in [G.984.1]. The Access
	Node can send the result of the test to the NAS via a Control
	Response message.
	8. Access Topology Discovery		In order to avoid congestion in the network, manage and utilize the
			network resources better, and ensure subscriber fairness, NAS
			performs hierarchical shaping and scheduling of the traffic by
			modeling different congestion points in the network (such as the last
			mile, Access Node uplink, and the access-facing port).
	In order to avoid congestion in the network, manage and utilize the		Such mechanisms require that the NAS gains knowledge about the
	network resources better, and ensure subscriber fairness, NAS		topology of the access network, the various links being used, and
	performs hierarchical shaping and scheduling of the traffic by		their respective rates. Some of the information required is somewhat
	modeling different congestion points in the network (such as the		dynamic in nature (e.g., DSL line rate if the last mile is xDSL
	last-mile, access Node uplink, and the access facing port).		based, such as in the case of "PON-fed DSLAMs" for FTTC/FTTB
			scenarios) and hence cannot come from a provisioning and/or inventory
			management Operations Support System (OSS). Some of the information
			varies less frequently (e.g., capacity of the OLT uplink) but
			nevertheless needs to be kept strictly in sync between the actual
			capacity of the uplink and the image the NAS has of it.
	Such mechanisms require that the NAS gains knowledge about the		OSSs are rarely able to enforce the consistency of such data in a
	topology of the access network, the various links being used and		reliable and scalable manner, notably across organizational
	their respective rates. Some of the information required is somewhat		boundaries under certain deployment scenarios. The Access Topology
	dynamic in nature (e.g., DSL line rate in case the last mile is xDSL		Discovery function allows the NAS to perform these advanced functions
	based, e.g., in case of "PON fed DSLAMs" for FTTC/FTTB scenarios),		without having to depend on an error-prone and possibly complex
	hence cannot come from a provisioning and/or inventory management		integration with an OSS.
	Operations Support System (OSS). Some of the information varies less
	frequently (e.g., capacity of the OLT uplink), but nevertheless needs
	to be kept strictly in sync between the actual capacity of the uplink
	and the image the NAS has of it.
	OSS systems are rarely able to enforce in a reliable and scalable		The rate of the access loop can be communicated via ANCP (Information
	manner the consistency of such data, notably across organizational		Report message) from the ONT/ONU to the OLT in the All-ANCP ANX
	boundaries under certain deployment scenarios. The Access Topology		control model or via OMCI in the ANCP+OMCI ANX control model, and
	Discovery function allows the NAS to perform these advanced functions		then from OLT to the NAS via ANCP. Additionally, during the time the
	without having to depend on an error-prone and possibly complex		DSL NT is active, data rate changes can occur due to environmental
	integration with an OSS system.		conditions (the DSL access loop can get "out of sync" and can retrain
			to a lower value, or the DSL access loop could use Seamless Rate
			Adaptation to make the actual data rate fluctuate while the line is
			active). In this case, ANX sends an additional Information Report to
			the NAS each time the access loop attributes change above a threshold
			value. Existing DSL procedures are not applicable in this case
			because an adapted message flow and additional TLVs are needed.
