draft-ietf-teas-rsvp-ingress-protection-00.txt		draft-ietf-teas-rsvp-ingress-protection-01.txt
	Internet Engineering Task Force H. Chen, Ed.		Internet Engineering Task Force H. Chen, Ed.
	Internet-Draft Huawei Technologies		Internet-Draft Huawei Technologies
	Intended status: Standards Track R. Torvi, Ed.		Intended status: Standards Track R. Torvi, Ed.
	Expires: July 4, 2015 Juniper Networks		Expires: July 14, 2015 Juniper Networks
	December 31, 2014		January 10, 2015
	Extensions to RSVP-TE for LSP Ingress Local Protection		Extensions to RSVP-TE for LSP Ingress Local Protection
	draft-ietf-teas-rsvp-ingress-protection-00.txt		draft-ietf-teas-rsvp-ingress-protection-01.txt
	Abstract		Abstract
	This document describes extensions to Resource Reservation Protocol -		This document describes extensions to Resource Reservation Protocol -
	Traffic Engineering (RSVP-TE) for locally protecting the ingress node		Traffic Engineering (RSVP-TE) for locally protecting the ingress node
	of a Traffic Engineered (TE) Label Switched Path (LSP) in a Multi-		of a Traffic Engineered (TE) Label Switched Path (LSP) in a Multi-
	Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) network.		Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) network.
	Status of this Memo		Status of this Memo
	skipping to change at page 1, line 34		skipping to change at page 1, line 34
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on July 4, 2015.		This Internet-Draft will expire on July 14, 2015.
	Copyright Notice		Copyright Notice
	Copyright (c) 2014 IETF Trust and the persons identified as the		Copyright (c) 2015 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	skipping to change at page 2, line 24		skipping to change at page 2, line 24
	4. Backup Forwarding State . . . . . . . . . . . . . . . . . . . 5		4. Backup Forwarding State . . . . . . . . . . . . . . . . . . . 5
	4.1. Forwarding State for Backup LSP . . . . . . . . . . . . . 5		4.1. Forwarding State for Backup LSP . . . . . . . . . . . . . 5
	5. Protocol Extensions . . . . . . . . . . . . . . . . . . . . . 6		5. Protocol Extensions . . . . . . . . . . . . . . . . . . . . . 6
	5.1. INGRESS_PROTECTION Object . . . . . . . . . . . . . . . . 6		5.1. INGRESS_PROTECTION Object . . . . . . . . . . . . . . . . 6
	5.1.1. Subobject: Backup Ingress IPv4/IPv6 Address . . . . . 7		5.1.1. Subobject: Backup Ingress IPv4/IPv6 Address . . . . . 7
	5.1.2. Subobject: Ingress IPv4/IPv6 Address . . . . . . . . . 8		5.1.2. Subobject: Ingress IPv4/IPv6 Address . . . . . . . . . 8
	5.1.3. Subobject: Traffic Descriptor . . . . . . . . . . . . 8		5.1.3. Subobject: Traffic Descriptor . . . . . . . . . . . . 8
	5.1.4. Subobject: Label-Routes . . . . . . . . . . . . . . . 9		5.1.4. Subobject: Label-Routes . . . . . . . . . . . . . . . 9
	6. Behavior of Ingress Protection . . . . . . . . . . . . . . . . 9		6. Behavior of Ingress Protection . . . . . . . . . . . . . . . . 9
	6.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 9		6.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . 9
	6.1.1. Relay-Message Method . . . . . . . . . . . . . . . . . 9		6.2. Ingress Behavior . . . . . . . . . . . . . . . . . . . . . 9
	6.1.2. Proxy-Ingress Method . . . . . . . . . . . . . . . . . 10		6.3. Backup Ingress Behavior . . . . . . . . . . . . . . . . . 11
	6.1.3. Comparing Two Methods . . . . . . . . . . . . . . . . 11		6.3.1. Backup Ingress Behavior in Off-path Case . . . . . . . 11
	6.2. Ingress Behavior . . . . . . . . . . . . . . . . . . . . . 11		6.3.2. Backup Ingress Behavior in On-path Case . . . . . . . 13
	6.2.1. Relay-Message Method . . . . . . . . . . . . . . . . . 12		6.3.3. Failure Detection and Refresh PATH Messages . . . . . 13
	6.2.2. Proxy-Ingress Method . . . . . . . . . . . . . . . . . 12		6.4. Revertive Behavior . . . . . . . . . . . . . . . . . . . . 14
	6.3. Backup Ingress Behavior . . . . . . . . . . . . . . . . . 13		6.4.1. Revert to Primary Ingress . . . . . . . . . . . . . . 14
	6.3.1. Backup Ingress Behavior in Off-path Case . . . . . . . 14		6.4.2. Global Repair by Backup Ingress . . . . . . . . . . . 14
