Network Working Group
   INTERNET-DRAFT
   Expires in: October December 2005
                                                Scott Poretsky
                                                Quarry Technologies

                                                Brent Imhoff
                                                LightCore

                                       		February

                                                June 2005

                    Benchmarking Methodology for
                  IGP Data Plane Route Convergence

	<draft-ietf-bmwg-igp-dataplane-conv-meth-05.txt>

          <draft-ietf-bmwg-igp-dataplane-conv-meth-06.txt>

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aware will be disclosed, in accordance with RFC 3668. Section 6 of BCP 79.

   Status of this Memo

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   ABSTRACT
   This draft describes the methodology for benchmarking IGP Route
   Convergence as described in Applicability document [1] and
   Terminology document [2].  The methodology and terminology are
   to be used for benchmarking route convergence and can be applied
   to any link-state IGP such as ISIS [3] and OSPF [4].  The terms
   used in the procedures provided within this document are
   defined in [2].

           	      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
     3.3 Reporting Format...........................................6
     4. Test Cases..................................................6 Cases..................................................7
     4.1 Convergence Due to Link Failure............................6 Failure............................7
     4.1.1 Convergence Due to Local Interface Failure...............6 Failure...............7
     4.1.2 Convergence Due to Neighbor Interface Failure............7
     4.1.3 Convergence Due to Remote Interface Failure..............7 Failure..............8
     4.2 Convergence Due to Layer 2 Session Failure.................8 Failure.................9
     4.3 Convergence Due to IGP Adjacency Failure...................9 Failure...................10
     4.4 Convergence Due to Route Withdrawal........................9 Withdrawal........................10
     4.5 Convergence Due to Cost Change.............................10 Change.............................11
     4.6 Convergence Due to ECMP Member Interface Failure...........10 Failure...........12
     4.7 Convergence Due to Parallel Link Interface Failure.........11 Failure.........12
     5. Security Considerations.....................................12 Considerations.....................................13
     6. Normative References........................................12 References........................................13
     7. Author's Address............................................12 Address............................................13

   1. Introduction
   This draft describes the methodology for benchmarking IGP Route
   Convergence.  The applicability of this testing is described in
   [1] and the new terminology that it introduces is defined in [2].
   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 [1].  The
   black-box test designs benchmark the data plane accounting for
   all of the factors contributing to convergence time, as discussed
   in [1].  The methodology (and terminology) for benchmarking route
   convergence can be applied to any link-state  IGP such as ISIS [3]
   and OSPF [4].  These methodologies apply to IPv4 and IPv6 traffic
   as well as IPv4 and IPv6 IGPs.

   2.  Existing definitions
   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", "JUNE", 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

   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.

        ---------       Ingress Interface         ---------
        |       |<------------------------------|       |<--------------------------------|       |
        |       |                                 |       |
        |       |    Preferred Egress Interface   |       |
        |  DUT  |------------------------------>|Tester	|  |-------------------------------->| 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.  In this
   topology the three routers are considered a System Under Test (SUT).
   NOTE: All routers in the SUT must be the same model and identically
   configured.

                -----              	    -----------                       ---------
                |   | Preferred             |       |
        -----   |R2 |---------------------->|	    |
        |   |-->|   | Egress Interface      |       |
        |   |   -----                       |       |
        |R1 |			     	    |  Tester                               |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.  In this topology,
   the DUT
                      IGP Data Plane Route Convergence

   is configured with each Egress interface 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.  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.

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

        Figure 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 BGP Configuration
   The obtained results for IGP Route Convergence may June vary if
   BGP routes are installed.  It is recommended that the IGP
   Convergence times be benchmarked without BGP routes installed.

                      IGP Data Plane Route Convergence

   3.2.3 IGP Route Scaling
   The number of IGP routes will impact the measured IGP Route
   Convergence because convergence for the entire IGP route table is
   measured.   For results similar to those that would be observed in
   an operational network it is recommended that the number of
   installed routes closely approximate that for routers in the
   network.  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. The following timers should be configured to the minimum value
   prior to beginning execution of the test cases:

        Timer                                   Recommended Value
        -----                                   -----------------
        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

   3.2.5 Convergence Time Metrics
   The recommended value for the Packet Sampling Interval [2] is
   100 milliseconds.  Rate-Derived Convergence Time [2] is the
   preferred benchmark for IGP Route Convergence.  This benchmark
   must always be reported when the Packet Sampling Interval [2]
   <= 100 milliseconds.  If the test equipment does not permit
   the Packet Sampling Interval to be set as low as 100 msec,
   then both the Rate-Derived Convergence Time and Loss-Derived
   Convergence Time [2] must be reported.  The Packet Sampling
   Interval value is MUST be the smallest measurable convergence
   time.