	The rate of the access-loop can be communicated via ANCP (Information		+--------+
	Report Message) from the ONT/ONU to the OLT in the All-ANCP ANX		| Policy |
	control model or via OMCI in the ANCP+OMCI ANX control model, and		| Server |
	then from OLT to the NAS via ANCP. Additionally, during the time the		+--------+ +---+ +---+
	DSL NT is active, data rate changes can occur due to environmental		| +-----------|ONT|---|HGW|
	conditions (the DSL Access Loop can get "out of sync" and can retrain		| | +---+ +---+
	to a lower value, or the DSL Access Loop could use Seamless Rate		| +--------------- |-----------------+
	Adaptation making the actual data rate fluctuate while the line is		+----+ | +----+ | +-----+ | +---+
	active). In this case, ANX sends an additional Information Report to		|NAS |------------ | | | | | |-|-|HGW|
	the NAS each time the Access Loop attributes change above a threshold		| |<----------> | | | | |ONT/ | | +---+
	value. Existing DSL procedures are not applicable in this case		+----+ ANCP | |OLT |------<PON>--------|ONU | |
	because an adapted message flow and additional TLVs are needed.		| | | | | | | +---+
			| | | |<----------------->| |---|HGW|
			| | +----+ OMCI +-----+ | +---+
			| +----------------------------------+
			| | Access Node |
			| | |
			| |------GPON Ranging------|
			| Port Status Message| ONT Port UP |
			|<------------------ |<-----------------------|
			|Port Configuration GPON Line/Service Profile|
			|------------------> |<---------------------->|
			| ONT/ONI Port UP| |
			|<------------------ | |
			| | |
			| ANCP | OMCI |
			<-------------------><----------------------->|
			PPP, DHCP, IP
			<------------------------------------------------------>
	+--------+		Figure 12: Message Flow for the Use Case of Topology Discovery for
	| Policy |		the ANCP+OMCI Control Model
	| Server |
	+--------+ +---+ +---+
	| +-----------|ONT|---|HGW|
	| | +---+ +---+
	| +--------------- |-----------------+
	+----+ | +----+ | +-----+ | +---+
	|NAS |------------ | | | | | |-|-|HGW|
	| |<----------> | | | | |ONT/ | | +---+
	+----+ ANCP | |OLT |------<PON>--------|ONU | |
	| | | | | | | +---+
	| | | |<----------------->| |---|HGW|
	| | +----+ OMCI +-----+ | +---+
	| +----------------------------------+
	| | Access Node |
	| | |
	| |------GPON Ranging------|
	| Port Status Message| ONT Port UP |
	|<------------------ |<-----------------------|
	|Port Configuration GPON Line/Service Profile|
	|------------------> |<---------------------->|
	| ONT/ONI Port UP| |
	|<------------------ | |
	| | |
	| ANCP | OMCI |
	<-------------------><----------------------->|
	PPP, DHCP, IP
	<------------------------------------------------------>
	Figure 12: Message Flow for the use case of Topology Discovery for		Figure 12 depicts a message flow for topology discovery when using
	the ANCP+OMCI access control model.		the ANCP+OMCI control model. Basically, when an ONT/ONU gets
			connected to a PON, the OLT detects a new device and a GPON Ranging
			process starts. During this process, the ONT/ONU becomes authorized
			by the OLT and identified by ONT/ONU ID, PON Port ID, and max
			Bandwidth. This port status is reported via ANCP to the NAS and then
			potentially the policy server via another mechanism that is out of
			scope of this document. In a second step, after the GPON service
			profile is assigned from OLT to ONT/ONU, the OLT reports the final
			status to NAS with information about the service profile and other
			information such as the ONT/ONU port rate to the subscriber, for
			instance.
	Figure 12 depicts a message flow for topology discovery when using		9. Access Loop Configuration
	the ANCP+OMCI access control model. Basically, when an ONT/ONU gets
	connected to a PON, the OLT detects a new device and a GPON Ranging
	process starts. During this process the ONT/ONU becomes authorized by
	the OLT and identified by ONT/ONU ID, PON Port ID and max Bandwidth.
	This port status is reported via ANCP to the NAS and then potentially
	the policy server via another mechanism that is out of scope of this
	document. In a second step after GPON Service profile is assigned
	from OLT to ONT/ONU, the OLT reports the final status to NAS with
	information about service profile and other information such as the
	ONT/ONU port rate to the subscriber for instance.
	9. Access Loop Configuration		Topology Discovery provides Access Port Identification to the NAS
	Topology Discovery reports access port identification to NAS when		when sending an Access Port Discovery message. This informs NAS
	sending an Access Port Discovery message. This informs NAS		identification of a PON port on an Access Node. Based on Access Port
	identification of PON port on an Access Node. Based on Access Port		Identification and on customer identification, service-related
	Identification and on customer identification, service related		parameters could be configured on an OLT and an ONU/ONT.
	parameters could be configured on an OLT and an ONU/ONT.
	Service related parameters could be sent to OLT via ANCP before or		Service-related parameters could be sent to OLT via ANCP before or
	after an ONU/ONT is up. Sending of ANCP loop Configuration messages		after an ONU/ONT is up. Sending of ANCP loop configuration messages
	from NAS can be triggered by a management system or by customer		from NAS can be triggered by a management system or by customer
	identification and authentication after Topology Discovery. It may be		identification and authentication after Topology Discovery. It may
	used for first time configuration (zero touch) or for		be used for first-time configuration (zero touch) or for
	updating/upgrading customer's profile like C-VLAN ID, S-VLAN ID, and		updating/upgrading customer's profile like C-VLAN ID, S-VLAN ID, and
	service bandwidth.		service bandwidth.