	6.3.2. Backup Ingress Behavior in On-path Case . . . . . . . 16		7. Security Considerations . . . . . . . . . . . . . . . . . . . 15
	6.3.3. Failure Detection and Refresh PATH Messages . . . . . 17		8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
	6.4. Revertive Behavior . . . . . . . . . . . . . . . . . . . . 17		9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 15
	6.4.1. Revert to Primary Ingress . . . . . . . . . . . . . . 18		10. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 16
	6.4.2. Global Repair by Backup Ingress . . . . . . . . . . . 18		11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
	7. Security Considerations . . . . . . . . . . . . . . . . . . . 18		11.1. Normative References . . . . . . . . . . . . . . . . . . . 16
	8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19		11.2. Informative References . . . . . . . . . . . . . . . . . . 17
	9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 19		A. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 17
	10. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 20
	11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 20
	11.1. Normative References . . . . . . . . . . . . . . . . . . . 20
	11.2. Informative References . . . . . . . . . . . . . . . . . . 21
	A. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 21
	1. Co-authors		1. Co-authors
	Ning So, Autumn Liu, Alia Atlas, Yimin Shen, Tarek Saad, Fengman Xu,		Ning So, Autumn Liu, Alia Atlas, Yimin Shen, Tarek Saad, Fengman Xu,
	Mehmet Toy, Lei Liu		Mehmet Toy, Lei Liu
	2. Introduction		2. Introduction
	For MPLS LSPs it is important to have a fast-reroute method for		For MPLS LSPs it is important to have a fast-reroute method for
	protecting its ingress node as well as transit nodes. This is not		protecting its ingress node as well as transit nodes. This is not
	skipping to change at page 9, line 43		skipping to change at page 9, line 43
	6. Behavior of Ingress Protection		6. Behavior of Ingress Protection
	6.1. Overview		6.1. Overview
	There are four parts of ingress protection: 1) setting up the		There are four parts of ingress protection: 1) setting up the
	necessary backup LSP forwarding state; 2) identifying the failure and		necessary backup LSP forwarding state; 2) identifying the failure and
	providing the fast repair (as discussed in Sections 3 and 4); 3)		providing the fast repair (as discussed in Sections 3 and 4); 3)
	maintaining the RSVP-TE control plane state until a global repair can		maintaining the RSVP-TE control plane state until a global repair can
	be done; and 4) performing the global repair(see Section 6.4).		be done; and 4) performing the global repair(see Section 6.4).
	There are two different proposed signaling approaches to obtain
	ingress protection. They both use the same new INGRESS_PROTECTION
	object. The object is sent in both PATH and RESV messages.
	6.1.1. Relay-Message Method
	The primary ingress relays the information for ingress protection of
	an LSP to the backup ingress via PATH messages. Once the LSP is
	created, the ingress of the LSP sends the backup ingress a PATH
	message with an INGRESS_PROTECTION object with Label-Routes
	subobject, which is populated with the next-hops and labels. This
	provides sufficient information for the backup ingress to create the
	appropriate forwarding state and backup LSP(s).
	The ingress also sends the backup ingress all the other PATH messages
	for the LSP with an empty INGRESS_PROTECTION object. Thus, the
	backup ingress has access to all the PATH messages needed for
	modification to refresh control-plane state after a failure.
	The advantages of this method include: 1) the primary LSP is
	independent of the backup ingress; 2) simple; 3) less configuration;
	and 4) less control traffic.
	6.1.2. Proxy-Ingress Method
	Conceptually, a proxy ingress is created that starts the RSVP
	signaling. The explicit path of the LSP goes from the proxy ingress
	to the backup ingress and then to the real ingress. The behavior and
	signaling for the proxy ingress is done by the real ingress; the use
	of a proxy ingress address avoids problems with loop detection.
