Network Model for Evaluating Multimedia Transmission Performance Over Internet Protocol PN-3-0062 Will become TIA/EIA-921

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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
• March 2004
• TR30.3 30403002
• jack.douglass_at_spirentcom.com

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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 SG11
• ITU-T SG13
• ITU-T SG12
• ITU-T SG15 Q7
• ITU-T SG16 Q11, Q14 (QF)
• IETF
• Etc.
• Invite TR41 members to TR30.3 meetings to work on
  IP Network Model
• IP Network Statistics
• Network Architecture
• Test Scenarios

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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

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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

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Network Model for Evaluating Multimedia
Transmission Performance -- PN-3-0062
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Converged Network Reference Model Diagram
TIA-793 Network Model
TIA-793 Network Model
D
A
D

A
L
L
TE
Telco Switch
Gateway
TE
Telco Switch
Gateway
IP Network
R,G,S
L
L
Gateway
R,G,S
R,G,S
Gateway
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Test Scenario PSTN to PSTN connections through
a managed IP network
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Test Scenario PSTN IP connections
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Test Scenario IP IP connections
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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, IP Phones, IAF (Internet Aware Fax)
• Plain Old Telephone Service (POTS) and IP
  telephones
• Voice-over-IP (VoIP) gateways
• 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
• PSTN Video H320 and H324

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Test Voice, Fax or Data over IP using Converged
Network Model
IP Simulator
Analog PSTN Simulator 2
Analog PSTN Simulator 1
Voice, Video, Data, Fax, etc.
Gateway
Gateway
Voice, Video, Data, Fax, etc.
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Test IP Network Devices using IP Network Model
IP Simulator
IP Network Devices
IP Network Devices
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Example of Test Profile with Fixed Values of
Network Impairments
Impairment Type Units Range

Jitter ms /- 75
One Way Latency ms 50 to 150
Sequential Packet Loss sequential packets losses 0 to 3
Rate of Sequential Loss sec-1 lt 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

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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
• Packet Loss
• Background Traffic (Congestion, Bandwidth,
  Utilization, Network Load)
• One Way Delay

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Example of Test Profile with Time Variable
Network Impairments
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Time Varying Statistically Based IP Network
Impairment Conditions (ICs)

• 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.

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Test Profiles Based on QoS Classes
Test Profiles QoS Class (Y.1541) Applications (Examples) Node Mechanisms Network Techniques
A (VoIP, MoIP, FoIP, ToIP) 0 Real-Time, loss sensitive, Jitter sensitive, high interaction (VoIP, VTC) Strict QoS. Guaranteed no over subscription on links. Constrained Routing and Distance
B (VoIP, MoIP, FoIP, ToIP) 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 Constrained Routing and Distance
C (FoIP only) 3 Transaction Data, Interactive Separate Queue, Drop priority Less constrained Routing and Distances
C (FoIP only) 4 Low Loss Only (Short Transactions, Bulk Data, Video Streaming) Long Queue, Drop priority Any route/path
C (FoIP only) 5 Traditional Applications of Default IP Networks Separate Queue (lowest priority) Any route/path

• Statistically based models can be created for
  different QoS Classes

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Example of Network Model Coverage (NMC) Curve
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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

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Target Audience for Converged Network Model

• Operating Companies
• Service Providers
• Manufacturers
• Design Engineers
• Test houses
• Magazines and product reviewers

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Discussion

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