Network Working Group
   INTERNET-DRAFT
   Expires in: January 2008
   Intended Status: Informational
                                                Scott Poretsky
                                                Reef Point Systems

                                                Brent Imhoff
                                                Juniper Networks

                                                November 2007

                    Benchmarking Methodology for
             Link-State IGP Data Plane Route Convergence

          <draft-ietf-bmwg-igp-dataplane-conv-meth-13.txt>

          <draft-ietf-bmwg-igp-dataplane-conv-meth-14.txt>

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   Copyright (C) The IETF Trust (2007).

ABSTRACT
   This document describes the methodology for benchmarking Interior
   Gateway Protocol (IGP) Route Convergence.   The methodology is to
   be used for benchmarking IGP convergence time through externally
   observable (black box) data plane measurements.  The methodology
   can be applied to any link-state IGP, such as ISIS and OSPF.

                      IGP Data Plane Route Convergence

Table of Contents
     1. Introduction ...............................................2
     2. Existing definitions .......................................2
     3. Test Setup..................................................3
     3.1 Test Topologies............................................3
     3.2 Test Considerations........................................4 Considerations........................................5
     3.3 Reporting Format...........................................6 Format...........................................7
     4. Test Cases..................................................7
     4.1 Convergence Due to Link Failure............................7 Failure............................8
     4.1.1 Convergence Due to Local Interface Failure...............7 Failure...............8
     4.1.2 Convergence Due to Neighbor Interface Failure............7 Failure............8
     4.1.3 Convergence Due to Remote Interface Failure..............8 Failure..............9
     4.2 Convergence Due to Local Administrative Shutdown...........10
     4.3 Convergence Due to Layer 2 Session Failure.................9
     4.3 Failure.................11
     4.4 Convergence Due to IGP Adjacency Failure...................10
     4.4 Failure...................11
     4.5 Convergence Due to Route Withdrawal........................10
     4.5 Withdrawal........................12
     4.6 Convergence Due to Cost Change.............................11
     4.6 Change.............................13
     4.7 Convergence Due to ECMP Member Interface Failure...........11
     4.7 Failure...........13
     4.8 Convergence Due to ECMP Member Remote Interface Failure....14
     4.9 Convergence Due to Parallel Link Interface Failure.........12 Failure.........15
     5. IANA Considerations.........................................13 Considerations.........................................15
     6. Security Considerations.....................................13 Considerations.....................................15
     7. Acknowledgements............................................13 Acknowledgements............................................15
     8. Normative References........................................13 References........................................16
     9. Author's Address............................................14 Address............................................16

1. Introduction
   This document describes the methodology for benchmarking IGP Interior
   Gateway Protocol (IGP) Route Convergence.  The applicability of this
   testing is described in [Po07a] and the new terminology that it
   introduces is defined in [Po07t].  Service Providers use IGP
   Convergence time as a key metric of router design and architecture.
   Customers of Service Providers observe convergence time by packet
   loss, so IGP Route Convergence is considered a Direct Measure of
   Quality (DMOQ).  The test cases in this document are black-box tests
   that emulate the network events that cause route convergence, as
   described in [Po07a].  The black-box test designs benchmark the data
   plane and account for all of the factors contributing to convergence
   time, as discussed in [Po07a].  The methodology (and terminology) for
   benchmarking route convergence can be applied to any link-state IGP
   such as ISIS [Ca90] and OSPF [Mo98]. [Mo98] and other IGPs such as RIP.
   These methodologies apply to IPv4 and IPv6 traffic
   as well as IPv4 and IPv6 IGPs.

2. Existing definitions

   This document uses much of the terminology defined in [Po07t].  The
   term "Throughput" is defined in RFC 2544 [Br99].
   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
   [Br97].  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.

                      IGP Data Plane Route Convergence

   This document uses much of the terminology defined in [Po07t].
   This document uses existing terminology defined in other BMWG
   work.  Examples include, but are not limited to:

             Throughput                [Ref.[Br91], section 3.17]
             Device Under Test (DUT)   [Ref.[Ma98], section 3.1.1]
             System Under Test (SUT)   [Ref.[Ma98], section 3.1.2]
             Out-of-order Packet       [Ref.[Po06], section 3.3.2]
             Duplicate Packet          [Ref.[Po06], section 3.3.3]
             Packet Loss               [Ref.[Po07t], Section 3.5]

   This document adopts the definition format in Section 2 of RFC 1242
   [Br91].

3.  Test Setup

   3.1 Test Topologies

   Figure 1 shows the test topology to measure IGP Route Convergence
   due to local Convergence Events such as SONET Link Failure, Layer 2
   Session Failure, IGP  Adjacency Failure, Route Withdrawal, and route
   cost change.  These test cases discussed in section 4 provide route
   convergence times that account for the Event Detection time, SPF
   Processing time, and FIB Update time.  These times are measured
   by observing packet loss in the data plane at the Tester.