	Parameters of the User to Network Interface (UNI), which is the		Parameters of the User-Network Interface (UNI), which is the
	subscriber interface to HGW/CPE of ONU/ONT, can also be configured		subscriber interface to HGW/CPE of ONU/ONT, can also be configured
	via ANCP. When the ONU/ONT supports ANCP, parameters of the UNI on		via ANCP. When the ONU/ONT supports ANCP, parameters of the UNI on
	ONU/ONT are sent to the ONU/ONT via ANCP. If the ONU/ONT does not		ONU/ONT are sent to the ONU/ONT via ANCP. If the ONU/ONT does not
	support ANCP, but only OMCI, parameters have to be sent from the NAS		support ANCP but only OMCI, parameters have to be sent from the NAS
	to the OLT via ANCP first. Then, the OLT translates such		to the OLT via ANCP first. Then, the OLT translates such
	configuration into OMCI and sends it to the ONU/ONT.		configuration into OMCI and sends it to the ONU/ONT.
	10. Security Considerations		10. Security Considerations
	[RFC5713] lists the ANCP related security threats that could be		[RFC5713] lists the ANCP-related security threats that could be
	encountered on the Access Node and the NAS. It develops a threat		encountered on the Access Node and the NAS. It develops a threat
	model for ANCP security, and lists the security functions that are		model for ANCP security and lists the security functions that are
	required at the ANCP level.		required at the ANCP level.
	With Multicast handling as described in this document, ANCP protocol		With multicast handling as described in this document, ANCP protocol
	activity between the ANX and the NAS is triggered by join/leave		activity between the ANX and the NAS is triggered by join/leave
	requests coming from the end-user equipment. This could potentially		requests coming from the end-user equipment. This could potentially
	be used for denial of service attack against the ANX and/or the NAS.		be used for a denial-of-service attack against the ANX and/or the
			NAS.
	To mitigate this risk, the NAS and ANX may implement control plane		To mitigate this risk, the NAS and ANX may implement control plane
	protection mechanisms such as limiting the number of multicast flows		protection mechanisms such as limiting the number of multicast flows
	a given user can simultaneously join, or limiting the maximum rate of		a given user can simultaneously join or limiting the maximum rate of
	join/leave from a given user.		join/leave from a given user.
	Protection against invalid or unsubscribed flows can be deployed via		Protection against invalid or unsubscribed flows can be deployed via
	provisioning black lists as close to the subscriber as possible		provisioning black lists as close to the subscriber as possible
	(e.g., in the ONT).		(e.g., in the ONT).
	User activity logging for accounting or tracking purposes could raise		User activity logging for accounting or tracking purposes could raise
	privacy concerns if not appropriately protected. To protect such		privacy concerns if not appropriately protected. To protect such
	information, logging/accounting information can be exchanged with the		information, logging/accounting information can be exchanged with the
	corresponding server over a secure channel, and the information can		corresponding server over a secure channel, and the information can
	be stored securely with policy-driven controlled access.		be stored securely with policy-driven controlled access.
	11. Differences in ANCP applicability between DSL and PON		11. Differences in ANCP Applicability between DSL and PON
	As it currently stands, both ANCP framework [RFC5851] and protocol		As it currently stands, both ANCP framework [RFC5851] and protocol
	[RFC6320] are defined in context of DSL access. Due to inherent		[RFC6320] are defined in the context of DSL access. Due to inherent
	differences between PON and DSL access technologies, ANCP needs a few		differences between PON and DSL access technologies, ANCP needs a few
	extensions for supporting the use-cases outlined in this document for		extensions for supporting the use cases outlined in this document for
	PON based access. These specific differences and extensions are		PON-based access. These specific differences and extensions are
	outlined below.		outlined below.
