1. Network Model for Evaluating Multimedia Transmission Performance Over Internet Protocol PN Will become TIA/EIA-921
Jack Douglass, Spirent
Chair TIA TR30.3
November 10, 2003, TIA TR41 TR

2. 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 )
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

3. 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 : Test Procedures for Evaluation of 2-Wire 4 Kilohertz Voice Band Duplex Modems, which became ITU-T Recommendation V.56ter-1996
ANSI/TIA/EIA : Telephone Network Transmission Model for Evaluating Analog Modem Performance
ANSI/TIA/EIA : 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

4. 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

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

6. 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

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

8. Test Scenario: PSTN – IP connections

9. Test Scenario: IP – IP connections

10. 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 and voiceband data (VBD) modem-over-IP gateways
TIA-1001 (and V.toip) textphone-over-IP gateways

11. 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.

12. Test IP Network Devices using IP Network Model
Simulator
IP Network Devices
IP Network Devices

13. 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

14. 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

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

16. 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.

17. 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

18. 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

19. 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

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

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