draft-ietf-bmwg-igp-dataplane-conv-term-15.txt   draft-ietf-bmwg-igp-dataplane-conv-term-16.txt 
Network Working Group S. Poretsky Network Working Group S. Poretsky
Internet Draft NextPoint Networks Internet Draft Allot Communications
Expires: August 2008
Intended Status: Informational Brent Imhoff Intended Status: Informational Brent Imhoff
Juniper Networks Juniper Networks
February 25, 2008 October 15, 2008
Terminology for Benchmarking Terminology for Benchmarking
Link-State IGP Data Plane Route Convergence Link-State IGP Data Plane Route Convergence
<draft-ietf-bmwg-igp-dataplane-conv-term-15.txt> <draft-ietf-bmwg-igp-dataplane-conv-term-16.txt>
Intellectual Property Rights (IPR) statement: Intellectual Property Rights (IPR) statement:
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware 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 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. aware will be disclosed, in accordance with Section 6 of BCP 79.
Status of this Memo Status of this Memo
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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Table of Contents Table of Contents
1. Introduction .................................................2 1. Introduction .................................................2
2. Existing definitions .........................................3 2. Existing definitions .........................................3
3. Term definitions..............................................4 3. Term definitions..............................................4
3.1 Convergence Event.........................................4 3.1 Convergence Event.........................................4
3.2 Route Convergence.........................................4 3.2 Route Convergence.........................................4
3.3 Full Convergence..........................................5 3.3 Full Convergence..........................................5
3.4 Network Convergence.......................................5 3.4 Network Convergence.......................................5
3.5 Route-Specific Convergence................................6 3.5 Route-Specific Convergence................................6
3.6 Packet Loss...............................................6 3.6 Packet Loss...............................................7
3.7 Convergence Packet Loss...................................7 3.7 Convergence Packet Loss...................................7
3.8 Convergence Event Instant.................................7 3.8 Convergence Event Instant.................................8
3.9 Convergence Recovery Instant..............................8 3.9 Convergence Recovery Instant..............................8
3.10 First Route Convergence Instant..........................8 3.10 First Route Convergence Instant..........................9
3.11 Convergence Event Transition.............................9 3.11 Convergence Event Transition.............................9
3.12 Convergence Recovery Transition..........................9 3.12 Convergence Recovery Transition..........................10
3.13 Rate-Derived Convergence Time............................10 3.13 Rate-Derived Convergence Time............................10
3.14 Loss-Derived Convergence Time............................10 3.14 Loss-Derived Convergence Time............................11
3.15 Route-Specific Convergence Time..........................12 3.15 Route-Specific Convergence Time..........................12
3.16 Sustained Convergence Validation Time....................13 3.16 Sustained Convergence Validation Time....................13
3.17 First Route Convergence Time.............................13 3.17 First Route Convergence Time.............................14
3.18 Reversion Convergence Time...............................14 3.18 Reversion Convergence Time...............................15
3.19 Packet Sampling Interval.................................14 3.19 Packet Sampling Interval.................................15
3.20 Local Interface..........................................15 3.20 Local Interface..........................................16
3.21 Neighbor Interface.......................................15 3.21 Neighbor Interface.......................................16
3.22 Remote Interface.........................................15 3.22 Remote Interface.........................................17
3.23 Preferred Egress Interface...............................16 3.23 Preferred Egress Interface...............................17
3.24 Next-Best Egress Interface...............................16 3.24 Next-Best Egress Interface...............................17
3.25 Stale Forwarding.........................................17 3.25 Stale Forwarding.........................................18
3.26 Nested Convergence Events................................17 3.26 Nested Convergence Events................................18
4. IANA Considerations...........................................18 4. IANA Considerations...........................................19
5. Security Considerations.......................................18 5. Security Considerations.......................................19
6. Acknowledgements..............................................18 6. Acknowledgements..............................................19
7. References....................................................18 7. References....................................................19
8. Author's Address..............................................19 8. Author's Address..............................................20
1. Introduction 1. Introduction
This draft describes the terminology for benchmarking Interior This draft describes the terminology for benchmarking Interior
Gateway Protocol (IGP) Route Convergence. The motivation and Gateway Protocol (IGP) Route Convergence. The motivation and
applicability for this benchmarking is provided in [Po07a]. The applicability for this benchmarking is provided in [Po07a]. The
methodology to be used for this benchmarking is described in [Po07m]. methodology to be used for this benchmarking is described in [Po07m].