	- In PON, the access-node functionality is split between OLT and ONT.		- In PON, the access-node functionality is split between OLT and
	Therefore, ANCP interaction between NAS and AN translates to		ONT. Therefore, ANCP interaction between NAS and AN translates to
	transactions between NAS and OLT and between OLT and ONT. The		transactions between NAS and OLT and between OLT and ONT. The
	processing of ANCP messages (e.g., for multicast replication control)		processing of ANCP messages (e.g., for multicast replication
	on the OLT can trigger generation of ANCP messages from OLT to ONT.		control) on the OLT can trigger generation of ANCP messages from
	Similarly, ANCP messages from ONT to the OLT can trigger ANCP		OLT to ONT. Similarly, ANCP messages from ONT to the OLT can
	exchange between the OLT and the NAS (e.g., admission-request		trigger ANCP exchange between the OLT and the NAS (e.g., admission
	messages). This is illustrated in the generic message flows in		request messages). This is illustrated in the generic message
	Figures 5 and 6 of section 5. In case of DSL, the ANCP exchange is		flows in Figures 5 and 6 of Section 5. In the case of DSL, the
	contained between two network elements (NAS and the DSLAM).		ANCP exchange is contained between two network elements (NAS and
			the DSLAM).
	- The PON connection to the ONT is a shared medium between multiple		- The PON connection to the ONT is a shared medium between multiple
	ONTs on the same PON. The local-loop in case of DSL is point-to-		ONTs on the same PON. In the case of DSL, the local loop is
	point. In case of DSL access network, the access facing port on the		point-to-point. In the case of a DSL access network, the access-
	NAS (i.e., port to the network between NAS and the DSLAM), and the		facing port on the NAS (i.e., port to the network between NAS and
	access-facing ports on the DSLAM (i.e., customer's local-loop) are		the DSLAM) and the access-facing ports on the DSLAM (i.e.,
	the two bandwidth constraint points that need to be considered for		customer's local loop) are the two bandwidth constraint points
	performing bandwidth based admission control for multicast video and		that need to be considered for performing bandwidth-based
	VoD delivered to the customer. In case of PON access, in addition to		admission control for multicast video and VoD delivered to the
	the bandwidth constraint on the NAS to OLT facing ports, and the		customer. In the case of PON access, in addition to the bandwidth
	subscriber allocated bandwidth for video services, the bandwidth		constraint on the NAS to OLT facing ports and the subscriber-
	available on the PON for video is an additional constraint that needs		allocated bandwidth for video services, the bandwidth available on
	to be considered for bandwidth based admission control. If the		the PON for video is an additional constraint that needs to be
	bandwidth control is centralized in NAS (as described in option 1 of		considered for bandwidth-based admission control. If the
	section 6.2), then the NAS needs to support additional logic to		bandwidth control is centralized in the NAS (as described in the
	consider available PON bandwidth before admitting a multicast request		first approach in Section 6.2), then the NAS needs to support
	or a VoD request by the user. Accordingly, ANCP needs to identify the		additional logic to consider available PON bandwidth before
	customer access port and the PON on which the customer ONT is. If the		admitting a multicast request or a VoD request by the user.
	PON bandwidth control is performed on the OLT (as defined in second		Accordingly, ANCP needs to identify the customer Access Port and
	option in section 6.2), then additional ANCP request and response		the PON on which the customer ONT is. If the PON bandwidth
	messages are required for NAS to query the OLT to determine available		control is performed on the OLT (as defined in the second approach
	PON bandwidth when a request to admit a VOD flow is received on the		in Section 6.2), then additional ANCP request and response
	NAS (as shown in Figure 9 in section 6.2) or for the OLT to inform		messages are required for NAS to query the OLT to determine
	the NAS what stream bandwidth is sent to the subscriber for the NAS		available PON bandwidth when a request to admit a VoD flow is
	to take appropriate action (e.g., bandwidth adjustment for various		received on the NAS (as shown in Figure 9 in Section 6.2) or for
	types of traffic).		the OLT to inform the NAS what stream bandwidth is sent to the
			subscriber for the NAS to take appropriate action (e.g., bandwidth
			adjustment for various types of traffic).
	- In PON, the multicast replication can potentially be performed on		- In PON, the multicast replication can potentially be performed on
	three different network elements: (1) on the NAS (2) on the OLT for		three different network elements: (1) on the NAS, (2) on the OLT
	replication to multiple PON ports, and (3) on the ONT/ONU for		for replication to multiple PON ports, and (3) on the ONT/ONU for
	replication to multiple customer ports. In case of DSL, the		replication to multiple customer ports. In the case of DSL, the
	replication can potentially be performed on NAS and/or the DSLAM.		replication can potentially be performed on NAS and/or the DSLAM.
