Network Working Group INTERNET-DRAFT Expires in: April 2007 Scott Poretsky Reef Point Systems Vijay Gurbani Lucent Technologies Carol Davids Illinois Institute of Technology October 2006 Terminology for Benchmarking SIP Networking Devices 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 Internet Society (2006). Poretsky, Gurbani, Davids [Page 1] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices ABSTRACT This document provides a terminology for benchmarking SIP performance in networking devices. Terms are included for test components, test setup parameters, and performance benchmark metrics for black-box benchmarking of SIP networking devices. The Performance Benchmark Metrics are obtained for the SIP Control Plane and Media Plane. The terms are intedned for use in a companion Methodology document for complete performance characterization of a device in a variety of network conditions making it possible to compare performance of different devices. It is critical to provide Test Setup Parameters and a Methodology document for SIP performance benchmarking because SIP allows a wide range of configuration and operational conditions that can influence performance benchmark measurements. It is necessary to have terminology and methodology standards to ensure that reported benchmarks have consistent definition and were obtained following the same procedures. Benchmarks can be applied to compare performance of a variety of SIP networking devices. Poretsky, Gurbani, Davids [Page 2] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices Table of Contents 1. Introduction .................................................4 2. Existing definitions .........................................4 3. Term definitions..............................................5 3.1 Test Components...........................................5 3.1.1 SIP Control Plane....................................5 3.1.2 SIP Media Plane......................................5 3.1.3 Emulated Agents......................................6 3.1.4 Session Server.......................................6 3.1.5 SIP-Aware Stateful Firewall..........................6 3.1.6 Invite-Initiated Control Session.....................7 3.1.7 Non-Invite Initiated Control Session.................8 3.1.8 Registration.........................................8 3.1.9 Associated Media Stream..............................8 3.1.10 Associated Media Session............................9 3.2 Test Setup Parameters.....................................9 3.2.1 SIP Transport Protocol...............................9 3.2.2 Intended Media Session Duration......................10 3.2.3 Measured Media Session Duration......................10 3.2.4 Session Attempt Rate.................................11 3.2.4.1 Media Session Attempt Rate.........................11 3.2.4.2 NIICS Session Attempt Rate.........................12 3.2.5 Media Streams per Session............................12 3.2.6 Media Packet Size....................................13 3.2.7 Media Offered Load, per Media Stream.................13 3.2.8 Media Offered Load, Aggregate........................13 3.2.9 Media Session Hold Time..............................14 3.3 Benchmarks................................................14 3.3.1 Registration Rate....................................14 3.3.2 Session Rate.........................................14 3.3.3 Session Capacity.....................................15 3.3.4 Session Establishment Performance....................15 3.3.5 Session Setup Delay..................................16 3.3.6 Session Teardown Delay...............................16 3.3.7 Standing Sessions....................................17 3.3.8 IM Rate..............................................18 3.3.9 Presence Rate........................................18 4. IANA Considerations...........................................19 5. Security Considerations.......................................19 6. Acknowledgements..............................................19 7. References....................................................20 8. Author's Address..............................................21 9. Full Copyright Statement......................................22 Poretsky, Gurbani, Davids [Page 3] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 1. Introduction Service Providers are now planning Voice Over IP (VoIP) and Multimedia network deployments using the IETF developed Session Initiation Protocol (SIP) [Ro02]. VoIP has led to development of new networking devices including SIP Server, Session Border Controller, and SIP-Aware Stateful Firewall. The mix of voice and IP functions in this variety of devices has produced inconsistencies in vendor reported performance metrics and has caused confusion in the service provider community. SIP allows a wide range of configuration and operational conditions that can influence performance benchmark measurements. It is important to be able to correlate a signalling measurement with the media plane measurements to determine the system performance. When defining SIP performance benchmarks it is critical to also provide definitions for Test Setup Parameters and a corresponding Methodology document