Network Working Group INTERNET-DRAFT Expires in: October 2005 Scott Poretsky Quarry Technologies Brent Imhoff LightCore February 2005 Benchmarking Methodology for IGP Data Plane Route Convergence Intellectual Property Rights (IPR) statement: By submitting this Internet-Draft, I certify that any applicable patent or other IPR claims of which I am aware have been disclosed, or will be disclosed, and any of which I become aware will be disclosed, in accordance with RFC 3668. Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. 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]. Poretsky and Imhoff [Page 1] INTERNET-DRAFT Benchmarking Methodology for February 2005 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 4.1 Convergence Due to Link Failure............................6 4.1.1 Convergence Due to Local Interface Failure...............6 4.1.2 Convergence Due to Neighbor Interface Failure............7 4.1.3 Convergence Due to Remote Interface Failure..............7 4.2 Convergence Due to Layer 2 Session Failure.................8 4.3 Convergence Due to IGP Adjacency Failure...................9 4.4 Convergence Due to Route Withdrawal........................9 4.5 Convergence Due to Cost Change.............................10 4.6 Convergence Due to ECMP Member Interface Failure...........10 4.7 Convergence Due to Parallel Link Interface Failure.........11 5. Security Considerations.....................................12 6. Normative References........................................12 7. Author's Address............................................12 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", 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. Poretsky and Imhoff [Page 2] INTERNET-DRAFT Benchmarking Methodology for February 2005 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 | | | | | | |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>| | | | 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 | | | ----- | | | |-->| | 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 Poretsky and Imhoff [Page 3] INTERNET-DRAFT Benchmarking Methodology for February 2005 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 vary if BGP routes are installed. It is recommended that the IGP Convergence times be benchmarked without BGP routes installed. Poretsky and Imhoff [Page 4] INTERNET-DRAFT Benchmarking Methodology for February 2005 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 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 be executed with any interface type. All interfaces MUST BE the same media and link speed 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. Poretsky and Imhoff [Page 5] INTERNET-DRAFT Benchmarking Methodology for February 2005 IGP Data Plane Route Convergence 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 bytes IGP Routes number of IGP routes Packet Sampling Interval seconds or milliseconds IGP Timer Values 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 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 at maximum forwarding rate 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 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 on DUT's Local Interface by administratively enabling the interface. Poretsky and Imhoff [Page 6] INTERNET-DRAFT Benchmarking Methodology for February 2005 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 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 at maximum forwarding rate 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 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 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 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. Poretsky and Imhoff [Page 7] INTERNET-DRAFT Benchmarking Methodology for February 2005 IGP Data Plane Route Convergence 2. Send traffic at maximum forwarding rate 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 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 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 SONET 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 at maximum forwarding rate 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. Poretsky and Imhoff [Page 8] INTERNET-DRAFT Benchmarking Methodology for February 2005 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. 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 at maximum forwarding rate 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 at maximum forwarding rate to destinations matching all IGP routes from Tester to DUT on Ingress Interface [2]. Poretsky and Imhoff [Page 9] INTERNET-DRAFT Benchmarking Methodology for February 2005 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. 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 at maximum forwarding rate 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. 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. Poretsky and Imhoff [Page 10] INTERNET-DRAFT Benchmarking Methodology for February 2005 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 at maximum forwarding rate 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 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 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 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 at maximum forwarding rate 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 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. 8. Restore SONET on Tester's Neighbor Interface connected to DUT's Parallel Link member interface. Poretsky and Imhoff [Page 11] INTERNET-DRAFT Benchmarking Methodology for February 2005 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 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, work in progress, February 2005. [2] Poretsky, S., Imhoff, B., "Benchmarking Terminology for IGP Convergence", draft-ietf-bmwg-igp-dataplane-conv-term-05, work in progress, February 2005 [3] Callon, R., "Use of OSI IS-IS for Routing in TCP/IP and Dual Environments", RFC 1195, December 1990. [4] Moy, J., "OSPF Version 2", RFC 2328, IETF, April 1998. 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 Brent Imhoff LightCore USA EMail: bimhoff@planetspork.com Poretsky and Imhoff [Page 12] INTERNET-DRAFT Benchmarking Methodology for February 2005 IGP Data Plane Route Convergence Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intel- lectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this docu- ment or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. 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Disclaimer of Warranty This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMA- TION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2005). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Poretsky and Imhoff [Page 13]