	Section 6.2 defines options for multicast replication in case of PON.		Section 6.2 defines options for multicast replication in the case
	In the first option, the multicast replication is done on the AN, but		of PON. In the first option, the multicast replication is done on
	is controlled from NAS via ANCP (based on the reception of per-		the AN but is controlled from NAS via ANCP (based on the reception
	customer IGMP messages on the NAS). In this option, the NAS needs to		of per-customer IGMP messages on the NAS). In this option, the
	supply to the OLT the set of PON-customer-IDs (as defined in section		NAS needs to supply the OLT the set of PON-customer-IDs (as
	2) to which the multicast stream needs to be replicated. The PON-		defined in Section 2) to which the multicast stream needs to be
	customer-ID identifies the OLT and the PON ports on the OLT as well		replicated. The PON-customer-ID identifies the OLT and the PON
	as the ONT and the access-ports on the ONT where the multicast stream		ports on the OLT as well as the ONT and the Access Ports on the
	needs to be replicated. Upon receiving the request to update its		ONT where the multicast stream needs to be replicated. Upon
	multicast replication state, the OLT must update its replication		receiving the request to update its multicast replication state,
	state with the indicated PON ports, but may also need to interact		the OLT must update its replication state with the indicated PON
	with the ONT via ANCP to update the multicast replication state on		ports but may also need to interact with the ONT via ANCP to
	the ONT with the set of access-ports (as indicated by the NAS). In		update the multicast replication state on the ONT with the set of
	case of DSL, the DSLAM only needs to update its own replication state		Access Ports (as indicated by the NAS). In the case of DSL, the
	based on the set of access-ports indicated by the NAS.		DSLAM only needs to update its own replication state based on the
			set of Access Ports indicated by the NAS.
	- For reporting purposes, ANCP must enable the NAS to query the OLT		- For reporting purposes, ANCP must enable the NAS to query the OLT
	for channels replicated on a PON or a list of PONs and to specific		for channels replicated on a PON or a list of PONs and to specific
	access ports. The latter should trigger the OLT to query the ONT for		Access Ports. The latter should trigger the OLT to query the ONT
	a list of channels being replicated on all access ports or on		for a list of channels being replicated on all Access Ports or on
	specific access ports to the premises. In DSL case, it is sufficient		specific Access Ports to the premises. In a DSL case, it is
	to query the DSLAM for a list of channels being replicated on an		sufficient to query the DSLAM for a list of channels being
	access port or a list of access ports.		replicated on an Access Port or a list of Access Ports.
	12. ANCP versus OMCI between the OLT and ONT/ONU		12. ANCP versus OMCI between the OLT and ONT/ONU
	ONT Management and Control Interface (OMCI) [OMCI] is specified for		ONT Management and Control Interface (OMCI) [OMCI] is specified for
	in-band ONT management via the OLT. This includes configuring		in-band ONT management via the OLT. This includes configuring
	parameters on the ONT/ONU. Such configuration can include adding an		parameters on the ONT/ONU. Such configuration can include adding an
	access port on the ONT to a multicast tree and the ONT to a multicast		Access Port on the ONT to a multicast tree and the ONT to a multicast
	tree. Thus, OMCI can be a potential replacement for ANCP between the		tree. Thus, OMCI can be a potential replacement for ANCP between the
	OLT and ONT/ONU, albeit it may not a be suitable protocol for dynamic		OLT and ONT/ONU, albeit it may not be a suitable protocol for dynamic
	transactions as required for the multicast application.		transactions as required for the multicast application.