for SIP performance benchmarking. This enables benchmarks to be understood, fairly compared, and repeatable. This document provides the benchmarking terms for performance benchmarking the SIP control and media planes. Terms are included for Test Components, Test Setup Parameters, and Benchmarks. All benchmarks are black-box measurements of the SIP Control and Media Planes. It is intended that these terms be used in a companion Methodology document. SIP is used to create a growing number of very different applications and features. The set of benchmarking terms provided in this document is intended for application to each. SIP is frequently used to create streams of media. The control plane and the media plane are treated as orthogonal in this document. In order to characterize the performance of one or another application or feature it may be necessary to logically associate several of the benchmarking metrics provided here. Benchmarks to be obtained and compared for different types of Devices Under test (DUTs) such as SIP Proxy Server, SBC, P-CSCF, Proxy Server paired with a Firewall/NAT device, and P-CSCF paired with a Firewall/NAT device. Media benchmarks can also be made when testing Systems Under Test (SUTs). 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. 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. The term Throughput is defined in RFC 2544. Many SIP terms used in this document are defined in [Ro02]. Poretsky, Gurbani, Davids [Page 4] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 3. Term Definitions 3.1 Test Components 3.1.1 SIP Control Plane Definition: The logical plane in which SIP Signaling messages are exchanged between SIP Agents. Discussion: SIP signaling messages are used to establish SIP signaling sessions in several ways: directly between two User Agents; between a User Agent and a Proxy Server; or between a series of Proxy Servers. Measurement Units: N/A Issues: None See Also: SIP Media Plane Emulated Agents 3.1.2 SIP Media Plane Definition: The logical plane in which media streams, also known as the "payload" or "bearer channel", established by the SIP Signaling messages are exchanged. Discussion: The Media Plane is analagous to the Data Plane. Packets for the SIP Control Plane and the SIP Media Plane traverse different paths, which can produce variation in performance. For this reason it is necessary to benchmark performance of the SIP Control Plane and the SIP Media Plane. Measurement Units: N/A Issues: None See Also: SIP Control Plane Emulated Agents Poretsky, Gurbani, Davids [Page 5] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 3.1.3 Emulated Agent Definition: Device in test topology that initates/responds to SIP signaling as a session endpoint and sources/receives associated media for established connections. Discussion: The Emulated Agent (EA) is a function of the Tester. The Tester MAY be configured to be multiple EAs. Measurement Units: N/A Issues: None See Also: SIP Media Plane SIP Control Plane 3.1.4 Session Server Definition: Device in test topology that acts as proxy between Emulated Agents. This device is either a DUT or component of a SUT. Discussion: The Session Server MUST be a RFC 3261 [Ro02] compliant device. It MAY be a Proxy Server, Session Border Controller (SBC), or other type of device that is RFC 3261 compliant. Measurement Units: N/A Issues: None See Also: SIP Control Plane 3.1.5 SIP-Aware Stateful Firewall Definition: Device in test topology that provides SIP DoS Protection for the Emulated Agents and Session Server Discussion: The SIP-Aware Stateful Firewall MAY be an internal component or function of the Session Server. The SIP-Aware Stateful Firewall MAY be a standalone device that MUST be pairedwith a Session Server to be benchmarked as a SUT. SIP-Aware Stateful Firewalls MAY include Network Address Translation (NAT) functionality. Additional functionality MAY NOT be supported. Poretsky, Gurbani, Davids [Page 6] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices Measurement Units: N/A Issues: None See Also: 3.1.6 Invite-Initiated Control Session (IICS) Definition: A SIP signaling exchange that includes an initial SIP INVITE message exchanged between Emulated Agent and DUT/SUT. Discussion: An Invite-Initiated Control Session (IICS) MAY have associated media. The inclusion of media is test case dependent. An IICS may be in one of several different states: Attempting , Established, Disconnecting. These states are distinguished as follows: Attempting - the state after the invite is sent by or received at the Tester and before the ack to that Invite is received at or sent by the Tester. This definition includes possible reinvites as well as redirects. It also includes all Invites that are rejected for lack of authentication information. Established - the state after the 200 OK for the initiating Invite is sent by or received at the Tester. This definition includes possible reinvites as well as redirects. It also includes all invites that are rejected for lack of authentication information. Disconnecting - the state after a BYE is sent by or received at the Tester. Measurement Units: N/A Issues: None See Also: Poretsky, Gurbani, Davids [Page 7] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 3.1.7 Non-INVITE-initiated Control Session (NIICS) Definition: A SIP signaling exchange that does not include an initial SIP INVITE message exchanged between Emulated Agent and DUT/SUT. Discussion: A Non-INVITE-initiated Control Session (N-IICS) does not have Associated media. Measurement Units: N/A Issues: None See Also: 3.1.8 Registration Definition: A NIICS whose initial SIP message is a REGISTER request. Discussion: Registrations represent a percent of SIP network traffic. As such they represent a significant part of the work of some elements of the DUT/SUT. A Registration attempt MAY be sussessful or unsuccessful. A suuccessful registration is determined by receipt of a 200 OK response. An unsuccessful registration is one that does not receive a 200 OK response. Measurement Units: N/A Issues: None See Also: 3.1.9 Associated Media Stream Definition: A media stream that is associated with an IICS. Poretsky, Gurbani, Davids [Page 8] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices Discussion: Any media protocol MAY be used. If RTP is used, the Associated Media Stream of the IICS is identified as the concatenation of (1) the IP address and transport port identified by the originator in its SDP. (2) the IP address and transport port identified by the destination in its SDP. (3) the SSRC in the RTP sent by the originator. (4) the SSRC in the RTP sent by the destination. (5) the RTCP ports identified by the originator and destination. Measurement Units: NA Issues: None 3.1.10 Associated Media Session Definition: The collection of associated media streams created by an IICS and identified by a SIP Call-ID. Discussion: A session, as defined by SDP, can comprise one or more media streams. Measurement Units: NA Issues: None 3.2 Test Setup Parameters 3.2.1 SIP Transport Protocol Definition: The protocol used for transport of the SIP Control Plane messages. Discussion: Performance benchmarks may vary for the same SIP networking device depending upon whether TCP, UDP, TLS, SCTP, or another transport layer protocol is used. For this reason it MAY be necessary to measure the SIP Performance Benchmarks using these various transport protocols. Performance Benchmarks MUST report the SIP Transport Protocol used to obtain the benchmark results. Poretsky, Gurbani, Davids [Page 9] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices Measurement Units: TCP or UDP Issues: None See Also: 3.2.2 Intended Session Duration Definition: Configuration on the Emulated Agent for time from an IICS establishment to BYE. This is the duration of the Established State. Discussion: The Intended Session Duration is configured on the Emulated Agent. This value is used for all sessions. When benchmarking Session Capacity the effective value of the Session Duration is infinite. Measurement Units: seconds Issues: None See Also: Session Attempt Rate 3.2.3 Measured Session Duration Definition: Average measurement on the DUT/SUT for time from session establishment to BYE. Discussion: The value of the Measured Session Duration MAY not equal the Intended Session Duration. This parameter requires that the session duration be measured for every session through the test duration. Measurement Units: seconds Issues: None See Also: Intended Session Duration Session Attempt Rate Poretsky, Gurbani, Davids [Page 10] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 3.2.4 Session Attempt Rate Definition: Configuration on the Emulated Agent for number of sessions to be established at the DUT per continuous one-second intervals. Discussion: The Session Attempt Rate can cause variation in performance benchmark measurements. Since this is the number of sessions configured on the Tester, some sessions may not be successfully established on the DUT. Sessions may be IICS or NIICS. For a fixed value of Session Attempt Rate, more stress may be incurred on the DUT/SUT when it processes sessions setups and teardowns concurrently during each one-second interval. Measurement Units: session attempts per second (saps) Issues: None See Also: Measured Session Duration Session Attempt Rate 3.2.4.1 Media Session Attempt Rate Definition: Configuration on the Emulated Agent for number of media sessions to be established at the DUT per continuous one-second intervals. Discussion: The Media Session Attempt Rate can cause variation in performance benchmark measurements. Since this is the number of sessions configured on the Tester, some sessions may not be successfully established on the DUT. Media Sessions MUST be associated to IICSes. Measurement Units: session attempts per second (saps) Issues: None See Also: Measured Media Session Duration Session Attempt Rate Poretsky, Gurbani, Davids [Page 11] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 3.2.4.2 NIICS Attempt Rate Definition: Configuration on the Emulated Agent for number of NIICSes to be established at the DUT per continuous one-second intervals. Discussion: The NIICS attempts include registrations, Instant Messages, and Presence-related messages. Measurement Units: session attempts per second (saps) Issues: None See Also: Measured Session Duration Session Attempt Rate 3.2.5 Media Streams per