VoIP Best Practices for Fejlanalyse
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Transcript of VoIP Best Practices for Fejlanalyse
Welcome toImplementing VoIP:
VoIP Network Best Practices
Implementing VoIP:VoIP Network Best Practices
© 2006 Network Instruments, LLC
Agenda Introductions From Hype to Adoption VoIP Myths Anatomy of a VoIP Call VoIP Metrics Lab 1: VoIP in ActionBreak The Three Phases of Successful VoIP Deployment
Phase 1: Site Survey and Testing Phase 2: Monitoring the Roll Out Phase 3: Ongoing Troubleshooting and Maintenance
Break Lab 2: VoIP Call Monitoring Best Practices Summary Network Instruments Solutions Set Q&A
First things first:Introductions
© 2006 Network Instruments, LLC
Douglas Smith
President and Co-Founder of Network Instruments Oversees
FinanceSalesMarketingProduction
Works closely on product design with company CEO, Roman Oliynyk
A part of the networking community since 1985 Awarded degrees in Math and Economics
from University of Wisconsin-Madison
© 2006 Network Instruments, LLC
Charles Thompson
Manager of Sales Engineering Works directly with the Network Instruments
sales team and partner channel to provide…Technical expertiseProfessional services In-depth product information for enterprise
accounts Travels throughout North America conducting
workshops and presentations on network analysis
Personally trained thousands of network managers on the Observer product line
© 2006 Network Instruments, LLC
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Network Instruments
Founded in 1994
40,000 licenses sold ~4K new customers
annually
12 offices worldwide
Sold in over 75 countries
2005 growth Overall: 24%
Celebrating 11 years of continued company growth
Network InstrumentsCompany Growth
© 2006 Network Instruments, LLC
History of Product Innovation 1st affordable Windows-based analyzer
1st distributed software-based protocol analyzer
1st to include SNMP for switched environments
1st 802.11 a/b/g wireless analyzer and remote probe
1st combined wired and wireless solution together
1st to support 64-bit Windows
1st to develop multi-session, multi-user probes
1st to integrate application analysis
1st to develop enterprise-ready VoIP Expert
Distributed Architecture Advantages
© 2006 Network Instruments, LLC
Distributed Network Analysis Architecture
© 2006 Network Instruments, LLC
NI-DNA™ - Distributed Network Analysis
NI-DNA provides Distributed and complete functionality for every type of Network topology in any location using the most intelligent Analysis tools
Unified Code Unified Code SetSet
Two key components: the console, which displays data and the probe, which is used for data collection and processing.
ScalabilityScalability
FlexibilityFlexibility
ModularityModularity
AffordabilitAffordabilit
yy
© 2006 Network Instruments, LLC
NI-DNA provides Distributed and complete functionality for every type of Network topology in any location using the most intelligent Analysis tools
Local/Remote Local/Remote VisibilityVisibility
Observer console includes a local probe for local analysis and connects to remote probes.
VisibilityVisibility
EfficiencyEfficiency
ProductivityProductivity
SecuritySecurity
NI-DNA™ - Distributed Network Analysis
© 2006 Network Instruments, LLC
Multi-Topology Multi-Topology SupportSupport
NI-DNA provides Distributed and complete functionality for every type of Network topology in any location using the most intelligent Analysis tools
Observer’s single user interface can manage multiple Gigabit links, 802.11 connections, 10/100/1000 Ethernet and Wide Area networks.
AdaptabilityAdaptability
SimplicitySimplicity
TransparencyTransparency
ReliabilityReliability
NI-DNA™ - Distributed Network Analysis
© 2006 Network Instruments, LLC
Analysis OptionsSoftware
Probe
GigaStor
10/100/1000 Probe Appliance
WAN and Gigabit Probe Appliances
Top TalkersMultiHop Analysis
Connection Dynamics
Application Analysis
SNMP Management
VoIP Analysis
Gigabit and WANObserver Suite System
© 2006 Network Instruments, LLC
Snapshot of Customers
From Hype to Adoption
© 2006 Network Instruments, LLC
From Hype to Adoption
Market researchers expect the number of VoIP users worldwide to increase
from around five million in 2004 to 200 million subscribers in 2010
http://www.heise.de/english/newsticker/news/64129
© 2006 Network Instruments, LLC
From Hype to Adoption
“Ninety-nine percent of all VoIP network implementations that fail
do so because IT departments didn’t do their homework.”