	If OMCI is selected to be enabled between the OLT and ONT/ONU to		If OMCI is selected to be enabled between the OLT and ONT/ONU to
	carry the same information elements that would be carried over ANCP,		carry the same information elements that would be carried over ANCP,
	the OLT must perform the necessary translation between ANCP and OMCI		the OLT must perform the necessary translation between ANCP and OMCI
	for replication control messages received via ANCP. OMCI is an		for replication control messages received via ANCP. OMCI is an
	already available control channel, while ANCP requires a TCP/IP stack		already available control channel, while ANCP requires a TCP/IP stack
	on the ONT/ONU that can be used by an ANCP client and accordingly it		on the ONT/ONU that can be used by an ANCP client, and accordingly,
	requires that the ONT/ONU be IP addressable for ANCP. Most ONTs/ONUs		it requires that the ONT/ONU be IP addressable for ANCP. Most
	today have a TCP/IP stack used by certain applications (e.g., VoIP,		ONTs/ONUs today have a TCP/IP stack used by certain applications
	IGMP snooping). ANCP may use the same IP address that is often		(e.g., VoIP and IGMP snooping). ANCP may use the same IP address
	assigned for VoIP or depending on the implementation may require a		that is often assigned for VoIP or, depending on the implementation,
	different address. Sharing the same IP address between VoIP and ANCP		may require a different address. Sharing the same IP address between
	may have other network implications on how the VoIP agent is		VoIP and ANCP may have other network implications on how the VoIP
	addressed and on traffic routing. For instance, the VoIP traffic		agent is addressed and on traffic routing. For instance, the VoIP
	to/from the ONT is often encapsulated in a VLAN-tagged Ethernet frame		traffic to/from the ONT is often encapsulated in a VLAN-tagged
	and switched at layer2 through the OLT to the NAS where it is routed.		Ethernet frame and switched at Layer 2 through the OLT to the NAS
	The VoIP agent in this case looks like another subscriber to the NAS.		where it is routed. The VoIP agent in this case looks like another
	On the other hand, the ANCP session between the ONT and OLT is		subscriber to the NAS. On the other hand, the ANCP session between
	terminated at the OLT. Thus, the OLT must be able to receive/send IP		the ONT and OLT is terminated at the OLT. Thus, the OLT must be able
	traffic to/from the OLT, which will not work using this setting.		to receive/send IP traffic to/from the OLT, which will not work using
	Using a separate IP address for the purpose of ONT/ONU management or		this setting. Using a separate IP address for the purpose of ONT/ONU
	ANCP specifically may often be required when supporting ANCP. These		management or ANCP specifically may often be required when supporting
	considerations may favor OMCI in certain environments. However, OMCI		ANCP. These considerations may favor OMCI in certain environments.
	will not allow some of the transactions required in approach 2, where		However, OMCI will not allow some of the transactions required in
	the ONT/ONU sends unsolicited requests to the OLT rather than being		approach 2, where the ONT/ONU sends unsolicited requests to the OLT
	queried or configured by OLT requests.		rather than being queried or configured by OLT requests.
	13. IANA Considerations		13. Acknowledgements
	This document does not require actions by IANA.		The authors thank Rajesh Yadav and Francois Le Faucheur for their
			valuable comments and discussions.
	14. Acknowledgements		14. References
	The authors are thanksful to Rajesh Yadav and Francois Le Faucheur		14.1. Normative References
	for valuable comments and discussions.
	15. References		[RFC2516] Mamakos, L., Lidl, K., Evarts, J., Carrel, D., Simone, D.,
			and R. Wheeler, "A Method for Transmitting PPP Over
			Ethernet (PPPoE)", RFC 2516, February 1999.
	15.1. Normative References		[RFC2684] Grossman, D. and J. Heinanen, "Multiprotocol Encapsulation
			over ATM Adaptation Layer 5", RFC 2684, September 1999.
	[RFC2516] Mamakos, L., Lidl, K., Evarts, J., Carrel, D., Simone, D.,		[RFC3376] Cain, B., Deering, S., Kouvelas, I., Fenner, B., and A.
	and R. Wheeler, "A Method for Transmitting PPP Over		Thyagarajan, "Internet Group Management Protocol, Version
	Ethernet (PPPoE)", RFC 2516, February 1999.		3", RFC 3376, October 2002.
	[RFC2684] Grossman, D. and J. Heinanen, "Multiprotocol Encapsulation		[RFC4605] Fenner, B., He, H., Haberman, B., and H. Sandick,
	over ATM Adaptation Layer 5", RFC 2684, September 1999.		"Internet Group Management Protocol (IGMP) / Multicast
			Listener Discovery (MLD)-Based Multicast Forwarding
			("IGMP/MLD Proxying")", RFC 4605, August 2006.
	[RFC3376] Cain, B., et al, "Internet Group Management Interface,		14.2. Informative References
	Version 3", RFC 3376, October 2002.
	[RFC4605] Fenner, W., et al, "Internet Group Management Protocol		[802.1ag] IEEE 802.1ag, "Connectivity Fault Management", December
	(IGMP)/Multicast Listener Discovery (MLD)-Based Multicast Forwarding		2007.
	("IGMP/MLD Proxying")", RFC 4605, August 2006.
	15.2. Informative References		[RFC2881] Mitton, D. and M. Beadles, "Network Access Server
			Requirements Next Generation (NASREQNG) NAS Model", RFC
			2881, July 2000.