   3.2.6 Offered Load
   An offered Load of maximum forwarding rate at a fixed packet size
   is recommended for accurate measurement.  Forwarding Rate 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 destinations for the offered load
   must be distributed such that all routes are matched.  This
   enables Full Convergence [2] to be observed.

   3.2.7 Interface Types
   All test cases in this methodology document may June be executed with
   any interface type.  All interfaces MUST BE be the same media and
   link speed
   Throughout [5,6] for each test case.  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  minimum carrier-loss-delay. carrier-loss-delay or Bi-directional
   Forwarding Detection (BFD) [7].

                      IGP Data Plane Route Convergence

   3.2.7 Offered Load
   The offered Load MUST be the Throughput of the device as defined
   in [5] and benchmarked in [6] at a fixed packet size.  The packet
   size is selectable and MUST be recorded.  The Throughput 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 [2] to be observed.

   3.3 Reporting Format
   For each test case, it is recommended that the following reporting
   format be completed:

        Parameter                                 Units
        ---------                                 -----
   	IGP                                       (ISIS or OSPF)
   	Interface Type                            (GigE, POS, ATM, etc.)
   	Packet Size offered to DUT                bytes
   	IGP Routes advertised to DUT              number of IGP routes
   	Packet Sampling Interval on Tester        seconds or milliseconds
   	IGP Timer Values configured on DUT
	        SONET 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
	        Rate-Derived Convergence Time     seconds or milliseconds
	        Loss-Derived Convergence Time     seconds or milliseconds
	        Restoration Convergence Time      seconds or milliseconds
                      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 [2] and Next-Best Egress Interface
	   [2] 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 traffic offered load at maximum forwarding rate measured Throughput with fixed packet size
           to destinations matching all IGP routes from Tester to DUT on
           Ingress Interface [2].
	3. Verify traffic routed over Preferred Egress Interface.
	4. Remove SONET link on DUT's Local Interface [2] by performing an
	   administrative shutdown of the interface.
	5. Measure Rate-Derived Convergence Time [2] as DUT detects the
	   link down event and converges all IGP routes and traffic over
	   the Next-Best Egress Interface.
	6. Stop offered load.  Wait 30 seconds for queues to drain.
	   Restart Offered Load.
	7. Restore SONET link on DUT's Local Interface by administratively
	   enabling the interface.

           	      IGP Data Plane Route Convergence

	8. Measure Restoration Convergence Time [2] 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
	SONET
	link failure indication, SPF delay, SPF Holdtime, SPF Execution
	Time, Tree Build Time, and Hardware Update Time.

   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 [2] and Next-Best Egress Interface
           [2] 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 traffic offered load at maximum forwarding rate measured Throughput with fixed packet size
           to destinations matching all IGP routes from Tester to DUT on
           Ingress Interface [2].

                      IGP Data Plane Route Convergence

	3. Verify traffic routed over Preferred Egress Interface.
	4. Remove SONET link on Tester's Neighbor Interface [2] connected to
   	   DUT' s Preferred Egress Interface.
	5. Measure Rate-Derived Convergence Time [2] as DUT detects the
	   link down event and converges all IGP routes and traffic over
	   the Next-Best Egress Interface.
	6. Stop offered load.  Wait 30 seconds for queues to drain.
	   Restart Offered Load.
	7. Restore SONET link on Tester's Neighbor Interface connected to
   	   DUT's Preferred Egress Interface.
	8. Measure Restoration Convergence Time [2] 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
	SONET
	link failure indication, SPF delay, SPF Holdtime, SPF Execution
	Time, Tree Build Time, and Hardware Update Time.

   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 [2] and Next-Best Egress Interface
           [2] using the topology shown in Figure 2.  Set the cost of the
           routes so that the Preferred Egress Interface is the preferred
           next-hop.