	[ traffic source ] *** Primary LSP
	$ $ --- Backup LSP
	$ $ $$ Link
	$ $
	[ proxy ingress ] [ backup ]
	[ & ingress ] |
	* |
	*****[ MP ]----|
	Figure 2: Example Protected LSP with Proxy Ingress Node
	The backup ingress must know the merge points or next-hops and their
	associated labels. This is accomplished by having the RSVP PATH and
	RESV messages go through the backup ingress, although the forwarding
	path need not go through the backup ingress. If the backup ingress
	fails, the ingress simply removes the INGRESS_PROTECTION object and
	forwards the PATH messages to the LSP's next-hop(s). If the ingress
	has its LSP configured for ingress protection, then the ingress can
	add the backup ingress and itself to the ERO and start forwarding the
	PATH messages to the backup ingress.
	Slightly different behavior can apply for the on-path and off-path
	cases. In the on-path case, the backup ingress is a next hop node
	after the ingress for the LSP. In the off-path, the backup ingress
	is not any next-hop node after the ingress for all associated sub-
	LSPs.
	The key advantage of this approach is that it minimizes the special
	handling code requires. Because the backup ingress is on the
	signaling path, it can receive various notifications. It easily has
	access to all the PATH messages needed for modification to be sent to
	refresh control-plane state after a failure.
	6.1.3. Comparing Two Methods
	+-------+-----------+------+--------+-----------------+---------+
	| |Primary LSP|Simple|Config |PATH Msg from |Reuse |
	|Method |Depends on | |Proxy- |Backup to primary|Some of |
	| |Backup | |Ingress-|RESV Msg from |Existing |
	| |Ingress | |ID |Primary to backup|Functions|
	+-------+-----------+------+--------+-----------------+---------+
	|Relay- | No |Yes | No | No | Yes- |
	|Message| | | | | |
	+-------+-----------+------+--------+-----------------+---------+
	|Proxy- | Yes |Yes- | Yes | Yes | Yes |
	|Ingress| | | | | |
	+-------+-----------+------+--------+-----------------+---------+
	6.2. Ingress Behavior		6.2. Ingress Behavior
	The primary ingress must be configured with two or three pieces of		The primary ingress must be configured with a couple of pieces of
	information for ingress protection.		information for ingress protection.
	o Backup Ingress Address: The primary ingress must know an IP		o Backup Ingress Address: The primary ingress must know an IP
	address for it to be included in the INGRESS_PROTECTION object.		address for it to be included in the INGRESS_PROTECTION object.
	o Proxy-Ingress-Id (only needed for Proxy-Ingress Method): The
	Proxy-Ingress-Id is only used in the Record Route Object for
	recording the proxy-ingress. If no proxy-ingress-id is specified,
	then a local interface address that will not otherwise be included
	in the Record Route Object can be used. A similar technique is
	used in [RFC4090 Sec 6.1.1].
	o Application Traffic Identifier: The primary ingress and backup		o Application Traffic Identifier: The primary ingress and backup
	ingress must both know what application traffic should be directed		ingress must both know what application traffic should be directed
	into the LSP. If a list of prefixes in the Traffic Descriptor		into the LSP. If a list of prefixes in the Traffic Descriptor
	sub-object will not suffice, then a commonly understood		sub-object will not suffice, then a commonly understood
	Application Traffic Identifier can be sent between the primary		Application Traffic Identifier can be sent between the primary
	ingress and backup ingress. The exact meaning of the identifier		ingress and backup ingress. The exact meaning of the identifier
	should be configured similarly at both the primary ingress and		should be configured similarly at both the primary ingress and
	backup ingress. The Application Traffic Identifier is understood		backup ingress. The Application Traffic Identifier is understood
	within the unique context of the primary ingress and backup		within the unique context of the primary ingress and backup
	ingress.		ingress.
	With this additional information, the primary ingress can create and		With this additional information, the primary ingress can create and
	signal the necessary RSVP extensions to support ingress protection.		signal the necessary RSVP extensions to support ingress protection.
	6.2.1. Relay-Message Method		The primary ingress relays the information for ingress protection of
			an LSP to the backup ingress via PATH messages. Once the LSP is
			created, the ingress of the LSP sends the backup ingress a PATH
			message with an INGRESS_PROTECTION object with Label-Routes
			subobject, which is populated with the next-hops and labels. This
			provides sufficient information for the backup ingress to create the
			appropriate forwarding state and backup LSP(s).
			The ingress also sends the backup ingress all the other PATH messages
			for the LSP with an empty INGRESS_PROTECTION object. Thus, the
			backup ingress has access to all the PATH messages needed for
			modification to refresh control-plane state after a failure.
	To protect the ingress of an LSP, the ingress does the following		To protect the ingress of an LSP, the ingress does the following
	after the LSP is up.		after the LSP is up.
