Network Model for Evaluating Multimedia Transmission Performance Over Internet Protocol PN-3-0062 Will become TIA/EIA-921 Jack Douglass, Spirent Chair TIA TR30.3 November 10, 2003, TIA TR41 TR30.3 30312022 jack.douglass@spirentcom.com

Purpose of Presentation Establish a formal liaison between TR30.3 and TR41 to help develop Network Model for Evaluating Multimedia Transmission Performance Over Internet Protocol (PN-3-0062) Other Liaisons Activities ITU-T SG15 Questions 5, 6, 7 ITU-T SG16 Question IETF Etc. Invite TR41 members to TR30.3 meetings to work on IP Network Model IP Network Statistics Network Architecture Test Scenarios

TR30.3 Modem Test Standards TIA/EIA 496A-1989: Interface Between Data Circuit Terminating Equipment (DCE) and the Public Switched Telephone Network Included Network Model for Evaluating Modem Performance TIA/EIA TSB 37A-1994: Telephone Network Transmission Model for Evaluating Analog Modem Performance, which became ITU-T Recommendation V.56bis-1995 EIA/TIA TSB 38-1994: Test Procedures for Evaluation of 2-Wire 4 Kilohertz Voice Band Duplex Modems, which became ITU-T Recommendation V.56ter-1996 ANSI/TIA/EIA 3700-1999: Telephone Network Transmission Model for Evaluating Analog Modem Performance ANSI/TIA/EIA 793 -2000: North American Telephone Network Transmission Model for Evaluating Analog Client and Digitally Connected Server Modems ANSI/TIA 876 – 2002: North American Network Access Transmission Model for Evaluating xDSL Modem Performance

Network Model Coverage (NMC) Methodology Waterfall Curves Traditional method of measuring modem performance Error rate measured against single impairments such as Gaussian noise Severe stress conditions Network Model Coverage (NMC) Introduced by TR30.3 in TIA/EIA-1992 TSB37 Network Model is a portrait of the real network Statistically based Network Model -- Likelihood of Occurrence (LOO) of a given connection Modem performance evaluated using a Impairment Combinations and Local Loop Combinations Curve showing Percentage of Network Model Vs Throughput Estimates percentage of network of the real network over which the modem can be expected to operate Compare performance of different models or manufactures of modems Network Model is independent of modem technology

Network Model for Evaluating Multimedia Transmission Performance -- PN-3-0062

Converged Network Reference Model Diagram TIA-793 Network Model TIA-793 Network Model A D L L A D TE Telco Switch Gateway TE Telco Switch Gateway IP Network R,G,S* L L Gateway R,G,S* R,G,S* Gateway

Test Scenario: PSTN to PSTN connections through a managed IP network

Test Scenario: PSTN – IP connections

Test Scenario: IP – IP connections

Examples of Communication Equipment that can be tested over the Converged Network Model IP Network Devices such as User Agents, Call Agents, Media Servers, Media Gateway Controllers, Gatekeepers, Application Servers, Edge Routers, Gateways Plain Old Telephone Service (POTS) and IP telephones Voice-over-IP (VoIP) gateways ITU-T V-series data modems, both analog client and digitally connected server T.30 and T.38 facsimile devices and gateways V.150.1 and voiceband data (VBD) modem-over-IP gateways TIA-1001 (and V.toip) textphone-over-IP gateways

Test Voice, Fax or Data over IP using Converged Network Model Simulator Analog PSTN Simulator 2 Analog PSTN Simulator 1 Voice, Video, Data, Fax, etc. Gateway Gateway Voice, Video, Data, Fax, etc.

Test IP Network Devices using IP Network Model Simulator IP Network Devices IP Network Devices

Example of Test Profile with Fixed Values of Network Impairments Impairment Type Units Range Jitter ms +/- 75 One Way Latency 50 to 150 Sequential Packet Loss #sequential packets losses 0 to 3 Rate of Sequential Loss sec-1 < 10-3* Random Packet Loss % 0 to 2 Out of Sequence Packets 0 to 10-1** Network Impairments Conditions could be based on set of impairment combination that have fixed values Stress IP Network Device Impairments on a real IP Network are not fixed

Parameters that Need to be Considered when Simulating an IP Network Network Architecture Types of Access Links QoS controlled Edge Routing Route Flapping Link Failure Load Sharing Time Drift MTU Size Background Traffic One Way Delay

Example of Test Profile with Time Variable Network Impairments Packet Delay Time

Time Varying Statistically Based IP Network Impairment Condition (IC) LOO X% IC2 LOO X% IC100 LOO X% Each Impairment Condition is assigned a Likely-hood of Occurrence (LOO) based on real IP Network Statistics, Network Architecture, Classes of Service The goal is to have approximately 100 test combinations so that an automated run of the test suite completes in less than a day.

Test Profiles Based on QoS Classes (Y.1541) Applications (Examples) Node Mechanisms Network Techniques A (VoIP, MoIP, FoIP, ToIP) Real-Time, loss sensitive, Jitter sensitive, high interaction (VoIP, VTC) Strict QoS. Guaranteed no over subscription on links. Constrained Routing and Distance B 1 Real-Time, Jitter sensitive, interactive (VoIP, VTC). Separate Queue with preferential servicing, Traffic grooming Less constrained Routing and Distances C (FoIP only) 2 Transaction Data, Highly Interactive (Signaling) Separate Queue, Drop priority 3 Transaction Data, Interactive 4 Low Loss Only (Short Transactions, Bulk Data, Video Streaming) Long Queue, Drop priority Any route/path 5 Traditional Applications of Default IP Networks Separate Queue (lowest priority) Statistically based models can be created for different QoS Classes

Example of Network Model Coverage (NMC) Curve Parameter X Vs Network Model Coverage Percentage Device A Device B Device C QoS, PESQ, PSQM, MOS, Throughput, Connect Rate, etc. 10 20 30 40 50 60 70 80 90 100 Percentage of Network Coverage

Value of Converged Network Model Predicts product performance under statistically base network conditions Finds design weaknesses Find compatibility issues between network equipment Facilitates isolating and resolving field problems Assists in evaluating different technologies

Target Audience for Converged Network Model Operating Companies Service Providers Manufacturers Design Engineers Test houses Magazines and product reviewers

Discussion Comments, Suggestions and Recommendations Input for Network Model IP Network Statistics Network Architecture Test Scenarios Invited to participate in TR30.3