           	      IGP Data Plane Route Convergence
        2. Send traffic offered load at maximum forwarding rate measured Throughput with fixed packet size
           to destinations matching all IGP routes from Tester to DUT on
           Ingress Interface [2].
        3. Verify traffic is routed over Preferred Egress Interface.
        4. Remove SONET link on Tester's Neighbor Interface [2] connected to
           SUT' s Preferred Egress Interface.
        5. Measure Rate-Derived Convergence Time [2] as SUT detects
           the link down event and converges all IGP routes and traffic
           over the Next-Best Egress Interface.
        6. Stop offered load.  Wait 30 seconds for queues to drain.
           Restart Offered Load.
        7. Restore SONET link on Tester's Neighbor Interface connected to
           DUT's Preferred Egress Interface.
        8. Measure Restoration Convergence Time [2] 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
	SONET
	link failure failure indication, LSA/LSP Flood Packet Pacing,
	LSA/LSP Retransmission Packet Pacing, LSA/LSP Generation
	time, SPF delay, SPF Holdtime, SPF Execution Time, Tree
	Build Time, and Hardware Update Time.  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 to Neighbor Interface
	Failure) from the Rate-Derived Convergence Time measured in
	this test case.

   4.2 Convergence Due to Layer 2 Session Failure
	Objective
	To obtain the IGP Route Convergence due to a Local Layer 2 Session
	failure event.

	Procedure
	1. Advertise matching IGP routes from Tester to DUT on
           Preferred Egress Interface [2] and Next-Best Egress Interface
	   [2] 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 traffic offered load at maximum forwarding rate measured Throughput with fixed packet size
           to destinations matching all IGP routes from Tester to DUT on
           Ingress Interface [2].
	3. Verify traffic routed over Preferred Egress Interface.
	4. Remove Layer 2 session from Tester's Neighbor Interface [2]
	   connected to Preferred Egress Interface.
	5. Measure Rate-Derived Convergence Time [2] as DUT detects the
	   Layer 2 session down event and converges all IGP routes and
	   traffic over the Next-Best Egress Interface.
	6. Restore Layer 2 session on DUT's Preferred Egress Interface.
	7. Measure Restoration Convergence Time [2] as DUT detects the
	   session up event and converges all IGP routes and traffic over
	   the Preferred Egress Interface.

           	      IGP Data Plane Route Convergence

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

                      IGP Data Plane Route Convergence

   4.3 Convergence Due to IGP Adjacency Failure

	Objective
	To obtain the IGP Route Convergence due to a Local IGP Adjacency
	failure event.

	Procedure
	1. Advertise matching IGP routes from Tester to DUT on
           Preferred Egress Interface [2] and Next-Best Egress Interface
	   [2] 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 traffic offered load at maximum forwarding rate measured Throughput with fixed packet size
           to destinations matching all IGP routes from Tester to DUT on
           Ingress Interface [2].
	3. Verify traffic routed over Preferred Egress Interface.
	4. Remove IGP adjacency from Tester's Neighbor Interface [2]
	   connected to Preferred Egress Interface.
	5. Measure Rate-Derived Convergence Time [2] as DUT detects the
	   IGP session failure event and converges all IGP routes and
	   traffic over the Next-Best Egress Interface.
	6. Stop offered load.  Wait 30 seconds for queues to drain.
	   Restart Offered Load.
	7. Restore IGP session on DUT's Preferred Egress Interface.
	8. Measure Restoration Convergence Time [2] 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, SPF delay, SPF Holdtime,
	SPF Execution Time, Tree Build Time, and Hardware Update
	Time.

  4.4 Convergence Due to Route Withdrawal

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

	Procedure
	1. Advertise matching IGP routes from Tester to DUT on
         Preferred Egress Interface [2] and Next-Best Egress Interface
	   [2] 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 traffic offered load at maximum forwarding rate measured Throughput with fixed packet size
           to destinations matching all IGP routes from Tester to DUT on
           Ingress Interface [2].

                      IGP Data Plane Route Convergence

	3. Verify traffic routed over Preferred Egress Interface.
	4. Tester withdraws all IGP routes from DUT's Local Interface
	   on Preferred Egress Interface.
	5. Measure Rate-Derived Convergence Time [2] as DUT detects the
	   Layer 2 session down event and converges all IGP routes and
	   traffic over the Next-Best Egress Interface.
	6. Stop offered load.  Wait 30 seconds for queues to drain.
	   Restart Offered Load.
	7. Re-advertise IGP routes to DUT's Preferred Egress Interface.
	8. Measure Restoration Convergence Time [2] 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 Holdtime,
	SPF Execution Time, Tree Build Time, and Hardware Update Time.