	1. Select a PATH message.		1. Select a PATH message.
	2. If the backup ingress is off-path, then send it a PATH message		2. If the backup ingress is off-path, then send it a PATH message
	with the content from the selected PATH message and an		with the content from the selected PATH message and an
	INGRESS_PROTECTION object; else (the backup ingress is a next		INGRESS_PROTECTION object; else (the backup ingress is a next
	hop, i.e., on-path case) add an INGRESS_PROTECTION object into		hop, i.e., on-path case) add an INGRESS_PROTECTION object into
	skipping to change at page 12, line 35		skipping to change at page 11, line 10
	object. The flags is set to indicate whether a Backup P2MP LSP		object. The flags is set to indicate whether a Backup P2MP LSP
	is desired. A second LSP-ID is allocated (if it is not allocated		is desired. A second LSP-ID is allocated (if it is not allocated
	yet) and used in the object. The Label-Routes sub-object		yet) and used in the object. The Label-Routes sub-object
	contains the next-hops of the ingress and their labels.		contains the next-hops of the ingress and their labels.
	3. For each of the other PATH messages, send the backup ingress a		3. For each of the other PATH messages, send the backup ingress a
	PATH message with the content copied from the message and an		PATH message with the content copied from the message and an
	empty INGRESS_PROTECTION object, which is an object without any		empty INGRESS_PROTECTION object, which is an object without any
	Traffic-Descriptor sub-object.		Traffic-Descriptor sub-object.
	6.2.2. Proxy-Ingress Method
	The primary ingress is responsible for starting the RSVP signaling
	for the proxy-ingress node. To do this, the following is done for
	the RSVP PATH message.
	1. Compute the EROs for the LSP as normal for the ingress.
	2. If the selected backup ingress node is not the first node on the
	path (for all sub-LSPs), then insert at the beginning of the ERO
	first the backup ingress node and then the ingress node.
	3. In the PATH RRO, instead of recording the ingress node's address,
	replace it with the Proxy-Ingress-Id.
	4. Leave the HOP object populated as usual with information for the
	ingress-node.
	5. Add the INGRESS_PROTECTION object to the PATH message. Allocate
	a second LSP-ID to be used in the INGRESS-PROTECTION object.
	Include the Backup Ingress Address (IPv4 or IPv6) sub-object and
	the Traffic-Descriptor sub-object. Set or clear the flag
	indicating that a Backup P2MP LSP is desired.
	6. Optionally, add the FAST-REROUTE object [RFC4090] to the Path
	message. Indicate whether one-to-one backup is desired.
	Indicate whether facility backup is desired.
	7. The RSVP PATH message is sent to the backup node as normal.
	If the ingress detects that it can't communicate with the backup
	ingress, then the ingress should instead send the PATH message to the
	next-hop indicated in the ERO computed in step 1. Once the ingress
	detects that it can communicate with the backup ingress, the ingress
	SHOULD follow the steps 1-7 to obtain ingress failure protection.
	When the ingress node receives an RSVP PATH message with an INGRESS-
	PROTECTION object and the object specifies that node as the ingress
	node and the PHOP as the backup ingress node, the ingress node SHOULD
	remove the INGRESS_PROTECTION object from the PATH message before
	sending it out. Additionally, the ingress node must store that it
	will install ingress forwarding state for the LSP rather than
	midpoint forwarding.
	When an RSVP RESV message is received by the ingress, it uses the
	NHOP to determine whether the message is received from the backup
	ingress or from a different node. The stored associated PATH message
	contains an INGRESS_PROTECTION object that identifies the backup
	ingress node. If the RESV message is not from the backup node, then
	ingress forwarding state should be set up, and the INGRESS_PROTECTION
	object MUST be added to the RESV before it is sent to the NHOP, which
	should be the backup node. If the RESV message is from the backup
	node, then the LSP should be considered available for use.
	If the backup ingress node is on the forwarding path, then a RESV is
	received with an INGRESS_PROTECTION object and an NHOP that matches
	the backup ingress. In this case, the ingress node's address will
	not appear after the backup ingress in the RRO. The ingress node
	should set up ingress forwarding state, just as is done if the LSP
	weren't ingress-node protected.
