< draft-ietf-mpls-entropy-label-03.txt		draft-ietf-mpls-entropy-label-04.txt >
	Network Working Group K. Kompella		Network Working Group K. Kompella
	Internet-Draft J. Drake		Internet-Draft J. Drake
	Updates: 3031, 5036 (if approved) Juniper Networks		Updates: 3031, 5036 (if approved) Juniper Networks
	Intended status: Standards Track S. Amante		Intended status: Standards Track S. Amante
	Expires: November 10, 2012 Level 3 Communications, LLC		Expires: January 11, 2013 Level 3 Communications, LLC
	W. Henderickx		W. Henderickx
	Alcatel-Lucent		Alcatel-Lucent
	L. Yong		L. Yong
	Huawei USA		Huawei USA
	May 9, 2012		July 10, 2012
	The Use of Entropy Labels in MPLS Forwarding		The Use of Entropy Labels in MPLS Forwarding
	draft-ietf-mpls-entropy-label-03		draft-ietf-mpls-entropy-label-04
	Abstract		Abstract
	Load balancing is a powerful tool for engineering traffic across a		Load balancing is a powerful tool for engineering traffic across a
	network. This memo suggests ways of improving load balancing across		network. This memo suggests ways of improving load balancing across
	MPLS networks using the concept of "entropy labels". It defines the		MPLS networks using the concept of "entropy labels". It defines the
	concept, describes why entropy labels are useful, enumerates		concept, describes why entropy labels are useful, enumerates
	properties of entropy labels that allow maximal benefit, and shows		properties of entropy labels that allow maximal benefit, and shows
	how they can be signaled and used for various applications.		how they can be signaled and used for various applications.
	skipping to change at page 1, line 41 ¶		skipping to change at page 1, line 41 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on November 10, 2012.		This Internet-Draft will expire on January 11, 2013.
	Copyright Notice		Copyright Notice
	Copyright (c) 2012 IETF Trust and the persons identified as the		Copyright (c) 2012 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 5, line 48 ¶		skipping to change at page 5, line 48 ¶
	The term ingress (or egress) LSR is used interchangeably with ingress		The term ingress (or egress) LSR is used interchangeably with ingress
	(or egress) LER. The term application throughout the text refers to		(or egress) LER. The term application throughout the text refers to
	an MPLS application (such as a VPN or VPLS).		an MPLS application (such as a VPN or VPLS).
	A label stack (say of three labels) is denoted by <L1, L2, L3>, where		A label stack (say of three labels) is denoted by <L1, L2, L3>, where
	L1 is the "outermost" label and L3 the innermost (closest to the		L1 is the "outermost" label and L3 the innermost (closest to the
	payload). Packet flows are depicted left to right, and signaling is		payload). Packet flows are depicted left to right, and signaling is
	shown right to left (unless otherwise indicated).		shown right to left (unless otherwise indicated).
	The term 'label' is used both for the entire 32-bit label and the 20-		The term 'label' is used both for the entire 32-bit label stack entry
	bit label field within a label. It should be clear from the context		and the 20-bit label field within a label stack entry. It should be
	which is meant.		clear from the context which is meant.
	1.2. Motivation		1.2. Motivation
	MPLS is very successful generic forwarding substrate that transports		MPLS is very successful generic forwarding substrate that transports
	several dozen types of protocols, most notably: IP, PWE3, VPLS and IP		several dozen types of protocols, most notably: IP, PWE3, VPLS and IP
	VPNs. Within each type of protocol, there typically exist several		VPNs. Within each type of protocol, there typically exist several
	variants, each with a different set of load balancing keys, e.g., for		variants, each with a different set of load balancing keys, e.g., for
	IP: IPv4, IPv6, IPv6 in IPv4, etc.; for PWE3: Ethernet, ATM, Frame-		IP: IPv4, IPv6, IPv6 in IPv4, etc.; for PWE3: Ethernet, ATM, Frame-
	Relay, etc. There are also several different types of Ethernet over		Relay, etc. There are also several different types of Ethernet over
	PW encapsulation, ATM over PW encapsulation, etc. as well. Finally,		PW encapsulation, ATM over PW encapsulation, etc. as well. Finally,
	skipping to change at page 9, line 14 ¶		skipping to change at page 9, line 14 ¶
	load balancing information. However, they MUST NOT have values in		load balancing information. However, they MUST NOT have values in
	the reserved label space (0-15) [IANA MPLS Label Values]. To ensure		the reserved label space (0-15) [IANA MPLS Label Values]. To ensure
	that they are not used inadvertently for forwarding, entropy labels		that they are not used inadvertently for forwarding, entropy labels
	SHOULD have a TTL of 0. The CoS field of an entropy label can be set		SHOULD have a TTL of 0. The CoS field of an entropy label can be set
	to any value deemed appropriate.		to any value deemed appropriate.
	Since entropy labels are generated by an ingress LSR, an egress LSR		Since entropy labels are generated by an ingress LSR, an egress LSR
	MUST be able to distinguish unambiguously between entropy labels and		MUST be able to distinguish unambiguously between entropy labels and
	application labels. This is accomplished by REQUIRING that the label		application labels. This is accomplished by REQUIRING that the label
	immediately preceding an entropy label (EL) in the MPLS label stack		immediately preceding an entropy label (EL) in the MPLS label stack
	be an 'entropy label indicator' (ELI). The ELI is a reserved label		be an 'entropy label indicator' (ELI), where preceding means closer
	with value (TBD by IANA). An ELI MUST have 'Bottom of Stack' (BoS)		to the top of the label stack (farther from bottom of stack
	bit = 0 ([RFC3032]). The TTL SHOULD be set to whatever value the		indication). The ELI is a reserved label with value (TBD by IANA).
	label above it in the stack has. The CoS field can be set to any		An ELI MUST have 'Bottom of Stack' (BoS) bit = 0 ([RFC3032]). The
	value deemed appropriate; typically, this will be the value in the		TTL SHOULD be set to whatever value the label above it in the stack
	label above the ELI in the label stack.		has. The CoS field can be set to any value deemed appropriate;
			typically, this will be the value in the label above the ELI in the
			label stack.
	Entropy labels are useful for pseudowires ([RFC4447]). [RFC6391]		Entropy labels are useful for pseudowires ([RFC4447]). [RFC6391]
	explains how entropy labels can be used for RFC 4447-style		explains how entropy labels can be used for RFC 4447-style
	pseudowires, and thus is complementary to this memo, which focuses on		pseudowires, and thus is complementary to this memo, which focuses on
	how entropy labels can be used for tunnels, and thus for all other		how entropy labels can be used for tunnels, and thus for all other
	MPLS applications.		MPLS applications.
	4. Data Plane Processing of Entropy Labels		4. Data Plane Processing of Entropy Labels
	4.1. Egress LSR		4.1. Egress LSR
End of changes. 6 change blocks.
	13 lines changed or deleted		15 lines changed or added
This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/