        ---------       Ingress Interface         ---------
        |       |<--------------------------------|       |
        |       |                                 |       |
        |       |    Preferred Egress Interface   |       |
        |  DUT  |-------------------------------->| Tester|
        |       |                                 |       |
        |       |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|       |
        |       |    Next-Best Egress Interface   |       |
        ---------                                 ---------

      Figure 1.  IGP Route Convergence Test Topology for Local Changes

   Figure 2 shows the test topology to measure IGP Route Convergence
   time due to remote changes in the network topology.  These times
   are measured by observing packet loss in the data plane at the
   Tester.  In this topology the three routers are considered a System
   Under Test (SUT).  A Remote Interface [Po07t] failure on router R2
   MUST result in convergence of traffic to router R3.  NOTE: All
   routers in the SUT must be the same model and identically
   configured.

                -----                       ---------
                |   | Preferred             |       |
        -----   |R2 |---------------------->|       |
        |   |-->|   | Egress Interface      |       |
        |   |   -----                       |       |
        |R1 |                               |Tester |
        |   |   -----                       |       |
        |   |-->|   |   Next-Best           |       |
        -----   |R3 |~~~~~~~~~~~~~~~~~~~~~~>|       |
          ^     |   |   Egress Interface    |       |
          |     -----                       ---------
          |                                     |
          |--------------------------------------
                      Ingress Interface

        Figure 2.  IGP Route Convergence Test Topology
                         for Remote Changes

   Figure 3 shows the test topology to measure IGP Route Convergence
   time with members of an Equal Cost Multipath (ECMP) Set.  These
   times are measured by observing packet loss in the data plane at
   the Tester.  In this topology, the DUT is configured with each
   Egress interface
                      IGP Data Plane Route Convergence as a member of an ECMP set and the Tester emulates
   multiple next-hop routers (emulates one router for each member).

        ---------       Ingress Interface         ---------
        |       |<--------------------------------|       |
        |       |                                 |       |
        |       |     ECMP Set Interface 1        |       |
        |  DUT  |-------------------------------->| Tester|
        |       |               .                 |       |
        |       |               .                 |       |
        |       |               .                 |       |
        |       |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|       |
        |       |     ECMP Set Interface N        |       |
        ---------                                 ---------

        Figure 3.  IGP Route Convergence Test Topology
                         for ECMP Convergence

   Figure 4 shows the test topology to measure IGP Route Convergence
   time with members of a Parallel Link.  These times are measured by
   observing packet loss in the data plane at the Tester.  In this
   topology, the DUT is configured with each Egress interface as a
   member of a Parallel Link and the Tester emulates the single
   next-hop router.

                      IGP Data Plane Route Convergence

        ---------       Ingress Interface         ---------
        |       |<--------------------------------|       |
        |       |                                 |       |
        |       |    Preferred Egress Interface   |       |
        |  DUT  |-------------------------------->| Tester|
        |       |                                 |       |
        |       |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|       |
        |       |    Next-Best Egress Interface   |       |
        ---------                                 ---------

      Figure 1.  Test Topology 1: IGP Convergence Test Topology
                 for Local Changes

                -----                       ---------
                |   | Preferred             |       |
        -----   |R2 |---------------------->|       |
        |   |-->|   | Egress Interface      |       |
        |   |   -----                       |       |
        |R1 |                               |Tester |
        |   |   -----                       |       |
        |   |-->|   |   Next-Best           |       |
        -----   |R3 |~~~~~~~~~~~~~~~~~~~~~~>|       |
          ^     |   |   Egress Interface    |       |
          |     -----                       ---------
          |                                     |
          |--------------------------------------
                      Ingress Interface

      Figure 2. Test Topology 2: IGP Convergence Test Topology
                for Convergence Due to Remote Changes

        ---------       Ingress Interface         ---------
        |       |<--------------------------------|       |
        |       |                                 |       |
        |       |     ECMP Set Interface 1        |       |
        |  DUT  |-------------------------------->| Tester|
        |       |               .                 |       |
        |       |               .                 |       |
        |       |               .                 |       |
        |       |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|       |
        |       |     ECMP Set Interface N        |       |
        ---------                                 ---------

      Figure 3. Test Topology 3: IGP Convergence Test Topology
                for ECMP Convergence
                      IGP Data Plane Route Convergence

        ---------       Ingress Interface         ---------
        |       |<--------------------------------|       |
        |       |                                 |       |
        |       |     Parallel Link Interface 1   |       |
        |  DUT  |-------------------------------->| Tester|
        |       |               .                 |       |
        |       |               .                 |       |
        |       |               .                 |       |
        |       |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|       |
        |       |     Parallel Link Interface N   |       |
        ---------                                 ---------

      Figure 4. Test Topology 4: IGP Route Convergence Test Topology
                for Parallel Link Convergence

   3.2 Test Considerations
   3.2.1 IGP Selection
   The test cases described in section 4 can be used for ISIS or
   OSPF.  The Route Convergence test methodology for both is
   identical.  The IGP adjacencies are established on the Preferred
   Egress Interface and Next-Best Egress Interface.

