Network Working Group Internet Draft Expires: May 2008 Intended Status: Informational S. Poretsky Reef Point Systems R. Papneja Isocore J. Karthik S. Vapiwala Cisco Systems November 2007 Benchmarking Terminology for Protection Performance <draft-ietf-bmwg-protection-term-03.txt > Intellectual Property Rights (IPR) statement: By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Status of this Memo 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. Copyright Notice Copyright (C) The IETF Trust (2007). Abstract This document provides common terminology and metrics for benchmarking the performance of sub-IP layer protection mechanisms. The performance benchmarks are measured at the IP-Layer, so avoid dependence on specific sub-IP protection mechanisms. The benchmarks and terminology can be applied in methodology documents for different sub-IP layer protection mechanisms such as Automatic Protection Switching (APS), Virtual Router Redundancy Protocol (VRRP), Stateful High Availability (HA), and Multi-Protocol Label Switching Fast Reroute (MPLS-FRR). Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 1]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance Table of Contents 1. Introduction..............................................3 2. Existing definitions......................................4 3. Test Considerations.......................................5 3.1. Path.................................................5 3.1.1. Path............................................5 3.1.2. Working Path....................................6 3.1.3. Primary Path....................................6 3.1.4. Protected Primary Path..........................6 3.1.5. Backup Path.....................................7 3.1.6. Standby Backup Path.............................8 3.1.7. Dynamic Backup Path.............................8 3.1.8. Disjoint Paths..................................8 3.1.9. Shared Risk Link Group (SRLG)...................9 3.2. Protection...........................................9 3.2.1. Protection Switching System.....................9 3.2.2. Link Protection.................................10 3.2.3. Node Protection.................................10 3.2.4. Path Protection.................................10 3.2.5. Backup Span.....................................11 3.2.6 Protected Interface.............................11 3.3. Protection Switching.................................12 3.3.1. Failover Event..................................12 3.3.2. Failure Detection...............................12 3.3.3. Failover........................................13 3.3.4. Restoration.....................................13 3.3.5. Reversion.......................................14 3.4. Nodes................................................14 3.4.1. Protection-Switching Node.......................14 3.4.2. Non-Protection Switching Node...................14 3.4.3. Failover Node...................................15 3.4.4. Merge Node......................................15 3.4.5. Point of Local repair (PLR).....................16 3.4.6. Head-end Failover Node..........................16 3.5. Benchmarks...........................................17 3.5.1. Failover Packet Loss............................17 3.5.2. Reversion Packet Loss...........................17 3.5.3. Failover Time...................................18 3.5.4. Reversion Time..................................18 3.5.5. Additive Backup Latency.........................19 3.6 Failover Time Calculation Methods.....................19 3.6.1 Time-Based Loss Method...........................19 3.6.2 Packet-Loss Based Method.........................20 3.6.3 Timestamp-Based Method...........................21 4. Acknowledgments...........................................22 5. IANA Considerations.......................................22 6. Security Considerations...................................22 7. References................................................22 8. Author's Address..........................................23 Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 2]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 1. Introduction The IP network layer provides route convergence to protect data traffic against planned and unplanned failures in the internet. Fast convergence times are critical to maintain reliable network connectivity and performance. Technologies that function at sub-IP layers can be enabled to provide further protection of IP traffic by providing the failure recovery at the sub-IP layers so that the outage is not observed at the IP-layer. Such technologies includes High Availability (HA) stateful failover. Virtual Router Redundancy Protocol (VRRP), Automatic Link Protection (APS) for SONET/SDH, Resilient Packet Ring (RPR) for Ethernet, and Fast Reroute for Multi-Protocol Label Switching (MPLS-FRR) [8]. Benchmarking terminology have been defined for IP-layer route convergence [7]. New terminology and methodologies specific to benchmarking sub-IP layer protection mechanisms are required. This will enable different implementations of the same protection