-- William Stofega, VoIP research director, IDC
© 2006 Network Instruments, LLC
VoIP Monitoring and Analysis Challenges
Current, competing tools were designed for lab use No method of quickly determining status and health No mechanism for understanding aggregate call quality VoIP dependencies are not implemented properly Separate tools increase learning curve, reduce ROI
Other VoIP tools
Observer 11
Common VoIP Myths
© 2006 Network Instruments, LLC
VoIP Myths
Myth #1
Running VoIP without Quality of Service
is acceptable
© 2006 Network Instruments, LLC
Contention = Delay Why is Quality of Service important?
Managing VoIP means managing delay
Even a network with large bandwidth capabilities can have poor call quality due to network contention
QoS measures can help make VoIP traffic less susceptible to adverse network conditions
QoS offers VoIP traffic more consistent availability
© 2006 Network Instruments, LLC
VoIP Myths
Myth #2
No VoIP Site Survey is necessary
© 2006 Network Instruments, LLC
Site Surveys are Critical
With the decision to implement VoIP, one of two choices are usually made
IT managers keep network conditions the same and add VoIP traffic
IT managers upgrade their bandwidth capacity
© 2006 Network Instruments, LLC
Site Surveys are Critical Result
Does not solve or address potential VoIP problems
Network adjustments are made after deployment has begun
Deployment issues can cause user resistance to VoIP technology
Adding bandwidth may not be necessary or offer value
© 2006 Network Instruments, LLC
Common VoIP Myths
Myth #3
Voice conversations are secure
© 2006 Network Instruments, LLC
VoIP Conversations are a Security Risk
VoIP is another piece of network data
Tools are used to capture not only voice conversations but to also generate audio playback for later use
Higher-end VoIP systems may offer a way to encrypt data but many existing or lower-end systems do not
VoIP traffic is most vulnerable on the LAN since Internet WAN traffic is typically through VPNs
Consider wiretapping rules and regulations
Anatomy of a VoIP Call
© 2006 Network Instruments, LLC
How does VoIP work?
H ow VoIP phones send audio s tream s over a network
W A NLA N LA N
S e nd R e ce ive
LA N
01001101 01001101
E n cod e a nd pac ke t ize N e tw o rk d e la y, jitte r, & pa cke t los s J it te r sm o o th ing , de cod e , & p la yb ack
To ta l de la y b udg e t o f 1 50 m s o r le ss (one w a y)
© 2006 Network Instruments, LLC
How does VoIP work?
VoIP phones use codecs to translate analog sound streams into digital packets for transmission
On the receiving end, the codec translates the packets back to analog
To ensure normal conversations, all of this musthappen as close to real-time as possible
VoIP Metrics
© 2006 Network Instruments, LLC
VoIP Basics
What is VoIP?
Packetized voice traffic sent over an IP network
What challenges does it bring?
Competes with other traffic on the network
A new technology that needs real-time, consistent monitoring
Sensitive to delay
© 2006 Network Instruments, LLC
VoIP Basics Understanding VoIP begins with understanding
delay
Normal trafficNot sensitive to delayExample: FTP, HTTP, e-mail, etc.
Tolerant trafficSensitive to delayLoss tolerantBuffered by receiverExample: streaming video, Internet radio,
etc.
Real-time trafficDelay and loss sensitiveExample: VoIP
© 2006 Network Instruments, LLC
VoIP Terms
Jitter
R-Factor / MOS
Burstiness / Gap / Gap Duration
QoS / TOS / Precedence
Compression Techniques (Codecs)
© 2006 Network Instruments, LLC
Jitter What is it?