   3.2.2 Routing Protocol Configuration
   The obtained results for IGP Route Convergence may vary if
   other routing protocols are enabled and routes learned via those
   protocols are installed.  IGP convergence times MUST be benchmarked
   without routes installed from other protocols.

                      IGP Data Plane Route Convergence

   3.2.3 IGP Route Scaling
   The number of IGP routes will impact the measured IGP Route
   Convergence.  To obtain results similar to those that would be
   observed in an operational network, it is recommended reocmmended that the
   number of installed routes and nodes closely approximates that
   of the network. network (e.g. thousands of routes with tens of nodes).
   The number of areas (for OSPF) and levels (for ISIS) can impact
   the benchmark results.

   3.2.4 Timers
   There are some timers that will impact the measured IGP Convergence
   time. Benchmarking metrics may be measured at any fixed values for
   these timers.  It is RECOMMENDED that the following timers be
   configured to the minimum values listed:

        Timer                                   Recommended Value
        -----                                   -----------------
        Link Failure Indication Delay           <10milliseconds
        IGP Hello Timer                         1 second
        IGP Dead-Interval                       3 seconds
        LSA Generation Delay                    0
        LSA Flood Packet Pacing                 0
        LSA Retransmission Packet Pacing        0
        SPF Delay                               0
                      IGP Data Plane Route Convergence

   3.2.5 Convergence Time Metrics
   The recommended value for the Packet Sampling Interval [Po07t] value is
   100 milliseconds.  Rate-Derived the fastest
   measurable convergence time.  The RECOMMENDED value for the
   Packet Sampling Interval is 10 milliseconds.  Rate-Derived
   Convergence Time [Po07t] is the preferred benchmark for IGP
   Route Convergence.  This benchmark must always be reported
   when the Packet Sampling Interval [Po07t] is set <= 100 milliseconds. 10 milliseconds
   on the test equipment.  If the test equipment does not permit
   the Packet Sampling Interval to be set as low as 100 msec, 10
   milliseconds, then both the Rate-Derived Convergence Time and
   Loss-Derived Convergence Time [Po07t] must be reported.  The Packet Sampling
   Interval value MUST be reported as the smallest measurable
   convergence time. reported.

   3.2.6 Interface Types
   All test cases in this methodology document may be executed with
   any interface type.  All interfaces MUST be the same media and
   Throughput [Br91][Br99] for each test case.  The type of media
   may dictate which test cases may be executed.  This is because
   each interface type has a unique mechanism for detecting link
   failures and the speed at which that mechanism operates will
   influence the measure results.  Media and protocols MUST be
   configured for minimum failure detection delay to minimize the
   contribution to the measured Convergence time.  For example,
   configure SONET with the minimum carrier-loss-delay.

                      IGP Data Plane Route Convergence  All
   interfaces SHOULD be configured as point-to-point.

   3.2.7 Offered Load offered load
   The offered Load load MUST be the Throughput of the device as defined
   in [Br91] and benchmarked in [Br99] at a fixed packet size.
   Packet size is measured in bytes and includes the IP header and
   payload.  The packet size is selectable and MUST be recorded.
   The Forwarding Rate [Ma98] MUST be measured at the Preferred Egress
   Interface and the Next-Best Egress Interface.  The duration of
   offered load MUST be greater than the convergence time.  The
   destination addresses for the offered load MUST be distributed
   such that all routes are matched.  This enables Full Convergence
   [Po07t] to be observed.

                      IGP Data Plane Route Convergence

   3.3 Reporting Format
   For each test case, it is recommended that the following reporting
   format table below
   is completed: completed and all time values SHOULD be reported with resolution
   as specified in [Po07t].

        Parameter                              Units
        ---------                              -----
        IGP                                    (ISIS or OSPF)
        Interface Type                         (GigE, POS, ATM, etc.)
        Test Topology                          (1, 2, 3, or 4)
        Packet Size offered to DUT             bytes
        Total Packets Offered to DUT           number of Packets
        Total Packets Routed by DUT            number of Packets
        IGP Routes advertised to DUT           number of IGP routes
        Nodes in emulated network              number of nodes
        Packet Sampling Interval on Tester     seconds or     milliseconds
        IGP Timer Values configured on DUT
            SONET
            Interface Failure Indication Delay seconds or milliseconds
            IGP Hello Timer                    seconds or milliseconds
            IGP Dead-Interval                  seconds or milliseconds
            LSA Generation Delay               seconds or milliseconds
            LSA Flood Packet Pacing            seconds or milliseconds
            LSA Retransmission Packet Pacing   seconds or milliseconds
            SPF Delay                          seconds or milliseconds
        Benchmarks
              First Prefix Conversion Time     seconds
              Rate-Derived Convergence Time    seconds or milliseconds
              Loss-Derived Convergence Time    seconds or milliseconds
              Restoration
              Reversion Convergence Time       seconds or milliseconds