mechanisms to be benchmarked and evaluated. In addition, different protection mechanisms can be benchmarked and evaluated. The metrics for benchmarking the performance of sub-IP protection mechanisms are measured at the IP layer, so that the results are always measured in reference to IP and independent of the specific protection mechanism being used. The purpose of this document is to provide a single terminology for benchmarking sub-IP protection mechanisms. It is intended that there can exist unique methodology documents for each sub-IP protection mechanism. The sequence of events is as follows: 1. Failover Event - Primary Path fails 2. Failure Detection- Failover Event is detected 3. Failover - Backup Path becomes the Working Path due to Failover Event 4. Restoration - Primary Path recovers from a Failover Event 5. Reversion (optional) - Primary Path becomes the Working Path These terms are further defined in this document. Figure 1 shows the fundamental model that is to be used in benchmarking sub-IP protection mechanisms. A Protection Switching consists of a minimum of two Protection-Switching Nodes with a Primary Path and a Backup Path. A Failover Event occurs along the Primary Path. A Tester is set outside the two nodes as it sends and receives IP traffic along the Working Path. The Working Path is the Primary Path prior to the Failover Event and the Backup Path after the Failover Event. If Reversion is supported then the Working Path is the Primary Path after Restoration (Failure Recovery) of the Primary Path. The tester MUST record the IP packet sequence numbers, departure time, and arrival time so that the metrics of Failover Time, Additive Latency, Packet Reordering, Duplicate Packets, and Reversion Time can be measured. The Tester may be a single device or a test system. Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 3]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance +-----------+ +--------------------| Tester |<-------------------+ | +-----------+ | | IP Traffic | Failover IP Traffic | | | Event | | Primary | | | +--------+ Path v +--------+ | | | |------------------------>| | | +--->| Node 1 | | Node 2 |----+ | |- - - - - - - - - - - - >| | +--------+ Backup Path +--------+ ^ ^ | IP-Layer Forwarding | +-------------------------------------------+ Figure 1. System Under Test (SUT) for Sub-IP Protection Mechanisms 2. Existing definitions This document uses existing terminology defined in other BMWG work. Examples include, but are not limited to: Latency [Ref.[2], section 3.8] Frame Loss Rate [Ref.[2], section 3.6] Throughput [Ref.[2], section 3.17] Device Under Test (DUT) [Ref.[3], section 3.1.1] System Under Test (SUT) [Ref.[3], section 3.1.2] Out-of-order Packet [Ref.[4], section 3.3.2] Duplicate Packet [Ref.[4], section 3.3.3] Forwarding Delay [Ref.[4], section 3.2.4] Jitter [Ref.[4], section 3.2.5] Packet Loss [Ref.[7], Section 3.5] Packet Reordering [Ref.[10], section 3.3] This document has the following frequently used acronyms: DUT Device Under Test SUT System Under Test This document adopts the definition format in Section 2 of RFC 1242 [2]. 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 [5]. 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, Papneja, Karthik, Vapiwala Expires May 2008 [Page 4]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 3. Test Considerations 3.1. Path 3.1.1 Path Definition: A unidirectional sequence of nodes, <R1, ..., Rn>, and links <L12,... L(n-1)n> with the following properties: a. R1 is the ingress node and forwards IP packets, which input into DUT/SUT, to R2 as sub-IP frames over link L12. b. Ri is a node which forwards data frames to R[i+1] over Link Li[i+1] for all i, 1<i<n, based on information in the sub-IP layer. c. Rn is the egress node and it outputs sub-IP frames from DUT/SUT as IP packets. Discussion: The path is defined in the sub-IP layer in this document, unlike an IP path in RFC 2026 [1]. One path may be regarded as being equivalent to one IP link between two IP nodes, i.e., R1 and Rn. The two IP nodes may have multiple paths for protection. A packet will travel on only one path between the nodes. Packets belonging to a microflow [9] will traverse one or more paths. The path is unidirectional. Example paths are the SONET/SDH path and the label switched path for MPLS. Measurement units: n/a Issues: "A bidirectional path", which transmits traffic in both directions along the same nodes, consists of two unidirectional paths. Therefore, the two unidirectional paths belonging to "one bidirectional path" will be treated independently when benchmarking for "a bidirectional path". See Also: Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 5]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 3.1.2. Working Path Definition: The path that the DUT/SUT is currently using to forward packets. Discussion: A Primary Path is the Working Path before occurrence of a Failover Event. A Backup Path becomes the Working Path after a Failover Event. Measurement units: n/a Issues: See Also: Path Primary Path Backup Path 3.1.3. Primary Path Definition: The preferred path for forwarding traffic between two or more nodes. Discussion: Measurement units: n/a Issues: None See Also: Path 3.1.4. Protected Primary Path Definition: A Primary Path that is protected with a Backup Path. Discussion: A Protected Primary Path MUST include at least one Protection Switching Node. Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 6]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance Measurement units: n/a Issues: None See Also: Path Primary Path 3.1.5. Backup Path Definition: A path that exists to carry data traffic only if a Failover Event occurs on a Primary Path. Discussion: The Backup Path SHALL be the Working Path upon a Failover Event. A Path MAY have one or more Backup Paths. A Backup Path MAY protect one or more Primary Paths. There are various types of Backup Paths: a. dedicated recovery Backup Path (1+1), which has 100% redundancy for a specific ordinary path, b. shared Backup Path (1:N), which is dedicated to the protection for more than one specific Primary Path c. associated shared Backup Path (M:N) for which a specific set of Backup Paths protects a specific set of more than one Primary Path. A Backup Path may be signaled or unsignaled. The Backup Path MUST be created prior to the Failover Event. A new Path computed after the Failover Event is simply Convergence [7] to a new Primary Path. Measurement units: n/a Issues: See Also: Path Working Path Primary Path Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 7]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 3.1.6. Standby Backup Path Definition: A Backup Path that is established prior to a Failover Event to protect a Primary Path. Discussion: Measurement units: n/a Issues: See Also: Path Working Path Primary Path Failover Event 3.1.7. Dynamic Backup Path Definition: A Backup Path that is established upon occurrence of a Failover Event. Discussion: Measurement units: n/a Issues: See Also: Path Working Path Primary Path Failover Event 3.1.8. Disjoint Paths Definition: A pair of paths is considered disjoint if they do not share a common link. Discussions: Paths that protect a segment of a path may merge beyond the segment being protected and are considered disjoint if they do not use a link from the set of links in the protected segment. A path is node disjoint if it does not share a common node other than the ingress and egress. Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 8]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance Measurement units: n/a Issues: See Also: Path Primary Path SRLG 3.1.9. Shared Risk Link Group (SRLG) Definition: SRLG is a set of links which share a physical resource. Discussion: SRLG is considered the set of links to be avoided when the primary and secondary paths are considered disjoint. The SRLG will fail as a group if the shared resource fails. Measurement units: n/a Issues: None See Also: Path Primary Path 3.2. Protection 3.2.1. Protection Switching System Definition: A DUT/SUT that is capable of Failure Detection and Failover from a Primary Path to a Backup Path when a Failover Event occurs. Discussion: The Protection Switching System MUST have a Primary Path and a Backup Path. The Backup Path MAY be a Standby Backup Path or a dynamic Backup Path. The Protection Switching System includes the mechanisms for both Failure Detection and Failover. Measurement units: n/a Issues: None See Also: Primary Path Backup Path Failover Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 9]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 3.2.2. Link Protection Definition: A Backup Path that is signaled to protect for failure of interfaces and links along a Primary Path. Discussion: Link Protection may or may not protect the entire Primary Path. Measurement units: n/a Issues: None See Also: Primary Path Backup Path 3.2.3. Node Protection Definition: A Backup Path that is signaled to protect for failure of interfaces, links and nodes along a Primary Path. Discussion: Node Protection may or may not protect the entire Primary Path. Node Protection also provides Link Protection. Measurement units: n/a Issues: None See Also: Link Protection 3.2.4. Path Protection Definition: A Backup Path that provides protection for the entire Primary Path. Discussion: Path Protection provides Node Protection and Link Protection for every node and link along the Primary Path. A Backup Path providing Path Protection MUST have the same ingress node as the Primary Path. Measurement units: n/a Issues: None Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 10]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance See Also: Primary Path Backup Path Node Protection Link protection 3.2.5. Backup Span Definition: The numbers of hop used by a Backup Path. Discussion: Measurement units: number of nodes Issues: None See Also: Primary Path Backup Path 3.2.6 Protected Interface Definition: An interface along the Primary Path that is protected by a Backup Path Discussion: Measurement units: None Issues: None See Also: Primary Path Backup Path Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 