Jitter is the variation in the time between packets transmitted and received
For example, if a packet stream leaves a device with 30 ms packet spacing and arrives with 50 ms packet spacing, the jitter is 20 ms
3
N etw orkIP P hone
010011011234
567
8
9
54
Jitte r buffer Codec
8
VoIP packets can arrive at the receiving phone out of sequence, late, early, or not at a ll. IP phones use a to reconstruct the packet stream at the receiving end, duplicating m issing packets or filling in with white when necessary.
jitter buffercomfort noise
Jitter buffe ring and packe t loss concea lm ent
67
9
© 2006 Network Instruments, LLC
Jitter Why measure it?
Understanding jitter gives hard facts to help improve call quality
Excessive jitter will confuse callers about who is speaking and who is listening
Adjusting jitter buffers can help at the expense of increased latency and thus, clipping. Jitter buffer overflow will introduce dropped packets.
© 2006 Network Instruments, LLC
Observer’s Jitter MeasurementIn aggregate…
and per call…
© 2006 Network Instruments, LLC
Call Quality Scoring
What is it?
Industry standard methodologies for associating a grade to a call
© 2006 Network Instruments, LLC
Call Quality Scoring
R-factor Identifies live call quality using a single
source of visibility Based on E-Model (ITU G.107)Scale: 1-100Typically the maximum value would be
93.2 after standard degradation Codec usedNetwork delay Jitter bufferPacket loss
© 2006 Network Instruments, LLC
Call Quality Scoring
MOS User satisfaction level with a callTakes into account a number of different factors
Handset qualityAmbient noiseNetwork performance
Scale: 1-54.0 and higher considered satisfied4.5 and higher extremely satisfied
On simulated calls, traffic is captured at the destination and compared to the originalsent data to identify degradation
© 2006 Network Instruments, LLC
Call Quality Scoring
Why measure Call Quality?Provides objective and subjective scores
to evaluate existing conditions to compare with historical conditions.
© 2006 Network Instruments, LLC
Observer’s Call Quality Scoring
In aggregate…
per call…
and Expert…
© 2006 Network Instruments, LLC
Burstiness and Burst Density What is it?
A burst is a period of time characterized by high rates of packet loss
Burst percentage is the % of time bursts are occurring Burst density is the rate of VoIP data packets lost
during a burst period
Why measure it?
Higher rates affect call quality, especially when coupled with long average burst duration times
Possible reason for packet loss include network congestion, media failure, and link failure
© 2006 Network Instruments, LLC
Gap Density and Duration What is it?
Gaps are the periods between bursts A gap is a period of time characterized by lower levels of
packet loss than the burst periods that bound it Gap density is the percent of packet loss during gaps Average gap duration is measured in time
Why measure it?
Knowing the gap helps define the burst In most cases, packet loss during gaps is rendered
insignificant by concealment techniques built into the VoIP infrastructure
© 2006 Network Instruments, LLC
Observer’s Burst and Gap Density
In aggregate…
and per call…
© 2006 Network Instruments, LLC
Settings for QoS / Precedence Support for multiple definitions of Quality of Service (QoS)
Also known as Precedence or Type Of Service (TOS)
What is it? QoS is a bit setting used by routers and switches to
prioritize packet flow
Why measure it? Incorrectly set QoS can
lead to VoIP or other network contention
Contention will lead to delays in packet delivery, reducing call quality
© 2006 Network Instruments, LLC
Observer’s QoS/TOS/Precedence
In aggregate…
per call…
and Decode…
© 2006 Network Instruments, LLC
Compression Techniques
Codec is a term for Coder/Decoder
Different compression techniques (codecs) G.711: 64kbps (no compression) G.729: 8kbps G.723: 6.3kbps, 5.3kbps
Higher compression reduces R-Factor and MOS but also reduces potential contention
© 2006 Network Instruments, LLC
Which Codecs Are Used?In aggregate…
per call…
and Decode…
© 2006 Network Instruments, LLC
How does VoIP work?