	[RFC2881] Mitton, D. and M. Beadles, "Network Access Server		[RFC5851] Ooghe, S., Voigt, N., Platnic, M., Haag, T., and S.
	Requirements Next Generation (NASREQNG) NAS Model", RFC 2881, July		Wadhwa, "Framework and Requirements for an Access Node
	2000.		Control Mechanism in Broadband Multi-Service Networks",
			RFC 5851, May 2010.
	[RFC5851] Ooghe, S., et al., "Framework and Requirements for Access		[G.983.1] ITU-T G.983.1, "Broadband optical access systems based on
	Node Control Mechanism in Broadband Networks", RFC 5851, May 2010.		Passive Optical Networks (PON)", January 2005.
	[G.983.1] ITU-T G.983.1, "Broadband optical access systems based on		[G.984.1] ITU-T G.984.1, "Gigabit-capable Passive Optical Networks
	Passive Optical Networks (PON)".		(GPON): General characteristics", March 2008.
	[G.984.1] ITU-T G.984.1, "Gigabit-capable Passive Optical Networks		[RFC3046] Patrick, M., "DHCP Relay Agent Information Option", RFC
	(G-PON): General characteristics".		3046, January 2001.
	[RFC3046] Patrick, M., "DHCP Relay Agent Information Option",		[TR-101] Cohen, A. and E. Shrum, "Migration to Ethernet-Based DSL
	RFC3046, January 2011.		Aggregation", DSL Forum TR-101, May 2006.
	[TR-101] Cohen, A. and E. Shrum, "Migration to Ethernet-Based DSL		[RFC5713] Moustafa, H., Tschofenig, H., and S. De Cnodder, "Security
	Aggregation", DSL Forum TR-101, May 2006.		Threats and Security Requirements for the Access Node
			Control Protocol (ANCP)", RFC 5713, January 2010.
	[RFC5713] Moustafa, H., Tschofenig, H., and S. De Cnodder,		[OMCI] ITU-T G.984.4, "Gigabit-capable passive optical networks
	"Security Threats and Security Requirements for the Access Node		(G-PON): ONT management and control interface
	Control Protocol (ANCP)", RFC 5713, January 2010.		specification", February 2008.
	[OMCI] ITU-T G.984.4, "GPON ONT Management and Control Interface		[RFC6320] Wadhwa, S., Moisand, J., Haag, T., Voigt, N., and T.
	(OMCI) Specifications".		Taylor, Ed., "Protocol for Access Node Control Mechanism
			in Broadband Networks", RFC 6320, October 2011.
	[RFC6320] Taylor, T., et al, "Protocol for Access Node Control		[G.987.3] ITU-T G.987.3, "10-Gigabit-capable passive optical
	Mechanism in Broadband Networks", RFC 6320, October 2011.		networks(XG-PON): Transmission convergence (TC) layer
			specification", October 2010.
	[G.987.3] ITU-T G.987.3, "10-Gigabit-capable passive optical		[Y.1731] ITU-T Y.1731, "OAM functions and mechanisms for Ethernet
	networks(XG-PON): Transmission convergence (TC) layer specification".		based networks", May 2006.
	Authors' Addresses		Authors' Addresses
	Nabil Bitar		Nabil Bitar (editor)
	Verizon		Verizon
	60 Sylvan Road		60 Sylvan Road
	Waltham, MA 02451		Waltham, MA 02451
	Email: nabil.n.bitar@verizon.com		EMail: nabil.n.bitar@verizon.com
	Sanjay Wadhwa		Sanjay Wadhwa (editor)
	Alcatel-Lucent		Alcatel-Lucent
	701 East Middlefield Road		701 East Middlefield Road
	Mountain View, CA, 94043		Mountain View, CA, 94043
	Email: sanjay.wadhwa@alcatel-lucent.com		EMail: sanjay.wadhwa@alcatel-lucent.com
	Thomas Haag		Thomas Haag
	Deutsche Telekom		Deutsche Telekom
	Email: HaagT@telekom.de		EMail: HaagT@telekom.de
	Hongyu Li		Hongyu Li
	Huawei Technologies		Huawei Technologies
	Email: hongyu.lihongyu@huawei.com		EMail: hongyu.lihongyu@huawei.com
End of changes. 186 change blocks.
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