The methodology and terminology to be used for benchmarking Route The methodology and terminology to be used for benchmarking Route
Convergence can be applied to any link-state IGP such as ISIS [Ca90] Convergence can be applied to any link-state IGP such as ISIS [Ca90]
and OSPF [Mo98]. The data plane is measured to obtain black-box and OSPF [Mo98]. The data plane is measured to obtain black-box
(externally observable) convergence benchmarking metrics. The (externally observable) convergence benchmarking metrics. The
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An example of Route Convergence as observed and measured from the An example of Route Convergence as observed and measured from the
data plane is shown in Figure 1. The graph in Figure 1 shows data plane is shown in Figure 1. The graph in Figure 1 shows
Forwarding Rate versus Time. Time 0 on the X-axis is on the far Forwarding Rate versus Time. Time 0 on the X-axis is on the far
right of the graph. The Offered Load to the ingress interface of right of the graph. The Offered Load to the ingress interface of
the DUT SHOULD equal the measured maximum Throughput [Ba99][Ma98] the DUT SHOULD equal the measured maximum Throughput [Ba99][Ma98]
of the DUT and the Forwarding Rate [Ma98] is measured at the egress of the DUT and the Forwarding Rate [Ma98] is measured at the egress
interfaces of the DUT. The components of the graph and the metrics interfaces of the DUT. The components of the graph and the metrics
are defined in the Term Definitions section. are defined in the Term Definitions section.
Full Convergence,
Convergence Convergence Convergence Convergence
Recovery Event Recovery Event
Instant Instant Time = 0sec Instant Instant Time = 0sec
Forwarding Rate = ^ ^ ^ Offered Load = Forwarding Rate = ^ ^ ^ Offered Load =
Offered Load --> ------\ Packet /-------- <---Max Throughput Offered Load --> ------\ Packet /-------- <---Max Throughput
\ Loss /<----Convergence \ Loss /<----Convergence
Convergence------->\ / Event Transition Convergence------->\ / Event Transition
Recovery Transition \ / Recovery Transition \ /
\_____/<------Maximum Packet Loss \_____/<------Maximum Packet Loss
^ ^
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equal to the offered load. equal to the offered load.
Discussion: 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, the time to converge an entire FIB. For example,
a Convergence Event can be produced for an OSPF table of a Convergence Event can be produced for an OSPF table of
5000 routes so that the time to converge routes 1 through 5000 routes so that the time to converge routes 1 through
5000 is measured. Completion of Full Convergence is externally 5000 is measured. Completion of Full Convergence is externally
observable from the data plane when the Throughput of the data observable from the data plane when the Throughput of the data
plane traffic on the Next-Best Egress Interface equals the plane traffic on the Next-Best Egress Interface equals the
offered load. Full Convergence may or may not be sustained over offered load.
time. The Sustained Convergence Validation Time MUST be
applied. Full convergence MAY be measured using Rate-Derived Convergence
Time (3.13) or calculated using Loss-Derived Convergence Time
(3.14). When performing Route-Specific Convergence (3.5)
measurements, Full Convergence may be obtained by measuring the
maximum Route Specific Convergence Time (3.15). Full
Convergence may or may not be sustained over time. The
Sustained Convergence Validation Time (3.16) MUST be applied.
Measurement Units: Measurement Units:
N/A N/A
Issues: Issues:
None None
See Also: See Also:
Network Convergence Network Convergence
Route Convergence Route Convergence
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distributed FIBs, in all routers throughout the network. distributed FIBs, in all routers throughout the network.
Discussion: Discussion:
Network Convergence requires completion of all Route Network Convergence requires completion of all Route
Convergence operations for all routers in the network following Convergence operations for all routers in the network following
a Convergence Event. Completion of Network Convergence can be a Convergence Event. Completion of Network Convergence can be
observed by recovery of System Under Test (SUT) Throughput to observed by recovery of System Under Test (SUT) Throughput to
equal the offered load, with no Stale Forwarding, and no equal the offered load, with no Stale Forwarding, and no
Blenders [Ca01][Ci03]. Blenders [Ca01][Ci03].
