VoIP Webinar
-
Upload
catharine24 -
Category
Documents
-
view
549 -
download
0
Transcript of VoIP Webinar
1www.wildpackets.co
m
Deploying & Maintaining VoIPA WildPackets Web Seminar
11 am PDT August 3, 2006
Toll free: +1 (800) 373-0950 Toll: +1 (719) 785-4460
Participant code: 833800
www.wildpackets.com
Agenda
• Introduction• Quick Poll• VoIP Trends• VoIP Analysis Best Practices• The OmniAnalysis Solution• Q&A
www.wildpackets.com
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.
www.wildpackets.com
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
www.wildpackets.com
So What’s the Problem?
• 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 mediaOmniAnalysis allows us to see all VoIP problems
6www.wildpackets.co
m
VoIP Analysis Best Practices
www.wildpackets.com
Speech Quality Measurement Terms
www.wildpackets.com
MOS and E-Model
• 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
• 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, non-compressed)
OmniPeek Voice Computes the R-Factor and PMOS
www.wildpackets.com
Crunching the Voice Score
OmniPeek does the hard part…
… so you can see the bottom line
Source: ITU Recommendation G.108 – E-Model Guidelines
www.wildpackets.com
Jitter
• 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
Packets delayed more than the buffer delay (100 ms as an example) are dropped
. . .. .. . . ..............
Packets are buffered anddelayed at the Receiver
The “jitter” buffer releases a G.711 packet every 20 ms
A G.711 packet sent every 20 ms
Packet jitter and drops
31
2
4
www.wildpackets.com
Voice Quality and Jitter Analysis
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
The call goes through the network and…
www.wildpackets.com
Real Time Diagnosis of ALL Application Flows
www.wildpackets.com
OmniPeek Provides Total Coverage• 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
Analysis of VoIP near the end-points is the most effective
Remote Office
HQ
Engineer
www.wildpackets.com
OmniPeek In-Depth VoIP Analytics
www.wildpackets.com
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
16www.wildpackets.co
m
The OmniAnalysis Solution
www.wildpackets.com
Comprehensive “per-call” VoIP Analytics
Call View
Media Plane
Signaling Plane
www.wildpackets.com
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
www.wildpackets.com
Unified Solution for VoIP and Network Analysis
Complete Expert + VoIP Analysis Solution
www.wildpackets.com
Rich Set of Analytics
www.wildpackets.com
Integrated VoIP Experts
www.wildpackets.com
Set Expert Events to Meet Your Needs
www.wildpackets.com
WildPackets Vision: Make the Network Smarter
And Do It All In Real Time !
• The OmniAnalysis Platform makes network analysis “omnipresent”– 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
• Speed Troubleshooting and Resolution
You Can’t Fix What you Can’t Seeand You Can’t Optimize What You Can’t Measure!
www.wildpackets.com
WildPackets OmniAnalysis: Edge to Core
www.wildpackets.com
What Sets WildPackets Apart?How do we make you network smarter?
• 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
• 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
26www.wildpackets.co
m
Thank You!
Want more information?www.wildpackets.com
(925) 937-3200
Other Web seminars:www.wildpackets.com/smarter