 1/draftietfbmwgigpdataplaneconvterm08.txt 20060204 17:00:24.000000000 +0100
+++ 2/draftietfbmwgigpdataplaneconvterm09.txt 20060204 17:00:24.000000000 +0100
@@ 1,24 +1,25 @@
Network Working Group
INTERNETDRAFT
 Expires in: April 2006
+ Expires in: June 2006
Scott Poretsky
Reef Point Systems
Brent Imhoff
+ Juniper Networks
 October 2005
+ January 2006
Terminology for Benchmarking
IGP Data Plane Route Convergence

+
Intellectual Property Rights (IPR) statement:
By submitting this InternetDraft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
Status of this Memo
InternetDrafts are working documents of the Internet Engineering
@@ 31,27 +32,27 @@
time. It is inappropriate to use InternetDrafts as reference
material or to cite them other than as "work in progress."
The list of current InternetDrafts can be accessed at
http://www.ietf.org/ietf/1idabstracts.txt.
The list of InternetDraft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
Copyright Notice
 Copyright (C) The Internet Society (2005). All Rights Reserved.
+ Copyright (C) The Internet Society (2006).
ABSTRACT
 This draft describes the terminology for benchmarking IGP Route
 Convergence as described in Applicability document [1] and
 Methodology document [2]. The methodology and terminology is to
 be used for benchmarking Route Convergence and can be applied to
+ This document describes the terminology for benchmarking IGP
+ Route Convergence as described in Applicability document [1] and
+ Methodology document [2]. The methodology and terminology are to
+ be used for benchmarking Convergence Time and can be applied to
any linkstate IGP such as ISIS [3] and OSPF [4]. The data plane
is measured to obtain the convergence benchmarking metrics
described in [2].
IGP Data Plane Route Convergence
Table of Contents
1. Introduction .................................................2
2. Existing definitions .........................................3
@@ 90,55 +91,56 @@
terminology to be used for benchmarking Route Convergence can be
applied to any linkstate IGP such as ISIS [3] and OSPF [4]. The
data plane is measured to obtain blackbox (externally observable)
convergence benchmarking metrics. The purpose of this document is
to introduce new terms required to complete execution of the IGP
Route Convergence Methodology [2]. These terms apply to IPv4 and
IPv6 traffic as well as IPv4 and IPv6 IGPs.
An example of Route Convergence as observed and measured from the
data plane is shown in Figure 1. The graph in Figure 1 shows
 Forwarding Rate versus Time. Time 0 on the Xaxis is on the far
+ Throughput versus Time. Time 0 on the Xaxis is on the far
right of the graph. The components of the graph and metrics are
defined in the Term Definitions section.
IGP Data Plane Route Convergence
Convergence Convergence
Recovery Event
Instant Instant Time = 0sec
Maximum ^ ^ ^
 Forwarding Rate> \ Packet /
+ Throughput> \ Packet /
\ Loss /<Convergence
Convergence>\ / Event Transition
Recovery Transition \ /
\_____/<Maximum Packet Loss
Xaxis = Time
 Yaxis = Forwarding Rate
+ Yaxis = Throughput
Figure 1. Convergence Graph
2. Existing definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in BCP 14, RFC 2119.
RFC 2119 defines the use of these key words to help make the
intent of standards track documents as clear as possible. While this
document uses these keywords, this document is not a standards track
 document.
+ document. The term Throughput is defined in RFC 2544.
3. Term Definitions
3.1 Convergence Event
Definition:
The occurrence of a planned or unplanned action in the network
 that results in a change in the egress interface of the DUT for
+ that results in a change in the egress interface of the Device
+ Under Test (DUT) for
routed packets.
Discussion:
Convergence Events include link loss, routing protocol session
loss, router failure, configuration change, and better nexthop
learned via a routing protocol.
Measurement Units:
N/A
@@ 147,26 +149,27 @@
See Also:
Convergence Packet Loss
Convergence Event Instant
IGP Data Plane Route Convergence
3.2 Route Convergence
Definition:
Recovery from a Convergence Event indicated by the DUT
 forwarding rate equal to the offered load.
+ Throughput equal to the offered load.
Discussion:
Route Convergence is the action of all components of the router
being updated with the most recent route change(s) including the
 RIB and FIB, along with software and hardware tables. Route
+ Routing Information Base (RIB) and Forwaridng Information Base
+ (FIB), along with software and hardware tables. Route
Convergence can be observed externally by the rerouting of data
Traffic to a new egress interface.
Measurement Units:
N/A
Issues:
None
See Also:
@@ 176,97 +179,98 @@
3.3 Network Convergence
Definition:
The completion of updating of all routing tables, including the
FIB, in all routers throughout the network.
Discussion:
Network Convergence is bounded by the sum of Route Convergence
for all routers in the network. Network Convergence can be
 determined by recovery of the forwarding rate to equal the offered
 load, no Stale Forwarding, and no blenders[5][6].
+ determined by recovery of the Throughput to equal the
+ offered load, with no Stale Forwarding, and no blenders[5][6].
