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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 August 2004 TR30.3 TR30.3/04-08-018 jack.douglass@spirentcom.com. TR30.3 Network Model Standards.
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Network Model for Evaluating Multimedia Transmission Performance Over Internet ProtocolPN-3-0062 Will become TIA/EIA-921 Jack Douglass, Spirent Chair TIA TR30.3 August 2004 TR30.3 TR30.3/04-08-018 jack.douglass@spirentcom.com
TR30.3 Network Model 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, whichbecameITU-T Recommendation V.56bis-1995 • EIA/TIA TSB 38-1994:Test Procedures for Evaluation of 2-Wire 4 Kilohertz Voice Band Duplex Modems, whichbecame 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
Purpose of Presentation • Establish a formal liaison between TR30.3 and appropriate committees to help develop TIA-921 (PN-3-0062), Network Model for Evaluating Multimedia Transmission Performance Over Internet Protocol Other Liaisons Activities • TR41.4 • ITU-T SG12 -- Approved as Question M/12 • ITU-T SG11 • ITU-T SG13 • ITU-T SG15 Q7 • ITU-T SG16 Q11, Q14 (QF) • IETF • Etc. • Invite committee members to TR30.3 meetings to work on IP Network Model • IP Network Statistics • Network Architecture • Test Scenarios
Network Model for Evaluating Multimedia Transmission Performance – TIA-921 (PN-3-0062)
Network Architecture Types of Access Links QoS controlled Edge Routing Voice coding algorithm A/D and D/A Conversion MTU Size Signaling protocol mismatches Network faults Link Failure Time Drift Route Flapping Echo Out of order packets Noise – Circuit and External Packet Loss (Frame Loss) One Way Delay (Latency) Variable Delays (Jitter) Background Traffic (Congestion, Bandwidth, Utilization, Network Load, Load Sharing) Parameters and Impairments that Affect Voice Quality ITU G.113 defines the transmission impairments and their impact on voice quality
TIA-921 IP Network Impairment Emulator Types of DUTs IP Phones POTS over IP Media Gateways MGC User Agents Call Agents Media Servers Video Gatekeepers Application Servers Edge Routers Gateways Modems Fax Time Varying Statically Based IP Network Impairments Jitter, Latency, Burst Loss, Gap Loss Packet Loss, Out-of-Order Packets Route Flapping, Link Failure IP Network Impairment Emulator
Testing with Fixed Levels of IP Impairments • Impairments Placed in series between Tester and network equipment under test • Test Examples: • Evaluate jitter buffer and packet loss concealment algorithms • Ability of equipment to handle impairments Real Network Impairments Vary Over Time
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 500 test combinations so that an automated run of the test suite completes in less than a day. TIA-921 – Statistically Based IP Network 500 Impairment Conditions (ICs) IC1 Prob (LOO X%) Delay (ms) IC2 Prob (LOO X%) Delay (ms) IC500 Prob (LOO X%) Delay (ms) Time (s)
TIA-921 Test Profiles Based on QoS (Y.1541) Classes Different test profiles for different Service Level Agreements (SLAs) Service Test profile A 500 Impairment Combinations Well Managed Network Service Test profile B 500 Impairment Combinations Managed Network Service Test profile C 500 Impairment Combinations Unmanaged Network
TIA-921Example Impairment Combination Table • Approximately 1000 total test cases. • Run each Impairment Combination against rates Test Conditions (Impairment Combination – IC) IP Impairments Caused by Test Conditions (Impairment Combination – IC)
Parameter X Vs Network Model Coverage Percentage Device A Device B Device C QoS, PESQ, PSQM, MOS, Throughput, Connect Rate, etc. 0 0 10 20 30 40 50 60 70 80 90 100 Percentage of Network Coverage TIA-921 – Example of Network Model Coverage (NMC) Curve Test Results from 500 Impairment Combinations
Network Statistics/Characteristics Required to Validate IP Network Model • Other Statistics/Characteristics • Typical Impairment levels for SLAs • Usage of QOS Edge Routing • Route Flapping • One Way Delay • Packet loss • Occupancy Level (Background Traffic) • Validation of IP Impairment Characteristics (Algorithms) Likelihood of Occurrence of Business Data Rates Likelihood of Occurrence of Home Data Rates • Who are the contacts in the service providers, operating companies, network equipment manufacturers that can provide this information? • Similar network statistics were provided for the other TR30.3 network models anonymously by service providers, operating companies and network equipment manufacturers
TIA-921 Target Audience for Network Model • Operating Companies • Service Providers • Manufacturers • Design Engineers • Test houses • Magazines and product reviewers