Transcript Document

Who? What? When? Where?
Understanding the Possibilities & Pinpointing DPA Issues
Shared Realm (Cisco/AVAYA)
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Wiring
Software
Hardware
Misconfiguration
Signaling
OCTEL
DPA
Cisco’s IP Realm
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IP Network Stability
QoS
Software
Hardware
Misconfiguration
IP Network
IP
Internal Phone
Outside Cisco
* Bad connections
* PSTN issues
* Outside Jurisdiction
PSTN
POTS
External Phone
© 2002, Cisco Systems, Ic. All rights reserved.
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Voice Quality & Availability:
Cisco’s San Jose IP
Telephony Infrastructure
Session Number
Presentation_ID
Bill Hennenlotter
Kevin O’Healy
July 2, 2003
© 2001, Cisco Systems, Inc. All rights reserved.
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Introduction
How to measure voice quality for the San Jose Campus
Where are we now…
Industry Standards for Measuring Voice
Currently Deployed Tools
Where are we going…
Development of new methods for measuring voice
Providing accurate statistics on the performance of the
Cisco VOIP network
How we will get there…
Product Evaluation
Implementation
© 2002, Cisco Systems, Ic. All rights reserved.
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Industry Standards
How Does the Industry Measure Voice Quality?
MOS (Mean Opinion Score)
Relies on a panel of human interpreters
Calls are rated on a scale of 1 to 5
Results in a subjective measurement of voice quality
Other Methods include:
E-Model (ITU-T G.107)
PSQM / PSQM+ (ITU-T P.861)
PAMS
PESQ (ITU-T P.862)
© 2002, Cisco Systems, Ic. All rights reserved.
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Factors that Effect Voice Quality
• Leading Causes of Poor Voice Quality
Network Congestion / Packet Loss
Latency (One-way Delay)
Jitter (Variable Delay)
Codec Selection
© 2002, Cisco Systems, Ic. All rights reserved.
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How Cisco Measures Voice Quality
Analysis of the CDR/CMR Records
•CDR’s store call detail records
•Call Source / Destination
•CMR’s record voice quality measurements
•Packet Loss / Latency / Jitter
EMAN Reporting
•Generation of Call Quality Rating based on CMR’s
•Unable to report in real-time
•Does not provide an overall cluster measurement
© 2002, Cisco Systems, Ic. All rights reserved.
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Where we are going
Is there a more effective way to measure
voice quality?
• Voice Quality is one aspect of Voice Availability
• Voice Availability initiative started 3 months ago
• Project includes development of new standards and the
evaluation of tools
© 2002, Cisco Systems, Ic. All rights reserved.
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Criteria
• Criteria for Measuring Voice Availability
• 1) Server / Call Component Availability
• 2) CallManager Services Availability
• 3) TFTP Server Functionality
• 4) Device Registration
• 5) Off-Hook Test (Dial Tone)
• 6) Call Completion
• 7) Voice Quality
© 2002, Cisco Systems, Ic. All rights reserved.
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Gathering Voice Availability Data
Local IP
Phone #1
IP
IP
Local IP Phone #2
Local
IP Network
Call Manager
Cluster #1
IP
Call Manager
Cluster #2
Local IP Phone #3
(
T1 Gateway
)
Gatekeeper
Remote IP
Network
PSTN
IP
POTS
Local
© 2002, Cisco Systems, Ic. All rights reserved.
POTS
Long Distance
POTS
1-800
Remote
IP Phone
Remote Call
Manager Cluster
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Voice Availability Reporting
100%
100%
Target Availability
99.95%
0%
100%
Target Availability
99.95%
0%
Phone Availability
© 2002, Cisco Systems, Ic. All rights reserved.
Target Availability
99.95%
0%
Call Availability
Voice Quality Availability
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The End
• Q&A
© 2002, Cisco Systems, Ic. All rights reserved.
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