Link-State IGP Data Plane Route Convergence
Measurement Units: Measurement Units:
N/A N/A
Issues: Issues:
None None
See Also: See Also:
Route Convergence Route Convergence
Stale Forwarding Stale Forwarding
Link-State IGP Data Plane Route Convergence
3.5 Route-Specific Convergence 3.5 Route-Specific Convergence
Definition: Definition:
Route Convergence for one or more specific route entries in Route Convergence for one or more specific route entries in
the FIB in which recovery from the Convergence Event is the FIB in which recovery from the Convergence Event is
indicated by data-plane traffic for a flow [Po06] matching that indicated by data-plane traffic for a flow [Po06] matching that
route entry(ies) being routed to the Next-Best Egress Interface. route entry(ies) being routed to the Next-Best Egress Interface.
Discussion: Discussion:
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Measurement Units: Measurement Units:
N/A N/A
Issues: Issues:
None None
See Also: See Also:
Full Convergence Full Convergence
Route Convergence Route Convergence
Convergence Event Convergence Event
Link-State IGP Data Plane Route Convergence
3.6 Packet Loss 3.6 Packet Loss
Definition: Definition:
The number of packets that should have been forwarded The number of packets that should have been forwarded
by a DUT under a constant offered load that were by a DUT under a constant offered load that were
not forwarded due to lack of resources. not forwarded due to lack of resources.
Discussion: Discussion:
Packet Lss is a modified version of the term "Frame Loss Rate" Packet Loss is a modified version of the term "Frame Loss Rate"
as defined in [Ba91]. The term "Frame Loss" is intended for as defined in [Ba91]. The term "Frame Loss" is intended for
Ethernet Frames while "Packet Loss" is intended for IP packets. Ethernet Frames while "Packet Loss" is intended for IP packets.
Packet Loss can be measured as a reduction in forwarded traffic Packet Loss can be measured as a reduction in forwarded traffic
from the Throughput [Ba91] of the DUT. from the Throughput [Ba91] of the DUT.
Measurement units: Measurement units:
Number of offered packets that are not forwarded. Number of offered packets that are not forwarded.
Issues: None Issues: None
See Also: See Also:
Convergence Packet Loss Convergence Packet Loss
Link-State IGP Data Plane Route Convergence
3.7 Convergence Packet Loss 3.7 Convergence Packet Loss
Definition: Definition:
The number of packets lost due to a Convergence Event The number of packets lost due to a Convergence Event
until Full Convergence completes. until Full Convergence completes.
Discussion: Discussion:
Convergence Packet Loss includes packets that were lost and Convergence Packet Loss includes packets that were lost and
packets that were delayed due to buffering. The Convergence packets that were delayed due to buffering. The Convergence
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Measurement Units: Measurement Units:
number of packets number of packets
Issues: None Issues: None
See Also: See Also:
Packet Loss Packet Loss
Route Convergence Route Convergence
Convergence Event Convergence Event
Packet Sampling Interval Packet Sampling Interval
Link-State IGP Data Plane Route Convergence
3.8 Convergence Event Instant 3.8 Convergence Event Instant
Definition: Definition:
The time instant that a Convergence Event becomes observable in The time instant that a Convergence Event becomes observable in
the data plane. the data plane.
Discussion: Discussion:
Convergence Event Instant is observable from the data Convergence Event Instant is observable from the data
plane as the precise time that the device under test begins plane as the precise time that the device under test begins
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hh:mm:ss:nnn:uuu, hh:mm:ss:nnn:uuu,
where 'nnn' is milliseconds and 'uuu' is microseconds. where 'nnn' is milliseconds and 'uuu' is microseconds.
Issues: Issues:
None None
See Also: See Also:
Convergence Event Convergence Event
Convergence Packet Loss Convergence Packet Loss
Convergence Recovery Instant Convergence Recovery Instant
Link-State IGP Data Plane Route Convergence
3.9 Convergence Recovery Instant 3.9 Convergence Recovery Instant
Definition: Definition:
The time instant that Full Convergence completion is The time instant that Full Convergence completion is
measured and then maintained for an interval of duration measured and then maintained for an interval of duration
equal to the Sustained Convergence Validation Time. equal to the Sustained Convergence Validation Time.
Discussion: Discussion:
Convergence Recovery Instant is measurable from the data Convergence Recovery Instant is measurable from the data
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hh:mm:ss:nnn:uuu, hh:mm:ss:nnn:uuu,
where 'nnn' is milliseconds and 'uuu' is microseconds. where 'nnn' is milliseconds and 'uuu' is microseconds.