Media Session Definition: Configuration on the Emulated Agent for a fixed number of media streams offered for each session. Discussion: For a single benchmark test, all sessions use the same number of Media Streams per Session. Presence of media streams and the number of media streams per session can cause variation in performance benchmark measurements. The RECOMMENDED values for Media Streams per Session are 0,1,2,3,4, but higher values MAY be used. Measurement Units: media streams per session (msps) Issues: None See Also: Poretsky, Gurbani, Davids [Page 12] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 3.2.6 Media Packet Size Definition: Configuration on the Emulated Agent for a fixed size of packets used for media streams. Discussion: For a single benchmark test, all sessions use the same size packet for media streams. The size of packets can cause variation in performance benchmark measurements. Measurement Units: bytes Issues: None See Also: 3.2.7 Media Offered Load, per Media Stream Definition: The constant amount of media traffic offered by the Emulated Agent to the DUT/SUT for each media stream. Discussion: For a single benchmark test, all sessions use the same Media Offered Load, per Media Stream. Measurement Units: pps Issues: None See Also: 3.2.8 Media Offered Load, Aggregate Definition: The total amount of media traffic offered by the Emulated Agent to the DUT/SUT. Discussion: Measurement Units: pps Issues: None See Also: Poretsky, Gurbani, Davids [Page 13] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 3.2.9 Media Session Hold Time Definition: The amount of time during which media flows from the Tester to the DUT for a successful IICS. Discussion: Measurement Units: seconds Issues: None See Also: 3.3 Benchmarks 3.3.1 Registration Rate Definition: Maximum number of registrations successfully completed by the DUT/SUT. Discussion: This benchmark is obtained with zero failure in which 100% of the registrations attempteded by the Emulated Agent are successfully completed by the DUT/SUT. The maximum value is obtained by testing to failure. Measurement Units: registrations per second (rps) Issues: None See Also: 3.3.2 Session Rate Definition: Maximum number of Control Sessions successfully established per continuous one-second intervals with the sessions remaining active. Discussion: This benchmark is obtained with zero failure in which 100% of the sessions introduced by the Emulated Agent successfully establish. The maximum value is obtained by testing to failure. Sessions may be IICS or NIICS. Measurement Units: sessions per second (sps) Poretsky, Gurbani, Davids [Page 14] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices Issues: None See Also: Invite-Initiated Control Session (IICS) Non-Invite Initiated COntrol Session (NIICS) Session Attempt Rate 3.3.3 Session Capacity Definition: The maximum number of SIP sessions that the DUT/SUT can simultaneously have established. Discussion: The Session Duration MUST be infinite so that sessions remain established for the duration of the test to obtain the Session Capacity benchmark. The Session Capacity must be reported with the Session Rate used to reach the maximum. Since Session Rate is a zero-loss measurement, there must be zero failures to achieve the Session Capacity. Sessions may be IICS or NIICS. Measurement Units: sessions Issues: None See Also: Session Attempt Rate 3.3.4 Session Establishment Performance Definition: The percentage of sessions that successfully establish for the duration of a benchmarking test. Discussion: Session Establishment Performance is a benchmark to indicate session establishment success for the duration of a test. The duration for measuring this benchmark is to be specified in the Methodology. The Session Duration may be configured so that sessions terminate during the test duration. Established Sessions MAY be reported as the percentage of Session Attempts that failed or the percentage of Session Attempts that were successful. Measurement Units: Percentage, % Issues: None See Also: Session Rate Sesion Attempt Rate Poretsky, Gurbani, Davids [Page 15] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 3.3.5 Session Setup Delay Definition: The average time for a session to establish. Discussion: Time is from the Emulated Agent to signal the first INVITE. Session Setup Delay MUST be measured for every established session to calculate the average. Session Setup Delay MUST be measured at the Successful Setup Attempt Rate. Measurement Units: msec Issues: None See Also: Successful Setup Attempt Rate 3.3.6 Session Teardown Delay Definition: The average time for a session to teardown. Discussion: Time is from the Emulated Agent to signal the BYE. Session Teardown Delay MUST be measured for every established session to calculate the average. Session Setup Delay MUST be measured with the rate of teardowns configured to the value of the Successful Setup Attempt Rate. Measurement Units: msec Issues: None See Also: Successful Setup Attempt Rate Poretsky, Gurbani, Davids [Page 16] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 3.3.7 Standing Sessions Definition: Measurement of the number of Active Control Sessions concurrently established on