H ow VoIP phones send audio s tream s over a network
W A NLA N LA N
S e nd R e ce ive
LA N
01001101 01001101
E n cod e a nd pac ke t ize N e tw o rk d e la y, jitte r, & pa cke t los s J it te r sm o o th ing , de cod e , & p la yb ack
To ta l de la y b udg e t o f 1 50 m s o r le ss (one w a y)
Lab 1
Capture and Decode of a VoIP Call
Break
© 2006 Network Instruments, LLC
Agenda Introductions From Hype to Adoption VoIP Myths Anatomy of a VoIP Call VoIP Metrics Lab 1: VoIP in ActionBreak The Three Phases of Successful VoIP Deployment
Phase 1: Site Survey and Testing Phase 2: Monitoring the Roll Out Phase 3: Ongoing Troubleshooting and Maintenance
Break Lab 2: VoIP Call Monitoring Best Practices Summary Network Instruments Solutions Set Q&A
Phase 1: Site Survey and Testing
© 2006 Network Instruments, LLC
Site Surveys are Critical
Conduct a Site Survey to review…WAN link bandwidth levelsCurrent traffic flowsView existing switches for bottlenecks and
choke pointsDetermine needs through testing and modelingPlacement of analysis tools
The more you know about your network the better prepared you are to properly integrate VoIP
© 2006 Network Instruments, LLC
WAN Link Bandwidth Levels
Summary
Port 1 Source DCE
Port 2 Source DTE
Port 2 Source DCE
Port 1 Source DTE
© 2006 Network Instruments, LLC
Long-Term Trending
© 2006 Network Instruments, LLC
Estimate VoIP Impact
How will VoIP traffic affect the network?
First, determine number of potential users Assume users spend 20% of their day on the phone
Includes active calls as well as VM retrievalVideo will add to utilization
Varies based on site
Determine the codec in use; for example: G.711: 64kbps (no compression) G.729: 8kbps G.723: 6.3kbps, 5.3kbps
© 2006 Network Instruments, LLC
Examples: VoIP Impact
100 users on site, 20% usage = 20 concurrent sessionsG.711 Codec: 1.28 MbpsG.729 Codec: 160 kbpsG.723 Codec: ~120 kbps
Bandwidth impact using a T1 at 1.54 MbpsG.711 Codec: 83%G.729 Codec: 10%G.723 Codec: 8%
© 2006 Network Instruments, LLC
Current Traffic Flows
Assuming one drop per user, evaluate connection speeds and current usage
If multiple network drops per user, not applicable
© 2006 Network Instruments, LLC
Find Bottlenecks and Choke Points
Determining switch, router, and device utilization Review uplinks and shared pipes
© 2006 Network Instruments, LLC
Testing and Modeling
Do a pilot test to generate sample calls in various network conditions
Capture live data and model hypothetical situations
Switch codecs to find optimal performance
Use Observer’s “What-If” Analysis to predict response
Here is an example using Observer…
© 2006 Network Instruments, LLC
Testing and Modeling
Review Observer’s UDP Events to find live calls
© 2006 Network Instruments, LLC
Testing and Modeling
G.711
1 User
© 2006 Network Instruments, LLC
Testing and Modeling
G.711
100 SimultaneousUsers
© 2006 Network Instruments, LLC
Testing and Modeling
G.711
1000 SimultaneousUsers
© 2006 Network Instruments, LLC
Placement of Analysis Tools
Where should you place your analyzer tools for maximum visibility?
Depends on what you’re wanting to seeEach call includes both client and server
communications
If you need access to all local conversations…Use a SPAN session on the access layerAssign all VoIP traffic to a dedicated VLAN
© 2006 Network Instruments, LLC
Points of Visibility Consider a sample network
VoIP ca llm anage r
C ore sw itch
A ccess layer
VoIP ca llm anage rC ore sw itch
A ccess layer
M PLSM esh
East CoastO ffice
W est CoastO ffice
© 2006 Network Instruments, LLC
Points of Visibility
Capturing local IP traffic shows
Phone’s communication with its local call manager
Both sides of the full-duplex connection between local phones
Both sides of the full-duplex connection between phones located across a WAN
© 2006 Network Instruments, LLC
Points of Visibility
VoIP C allM an ager
A ccess sw itch
VoIP C allM an ager
MPLSMesh
East CoastOffice
West CoastOffice
C onnection vis ible to ana lyzerC onnection h idden from ana lyzer
© 2006 Network Instruments, LLC
Points of Visibility
Need a more coherent view of calls across WAN links?