Issues: Issues:
None None
See Also: See Also:
Sustained Convergence Validation Time Sustained Convergence Validation Time
Convergence Packet Loss Convergence Packet Loss
Convergence Event Instant Convergence Event Instant
Link-State IGP Data Plane Route Convergence
3.10 First Route Convergence Instant 3.10 First Route Convergence Instant
Definition: Definition:
The time instant a first route entry has converged The time instant a first route entry has converged
following a Convergence Event, as observed by receipt of following a Convergence Event, as observed by receipt of
the first packet from the Next-Best Egress Interface. the first packet from the Next-Best Egress Interface.
Discussion: Discussion:
The First Route Convergence Instant is an indication that the The First Route Convergence Instant is an indication that the
process to achieve Full Convergence has begun. Any route may process to achieve Full Convergence has begun. Any route may
be the first to converge for First Route Convergence Instant. be the first to converge for First Route Convergence Instant.
Measurement on the data-plane enables the First Route Measurement on the data-plane enables the First Route
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the first packet from the Next-Best Egress Interface. the first packet from the Next-Best Egress Interface.
Discussion: Discussion:
The First Route Convergence Instant is an indication that the The First Route Convergence Instant is an indication that the
process to achieve Full Convergence has begun. Any route may process to achieve Full Convergence has begun. Any route may
be the first to converge for First Route Convergence Instant. be the first to converge for First Route Convergence Instant.
Measurement on the data-plane enables the First Route Measurement on the data-plane enables the First Route
Convergence Instant to be observed without any white-box Convergence Instant to be observed without any white-box
information from the DUT. information from the DUT.
Measurement Units: Measurement Units: N/A
N/A
Issues: Issues:
None None
See Also: See Also:
Route Convergence Route Convergence
Full Convergence Full Convergence
Stale Forwarding Stale Forwarding
Link-State IGP Data Plane Route Convergence
3.11 Convergence Event Transition 3.11 Convergence Event Transition
Definition: Definition:
A time interval observed following a Convergence Event in which A time interval observed following a Convergence Event in which
Throughput gradually reduces to a minimum value. Throughput gradually reduces to a minimum value.
Discussion: Discussion:
The Convergence Event Transition is best observed for Full The Convergence Event Transition is best observed for Full
Convergence. The egress packet rate observed during a Convergence. The egress packet rate observed during a
Convergence Event Transition may not decrease linearly and may Convergence Event Transition may not decrease linearly and may
not decrease to zero. Both the offered load and the Packet not decrease to zero. Both the offered load and the Packet
Sampling Interval influence the observations of the Convergence Sampling Interval influence the observations of the Convergence
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Measurement Units: Measurement Units:
seconds seconds
Issues: Issues:
None None
See Also: See Also:
Convergence Event Convergence Event
Full Convergence Full Convergence
Packet Sampling Interval Packet Sampling Interval
Link-State IGP Data Plane Route Convergence
3.12 Convergence Recovery Transition 3.12 Convergence Recovery Transition
Definition: Definition:
The characteristic of the DUT in which Throughput gradually The characteristic of the DUT in which Throughput gradually
increases to equal the offered load. increases to equal the offered load.
Discussion: Discussion:
The Convergence Recovery Transition is best observed for The Convergence Recovery Transition is best observed for
Full Convergence. The egress packet rate observed during Full Convergence. The egress packet rate observed during
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"Packet Sampling Interval". "Packet Sampling Interval".
Measurement Units: Measurement Units:
seconds seconds
Issues: None Issues: None
See Also: See Also:
Full Convergence Full Convergence
Packet Sampling Interval Packet Sampling Interval
Link-State IGP Data Plane Route Convergence
3.13 Rate-Derived Convergence Time 3.13 Rate-Derived Convergence Time
Definition: Definition:
The amount of time for Convergence Packet Loss to persist upon The amount of time for Convergence Packet Loss to persist upon
occurrence of a Convergence Event until Full Convergence has occurrence of a Convergence Event until Full Convergence has
completed. completed.
Rate-Derived Convergence Time can be measured as the time Rate-Derived Convergence Time can be measured as the time
difference from the Convergence Event Instant to the difference from the Convergence Event Instant to the
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Rate-Derived Convergence Time SHOULD be measured at the maximum Rate-Derived Convergence Time SHOULD be measured at the maximum
Throughput of the DUT. At least one packet per route in the FIB Throughput of the DUT. At least one packet per route in the FIB
for all routes in the FIB MUST be offered to the DUT within the for all routes in the FIB MUST be offered to the DUT within the
Packet Sampling Interval. Packet Sampling Interval.