11]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 3.3. Protection Switching 3.3.1. Failover Event Definition: The occurrence of a planned or unplanned action in the network that results in a change in the Path that data traffic traverses. Discussion: Failover Events include, but are not limited to, link failure and router failure. Routing changes are considered Convergence Events [7] and are not Failover Events. This restricts Failover Events to sub-IP layers. Failover may be at the PLR or at the ingress. If the failover is at the ingress it is generally on a disjoint path from the ingress to egress. Measurement units: n/a Issues: See Also: Path Failure Detection Disjoint Path 3.3.2. Failure Detection Definition: The process to identify at a sub-IP layer a Failover Event along the Primary Path. Discussion: Failure Detection occurs at the ingress node of the Primary Path. Failure Detection occurs via a sub-IP mechanism such as detection of a link down event or timeout for receipt of a control packet. A failure may be completely isolated. A failure may affect a set of links which share a single SRLG (e.g. port with many sub-interfaces). A failure may affect multiple links that are not part of SRLG. Measurement units: n/a Issues: See Also: Primary Path Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 12]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 3.3.3. Failover Definition: The process to switch data traffic from the Protected Primary Path to the Backup Path upon Failure Detection of a Failover Event. Discussion: Failover to a Backup Path provides Link Protection, Node Protection, or Path Protection. Failover is complete when Packet Loss [7], Out-of-order Packets [4], and Duplicate Packets [4] are no longer observed. Forwarding Delay [4] may continue to be observed. Measurement units: n/a Issues: See Also: Primary Path Backup Path Failover Event 3.3.4. Restoration Definition: The act of failover recovery in which the Primary Path recovers from a Failover Event, but is not yet forwarding packets because the Backup Path remains the Working Path. Discussion: Restoration MUST occur while the Backup Path is the Working Path. The Backup Path is maintained as the Working Path during Restoration. Restoration produces a Primary Path that is recovered from failure, but is not yet forwarding traffic. Traffic is still being forwarded by the Backup Path functioning as the Working Path. Measurement units: n/a Issues: See Also: Primary Path Failover Event Failure Recovery Working Path Backup Path Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 13]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 3.3.5. Reversion Definition: The act of failover recovery in which the Primary Path becomes the Working Path so that it is forwarding packets. Discussion: Protection Switching Systems may or may not support Reversion. Reversion, if supported, MUST occur after Restoration. Packet forwarding on the Primary Path resulting from Reversion may occur either fully or partially over the Primary Path. A potential problem with Reversion is the discontinuity in end to end delay when the Forwarding Delays [4] along the Primary Path and Backup Path are different, possibly causing Out of Order Packets [4], Duplicate Packets [4], and increased Jitter [4]. Measurement units: n/a Issues: None See Also: Protection Switching System Working Path Primary Path 3.4. Nodes 3.4.1. Protection-Switching Node Definition: A node that is capable to participate in a Protection Switching System. Discussion: The Protection Switching Node MAY be an ingress or egress for a Primary Path or Backup Path. Measurement units: n/a Issues: See Also: Protection Switching System 3.4.2. Non-Protection Switching Node Definition: A node that is not capable of participating in a Protection Switching System, however it MAY exist along the Primary Path or Backup Path. Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 14]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance Discussion: Measurement units: n/a Issues: See Also: Protection Switching System Primary Path Backup Path 3.4.3. Failover Node Definition: A node along the Primary Path that is capable of Failover. Discussion: The Failover Node can be any node along the Primary Path except the egress node of the Primary Path. There can be multiple Failover Nodes along a Primary Path. The Failover Node MUST be the ingress to the Backup Path. The Failover Node MAY also be the ingress of the Primary Path. Measurement units: n/a Issues: See Also: Primary Path Backup Path Failover 3.4.4. Merge Node Definition: A Node along the primary path where backup path terminates. Discussion: The Merge Node can be any node along the Primary Path except the ingress node of the Primary Path. There can be multiple Merge Nodes along a Primary Path. A Merge Node can be the egress node for a single or multiple Backup Paths. The Merge Node MUST be the egress to the Backup Path. The Merge Node MAY also be the egress of the Primary Path or point of local repair (PLR). Measurement units: n/a Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 