4. Test Cases

   The test cases follow a generic procedure tailored to the specific
   DUT configuration and Convergence Event.  This generic procedure is
   as follows:

      1. Establish DUT configuration and install routes.
      2. Send offered load with traffic traversing Preferred Egress
         Interface [Po07t].
      3. Introduce Convergence Event to force traffic to Next-Best
         Egress Interface [Po07t].
      4. Measure First Prefix Convergence Time.
      4. Measure Rate-Derived Convergence Time.
      5. Recover from Convergence Event.
      6. Measure Reversion Convergence Time.

                      IGP Data Plane Route Convergence

4. Test Cases
   4.1 Convergence Due to Link Failure

   4.1.1 Convergence Due to Local Interface Failure
   Objective
   To obtain the IGP Route Convergence due to a local link failure event
   at the DUT's Local Interface.

   Procedure
   1. Advertise matching IGP routes from Tester to DUT on
      Preferred Egress Interface [Po07t] and Next-Best Egress Interface
      [Po07t] using the topology shown in Figure 1.  Set the cost of
      the routes so that the Preferred Egress Interface is the
      preferred next-hop.
   2. Send offered load at measured Throughput with fixed packet
      size to destinations matching all IGP routes from Tester to
      DUT on Ingress Interface [Po07t].
   3. Verify traffic routed over Preferred Egress Interface.
   4. Remove Preferred Egress link on DUT's Local Interface Preferred Egress Interface.
   5. Measure First Prefix Convergence Time [Po07t] by
      performing an administrative shutdown of as DUT detects the interface.
   5.
      link down event and begins to converge IGP routes and traffic
      over the Next-Best Egress Interface.
   6. Measure Rate-Derived Convergence Time [Po07t] as DUT detects the
      link down event and converges all IGP routes and traffic over
      the Next-Best Egress Interface.
   6.
   7. Stop offered load.  Wait 30 seconds for queues to drain.
      Restart Offered Load.
   7. offered load.
   8. Restore Preferred Egress link on DUT's Local Interface by
      administratively enabling the interface.
   8. Preferred Egress Interface.
   9. Measure Restoration Reversion Convergence Time [Po07t] as DUT detects the
      link up event and converges all IGP routes and traffic back
      to the Preferred Egress Interface.

   Results
   The measured IGP Convergence time is influenced by the Local
   link failure indication, SPF delay, SPF Hold time, SPF Execution
   Time, Tree Build Time, and Hardware Update Time [Po07a].

   4.1.2 Convergence Due to Neighbor Interface Failure
   Objective
   To obtain the IGP Route Convergence due to a local link
   failure event at the Tester's Neighbor Interface.

   Procedure
   1. Advertise matching IGP routes from Tester to DUT on
      Preferred Egress Interface [Po07t] and Next-Best Egress Interface
      [Po07t] using the topology shown in Figure 1.  Set the cost of
      the routes so that the Preferred Egress Interface is the
      preferred next-hop.
   2. Send offered load at measured Throughput with fixed packet
      size to destinations matching all IGP routes from Tester to
      DUT on Ingress Interface [Po07t].

                      IGP Data Plane Route Convergence

   3. Verify traffic routed over Preferred Egress Interface.
   4. Remove link on Tester's Neighbor Interface [Po07t] connected to
      DUT's Preferred Egress Interface.
   5. Measure First Prefix Convergence Time [Po07t] as DUT detects the
      link down event and begins to converge IGP routes and traffic
      over the Next-Best Egress Interface.
   6. Measure Rate-Derived Convergence Time [Po07t] as DUT detects the
      link down event and converges all IGP routes and traffic over
      the Next-Best Egress Interface.
   6.
   7. Stop offered load.  Wait 30 seconds for queues to drain.
      Restart Offered Load.
   7. offered load.
   8. Restore link on Tester's Neighbor Interface connected to
      DUT's Preferred Egress Interface.
   8.
   9. Measure Restoration Reversion Convergence Time [Po07t] as DUT detects the
      link up event and converges all IGP routes and traffic back
      to the Preferred Egress Interface.

   Results
   The measured IGP Convergence time is influenced by the Local
   link failure indication, SPF delay, SPF Hold time, SPF Execution
   Time, Tree Build Time, and Hardware Update Time [Po07a].

   4.1.3 Convergence Due to Remote Interface Failure
   Objective
   To obtain the IGP Route Convergence due to a Remote Interface
   Failure event.

