Transcript 30406010 Presentation on IP Network Model

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
June 2004
TR30.3 TR30.3/04-6-011
[email protected]
Purpose of Presentation
• Establish a formal liaison between TR30.3 and appropriate committees to
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help develop Network Model for Evaluating Multimedia Transmission
Performance Over Internet Protocol (PN-3-0062)
Other Liaisons Activities
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ITU-T SG11
ITU-T SG13
ITU-T SG12
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
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
Converged IP Telephony Network is Very
Complex and has Many Impairments
Signaling Path
Network Topologies that need be considered when
testing Audio Quality over a Converged Network
Network Model for Evaluating Multimedia
Transmission Performance -- PN-3-0062
Converged Network Reference Model Diagram
TE
A Telco D
Gateway
Switch
L
IP Network
L
Gateway
TIA-793 Network
Model
D
Telco A
Switch
TE
TIA-793 Network
Model
R,G,S*
Gateway
L
L
R,G,S*
R,G,S*
Gateway
PN-3-0062 (TIA/EIA-921) Network Model will focus on
Transmission Performance Over Internet Protocol
Parameters and Impairments that Affect
Voice Quality
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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
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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)
Time Drift
Route Flapping
ITU G.113 defines the transmission impairments and their impact on voice quality
Sources of IP Network Impairments
IP Network Model
Source
Device A
LAN A
Local Access
B
Local Access
A
64 kbit/s
*128 kbit/s
256 kbit/s
1000BaseX
*384 kbit/s
* 100BaseT Switch
512 kbit/s
100BaseT Hub
*768 kbit/s
10BaseT
*T1 (1.536 kbit/s)
* WLAN (~4 Mbit/s) E1 (1.920 kbit/s)
---------------------E3 (34 Mbit/s)
Occupancy level
*T3 (44 Mbit/s)
Packet loss
ADSL (~256 kbit/s)
*Cable (~256 kbit/s)
Fiber (1-10 Gbit/s)
-------------------Occupancy level
QoS edge router
Core IP Network
Route flapping
One-way delay
Jitter
Packet loss
64 kbit/s
*128 kbit/s
256 kbit/s
*384 kbit/s
512 kbit/s
*768 kbit/s
*T1 (1.536 kbit/s)
E1 (1.920 kbit/s)
E3 (34 Mbit/s)
*T3 (44 Mbit/s)
ADSL (~2 Mbit/s)
*Cable (~3 Mbit/s)
Fiber (1-10 Gbit/s)
-------------------Occupancy level
QoS edge router
* Case used in impairment tables
LAN B
1000BaseX
* 100BaseT Switch
100BaseT Hub
10BaseT
* WLAN (~4 Mbit/s)
---------------------Occupancy level
Packet loss
Destination
Device B
Examples of Communication Equipment that
can be tested over the Converged Network
Model
• IP Network Devices such as User Agents, Call Agents,
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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
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
Packet Delay
Example of Test Profile with Time
Variable Network Impairments
Time
Time Varying Statistically Based IP
Network Impairment Conditions (ICs)
IC1
LOO X%
IC2
LOO X%
IC100
LOO X%
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 100 test combinations so that
an automated run of the test suite completes in less than a day.
Test Profiles Based on QoS Classes
Test Profiles
QoS Class
(Y.1541)
Applications (Examples)
Node Mechanisms
A
(VoIP, MoIP,
FoIP, ToIP)
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Real-Time, loss sensitive, Jitter
sensitive, high interaction (VoIP, VTC)
B
(VoIP, MoIP,
FoIP, ToIP)
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Real-Time, Jitter sensitive, interactive
(VoIP, VTC).
C
(FoIP only)
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Transaction Data, Highly Interactive
(Signaling)
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Transaction Data, Interactive
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Low Loss Only (Short Transactions,
Bulk Data, Video Streaming)
Long Queue, Drop priority
Any route/path
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Traditional Applications of Default IP
Networks
Separate Queue (lowest priority)
Any route/path
Strict QoS. Guaranteed no over
subscription on links.
Separate Queue with preferential
servicing, Traffic grooming
Network Techniques
Constrained Routing and Distance
Less constrained Routing and
Distances
Constrained Routing and Distance
Separate Queue, Drop priority
Less constrained Routing and
Distances
• Statistically based models can be created for different
QoS Classes
Example of Network Model Coverage
(NMC) Curve
QoS, PESQ, PSQM, MOS, Throughput, Connect Rate, etc.
Parameter X Vs Network Model Coverage Percentage
Device A
Device B
Device C
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10
20
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50
60
70
Percentage of Network Coverage
80
90
100
Value of Converged Network Model
• Predicts product performance under statistically base network
conditions
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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
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Operating Companies
Service Providers
Manufacturers
Design Engineers
Test houses
Magazines and product reviewers
Discussion
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Comments, Suggestions and Recommendations
Input for Network Model
– IP Network Statistics
– Network Architecture
– Test Scenarios
Invited to participate in TR30.3