Use a SPAN session to mirror…
Both the uplink traffic between the core and MPLS mesh
All traffic flowing to and from the call manager
© 2006 Network Instruments, LLC
Points of Visibility
VoIP C allM an ager
A ccess sw itch
VoIP C allM an ager
MPLSMesh
East CoastOffice
West CoastOffice
C onnection vis ible to ana lyzerC onnection h idden from ana lyzer
C oreS w itch
© 2006 Network Instruments, LLC
Points of Visibility
For complete coverage, and complete visibility connect analysis probes to both the core and access layers at each site
Phase 2: Monitoring the Roll Out
© 2006 Network Instruments, LLC
Verifying VoIP Health
Cumulative VoIP MetricsSatisfaction Scoring Aggregate Jitter Total CallsCodec Verification
Network Configuration and PerformanceQuality of Service / PrecedenceVerifying VLAN ConfigurationReviewing Link Utilization
© 2006 Network Instruments, LLC
Monitoring Overall VoIP Health
Call Scoring
Aggregate Jitter
High jitter or low call scoring is an issue
If this is the case, go back and review your setups
© 2006 Network Instruments, LLC
Monitoring Overall VoIP Health
Codecs Used
Total Calls
Is the network responding as expected with the total number of calls?
Is the right Codec being used?
© 2006 Network Instruments, LLC
Monitoring Overall VoIP Health
QoS
Is Quality of Service / Precedence configured properly?
© 2006 Network Instruments, LLC
Verifying VLAN Setup
Identify VLAN setups and verify that VoIP traffic exists in its appropriate VLAN
© 2006 Network Instruments, LLC
Verifying VLAN Setup
Is the station in its appropriate VLAN?
© 2006 Network Instruments, LLC
Link Utilization
Verify utilization for each link
Ensure that what you see here coincides with information gathered from “What-If” Analysis in the testing phase
Phase 3: Troubleshooting and Ongoing Maintenance
© 2006 Network Instruments, LLC
When Problems Arise
TroubleshootingReal-time nature of the callCall flow analysisAutomated problem identification and resolutionCall mapping for jitter, lost packets, and
utilization spikesUse trending data to report on period in question
for traffic analysis
Ongoing MaintenanceProactive MonitoringSchedule Reporting
© 2006 Network Instruments, LLC
Real-Time Call Analysis
Review calls in real-time
Track for any inconsistencies
© 2006 Network Instruments, LLC
Call Flow Analysis
Identify call in question Track individual stream that comprise the call Drill down to Connection Dynamics
© 2006 Network Instruments, LLC
Connection Dynamics
© 2006 Network Instruments, LLC
Expert Help
Speed problem resolution by obtaining instant possibilities of network issues
Automate problem resolution
© 2006 Network Instruments, LLC
Call Mapping
Compare jitter to bandwidth utilization to understand RTP/RTCP response time
Is this a bandwidth issue?