	6.3. Backup Ingress Behavior		6.3. Backup Ingress Behavior
	An LER determines that the ingress local protection is requested for		An LER determines that the ingress local protection is requested for
	an LSP if the INGRESS_PROTECTION object is included in the PATH		an LSP if the INGRESS_PROTECTION object is included in the PATH
	message it receives for the LSP. The LER can further determine that		message it receives for the LSP. The LER can further determine that
	it is the backup ingress if one of its addresses is in the Backup		it is the backup ingress if one of its addresses is in the Backup
	Ingress Address sub-object of the INGRESS_PROTECTION object. The LER		Ingress Address sub-object of the INGRESS_PROTECTION object. The LER
	as the backup ingress will assume full responsibility of the ingress		as the backup ingress will assume full responsibility of the ingress
	after the primary ingress fails. In addition, the LER determines		after the primary ingress fails. In addition, the LER determines
	that it is off-path if it is not a next hop of the primary ingress.		that it is off-path if it is not a next hop of the primary ingress.
	skipping to change at page 15, line 28		skipping to change at page 12, line 39
	primary ingress, and tear down the one-to-one backup LSPs for		primary ingress, and tear down the one-to-one backup LSPs for
	protecting the primary ingress if one-to-one backup is used or unbind		protecting the primary ingress if one-to-one backup is used or unbind
	the facility backup LSPs if facility backup is used.		the facility backup LSPs if facility backup is used.
	When the backup ingress receives a PATH message from the primary		When the backup ingress receives a PATH message from the primary
	ingress for locally protecting the primary ingress of a protected		ingress for locally protecting the primary ingress of a protected
	LSP, it checks to see if any critical information has been changed.		LSP, it checks to see if any critical information has been changed.
	If the next hops of the primary ingress are changed, the backup		If the next hops of the primary ingress are changed, the backup
	ingress SHALL update its backup LSP(s) accordingly.		ingress SHALL update its backup LSP(s) accordingly.
	6.3.1.1. Relay-Message Method
	When the backup ingress receives a PATH message with an non empty		When the backup ingress receives a PATH message with an non empty
	INGRESS_PROTECTION object, it examines the object to learn what		INGRESS_PROTECTION object, it examines the object to learn what
	traffic associated with the LSP. It determines the next-hops to be		traffic associated with the LSP. It determines the next-hops to be
	merged to by examining the Label-Routes sub-object in the object.		merged to by examining the Label-Routes sub-object in the object.
	The backup ingress stores the PATH message received from the primary		The backup ingress stores the PATH message received from the primary
	ingress, but does NOT forward it.		ingress, but does NOT forward it.
	The backup ingress MUST respond with a RESV to the PATH message		The backup ingress responds with a RESV to the PATH message received
	received from the primary ingress. If the INGRESS_PROTECTION object		from the primary ingress. If the INGRESS_PROTECTION object is not
	is not "empty", the backup ingress SHALL send the RESV message with		"empty", the backup ingress SHALL send the RESV message with the
	the state indicating protection is available after the backup LSP(s)		state indicating protection is available after the backup LSP(s) are
	are successfully established.		successfully established.
	6.3.1.2. Proxy-Ingress Method
	The backup ingress determines the next-hops to be merged to by
	collecting the set of the pair of (IPv4/IPv6 sub-object, Label sub-
	object) from the Record Route Object of each RESV that are closest to
	the top and not the Ingress router; this should be the second to the
	top pair. If a Label-Routes sub-object is included in the
	INGRESS_PROTECTION object, the included IPv4/IPv6 sub-objects are
	used to filter the set down to the specific next-hops where
	protection is desired. A RESV message must have been received before
	the Backup Ingress can create or select the appropriate backup LSP.
	When the backup ingress receives a PATH message with the
	INGRESS_PROTECTION object, the backup ingress examines the object to
	learn what traffic associated with the LSP. The backup ingress
	forwards the PATH message to the ingress node with the normal RSVP
	changes.
	When the backup ingress receives a RESV message with the
	INGRESS_PROTECTION object, the backup ingress records an IMPLICIT-
	NULL label in the RRO. Then the backup ingress forwards the RESV
	message to the ingress node, which is acting for the proxy ingress.