the DUT/SUT at an instant. Discussion: The number of Standing Sessions is influenced by the Session Duration and the Session Rate (or Session Attempt Rate). Benchmarks MUST be reported with the maximum and average Standing Sessions for the DUT/SUT. In order to determine the maximum and average Standing Sessions on the DUT/SUT for the duration of the test it is necessary to make periodic measurements of the number of Standing Sessions on the DUT/SUT. The recommended value for the measurement period is 1 second. Measurement Units: sessions Issues: None See Also: Active Control Sessions Session Duration Session Rate Session Attempt Rate Poretsky, Gurbani, Davids [Page 17] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 3.3.8 IM Rate Definition: Maximum number of IM messages completed successfully by the DUT/SUT. Discussion: For a UAS, the definition of success is the receipt of an IM request and the subsequent sending of a final response. For a UAC, the definition of success is the sending of an IM request and the receipt of a final response to it. For a proxy, the definition of success is as follows: a) the number of IM requests it receives from the upstream client MUST be equal to the number of IM requests it sent to the downstream server; and b) the number of IM responses it receives from the downstream server MUST be equal to the number of IM requests sent to the downstream server; and c) the number of IM responses it sends to the upstream client MUST be equal to the number of IM requests it received from the upstream client. Measurement Units: IM Messages Per Second Issues: None. See Also: 3.3.9 Presence Rate Definition: Maximum number of presence notifications sent out by the DUT/SUR acting as a Presence Agent [Ro04]. Discussion: The intent of this benchmark is to assess the throughput of a Presence Agent (PA, see [Ro04]). The PA will accept subscriptions from watchers, and when the target of the subscription is registered with the PA (who is acting as a registrar), a notification is generated to the watcher. This benchmark will use the presence event package as documented in [Ro04]. The Presence Rate will be less than or equal to the Registration Rate. Measurement Units: Presence Notifications Per Second See Also: Registration Rate. Poretsky, Gurbani, Davids [Page 18] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 4. IANA Considerations This document requires no IANA considerations. 5. Security Considerations Documents of this type do not directly affect the security of Internet or corporate networks as long as benchmarking is not performed on devices or systems connected to production networks. Security threats and how to counter these in SIP and the media layer is discussed in RFC3261, RFC3550, and RFC3711 and various other drafts. This document attempts to formalize a set of common terminology for benchmarking SIP networks. 6. Acknowledgements The authors would like to thank Keith Drage and Daryl Malas for their contributions to this document. Poretsky, Gurbani, Davids [Page 19] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 7. References 7.1 Normative References [Ba91] Bradner, S. "Benchmarking Terminology for Network Interconnection Devices", IETF RFC 1242, July 1991. [Ba99] Bradner, S. and McQuaid, J., "Benchmarking Methodology for Network Interconnect Devices", IETF RFC 2544, March 1999. [Ga05] Garcia-Martin, M., "Input 3rd-Generation Partnership Project (3GPP) Release 5 Requirements on the Session Initiation Protocol (SIP)", IETF RFC 4083, May 2005. [Li06] Lingle, K., Mule, J., Maeng, J., Walker, D., "Management Information Base for the Session Initiation Protocol (SIP)", draft-ietf-sip-mib-10.txt, work in progress, March 2006. [Ma98] Mandeville, R., "Benchmarking Terminology for LAN Switching Devices", IETF RFC 2285, February 1998. [Ma06] Malas, D. "SIP Performance Metrics", draft-malas-performance-metrics-01.txt, work in progress, October 2006. [Po06] Poretsky, S., Gurbani, V., and Davids, C., "SIP Performance Benchmarking Methodology", draft-poretsky-bmwg-sip-meth-00, work in progress, October 2006. [Ro02] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M. and E. Schooler, "SIP: Session Initiation Protocol", IETF RFC 3261, June 2002. [Ro04] Rosenberg, J., "A Presence Event Package for the Session Initiation Protocol (SIP)," IETF RFC 3856, August 2004. [Sp06] Sparks, R., et al, "Session Initiation Protocol (SIP) Torture Test Messages", IETF RFC 4475, October 2006. 7.2 Informative References None Poretsky, Gurbani, Davids [Page 20] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices 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 Vijay Gurbani 2000 Lucent Lane Lucent Technologies Room 6G-440 Naperville, IL 60566 USA Phone: + 1 630 224 0216 Email: vkg@lucent.com Carol Davids Illinois Institute of Technology Rice Campus 201 East Loop Road Wheaton, IL 60187 USA Phone: + 1 630 682 6000 Email: davids@iit.edu Poretsky, Gurbani, Davids [Page 21] INTERNET-DRAFT Benchmarking Terminology for October 2006 SIP Networking Devices Full Copyright Statement Copyright (C) The Internet Society (2006). 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. 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