   Procedure
   1. Advertise matching IGP routes from Tester to SUT on
      Preferred Egress Interface [Po07t] and Next-Best Egress
      Interface [Po07t] using the topology shown in Figure 2.
      Set the cost of the routes so that the Preferred Egress
      Interface is the preferred next-hop.
   2. Send offered load at measured Throughput with fixed packet
      size to destinations matching all IGP routes from Tester to
      DUT
      SUT on Ingress Interface [Po07t].
   3. Verify traffic is routed over Preferred Egress Interface.
   4. Remove link on Tester's Neighbor Interface [Po07t] connected to
      SUT's Preferred Egress Interface.
   5. Measure First Prefix Convergence Time [Po07t] as SUT detects the
      link down event and begins to converge IGP routes and traffic
      over the Next-Best Egress Interface.
   6. Measure Rate-Derived Convergence Time [Po07t] as SUT detects
      the link down event and converges all IGP routes and traffic
      over the Next-Best Egress Interface.
   6.
   7. Stop offered load.  Wait 30 seconds for queues to drain.
      Restart Offered Load.
   7. offered load.
   8. Restore link on Tester's Neighbor Interface connected to
      DUT's Preferred Egress Interface.
   8.
   9. Measure Restoration Reversion Convergence Time [Po07t] as DUT detects the
      link up event and converges all IGP routes and traffic back
      to the Preferred Egress Interface.

                      IGP Data Plane Route Convergence

   Results
   The measured IGP Convergence time is influenced by the link failure
   indication, LSA/LSP Flood Packet Pacing, LSA/LSP Retransmission
   Packet Pacing, LSA/LSP Generation time, SPF delay, SPF Hold time,
   SPF Execution Time, Tree Build Time, and Hardware Update Time
   [Po07a].  The additional
   convergence time contributed by LSP Propagation can be
   obtained by subtracting the Rate-Derived Convergence Time
   measured in 4.1.2 (Convergence Due  This test case may produce Stale Forwarding [Po07t] due to Neighbor Interface
   Failure) from
   microloops which may increase the Rate-Derived Convergence Time measured in
   this test case. Time.

   4.2 Convergence Due to Layer 2 Session Failure Local Adminstrative Shutdown
   Objective
   To obtain the IGP Route Convergence due to a Local Layer 2
   Session local link failure event. event
   at the DUT's Local Interface.

   Procedure
   1. Advertise matching IGP routes from Tester to DUT on
      Preferred Egress Interface [Po07t] and Next-Best Egress Interface
      [Po07t] using the topology shown in Figure 1.  Set the cost of
      the routes so that the IGP routes along the Preferred Egress Interface is the
      preferred next-hop.
   2. Send offered load at measured Throughput with fixed packet
      size to destinations matching all IGP routes from Tester to
      DUT on Ingress Interface [Po07t].
   3. Verify traffic routed over Preferred Egress Interface.
   4. Remove Layer 2 session from Tester's Neighbor Interface [Po07t]
      connected to Perform adminstrative shutdown on the DUT's Preferred Egress
      Interface.
   5. Measure Rate-Derived First Prefix Convergence Time [Po07t] as DUT detects the
      Layer 2 session
      link down event and begins to converge IGP routes and traffic
      over the Next-Best Egress Interface.
   6. Measure Rate-Derived Convergence Time [Po07t] as DUT converges
      all IGP routes and traffic over the Next-Best Egress Interface.
   6.
   7. Stop offered load.  Wait 30 seconds for queues to drain.
      Restart Offered Load.
   7. offered load.
   8. Restore Layer 2 session on DUT's Preferred Egress Interface.
   8. Interface by administratively enabling
      the interface.
   9. Measure Restoration Reversion Convergence Time [Po07t] as DUT detects the
      session up event and converges all
      IGP routes and traffic
      over back to the Preferred Egress Interface.

   Results
   The measured IGP Convergence time is influenced by the Layer 2
   failure indication, SPF delay,
   SPF Hold time, SPF Execution Time, Tree Build Time, and Hardware
   Update Time [Po07a].

                      IGP Data Plane Route Convergence

   4.3 Convergence Due to IGP Adjacency Layer 2 Session Failure
   Objective
   To obtain the IGP Route Convergence due to a Local IGP Adjacency Layer 2
   Session failure event. event, such as PPP session loss.