Measurement Units:
N/A
Issues:
None
See Also:
Route Convergence
Stale Forwarding
IGP Data Plane Route Convergence
3.4 Full Convergence
Definition:
Route Convergence for an entire FIB.
Discussion:
 When benchmarking convergence it is useful to measure
+ When benchmarking convergence, it is useful to measure
the time to converge an entire FIB. For example,
a Convergence Event can be produced for an OSPF table of
5000 routes so that the time to converge routes 1 through
5000 is measured. Full Convergence is externally observable
 from the data plane when the forwarding rate of the data
+ from the data plane when the Throughput of the data
plane traffic on the NextBest Egress Interface equals the
offered load.
Measurement Units:
N/A
 Issues:
 None
+ Issues: None
See Also:
Network Convergence
Route Convergence
Convergence Event
3.5 Convergence Packet Loss
Definition:
The amount of packet loss produced by a Convergence Event
until Route Convergence occurs.
Discussion:
 Packet loss can be observed as a reduction of forwarded traffic from
 the maximum forwarding rate. Convergence Packet Loss include packets
 that were lost and packets that were delayed due to buffering.
 Convergence Packet Loss may or may not reach 100%.
+ Packet loss can be observed as a reduction of forwarded traffic
+ from the maximum Throughput. Convergence Packet Loss
+ includes packets that were lost and packets that were delayed
+ due to buffering. The maximum Convergence Packet Loss observed
+ in a Packet Sampling Interval may or may not reach 100% during
+ Route Convergence (see Figure 1).
Measurement Units:
number of packets
 Issues:
 None
+ Issues: None
See Also:
Route Convergence
Convergence Event
RateDerived Convergence Time
LossDerived Convergence Time
+ Packet Sampling Interval
IGP Data Plane Route Convergence
3.6 Convergence Event Instant
Definition:
 The time instant that a Convergence Event becomes observable in the
 data plane.
+ The time instant that a Convergence Event becomes observable in
+ the data plane.
Discussion:
Convergence Event Instant is observable from the data
plane as the precise time that the device under test begins
to exhibit packet loss.
Measurement Units:
 hh:mm:ss:uuu
+ hh:mm:ss:nnn, where 'nnn' is milliseconds
Issues:
None
See Also:
Convergence Event
Convergence Packet Loss
Convergence Recovery Instant
3.7 Convergence Recovery Instant
@@ 301,38 +305,38 @@
RateDerived Convergence Time can be measured as the time
difference from the Convergence Event Instant to the
Convergence Recovery Instant, as shown with Equation 1.
(eq 1) RateDerived Convergence Time =
Convergence Recovery Instant  Convergence Event Instant.
Discussion:
RateDerived Convergence Time should be measured at the maximum
 forwarding rate. Failure to achieve Full Convergence results in
+ Throughput. Failure to achieve Full Convergence results in
a RateDerived Convergence Time benchmark of infinity.
Measurement Units:
seconds/milliseconds
Issues:
None
See Also:
Convergence Packet Loss
Convergence Recovery Instant
Convergence Event Instant
Full Convergence
3.9 Convergence Event Transition
Definition:
 The characteristic of a router in which forwarding rate
+ The characteristic of a router in which Throughput
gradually reduces to zero after a Convergence Event.
Discussion:
The Convergence Event Transition is best observed for
Full Convergence. The Convergence Event Transition may
not be linear.
Measurement Units:
seconds/milliseconds
@@ 342,21 +346,21 @@
See Also:
Convergence Event
RateDerived Convergence Time
Convergence Packet Loss
Convergence Recovery Transition
IGP Data Plane Route Convergence
3.10 Convergence Recovery Transition
Definition:
 The characteristic of a router in which forwarding rate
+ The characteristic of a router in which Throughput
gradually increases to equal the offered load.
Discussion:
The Convergence Recovery Transition is best observed for
Full Convergence. The Convergence Event Transition may
not be linear.
Measurement Units:
seconds/milliseconds
@@ 417,84 +421,84 @@
Convergence Recovery Transition
3.12 Sustained Forwarding Convergence Time
Definition:
The amount of time for which Full Convergence is maintained
without additional packet loss.
Discussion:
The purpose of the Sustained Forwarding Convergence Time is to
 produce Convergence Time benchmarks protected against fluctuation
 in Forwarding Rate after Full Convergence is observed. The
+ produce Convergence benchmarks protected against fluctuation
+ in Throughput after Full Convergence is observed. The
Sustained Forwarding Convergence Time to be used is calculated
as shown in Equation 3.
(eq 3)
 Sustained Forwarding Convergence Time =
 5 x (# routes in FIB) / (Offered Load)
+ Sustained Forwarding Convergence Time = 5 packets/Offered Load
+ units are packets/pps = sec
 for which at least one packet per destination MUST be received
 at the DUT.
+ for which at least one packet per route in the FIB for all
+ routes in the FIB MUST be offered to the DUT per second.
