Transcript Prezo Title - Draware A/S

Deploying & Maintaining VoIP
A WildPackets Web Seminar
11 am PDT August 3, 2006
Toll free: +1 (800) 373-0950
Toll: +1 (719) 785-4460
Participant code: 833800
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Agenda
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Introduction
Quick Poll
VoIP Trends
VoIP Analysis Best Practices
The OmniAnalysis Solution
Q&A
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Trends
• As networks stabilize, everything is moving to the network
– Telephony
– Video
– Web services (and further business automation)
• The perimeter is gone; 24/7 access is assumed
• Small, medium, and large companies are all facing challenges
– 110,000 SMBs in the US expected to deploy VoIP this year
• Growing emphasis on applications
– Application performance → productivity
– Application security → SOX compliance, GLB, HIPAA, etc.
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The Rush to VoIP
• IP phone systems as a percentage of total business telephone
equipment sales:
– 1.4% (1999)
– 56% (2003)
– 97% (2007) (Gartner)
• Worldwide corporate telephone lines using VoIP will grow from
4% to 44% by 2008. (Radicati Group)
• Enterprise spending on IP phone systems in North America will
double, reaching $4.2 billion in 2007 (Gartner Dataquest)
• 130,000 SMBs have already adopted VoIP; another 110,000
SMBs will do adopt VoIP this year. (AMI Partners)
• Conclusion: Businesses are relying on VoIP, so they need VoIP
analysis and troubleshooting
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So What’s the Problem?
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Unlike traditional data protocols, VoIP is sensitive to delays, burstiness,
and jitter as it passes through the network
Dropped packets in a media stream are not recovered
Jitter buffer drops late packets
Distance can affect quality – “mouth to ear time”
Codecs can matter - G.711 (64 Kbps) is generally of better quality than
G.729 (8 Kbps) but requires more bandwidth (approximately 80 Kbps per
user)
Best VoIP is a nice steady delivery of packets – Typically every 20 ms for
typical G.711 call, if not, we have “jitter”
Some issues are signaling and some are media
OmniAnalysis allows us to see all VoIP problems
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VoIP Analysis Best Practices
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Speech Quality Measurement Terms
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MOS and E-Model
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Mean Opinion Score (MOS)
– Subjective MOS -Listening speech quality calculated by a "Subjective Test"
according to ITU Recommendation P.800
– Objective MOS - Measured listening speech quality, typically a comparison rating
method
– Predicted MOS - Estimated conversational quality
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The E-Model - Recommendation ITU G.107
– The "E-Model" is a parameter based algorithm based on subjective test results of
auditory tests done in the past compared with current “system parameters”
– Provides a prediction of the expected quality, as perceived by the user
– The result of the E-Model calculation is “E-Model Rating R” (0 - 100) which can
be transformed to “Predicted MOS (PMOS)” (1 – 5; 5 is non-extended, noncompressed)
OmniPeek Voice Computes the R-Factor and PMOS
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Crunching the Voice Score
OmniPeek does the hard part…
… so you can see the bottom line
Source: ITU Recommendation G.108 – E-Model Guidelines
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Jitter
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Jitter is the variance in packet delivery intervals to the listener
Jitter buffer adds additional delay to voice reaching the ear piece in case
other packets need to catch up
Packets delayed too long in the network are not allowed to enter the jitter
buffer
1 A G.711 packet sent
every 20 ms
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Packets are buffered and
delayed at the Receiver
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2 Packet jitter and drops
Packets delayed more than the buffer delay
(100 ms as an example) are dropped
The “jitter” buffer releases
4 a G.711 packet every 20 ms
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Voice Quality and Jitter Analysis
The call goes through the network and…
HQ user IP
Remote user IP
… note the decrease in quality at the other end
Let’s replay the VoIP call at different jitter buffer settings
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Real Time Diagnosis of ALL Application
Flows
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OmniPeek Provides Total Coverage
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Monitor SIP and H.323 signaling failures to gateways, call manager, or peer-to-peer
Monitor early indicators of voice problems – jitter, late packet arrival, dropped packets
Jitter problems analyzed both at the device level via RTCP report packets from that device (VoIP
handsets, softphones, PSTN gateways, etc.) and at the stream level anywhere that the VoIP stream
is captured in the network
Engineer
Remote Office
HQ
Analysis of VoIP near the end-points is the most effective
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OmniPeek In-Depth VoIP Analytics
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VoIP Deployment and Management
• Pre-deployment Assessment
– What is the network utilization before the addition of VoIP?
– How is application response time?
– Baseline
• Deployment
– Is QoS properly configured?
– Converged or Isolated VoIP network?
– Testing features and call quality
• Maintenance
– Monitoring features and call quality
– Evaluating infrastructure enhancements
– Troubleshooting service failures
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The OmniAnalysis Solution
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Comprehensive “per-call” VoIP Analytics
Call View
Signaling
Plane
Media Plane
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Software-only Solution
• Eliminates expensive hardware to provide complete portability at
significantly lower cost
• affordability  procure more for budget  increased availability
 faster find-to-fix time
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Unified Solution for VoIP and Network
Analysis
Complete Expert + VoIP
Analysis Solution
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Rich Set of Analytics
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Integrated VoIP Experts
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Set Expert Events to Meet Your Needs
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WildPackets Vision: Make the Network
Smarter
You Can’t Fix What you Can’t See
and You Can’t Optimize What You Can’t Measure!
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The OmniAnalysis Platform makes network analysis “omnipresent”
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Capture - See All the Information
Analyze - Understand the Information
Visualize – Measure and Compare to Baseline
Optimize – Alert , Recommend, Respond
Improve Every Network Layer, including…
– Security: Locate Breaches and Isolate virus-infected systems
– Application: Content and Context Interpretation with Source
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Speed Troubleshooting and Resolution
And Do It All In Real Time !
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WildPackets OmniAnalysis: Edge to Core
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What Sets WildPackets Apart?
How do we make you network smarter?
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Innovation and industry leadership
Award-winning products and services
– Ease-of-Use
• Single click to make filters, select packets, create alarms, etc.
• High-level overviews and simple drill-down details
– Real-time capabilities
– Unique “Expert” intelligence
– Extensible architecture
– Multiple NIC support providing multiple simultaneous captures
– Peer map and Visual Expert for instant network visualization
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Delivered value - “Making Networks Smarter”
Partnerships
Collaborative
– Share trace files for expert analysis and voice play-back
– Multiple views into same engine for collaborative troubleshooting
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Thank You!
Want more information?
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(925) 937-3200
Other Web seminars:
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