	6.3.2. Backup Ingress Behavior in On-path Case		6.3.2. Backup Ingress Behavior in On-path Case
	An LER as the backup ingress determines that it is on-path if one of		An LER as the backup ingress determines that it is on-path if one of
	its addresses is a next hop of the primary ingress (and the primary		its addresses is a next hop of the primary ingress. The LER on-path
	ingress is not its next hop via checking the PATH message with the		sends the corresponding PATH messages without any INGRESS_PROTECTION
	INGRESS_PROTECTION object received from the primary ingress for		object to its next hops. It creates a number of backup P2P LSPs or a
	Proxy-Ingress Method). The LER on-path sends the corresponding PATH		backup P2MP LSP from itself to the other next hops (i.e., the next
	messages without any INGRESS_PROTECTION object to its next hops. It		hops other than the backup ingress) of the primary ingress. The
	creates a number of backup P2P LSPs or a backup P2MP LSP from itself		other next hops are from the Label-Routes sub object.
	to the other next hops (i.e., the next hops other than the backup
	ingress) of the primary ingress. The other next hops are from the
	Label-Routes sub object.
	It also creates a forwarding entry, which sends/multicasts the		It also creates a forwarding entry, which sends/multicasts the
	traffic from the source to the next hops of the backup ingress along		traffic from the source to the next hops of the backup ingress along
	the protected LSP when the primary ingress fails. The traffic is		the protected LSP when the primary ingress fails. The traffic is
	described by the Traffic-Descriptor.		described by the Traffic-Descriptor.
	After the forwarding entry is created, all the backup P2P LSPs or the		After the forwarding entry is created, all the backup P2P LSPs or the
	backup P2MP LSP is up and associated with the protected LSP, the		backup P2MP LSP is up and associated with the protected LSP, the
	backup ingress sends the primary ingress the RESV message with the		backup ingress sends the primary ingress the RESV message with the
	INGRESS_PROTECTION object containing the state of the local		INGRESS_PROTECTION object containing the state of the local
	skipping to change at page 18, line 9		skipping to change at page 14, line 35
	- Global Repair by Backup Ingress: After determining that the		- Global Repair by Backup Ingress: After determining that the
	primary ingress of an LSP has failed, the backup ingress computes		primary ingress of an LSP has failed, the backup ingress computes
	a new optimal path, signals a new LSP along the new path, and		a new optimal path, signals a new LSP along the new path, and
	switches the traffic to the new LSP.		switches the traffic to the new LSP.
	6.4.1. Revert to Primary Ingress		6.4.1. Revert to Primary Ingress
	If "Revert to Primary Ingress" is desired for a protected LSP, the		If "Revert to Primary Ingress" is desired for a protected LSP, the
	(primary) ingress of the LSP re-signals the LSP that starts from the		(primary) ingress of the LSP re-signals the LSP that starts from the
	primary ingress after the primary ingress restores. When the LSP is		primary ingress after the primary ingress restores. After the LSP is
	re-signaled successfully, the traffic is switched back to the primary		re-signaled successfully, the traffic can be switched back to the
	ingress from the backup ingress and redirected into the LSP starting		primary ingress from the backup ingress on the source node and
	from the primary ingress.		redirected into the LSP starting from the primary ingress.
	If the ingress can resignal the PATH messages for the LSP, then the
	ingress can specify the "Revert to Ingress" control-option in the
	INGRESS_PROTECTION object. Doing so may cause a duplication of
	traffic while the Ingress starts sending traffic again before the
	Backup Ingress stops; the alternative is to drop traffic for a short
	period of time.
	Additionally, the Backup Ingress can set the "Revert To Ingress"		The primary ingress can specify the "Revert to Ingress" control-
	control-option as a request for the Ingress to take over.		option in the INGRESS_PROTECTION object in the PATH messages to the
			backup ingress. After receiving the "Revert to Ingress" control-
			option, the backup ingress stops sending/refreshing PATH messages for
			the protected LSP.
	6.4.2. Global Repair by Backup Ingress		6.4.2. Global Repair by Backup Ingress
	When the backup ingress has determined that the primary ingress of		When the backup ingress has determined that the primary ingress of
	the protected LSP has failed (e.g., via the IGP), it can compute a		the protected LSP has failed (e.g., via the IGP), it can compute a
	new path and signal a new LSP along the new path so that it no longer		new path and signal a new LSP along the new path so that it no longer
	relies upon local repair. To do this, the backup ingress uses the		relies upon local repair. To do this, the backup ingress uses the
	same tunnel sender address in the Sender Template Object and uses the		same tunnel sender address in the Sender Template Object and uses the
	previously allocated second LSP-ID in the INGRESS_PROTECTION object		previously allocated second LSP-ID in the INGRESS_PROTECTION object
	of the PATH message as the LSP-ID of the new LSP. This allows the		of the PATH message as the LSP-ID of the new LSP. This allows the
End of changes. 15 change blocks.
	227 lines changed or deleted		54 lines changed or added
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