Failure to achieve Full Convergence results in a Rate-Derived Failure to achieve Full Convergence results in a Rate-Derived
Convergence Time benchmark of infinity. It is RECOMMENDED that Convergence Time benchmark of infinity. It is RECOMMENDED that
the Rate-Derived Convergence Time be measured when benchmarking the Rate-Derived Convergence Time be measured when benchmarking
Full Convergence. Full Convergence.
Link-State IGP Data Plane Route Convergence
Measurement Units: Measurement Units:
seconds seconds
Issues: None Issues: None
See Also: See Also:
Convergence Packet Loss Convergence Packet Loss
Convergence Recovery Instant Convergence Recovery Instant
Convergence Event Instant Convergence Event Instant
Full Convergence Full Convergence
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The amount of time it takes for Full Convergence to be The amount of time it takes for Full Convergence to be
completed as calculated from the amount of Convergence completed as calculated from the amount of Convergence
Packet Loss. Loss-Derived Convergence Time can be Packet Loss. Loss-Derived Convergence Time can be
calculated from Convergence Packet Loss as shown with calculated from Convergence Packet Loss as shown with
Equation 2. Equation 2.
Equation 2 - Equation 2 -
Loss-Derived Convergence Time = Loss-Derived Convergence Time =
Convergence Packets Loss / Offered Load Convergence Packets Loss / Offered Load
where units are packets / packets/second = seconds where units are packets / packets/second = seconds
Link-State IGP Data Plane Route Convergence
Discussion: Discussion:
Optimally, the Convergence Event Transition and Convergence Optimally, the Convergence Event Transition and Convergence
Recovery Transition are instantaneous so that the Recovery Transition are instantaneous so that the
Rate-Derived Convergence Time = Loss-Derived Convergence Time. Rate-Derived Convergence Time = Loss-Derived Convergence Time.
However, router implementations are less than ideal. However, router implementations are less than ideal.
Loss-Derived Convergence Time gives a better than Loss-Derived Convergence Time gives a better than
actual result when converging many routes simultaneously actual result when converging many routes simultaneously
because it ignores the Convergence Recovery Transition. because it ignores the Convergence Recovery Transition.
Rate-Derived Convergence Time takes the Convergence Recovery Rate-Derived Convergence Time takes the Convergence Recovery
Transition into account. Equation 2 calculates the average Transition into account. Equation 2 calculates the average
convergence time over all routes to which packets have been convergence time over all routes to which packets have been
sent. Since this average convergence time is in general sent. Since this average convergence time is in general
smaller than the maximum convergence time over all routes, smaller than the maximum convergence time over all routes,
Loss-Derived Convergence Time is not the preferred metric to Loss-Derived Convergence Time is not the preferred metric to
indicate Full Convergence completion. For this reason the indicate Full Convergence completion. For this reason the
RECOMMENDED benchmark metric for Full Convergence is the RECOMMENDED benchmark metric for Full Convergence is the
Rate-Derived Convergence Time. Rate-Derived Convergence Time.
Link-State IGP Data Plane Route Convergence
Guidelines for reporting Loss-Derived Convergence Time are Guidelines for reporting Loss-Derived Convergence Time are
provided in [Po07m]. provided in [Po07m].
Measurement Units: Measurement Units:
seconds seconds
Issues: Issues:
None None
See Also: See Also:
Convergence Event Convergence Event
Convergence Packet Loss Convergence Packet Loss
Rate-Derived Convergence Time Rate-Derived Convergence Time
Route-Specific Convergence Route-Specific Convergence
Convergence Event Transition Convergence Event Transition
Convergence Recovery Transition Convergence Recovery Transition
Link-State IGP Data Plane Route Convergence
3.15 Route-Specific Convergence Time 3.15 Route-Specific Convergence Time
Definition: Definition:
The amount of time it takes for Route-Specific Convergence to The amount of time it takes for Route-Specific Convergence to
be completed as calculated from the amount of Convergence be completed as calculated from the amount of Convergence
Packet Loss per flow. Packet Loss per flow.
Route-Specific Convergence Time can be calculated from Route-Specific Convergence Time can be calculated from
Convergence Packet Loss as shown with Equation 3. Convergence Packet Loss as shown with Equation 3.
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Route-Specific Convergence, Convergence Packet Loss is measured Route-Specific Convergence, Convergence Packet Loss is measured
for specific flow(s) and Equation 3 is applied for each flow. for specific flow(s) and Equation 3 is applied for each flow.