   Procedure
   1. Advertise matching IGP routes from Tester to DUT on
      Preferred Egress Interface [Po07t] and Next-Best Egress Interface
      [Po07t] using the topology shown in Figure 1.  Set the cost of
      the routes so that the IGP routes along the Preferred Egress
      Interface is the preferred next-hop.
   2. Send offered load at measured Throughput with fixed packet
      size to destinations matching all IGP routes from Tester to
      DUT on Ingress Interface [Po07t].
   3. Verify traffic routed over Preferred Egress Interface.
   4. Remove IGP adjacency Layer 2 session from Tester's Neighbor Interface [Po07t]
      connected to Preferred Egress Interface.
   5. Measure Rate-Derived First Prefix Convergence Time [Po07t] as DUT detects the
      link down event and begins to converge IGP routes and traffic
      over the Next-Best Egress Interface.
   6. Measure Rate-Derived Convergence Time [Po07t] as DUT detects the
      Layer 2 session failure down event and converges all IGP routes and
      traffic over the Next-Best Egress Interface.
   6.
   7. Stop offered load.  Wait 30 seconds for queues to drain.
      Restart Offered Load.
   7. offered load.
   8. Restore IGP Layer 2 session on DUT's Preferred Egress Interface.
   8.
   9. Measure Restoration Reversion Convergence Time [Po07t] as DUT detects the
      session up event and converges all IGP routes and traffic
      over the Preferred Egress Interface.

   Results
   The measured IGP Convergence time is influenced by the IGP Hello
   Interval, IGP Dead Interval, Layer 2
   failure indication, SPF delay, SPF Hold time, SPF Execution
   Time, Tree Build Time, and Hardware Update Time [Po07a].

   4.4 Convergence Due to Route Withdrawal IGP Adjacency Failure

   Objective
   To obtain the IGP Route Convergence due to Route Withdrawal.

   Procedure
   1. Advertise matching IGP a Local IGP Adjacency
   failure event.

   Procedure
   1. Advertise matching IGP routes from Tester to DUT on
      Preferred Egress Interface [Po07t] and Next-Best Egress Interface
      [Po07t] using the topology shown in Figure 1.  Set the cost of
      the routes so that the Preferred Egress Interface is the
      preferred next-hop.
   2. Send offered load at measured Throughput with fixed packet
      size to destinations matching all IGP routes from Tester to
      DUT on Ingress Interface [Po07t].
   3. Verify traffic routed over Preferred Egress Interface.

                      IGP Data Plane Route Convergence

   4. Tester withdraws all Remove IGP routes adjacency from DUT's Local Tester's Neighbor Interface
      on [Po07t]
      connected to Preferred Egress Interface.

                      IGP Data Plane Route Convergence
   5. Measure Rate-Derived First Prefix Convergence Time [Po07t] as DUT withdraws detects the
      link down event and begins to converge IGP routes and traffic
      over the Next-Best Egress Interface.
   6. Measure Rate-Derived Convergence Time [Po07t] as DUT detects the
      IGP session failure event and converges all IGP routes and
      traffic over the Next-Best Egress Interface.
   6.
   7. Stop offered load.  Wait 30 seconds for queues to drain.
      Restart Offered Load.
   7. Re-advertise offered load.
   8. Restore IGP routes to session on DUT's Preferred Egress Interface.
   8.
   9. Measure Restoration Reversion Convergence Time [Po07t] as DUT detects the
      session up event and converges all IGP routes and traffic
      over the Preferred Egress Interface.

   Results
   The measured IGP Convergence time is the SPF Processing and FIB
   Update time as influenced by the IGP Hello
   Interval, IGP Dead Interval, SPF delay, SPF Hold time, SPF
   Execution Time, Tree Build Time, and Hardware Update Time [Po07a].

   4.5 Convergence Due to Cost Change Route Withdrawal

   Objective
   To obtain the IGP Route Convergence due to route cost change. Route Withdrawal.

   Procedure
   1. Advertise matching IGP routes from Tester to DUT on Preferred
      Egress Interface [Po07t] and Next-Best Egress Interface [Po07t]
      using the topology shown in Figure 1.  Set the cost of the routes
      so that the Preferred Egress Interface is the preferred next-hop.
   2. Send offered load at measured Throughput with fixed packet
      size to destinations matching all IGP routes from Tester to
      DUT on Ingress Interface [Po07t].
   3. Verify traffic routed over Preferred Egress Interface.
   4. Tester increases cost for withdraws all IGP routes at from DUT's Local Interface
      on Preferred Egress Interface so that Interface.
   5. Measure Rate-Derived Convergence Time [Po07t] as DUT withdraws
      routes and converges all IGP routes and traffic over the
      Next-Best Egress Interface
      has lower cost Interface.
   6. Measure First Prefix Convergence Time [Po07t] as DUT detects the
      link down event and becomes preferred path.
   5. begins to converge IGP routes and traffic
      over the Next-Best Egress Interface.
   7. Stop offered load.  Wait 30 seconds for queues to drain.
      Restart offered load.
   8. Re-advertise IGP routes to DUT's Preferred Egress Interface.
   9. Measure Reversion Convergence Time [Po07t] as DUT converges all
      IGP routes and traffic over the Preferred Egress Interface.

   Results
   The measured IGP Convergence time is the SPF Processing and FIB
   Update time as influenced by the SPF delay, SPF Hold time, SPF
   Execution Time, Tree Build Time, and Hardware Update Time [Po07a].

                      IGP Data Plane Route Convergence

   4.6 Convergence Due to Cost Change
   Objective
   To obtain the IGP Route Convergence due to route cost change.

   Procedure
   1. Advertise matching IGP routes from Tester to DUT on Preferred
      Egress Interface [Po07t] and Next-Best Egress Interface [Po07t]
      using the topology shown in Figure 1.  Set the cost of the routes
      so that the Preferred Egress Interface is the preferred next-hop.
   2. Send offered load at measured Throughput with fixed packet
      size to destinations matching all IGP routes from Tester to
      DUT on Ingress Interface [Po07t].
   3. Verify traffic routed over Preferred Egress Interface.
   4. Tester increases cost for all IGP routes at DUT's Preferred
      Egress Interface so that the Next-Best Egress Interface
      has lower cost and becomes preferred path.
   5. Measure First Prefix Convergence Time [Po07t] as DUT detects the
      link down event and begins to converge IGP routes and traffic
      over the Next-Best Egress Interface.
   6. Measure Rate-Derived Convergence Time [Po07t] as DUT detects the
      cost change event and converges all IGP routes and traffic
      over the Next-Best Egress Interface.
   7. Stop offered load.  Wait 30 seconds for queues to drain.
      Restart offered load.
   8. Re-advertise IGP routes to DUT's Preferred Egress Interface
      with original lower cost metric.
   9. Measure Reversion Convergence Time [Po07t] as DUT converges all
      IGP routes and traffic over the Preferred Egress Interface.

   Results
   There should be no measured packet loss for this case.

   4.7 Convergence Due to ECMP Member Interface Failure

   Objective
   To obtain the IGP Route Convergence due to a local link failure event
   of an ECMP Member.

   Procedure
   1. Configure ECMP Set as shown in Figure 3.
   2. Advertise matching IGP routes from Tester to DUT on each ECMP
      member.
   3. Send offered load at measured Throughput with fixed packet size to
      destinations matching all IGP routes from Tester to DUT on Ingress
      Interface [Po07t].
   4. Verify traffic routed over all members of ECMP Set.
   5. Remove link on Tester's Neighbor Interface [Po07t] connected to
      one of the DUT's ECMP member interfaces.
   6. Measure First Prefix Convergence Time [Po07t] as DUT detects the
      link down event and begins to converge IGP routes and traffic
      over the Next-Best Egress Interface.

                      IGP Data Plane Route Convergence

   7. Measure Rate-Derived Convergence Time [Po07t] as DUT detects the
      cost change
      link down event and converges all IGP routes and traffic
      over the Next-Best Egress Interface.
   6. other ECMP members. At the same time measure
      Out-of-Order Packets [Po06] and Duplicate Packets [Po06].
   8. Stop offered load.  Wait 30 seconds for queues to drain.
      Restart Offered Load.
   7. Re-advertise IGP routes offered load.
   9. Restore link on Tester's Neighbor Interface connected to
      DUT's Preferred Egress Interface
      with original lower cost metric.
   8. ECMP member interface.
   10. Measure Restoration Reversion Convergence Time [Po07t] as DUT detects the
      link up event and converges all IGP routes and some distribution
      of traffic over the Preferred Egress Interface. restored ECMP member.

   Results
   There should be no externally observable
   The measured IGP Route Convergence time is influenced by Local link
   failure indication, Tree Build Time, and no measured packet loss for this case.

   4.6 Hardware Update Time
   [Po07a].

   4.8 Convergence Due to ECMP Member Remote Interface Failure

   Objective
   To obtain the IGP Route Convergence due to a local link remote interface
   failure event
   of for an ECMP Member.

                      IGP Data Plane Route Convergence

   Procedure
   1. Configure ECMP Set as shown in Figure 3. 2 in which the links
      from R1 to R2 and R1 to R3 are members of an ECMP Set.
   2. Advertise matching IGP routes from Tester to DUT on SUT to balance
      traffic to each ECMP member.
   3. Send offered load at measured Throughput with fixed packet
      size to destinations matching all IGP routes from Tester to
      DUT
      SUT on Ingress Interface [Po07t].
   4. Verify traffic routed over all members of ECMP Set.
   5. Remove link on Tester's Neighbor Interface to R2 or R3.
   6. Measure First Prefix Convergence Time [Po07t] connected as SUT detects
      the link down event and begins to
      one of converge IGP routes and
      traffic over the DUT's ECMP member interfaces.
   6. Next-Best Egress Interface.
   7. Measure Rate-Derived Convergence Time [Po07t] as DUT SUT detects
      the link down event and converges all IGP routes and traffic
      over the other ECMP members.
   7.  At the same time measure
      Out-of-Order Packets [Po06] and Duplicate Packets [Po06].
   8. Stop offered load.  Wait 30 seconds for queues to drain.
      Restart Offered Load.
   8. offered load.
   9. Restore link on Tester's Neighbor Interface connected to
      DUT's ECMP member interface.
   9. R2 or R3.
   10. Measure Restoration Reversion Convergence Time [Po07t] as DUT SUT detects the
      link up event and converges IGP routes and some distribution
      of traffic over the restored ECMP member.

