analyze assure accelerate network model for evaluating multimedia transmission performance over...
TRANSCRIPT
Analyze Assure Accelerate
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
TR41.4-03-11-060-L
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
TEA D L LTelco
Switch Gateway
TIA-793 Network Model
TEA DTelco
Switch GatewayIP Network
R,G,S*
R,G,S* R,G,S* GatewayGateway L L
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
Voice, Video, Data, Fax, etc.
Analog PSTN
Simulator 1
IPSimulator
Gateway Gateway
Analog PSTNSimulator 2
Voice, Video, Data, Fax, etc.
Test IP Network Devices using IP Network Model
IPSimulator
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 ms 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
Time
Pac
ket
Del
ay
Time Varying Statistically Based IP Network Impairment Condition (IC)
IC1
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 ClassesTest 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
3 Transaction Data, Interactive Less constrained Routing and Distances
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) Any route/path
• Statistically based models can be created for different QoS Classes
Example of Network Model Coverage (NMC) Curve
Parameter X Vs Network Model Coverage Percentage
0
0 10 20 30 40 50 60 70 80 90 100
Percentage of Network Coverage
Device ADevice BDevice C
Qo
S,
PE
SQ
, P
SQ
M,
MO
S,
Th
rou
gh
pu
t, C
on
ne
ct R
ate
, e
tc.
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