Transcript Abacus 5000 Hands-on Training Seminar

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
August 2004
TR30.3 TR30.3/04-08-018
[email protected]
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, 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
Analyze
Assure
Accelerate
Purpose of Presentation
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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
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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
Analyze
Assure
Accelerate
Network Model for Evaluating Multimedia
Transmission Performance – TIA-921 (PN-3-0062)
Analyze
Assure
Accelerate
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
Analyze
Assure
Accelerate
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
Analyze
Assure
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LAN B
1000BaseX
* 100BaseT Switch
100BaseT Hub
10BaseT
* WLAN (~4 Mbit/s)
---------------------Occupancy level
Packet loss
Destination
Device B
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
IP Network
Impairment
Emulator
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Accelerate
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
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**
Real Network Impairments Vary Over Time
Analyze
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Prob
(LOO X%)
IC2
Prob
(LOO X%)
IC500
Prob
(LOO X%)
Delay (ms)
IC1
Delay (ms) Delay (ms)
TIA-921 – Statistically Based IP Network
500 Impairment Conditions (ICs)
Time (s)
• 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.
Analyze
Assure
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TIA-921
Test Profiles Based on QoS (Y.1541) Classes
Different test profiles for different Service Level Agreements (SLAs)
Impairment Type
Units
Range
Impairment Type
Units
Range
Impairment Type
Units
Range
Jitter
ms
+/- 50
Jitter
ms
+/- 75
Jitter
ms
+/- 300
One Way Latency
ms
50 to 100
One Way Latency
ms
50 to 150
One Way Latency
ms
200 to 500
Sequential Packet Loss
#sequential
packets
Random
loss only
Sequential Packet Loss
#sequential
packets
0 to 3
Sequential Packet Loss
#sequential
packets
0 to 500
Rate of Sequential Loss
sec-1
Rate of Sequential Loss
sec-1
< 10-3*
Rate of Sequential Loss
sec-1
< 10-1*
Random Packet Loss
%
0 to 10-3*
Random Packet Loss
%
0 to 2
Random Packet Loss
%
0 to 10
Out of Sequence Packets
%
0 to 10-1**
Out of Sequence Packets
%
0 to 10-1**
Out of Sequence Packets
%
0 to 10
Service Test profile A
500 Impairment Combinations
Well Managed Network
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Service Test profile B
500 Impairment Combinations
Managed Network
Service Test profile C
500 Impairment Combinations
Unmanaged Network
TIA-921
Example Impairment Combination Table
•Approximately 1000
test Scenarios
•Run each
Impairment
Combination against
rates
Test
Scenario
Conditions
(Impairment
Combination
– IC)
IP
Impairments
Caused by
Test
Conditions
(Impairment
Combination
– IC)
Analyze
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TIA-921 – 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
Test Results from 500 Impairment Combinations
0
0
10
20
30
40
50
60
70
Percentage of Network Coverage
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80
90
100
Network Statistics/Characteristics
Required to Validate IP Network Model
Home
Egress
Other Statistics/Characteristics
Business
LOO %
128
20
256
80
Ingress
128
20
768
35
3000
45
4
60
10
40
LOO %
1536
75
•Usage of QOS Edge Routing
44000
25
•Route Flapping
LAN
LAN
Likelihood of Occurrence of
Home Data Rates
•Typical Impairment levels for SLAs
Access
4
35
100
50
1000
15
Likelihood of Occurrence
of Business Data Rates
•One Way Delay
•Packet loss
•Occupancy Level (Background
Traffic)
•Validation of IP Impairment
Characteristics (Algorithms)
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
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TIA-921
Target Audience for Network Model
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Operating Companies
Service Providers
Manufacturers
Design Engineers
Test houses
Magazines and product reviewers
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