© 2006 Network Instruments, LLC
Trending Obtain a snapshot of a
time period in question Check to see if current
conditions are deviating from historical data
© 2006 Network Instruments, LLC
Monitoring and Alerting
Select which VoIP characteristics should be continuously monitored
© 2006 Network Instruments, LLC
Monitoring and Alerting
Determine what threshold levels are acceptable and set triggers accordingly
© 2006 Network Instruments, LLC
Monitoring and Alerting
Customize the appropriate network action based on the event
© 2006 Network Instruments, LLC
Monitoring and Alerting
Review Expert thresholds crossed or exceeded
Shows where thresholds
were exceeded
© 2006 Network Instruments, LLC
Scheduled Reporting Customize reports to provide the necessary insight for long-
term analysis and planning Schedule the reports for automatic delivery on a daily,
weekly, monthly, or even yearly basis
© 2006 Network Instruments, LLC
Sample Report
Choose from a variety of report options and types or create custom reports
Break
Lab 2
Live VoIP Troubleshooting
Summary
© 2006 Network Instruments, LLC
Best Practice #1
Understand and measure the various components of call
quality
© 2006 Network Instruments, LLC
Best Practice #2
Implement Quality of Service
Prioritization
© 2006 Network Instruments, LLC
Best Practice #3
Conduct a Site Survey
© 2006 Network Instruments, LLC
Best Practice #4
Deploy analysis tools strategically for
maximum visibility
© 2006 Network Instruments, LLC
Best Practice #5
Implement VLANs to help isolate and
monitor VoIP issues
© 2006 Network Instruments, LLC
Best Practice #6
Monitor the rollout to ensure a positive user
experience
© 2006 Network Instruments, LLC
Best Practice #7
Compare jitter to overall network bandwidth utilization to understand response time
© 2006 Network Instruments, LLC
Best Practice #8
Set up your analyzer to proactively monitor
VoIP activity
© 2006 Network Instruments, LLC
Best Practice #9
Automate problem resolution
© 2006 Network Instruments, LLC
Best Practice #10
Baseline your network traffic
Network Instruments Solution Set
© 2006 Network Instruments, LLC
Analysis OptionsSoftware
Probe
GigaStor
10/100/1000 Probe Appliance
WAN and Gigabit Probe Appliances
Top TalkersMultiHop Analysis
Connection Dynamics
Application Analysis
SNMP Management
VoIP Analysis
Gigabit and WANObserver Suite System
© 2006 Network Instruments, LLC
Customer Feedback
“So far, Observer’s VoIP capabilities have helped cut down CI Travel’s
phone bill by about 25-30 percent.”
Paul Ingram, CI Travel
© 2006 Network Instruments, LLC
Solid Reviews and Testimonials
Observer continues to receive stellar reviews from industry pundits and our valued customers
“…it is the best packet analysis package we have tested .”
- Dave Bailey, IT Week, December 1, 2005
“Traffic statistics in Observer 11's VoIP Expert tool are more robust, with call summary, quality scoring and detailed per-call metrics such as call status, current jitter, call setup, duration, teardown, MOS/R-factor and QoS levels.”
- Dan Hong, Redmond, November 16, 2005
“Like all Observer features, VoIP Expert is based on the Network Instruments Distributed Network Analysis architecture, which means VOIP analysis is available across multiple topologies such as local-area network, wide-area network, Gigabit Ethernet and 802.11a/b/g.”
- Michelle Speir Hasse, Federal Computer Week, November 21, 2005
© 2006 Network Instruments, LLC
Recent Wins
Large-scale GigaStor deployment
Sniffer replacement For maintaining customer
networks
Large-scale 10/100/1000 appliance deployment for 90% of U.S. locations
Sniffer replacement For comprehensive visibility
Large-scale 10/100/1000 appliance deployment across U.S. locations
Sniffer replacement For distributed analysis
Large scale Expert probe deployment
For real-time network monitoring
Enterprise Pricing
© 2006 Network Instruments, LLC
Enterprise Pricing
VoIP Analysis included at no additional charge Shipped with a 64-bit Core, with support for 32-bit systems Gigabit and WAN Appliances are all 64-bit systems
Expert Observer Includes VoIP US$ 2,895
Observer Suite Includes VoIP US$ 3,995
10/100/1000 Probe Appliance Includes VoIP US$ 2,495
Gigabit Probe Appliance Includes VoIP US$ 11,995
2 TB GigaStor Includes VoIP US$ 19,995
4 TB GigaStor Includes VoIP US$ 35,000
8 TB GigaStor Includes VoIP US$ 50,000
Network Instruments continues to lead the analysis industry in performance and value
Thank You
For more information:Network Instruments, LLC
Chuck Oxleyphone: 416-285-9191
toll-free: 1-800-526-7919 x3897e-mail: [email protected]
www.networkinstruments.com