Each flow has a single destination address matching a different Each flow has a single destination address matching a different
route entry. The fastest measurable convergence time is equal route entry. The fastest measurable convergence time is equal
to the time between two consecutive packets of a flow offered to the time between two consecutive packets of a flow offered
by the Tester. by the Tester.
The Route-Specific Convergence Time benchmarks enable minimum, The Route-Specific Convergence Time benchmarks enable minimum,
maximum, average, and median convergence time measurements to be maximum, average, and median convergence time measurements to be
reported by comparing the results for the different route reported by comparing the results for the different route
Link-State IGP Data Plane Route Convergence
entries. It also enables benchmarking of convergence time when entries. It also enables benchmarking of convergence time when
configuring a priority value for route entry(ies). Since configuring a priority value for route entry(ies). Since
multiple Route-Specific Convergence Times can be measured it is multiple Route-Specific Convergence Times can be measured it is
possible to have an array of results. The format for reporting possible to have an array of results. The format for reporting
Route-Specific Convergence Time is provided in [Po07m]. Route-Specific Convergence Time is provided in [Po07m].
The Route-Specific Convergence Time MAY be used to benchmark The Route-Specific Convergence Time MAY be used to benchmark
Full Convergence when used in combination with many flows Full Convergence when used in combination with many flows
matching every FIB entry. matching every FIB entry. In this case
Full Convergence = max(Route-Specific Convergence Time).
Measurement Units: Measurement Units:
seconds seconds
Issues: Issues:
None None
See Also: See Also:
Convergence Event Convergence Event
Convergence Packet Loss Convergence Packet Loss
Route-Specific Convergence Route-Specific Convergence
3.16 Sustained Convergence Validation Time
Definition:
The amount of time for which the completion of Full
Convergence is maintained without additional packet loss.
Discussion:
The purpose of the Sustained Convergence Validation Time is to
produce Convergence benchmarks protected against fluctuation
in Throughput after the completion of Full Convergence is
observed. The RECOMMENDED Sustained Convergence Validation
Time to be used is 5 seconds. The BMWG selected 5 seconds
based upon RFC 2544 [Ba99] which recommends waiting 2 seconds
for residual frames to arrive and 5 seconds for DUT
restabilization.
Measurement Units:
seconds
Issues: None
See Also:
Full Convergence
Convergence Recovery Instant
Link-State IGP Data Plane Route Convergence Link-State IGP Data Plane Route Convergence
3.16 First Route Convergence Time 3.17 First Route Convergence Time
Definition: Definition:
The amount of time for Convergence Packet Loss until the The amount of time for Convergence Packet Loss until the
convergence of a first route entry on the Next-Best Egress convergence of a first route entry on the Next-Best Egress
Interface, as indicated by the First Route Convergence Interface, as indicated by the First Route Convergence
Instant. Instant.
Discussion: Discussion:
The First Route Convergence Time benchmarking metric can be The First Route Convergence Time benchmarking metric can be
measured when benchmarking either Full Convergence or measured when benchmarking either Full Convergence or
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benchmark of infinity. benchmark of infinity.
Measurement Units: Measurement Units:
seconds seconds
Issues: None Issues: None
See Also: See Also:
Convergence Packet Loss Convergence Packet Loss
First Route Convergence Instant First Route Convergence Instant
3.17 Sustained Convergence Validation Time
Definition:
The amount of time for which the completion of Full
Convergence is maintained without additional packet loss.
Link-State IGP Data Plane Route Convergence Link-State IGP Data Plane Route Convergence
Discussion:
The purpose of the Sustained Convergence Validation Time is to
produce Convergence benchmarks protected against fluctuation
in Throughput after the completion of Full Convergence is
observed. The RECOMMENDED Sustained Convergence Validation
Time to be used is 5 seconds.
Measurement Units:
seconds
Issues: None
See Also:
Full Convergence
Convergence Recovery Instant
3.18 Reversion Convergence Time 3.18 Reversion Convergence Time
Definition: Definition:
The amount of time for the DUT to complete Full Convergence The amount of time for the DUT to complete Full Convergence
to the Preferred Egress Interface, instead of the Next-Best to the Preferred Egress Interface, instead of the Next-Best
Egress Interface, upon recovery from a Convergence Event. Egress Interface, upon recovery from a Convergence Event.