Measurement Units:
seconds or milliseconds
Issues: None
See Also:
Full Convergence
Convergence Recovery Instant
3.13 Restoration Convergence Time
Definition:
The amount of time for the router under test to restore
traffic to the original outbound port after recovery from
a Convergence Event.
IGP Data Plane Route Convergence
Discussion:
 Restoration Convergence Time is the amount of time to
 Converge back to the original outbound port. This is achieved
+ Restoration Convergence Time is the amount of time for routes
+ to converge to the original outbound port. This is achieved
by recovering from the Convergence Event, such as restoring
the failed link. Restoration Convergence Time is measured
using the RateDerived Convergence Time calculation technique,
 as provided in Equation 1. It is possible, but not desired
 to have the Restoration Convergence Time differ from the
 RateDerived Convergence Time.
+ as provided in Equation 1. It is possible to have the
+ Restoration Convergence Time differ from the RateDerived
+ Convergence Time.
Measurement Units:
seconds or milliseconds
Issues:
None
See Also:
Convergence Event
RateDerived Convergence Time
3.14 Packet Sampling Interval
Definition:
The interval at which the tester (test equipment) polls to make
measurements for arriving packet flows.
Discussion:
Metrics measured at the Packet Sampling Interval may include
 Forwarding Rate and Convergence Packet Loss.
+ Throughput and Convergence Packet Loss.
Measurement Units:
seconds or milliseconds
Issues:
Packet Sampling Interval can influence the Convergence Graph.
 This is particularly true as implementations achieve Full
+ This is particularly true when implementations achieve Full
Convergence in less than 1 second. The Convergence Event
Transition and Convergence Recovery Transition can become
exaggerated when the Packet Sampling Interval is too long.
This will produce a larger than actual RateDerived
Convergence Time. The recommended value for configuration
of the Packet Sampling Interval is provided in [2].
See Also:
Convergence Packet Loss
Convergence Event Transition
@@ 557,42 +561,42 @@
Local Interface
Neighbor Interface
3.18 Preferred Egress Interface
Definition:
The outbound interface from the DUT for traffic routed to the
preferred nexthop.
Discussion:
 Preferred Egress Interface is the egress interface prior to
 a Convergence Event
+ The Preferred Egress Interface is the egress interface prior
+ to a Convergence Event.
Measurement Units:
N/A
Issues:
None
See Also:
NextBest Egress Interface
3.19 NextBest Egress Interface
Definition:
The outbound interface from the DUT for traffic routed to the
secondbest nexthop. It is the same media type and link speed
as the Preferred Egress Interface
Discussion:
 NextBest Egress Interface is the egress interface after
 a Convergence Event.
+ The NextBest Egress Interface becomes the egress interface
+ after a Convergence Event.
Measurement Units:
N/A
Issues:
None
See Also:
Preferred Egress Interface
IGP Data Plane Route Convergence
@@ 645,61 +649,69 @@
IGP Data Plane Route Convergence
5. Security Considerations
Documents of this type do not directly affect the security of
Internet or corporate networks as long as benchmarking
is not performed on devices or systems connected to production
networks.
6. Normative References
+6. References
+6.1 Normative References
[1] Poretsky, S., "Benchmarking Applicability for IGP Data Plane
 Route Convergence", draftietfbmwgigpdataplaneconvapp08,
 work in progress, October 2005.
+ Route Convergence", draftietfbmwgigpdataplaneconvapp09,
+ work in progress, January 2006.
[2] Poretsky, S., "Benchmarking Methodology for IGP Data Plane
 Route Convergence", draftietfbmwgigpdataplaneconvmeth08,
 work in progress, October 2005.
+ Route Convergence", draftietfbmwgigpdataplaneconvmeth09,
+ work in progress, January 2006.
[3] Callon, R., "Use of OSI ISIS for Routing in TCP/IP and Dual
Environments", RFC 1195, December 1990.
[4] Moy, J., "OSPF Version 2", RFC 2328, IETF, April 1998.
+6.2 Informative References
+
[5] S. Casner, C. Alaettinoglu, and C. Kuan, "A FineGrained View
of High Performance Networking", NANOG 22, June 2001.
[6] L. Ciavattone, A. Morton, and G. Ramachandran, "Standardized
Active Measurements on a Tier 1 IP Backbone", IEEE
Communications Magazine, pp9097, May 2003.
7. Author's Address
Scott Poretsky
Reef Point Systems
8 New England Executive Park
Burlington, MA 01803
USA
Phone: + 1 508 439 9008
EMail: sporetsky@reefpoint.com
+ IGP Data Plane Route Convergence
Brent Imhoff
+ Juniper Networks
+ 1194 North Mathilda Ave
+ Sunnyvale, CA 94089
USA
+
+ Phone: + 1 314 378 2571
EMail: bimhoff@planetspork.com
 IGP Data Plane Route Convergence
Full Copyright Statement
 Copyright (C) The Internet Society (2005).
+ Copyright (C) The Internet Society (2006).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE