draft-ietf-opsawg-large-flow-load-balancing-12.txt		draft-ietf-opsawg-large-flow-load-balancing-13.txt
	skipping to change at page 1, line 17		skipping to change at page 1, line 17
	Dell		Dell
	Ning So		Ning So
	Tata Communications		Tata Communications
	B. Khasnabish		B. Khasnabish
	ZTE Corporation		ZTE Corporation
	June 13, 2014		June 13, 2014
	Mechanisms for Optimizing LAG/ECMP Component Link Utilization in		Mechanisms for Optimizing LAG/ECMP Component Link Utilization in
	Networks		Networks
	draft-ietf-opsawg-large-flow-load-balancing-12.txt		draft-ietf-opsawg-large-flow-load-balancing-13.txt
	Status of this Memo		Status of this Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79. This document may not be modified,		provisions of BCP 78 and BCP 79. This document may not be modified,
	and derivative works of it may not be created, except to publish it		and derivative works of it may not be created, except to publish it
	as an RFC and to translate it into languages other than English.		as an RFC and to translate it into languages other than English.
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF), its areas, and its working groups. Note that		Task Force (IETF), its areas, and its working groups. Note that
	skipping to change at page 5, line 30		skipping to change at page 5, line 30
	2. Flow Categorization		2. Flow Categorization
	In general, based on the size and duration, a flow can be categorized		In general, based on the size and duration, a flow can be categorized
	into any one of the following four types, as shown in Figure 1:		into any one of the following four types, as shown in Figure 1:
	(a) Short-lived Large Flow (SLLF),		(a) Short-lived Large Flow (SLLF),
	(b) Short-lived Small Flow (SLSF),		(b) Short-lived Small Flow (SLSF),
	(c) Long-lived Large Flow (LLLF), and		(c) Long-lived Large Flow (LLLF), and
	(d) Long-lived Small Flow (LLSF).		(d) Long-lived Small Flow (LLSF).
	Flow Size		Flow Bandwidth
	^		^
	|--------------------|--------------------|		|--------------------|--------------------|
	| | |		| | |
	Large | SLLF | LLLF |		Large | SLLF | LLLF |
	Flow | | |		Flow | | |
	|--------------------|--------------------|		|--------------------|--------------------|
	| | |		| | |
	Small | SLSF | LLSF |		Small | SLSF | LLSF |
	Flow | | |		Flow | | |
	+--------------------+--------------------+-->Flow Duration		+--------------------+--------------------+-->Flow Duration
	skipping to change at page 7, line 11		skipping to change at page 7, line 11
	o The presence of 2 large flows causes congestion on this		o The presence of 2 large flows causes congestion on this
	component link.		component link.
	+-----------+ -> +-----------+		+-----------+ -> +-----------+
	| | -> | |		| | -> | |
	| | ===> | |		| | ===> | |
	| (1)|--------|(1) |		| (1)|--------|(1) |
	| | -> | |		| | -> | |
	| | -> | |		| | -> | |
	| (R1) | -> | (R2) |		| (R1) | -> | (R2) |
	| (2)|--------|(2) |		| (2)|--------|(2) |
	| | -> | |		| | -> | |
	| | -> | |		| | -> | |
	| | ===> | |		| | ===> | |
	| | ===> | |		| | ===> | |
	| (3)|--------|(3) |		| (3)|--------|(3) |
	| | | |		| | | |
	+-----------+ +-----------+		+-----------+ +-----------+
	Where: -> small flow		Where: -> small flow
	skipping to change at page 16, line 28		skipping to change at page 16, line 28
	flow -- and the link utilization is normal now.		flow -- and the link utilization is normal now.
	+-----------+ -> +-----------+		+-----------+ -> +-----------+
	| | -> | |		| | -> | |
	| | ===> | |		| | ===> | |
	| (1)|--------|(1) |		| (1)|--------|(1) |
	| | | |		| | | |
	| | ===> | |		| | ===> | |
	| | -> | |		| | -> | |
	| | -> | |		| | -> | |
	| (R1) | -> | (R2) |		| (R1) | -> | (R2) |
	| (2)|--------|(2) |		| (2)|--------|(2) |
	| | | |		| | | |
	| | -> | |		| | -> | |
	| | -> | |		| | -> | |
	| | ===> | |		| | ===> | |
	| (3)|--------|(3) |		| (3)|--------|(3) |
	| | | |		| | | |
	+-----------+ +-----------+		+-----------+ +-----------+
	Where: -> small flow		Where: -> small flow
	skipping to change at page 17, line 49		skipping to change at page 17, line 49
	threshold defined above.		threshold defined above.