   4.5 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 [2] and Next-Best Egress Interface
	   [2] 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 traffic offered load at maximum forwarding rate measured Throughput with fixed packet size
           to destinations matching all IGP routes from Tester to DUT
           on Ingress Interface [2].
	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 Rate-Derived Convergence Time [2] as DUT detects the
	   cost change event and converges all IGP routes and traffic
	   over the Next-Best Egress Interface.
	6. Stop offered load.  Wait 30 seconds for queues to drain.
	   Restart Offered Load.
	7. Re-advertise IGP routes to DUT's Preferred Egress Interface
	   with original lower cost metric.
	8. Measure Restoration Convergence Time [2] as DUT converges all
	   IGP routes and traffic over the Preferred Egress Interface.

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

                      IGP Data Plane Route Convergence

    4.6 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.

           	      IGP Data Plane Route Convergence

	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 traffic offered load at maximum forwarding rate measured Throughput with fixed packet size
           to destinations matching all IGP routes from Tester to DUT on
           Ingress Interface [2].
	4. Verify traffic routed over all members of ECMP Set.
	5. Remove SONET link on Tester's Neighbor Interface [2] connected to
   	   one of the DUT's ECMP member interfaces.
	6. Measure Rate-Derived Convergence Time [2] as DUT detects the
	   link down event and converges all IGP routes and traffic
	   over the other ECMP members.
	7. Stop offered load.  Wait 30 seconds for queues to drain.
	   Restart Offered Load.
	8. Restore SONET link on Tester's Neighbor Interface connected to
   	   DUT's ECMP member interface.
	9. Measure Restoration Convergence Time [2] as DUT 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 the Local
	SONET
	link failure indication, Tree Build Time, and Hardware Update Time.

   4.7 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 traffic offered load at maximum forwarding rate measured Throughput with fixed packet size
           to destinations matching all IGP routes from Tester to DUT on
           Ingress Interface [2].
	4. Verify traffic routed over all members of Parallel Link.
	5. Remove SONET link on Tester's Neighbor Interface [2] connected to
   	   one of the DUT's Parallel Link member interfaces.
	6. Measure Rate-Derived Convergence Time [2] as DUT detects the
	   link down event and converges all IGP routes and traffic over
	   the other Parallel Link members.
	7. Stop offered load.  Wait 30 seconds for queues to drain.
	   Restart Offered Load.

                      IGP Data Plane Route Convergence

	8. Restore SONET link on Tester's Neighbor Interface connected to
   	   DUT's Parallel Link member interface.

           	      IGP Data Plane Route Convergence
	9. Measure Restoration Convergence Time [2] 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
	SONET
	link failure indication, Tree Build Time, and Hardware Update Time.

   5. 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.

   6. Normative References
      [1] Poretsky, S., "Benchmarking Applicability for IGP
            Convergence", draft-ietf-bmwg-igp-dataplane-conv-app-05, draft-ietf-bmwg-igp-dataplane-conv-app-06, work
            in progress, February June 2005.

      [2] Poretsky, S., Imhoff, B., "Benchmarking Terminology for IGP
            Convergence", draft-ietf-bmwg-igp-dataplane-conv-term-05, draft-ietf-bmwg-igp-dataplane-conv-term-06, work
            in progress, February June 2005

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

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

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

      [6] Bradner, S. and McQuaid, J., "Benchmarking Methodology for
            Network Interconnect Devices", RFC 2544, IETF, March 1999.

      [7] Katz, D. and Ward, D., "Bidirectional Forwarding Detection",
            draft-ietf-bfd-base-02.txt, work in progress, IETF,
            March 2005.

   7. Author's Address

        Scott Poretsky
        Quarry Technologies
        8 New England Executive Park
        Burlington, MA 01803
        USA

        Phone: + 1 781 395 5090
        EMail: sporetsky@quarrytech.com
                      IGP Data Plane Route Convergence

        Brent Imhoff
        LightCore
        USA
        EMail: bimhoff@planetspork.com
           	      IGP Data Plane Route Convergence

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