   Results
   The measured IGP Convergence time is influenced by Local link
   failure indication, Tree Build Time, and Hardware Update Time
   [Po07a].

   4.7

                      IGP Data Plane Route Convergence
   4.9 Convergence Due to Parallel Link Interface Failure

   Objective
   To obtain the IGP Route Convergence due to a local link failure
   event for a Member of a Parallel Link.  The links can be used
   for data Load Balancing

   Procedure
   1. Configure Parallel Link as shown in Figure 4.
   2. Advertise matching IGP routes from Tester to DUT on
      each Parallel Link member.
   3. Send offered load at measured Throughput with fixed packet
      size to destinations matching all IGP routes from Tester to
      DUT on Ingress Interface [Po07t].
   4. Verify traffic routed over all members of Parallel Link.
   5. Remove link on Tester's Neighbor Interface [Po07t] connected to
      one of the DUT's Parallel Link member interfaces.
   6. Measure First Prefix Convergence Time [Po07t] as DUT detects the
      link down event and begins to converge IGP routes and traffic
      over the Next-Best Egress Interface.
   7. Measure Rate-Derived Convergence Time [Po07t] as DUT detects the
      link down event and converges all IGP routes and traffic over
      the other Parallel Link members.
   7.  At the same time measure
      Out-of-Order Packets [Po06] and Duplicate Packets [Po06].
   8. Stop offered load.  Wait 30 seconds for queues to drain.
      Restart Offered Load.
   8. offered load.
   9. Restore link on Tester's Neighbor Interface connected to
      DUT's Parallel Link member interface.

                      IGP Data Plane Route Convergence

   9.
   10. Measure Restoration Reversion Convergence Time [Po07t] as DUT detects the
      link up event and converges IGP routes and some distribution
      of traffic over the restored Parallel Link member.

   Results
   The measured IGP Convergence time is influenced by the Local
   link failure indication, Tree Build Time, and Hardware Update
   Time [Po07a].

5. IANA Considerations

   This document requires no IANA considerations.

6. Security Considerations
   Documents of this type do not directly affect the security of
   the Internet or corporate networks as long as benchmarking
   is not performed on devices or systems connected to operating
   networks.

7. Acknowledgements
   Thanks to Sue Hares, Al Morton, Kevin Dubray, Ron Bonica, David Ward,
   and participants of the BMWG for their contributions to this work.

                      IGP Data Plane Route Convergence

8. References
8.1 Normative References

   [Br91] Bradner, S., "Benchmarking Terminology for Network
          Interconnection Devices", RFC 1242, IETF, March 1991.

   [Br97] Bradner, S., "Key words for use in RFCs to Indicate
   [Br99] Bradner, S. and McQuaid, J., "Benchmarking Methodology for
          Network Interconnect Devices", RFC 2544, IETF, March 1999.

   [Ca90] Callon, R., "Use of OSI IS-IS for Routing in TCP/IP and Dual
          Environments", RFC 1195, IETF, December 1990.

   [Ma98] Mandeville, R., "Benchmarking Terminology for LAN
          Switching Devices", RFC 2285, February 1998.

   [Mo98] Moy, J., "OSPF Version 2", RFC 2328, IETF, April 1998.

   [Po06] Poretsky, S., et al., "Terminology for Benchmarking
          Network-layer Traffic Control Mechanisms", RFC 4689,
          November 2006.

   [Po07a] Poretsky, S., "Considerations for Benchmarking Link-State
           IGP Convergence", draft-ietf-bmwg-igp-dataplane-conv-app-13, draft-ietf-bmwg-igp-dataplane-conv-app-14,
           work in progress, July November 2007.

   [Po07t] Poretsky, S., Imhoff, B., "Benchmarking Terminology for
           Link-State IGP Convergence", draft-ietf-bmwg-igp-dataplane-conv-term-13,
           draft-ietf-bmwg-igp-dataplane-conv-term-14, work in
           progress, July November 2007.

8.2 Informative References
      None
                      IGP Data Plane Route Convergence

9. Author's Address

        Scott Poretsky
        Reef Point Systems
        8 New England Executive Park
        Burlington,
        3 Federal Street
        Billerica, MA 01803 01821
        USA
        Phone: + 1 508 439 9008
        EMail: sporetsky@reefpoint.com

        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

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                      IGP Data Plane Route Convergence

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