15]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance Issues: See Also: Primary Path Backup Path PLR Failover 3.4.5. Point of Local Repair (PLR) Definition: A node along the Primary Path that uses a Backup Path to protect another node or link. Discussion: Based on the functionality of the PLR, its role is defined based on the type of method used. If the one-to-one backup method is used, the PLR is responsible for computing a separate Backup Path for each Primary Path. In the case the facility backup method is used, the PLR creates a single Backup Path that can be used to protect multiple Primary Paths. Measurement units: n/a Issues: See Also: Primary Path Backup Path Failover 3.4.6. Head-end Failover Node Definition: A node along the Primary Path that is capable of Failover. Discussion: The Head-end Failover Node is the ingress node to the Backup Path. The Head-end Failover Node is always a PLR Measurement units: n/a Issues: See Also: Primary Path Point of Local Repair Failover Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 16]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 3.5. Benchmarks 3.5.1. Failover Packet Loss Definition: The amount of packet loss produced by a Failover Event until Failover completes, where the measurement begins when the last unimpaired packet is received by the Tester on the Protected Primary Path and ends when the first unimpaired packet is received by the Tester on the Backup Path. Discussion: Packet loss can be observed as a reduction of forwarded traffic from the maximum forwarding rate. Failover Packet Loss includes packets that were lost, reordered, or delayed. Failover Packet Loss MAY reach 100% of the offered load. Measurement units: Number of Packets Issues: None See Also: Failover Event Failover 3.5.2. Reversion Packet Loss Definition: The amount of packet loss produced by Reversion, where the measurement begins when the last unimpaired packet is received by the Tester on the Backup Path and ends when the first unimpaired packet is received by the Tester on the Protected Primary Path . Discussion: Packet loss can be observed as a reduction of forwarded traffic from the maximum forwarding rate. Reversion Packet Loss includes packets that were lost, reordered, or delayed. Reversion Packet Loss MAY reach 100% of the offered load. Measurement units: Number of Packets Issues: None See Also: Reversion Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 17]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 3.5.3. Failover Time Definition: The amount of time it takes for Failover to successfully complete. Discussion: Failover Time can be calculated using the Time-Based Loss Method (TBLM), Packet-Loss Based Method (PLBM), or Timestamp-Based Method (TBM). It is RECOMMENDED that the TBM is used. Measurement units: milliseconds Issues: None See Also: Failover Failover Time Time-Based Loss Method (TBLM) Packet-Loss Based Method (PLBM) Timestamp-Based Method (TBM) 3.5.4. Reversion Time Definition: The amount of time it takes for Reversion to complete so that the Primary Path is restored as the Working Path. Discussion: Reversion Time can be calculated using the Time-Based Loss Method (TBLM), Packet-Loss Based Method (PLBM), or Timestamp-Based Method (TBM). It is RECOMMENDED that the TBM is used. Measurement units: milliseconds Issues: None See Also: Reversion Primary Path Working Path Reversion Packet Loss Time-Based Loss Method (TBLM) Packet-Loss Based Method (PLBM) Timestamp-Based Method (TBM) Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 18]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 3.5.5. Additive Backup Delay Definition: The amount of increased Forwarding Delay [4] resulting from data traffic traversing the Backup Path instead of the Primary Path. Discussion: Additive Backup Delay is calculated using Equation 1 as shown below: (Equation 1) Additive Backup Delay = Forwarding Delay(Backup Path) - Forwarding Delay(Primary Path). Measurement units: milliseconds Issues: Additive Backup Latency MAY be a negative result. This is theoretically possible, but could be indicative of a sub-optimum network configuration . See Also: Primary Path Backup Path Primary Path Latency Backup Path Latency 3.6 Failover Time Calculation Methods 3.6.1 Time-Based Loss Method (TBLM) Definition: The method to calculate Failover Time (or Reversion Time) using a time scale on the Tester to measure the interval of Failover Packet Loss. Discussion: The Tester MUST provide statistics which show the duration of failure on a time scale to granularity of milliseconds based on occurrence of packet loss on a time scale. This is indicated by the duration of non-zero packet loss. The TBLM includes failure detection time and time for data traffic to begin traversing the Backup Path. Failover Time and Reversion Time are calculated using the TBLM as shown in Equation 2: Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 19]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance (Equation 2) (Equation 2a) TBLM Failover Time = Time(Failover) - Time(Failover Event) (Equation 2b) TBLM Reversion Time = Time(Reversion) - Time(Restoration) Measurement units: milliseconds Issues: None See Also: Failover Packet-Loss Based Method 3.6.2 Packet-Loss Based Method (PLBM) Definition: The method used to calculate Failover Time (or Reversion Time) from the amount of Failover Packet Loss. Discussion: PLBM includes failure detection time and time for data traffic to begin traversing the Backup Path. Failover Time can be calculated using PLBM from the amount Failover Packet Loss as shown below in Equation 3: (Equation 3) (Equation 3a) PLBM Failover Time = Number of packets lost / (Offered Load rate * 1000) (Equation 3b) PLBM Restoration Time = Number of packets lost / (Offered Load rate * 1000) Units are packets/(packets/second) = seconds Measurement units: milliseconds Issues: None See Also: Failover Time-Based Loss Method Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 20]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 3.6.3 Timestamp-Based Method (TBM) Definition: The method to calculate Failover Time (or Reversion Time) using a time scale to quantify the interval between unimpaired packets arriving in the test stream. Discussion: The purpose of this method is to quantify the duration of failure or reversion on a time scale with granularity of milliseconds based on the observation of unimpaired packets, using Equation 2 with the difference being that the time values are obtained from the timestamp in the packet payload rather than from the Tester. Unimpaired packets are normal packets that are not lost, reordered, or duplicated. A reordered packet is defined in [10, section 3.3]. A duplicate packet is defined in [4, section 3.3.3]. A lost packet is defined in [7, Section 3.5]. Unimpaired packets may be detected by checking a sequence number in the payload, where the sequence number equals the next expected number for an unimpaired packet. A sequence gap or sequence reversal indicates impaired packets. For calculating Failover Time, the TBM includes failure detection time and time for data traffic to begin traversing the Backup Path. For calculating Reversion Time, the TBM includes Reversion Time and time for data traffic to begin traversing the Primary Path. Measurement units: milliseconds Issues: None See Also: Failover Failover Time Reversion Reversion Time Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 21]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 4. Acknowledgements We would like thank the BMWG and particularly Al Morton and Curtis Villamizar for their reviews, comments, and contributions to this work. 5. IANA Considerations This document requires no IANA considerations. 6. Security Considerations This document only addresses terminology for the performance benchmarking of protection systems, and the information contained in this document has no effect on the security of the Internet. 7. References 7.1. Normative References [1] Bradner, S., "The Internet Standards Process -- Revision 3", RFC 2026, October 1996. [2] Bradner, S., Editor, "Benchmarking Terminology for Network Interconnection Devices", RFC 1242, July 1991. [3] Mandeville, R., "Benchmarking Terminology for LAN Switching Devices", RFC 2285, February 1998. [4] Poretsky, S., et al., "Terminology for Benchmarking Network-layer Traffic Control Mechanisms", RFC 4689, November 2006. [5] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, July 1997. [6] Paxson, V., et al., "Framework for IP Performance Metrics", RFC 2330, May 1998. [7] Poretsky, S., Imhoff, B., "Benchmarking Terminology for IGP Convergence", draft-ietf-bmwg-igp-dataplane-conv-term-13, work in progress, July 2007. [8] Pan., P. et al, "Fast Reroute Extensions to RSVP-TE for LSP Paths", RFC 4090, May 2005. [9] Nichols, K., et al, "Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers", RFC 2474, December 1998. [10] Morton, A., et al, "Packet Reordering Metrics", RFC 4737, November 2006. 7.2. Informative References None Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 22]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance 8. Author's Address Scott Poretsky Reef Point Systems 8 New England Executive Park Burlington, MA 01803 USA Phone: + 1 508 439 9008 EMail: sporetsky@reefpoint.com Rajiv Papneja Isocore 12359 Sunrise Valley Drive Reston, VA 22102 USA Phone: 1 703 860 9273 Email: rpapneja@isocore.com Jay Karthik Cisco Systems 300 Beaver Brook Road Boxborough, MA 01719 USA Phone: +1 978 936 0533 Email: jkarthik@cisco.com Samir Vapiwala Cisco System 300 Beaver Brook Road Boxborough, MA 01719 USA Phone: +1 978 936 1484 Email: svapiwal@cisco.com Full Copyright Statement Copyright (C) The IETF Trust (2007). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 23]
Internet-Draft Benchmarking Terminology for November 2007 Protection Performance Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document 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. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf- ipr@ietf.org. Acknowledgement Funding for the RFC Editor function is currently provided by the Internet Society. Poretsky, Papneja, Karthik, Vapiwala Expires May 2008 [Page 24]