Discussion: Discussion:
Reversion Convergence Time is the amount of time for Full Reversion Convergence Time is the amount of time for Full
COnvergence to the original egress interface. This is Convergence to the original egress interface. This is
achieved by recovering from the Convergence Event, such as achieved by recovering from the Convergence Event, such as
restoring the failed link. Reversion Convergence Time is restoring the failed link. Reversion Convergence Time is
measured using the Rate-Derived Convergence Time calculation measured using the Rate-Derived Convergence Time calculation
technique, as provided in Equation 1. It is possible to have technique, as provided in Equation 1. It is possible to have
the Reversion Convergence Time differ from the Rate-Derived the Reversion Convergence Time differ from the Rate-Derived
Convergence Time. Convergence Time.
Measurement Units: Measurement Units: seconds
seconds
Issues: None Issues: None
See Also: See Also:
Preferred Egress Interface Preferred Egress Interface
Convergence Event Convergence Event
Rate-Derived Convergence Time Rate-Derived Convergence Time
3.19 Packet Sampling Interval 3.19 Packet Sampling Interval
Definition: Definition:
The interval at which the tester (test equipment) polls to make The interval at which the tester (test equipment) polls to make
measurements for arriving packet flows. measurements for arriving packet flows.
Discussion: Discussion:
At least one packet per route in the FIB At least one packet per route in the FIB for all routes in the
for all routes in the FIB MUST be offered to the DUT within the FIB MUST be offered to the DUT within the Packet Sampling
Packet Sampling Interval. Metrics measured at the Packet Interval. Metrics measured at the Packet Sampling Interval
Sampling Interval MUST include Forwarding Rate and Convergence MUST include Forwarding Rate and Convergence Packet Loss.
Packet Loss.
Link-State IGP Data Plane Route Convergence
Measurement Units:
seconds
Issues:
Packet Sampling Interval can influence the Convergence Graph. Packet Sampling Interval can influence the Convergence Graph.
This is particularly true when implementations complete Full This is particularly true when implementations complete Full
Convergence in less than the Packet Sampling Interval. The Convergence in less than the Packet Sampling Interval. The
Convergence Event Transition and Convergence Recovery Transition Convergence Event Transition and Convergence Recovery Transition
can become exaggerated when the Packet Sampling Interval is too can become exaggerated when the Packet Sampling Interval is too
long. This will produce a larger than actual Rate-Derived long. This will produce a larger than actual Rate-Derived
Convergence Time. The recommended value for configuration of Convergence Time. The recommended value for configuration of
the Packet Sampling Interval is provided in [Po07m]. the Packet Sampling Interval is provided in [Po07m].
Measurement Units: seconds
Issues: None
See Also: See Also:
Convergence Packet Loss Convergence Packet Loss
Convergence Event Transition Convergence Event Transition
Convergence Recovery Transition Convergence Recovery Transition
Link-State IGP Data Plane Route Convergence
3.20 Local Interface 3.20 Local Interface
Definition: Definition:
An interface on the DUT. An interface on the DUT.
Discussion: Discussion:
A failure of the Local Interface indicates that the failure A failure of the Local Interface indicates that the failure
occurred directly on the DUT. occurred directly on the DUT.
skipping to change at page 16, line 4 skipping to change at page 16, line 38
The interface on the neighbor router or tester that is The interface on the neighbor router or tester that is
directly linked to the DUT's Local Interface. directly linked to the DUT's Local Interface.
Discussion: Discussion:
A failure of a Neighbor Interface indicates that a A failure of a Neighbor Interface indicates that a
failure occurred on a neighbor router's interface that failure occurred on a neighbor router's interface that
directly links the neighbor router to the DUT. directly links the neighbor router to the DUT.
Measurement Units: Measurement Units:
N/A N/A
Link-State IGP Data Plane Route Convergence
Issues: Issues:
None None
See Also: See Also:
Local Interface Local Interface
Remote Interface Remote Interface
Link-State IGP Data Plane Route Convergence
3.22 Remote Interface 3.22 Remote Interface
Definition: Definition:
An interface on a neighboring router that is not directly An interface on a neighboring router that is not directly
connected to any interface on the DUT. connected to any interface on the DUT.
Discussion: Discussion:
A failure of a Remote Interface indicates that the failure A failure of a Remote Interface indicates that the failure
occurred on a neighbor router's interface that is not occurred on a neighbor router's interface that is not
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See Also: See Also:
Next-Best Egress Interface Next-Best Egress Interface
3.24 Next-Best Egress Interface 3.24 Next-Best Egress Interface
Definition: Definition:
The outbound interface from the DUT for traffic routed to the The outbound interface from the DUT for traffic routed to the
second-best next-hop. It is the same media type and link speed second-best next-hop. It is the same media type and link speed
as the Preferred Egress Interface as the Preferred Egress Interface
Link-State IGP Data Plane Route Convergence
Discussion: Discussion:
The Next-Best Egress Interface becomes the egress interface The Next-Best Egress Interface becomes the egress interface
after a Convergence Event. after a Convergence Event.