	. Imbalance threshold: A measure of the deviation of the		. Imbalance threshold: A measure of the deviation of the
	component link utilizations from the utilization of the overall		component link utilizations from the utilization of the overall
	LAG/ECMP group. Since component links can be of a different		LAG/ECMP group. Since component links can be of a different
	speed, the imbalance can be computed as follows. Let the		speed, the imbalance can be computed as follows. Let the
	utilization of each component link in a LAG/ECMP group with n		utilization of each component link in a LAG/ECMP group with n
	links of speed b_1, b_2 ... b_n, be u_1, u_2 ... u_n. The mean		links of speed b_1, b_2 ... b_n, be u_1, u_2 ... u_n. The mean
	utilization is computed is u_ave = [ (u_1 x b_1) + (u_2 x b_2) +		utilization is computed is u_ave = [ (u_1 x b_1) + (u_2 x b_2) +
	... + (u_n x b_n) ] / [b_1 + b_2 + ... + b_n]. The imbalance is		... + (u_n x b_n) ] / [b_1 + b_2 + ... + b_n]. The imbalance is
	then computed as max_{i=1 ... n} | u_i - u_ave |.		then computed as max_{i=1...n} | u_i - u_ave |.
	. Rebalancing interval: The minimum amount of time between		. Rebalancing interval: The minimum amount of time between
	rebalancing events. This parameter ensures that rebalancing is		rebalancing events. This parameter ensures that rebalancing is
	not invoked too frequently as it impacts packet ordering.		not invoked too frequently as it impacts packet ordering.
	These parameters may be configured on a system-wide basis or it may		These parameters may be configured on a system-wide basis or it may
	apply to an individual LAG. It may be applied to an ECMP group		apply to an individual LAG. It may be applied to an ECMP group
	provided the component links are not shared with any other ECMP		provided the component links are not shared with any other ECMP
	group.		group.
	skipping to change at page 23, line 5		skipping to change at page 23, line 4
	10. Acknowledgements		10. Acknowledgements
	The authors would like to thank the following individuals for their		The authors would like to thank the following individuals for their
	review and valuable feedback on earlier versions of this document:		review and valuable feedback on earlier versions of this document:
	Shane Amante, Fred Baker, Michael Bugenhagen, Zhen Cao, Brian		Shane Amante, Fred Baker, Michael Bugenhagen, Zhen Cao, Brian
	Carpenter, Benoit Claise, Michael Fargano, Wes George, Sriganesh		Carpenter, Benoit Claise, Michael Fargano, Wes George, Sriganesh
	Kini, Roman Krzanowski, Andrew Malis, Dave McDysan, Pete Moyer,		Kini, Roman Krzanowski, Andrew Malis, Dave McDysan, Pete Moyer,
	Peter Phaal, Dan Romascanu, Curtis Villamizar, Jianrong Wong, George		Peter Phaal, Dan Romascanu, Curtis Villamizar, Jianrong Wong, George
	Yum, and Weifeng Zhang. As a part of the IETF Last Call process,		Yum, and Weifeng Zhang. As a part of the IETF Last Call process,
	valuable comments were received from Martin Thomson,		valuable comments were received from Martin Thomson and Carlos
			Pignataro.
	11. References		11. References
	11.1. Normative References		11.1. Normative References
	[802.1AX] IEEE Standards Association, "IEEE Std 802.1AX-2008 IEEE		[802.1AX] IEEE Standards Association, "IEEE Std 802.1AX-2008 IEEE
	Standard for Local and Metropolitan Area Networks - Link		Standard for Local and Metropolitan Area Networks - Link
	Aggregation", 2008.		Aggregation", 2008.
	[RFC 2991] Thaler, D. and C. Hopps, "Multipath Issues in Unicast and		[RFC 2991] Thaler, D. and C. Hopps, "Multipath Issues in Unicast and
End of changes. 6 change blocks.
	6 lines changed or deleted		7 lines changed or added
This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/