Link-State IGP Data Plane Route Convergence
Measurement Units: Measurement Units:
N/A N/A
Issues: None Issues: None
See Also: See Also:
Preferred Egress Interface Preferred Egress Interface
3.25 Stale Forwarding 3.25 Stale Forwarding
Definition: Definition:
Forwarding of traffic to route entries that no longer exist Forwarding of traffic to route entries that no longer exist
or to route entries with next-hops that are no longer preferred. or to route entries with next-hops that are no longer preferred.
Discussion: Discussion:
Stale Forwarding can be caused by a Convergence Event and can Stale Forwarding can be caused by a Convergence Event and can
manifest as a "black-hole" or microloop that produces packet manifest as a "black-hole" or microloop that produces packet
loss. Stale Forwarding can exist until Network Convergence is loss. Stale Forwarding can exist until Network Convergence is
completed. Stale Forwarding cannot be observed with a single completed. Stale Forwarding cannot be observed with a single
DUT. DUT.
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[Mo06] Morton, A., et al, "Packet Reordering Metrics", RFC 4737, [Mo06] Morton, A., et al, "Packet Reordering Metrics", RFC 4737,
November 2006. November 2006.
[Po06] Poretsky, S., et al., "Terminology for Benchmarking [Po06] Poretsky, S., et al., "Terminology for Benchmarking
Network-layer Traffic Control Mechanisms", RFC 4689, Network-layer Traffic Control Mechanisms", RFC 4689,
November 2006. November 2006.
[Po07a] Poretsky, S., "Benchmarking Applicability for Link-State [Po07a] Poretsky, S., "Benchmarking Applicability for Link-State
IGP Data Plane Route Convergence", IGP Data Plane Route Convergence",
draft-ietf-bmwg-igp-dataplane-conv-app-15, work in progress, draft-ietf-bmwg-igp-dataplane-conv-app-16, work in progress,
February 2008. October 2008.
Link-State IGP Data Plane Route Convergence
[Po07m] Poretsky, S. and Imhoff, B., "Benchmarking Methodology for [Po07m] Poretsky, S. and Imhoff, B., "Benchmarking Methodology for
Link-State IGP Data Plane Route Convergence", Link-State IGP Data Plane Route Convergence",
draft-ietf-bmwg-igp-dataplane-conv-meth-15, work in progress, draft-ietf-bmwg-igp-dataplane-conv-meth-16, work in progress,
February 2008. October 2008.
Link-State IGP Data Plane Route Convergence
7.2 Informative References 7.2 Informative References
[Ca01] S. Casner, C. Alaettinoglu, and C. Kuan, "A Fine-Grained View [Ca01] S. Casner, C. Alaettinoglu, and C. Kuan, "A Fine-Grained View
of High Performance Networking", NANOG 22, June 2001. of High Performance Networking", NANOG 22, June 2001.
[Ci03] L. Ciavattone, A. Morton, and G. Ramachandran, "Standardized [Ci03] L. Ciavattone, A. Morton, and G. Ramachandran, "Standardized
Active Measurements on a Tier 1 IP Backbone", IEEE Active Measurements on a Tier 1 IP Backbone", IEEE
Communications Magazine, pp90-97, May 2003. Communications Magazine, pp90-97, May 2003.
8. Author's Address 8. Author's Address
Scott Poretsky Scott Poretsky
NextPoint Networks Allot Communications
3 Federal Street 67 South Bedford Street, Suite 400
Billerica, MA 01821 Burlington, MA 01803
USA USA
Phone: + 1 508 439 9008 Phone: + 1 508 309 2179
EMail: sporetsky@nextpointnetworks.com Email: sporetsky@allot.com
Brent Imhoff Brent Imhoff
Juniper Networks Juniper Networks
1194 North Mathilda Ave 1194 North Mathilda Ave
Sunnyvale, CA 94089 Sunnyvale, CA 94089
USA USA
Phone: + 1 314 378 2571 Phone: + 1 314 378 2571
EMail: bimhoff@planetspork.com EMail: bimhoff@planetspork.com
Full Copyright Statement Full Copyright Statement
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