business case for voip assessment

8/8/2019 Business Case for Voip Assessment

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White Paper

Table of contents

Business case for VoIP Readiness

Network Assessment

Enterprises and equipment vendors are learn-

ing the value o a complete readiness assessment

beore deploying VoIP across an organization. The

assessments are a critical step to a successul VoIP

deployment, but many enterprises do not perorm an

assessment because o cost or because ater perorm-

ing a baseline on network utilization, they assume

that their network has enough bandwidth to accom-

modate the voice trafc. This white paper explains

why it is essential to perorm a readiness assessment

both or initial VoIP deployment and also or expan-

sion projects to avoid unplanned additional costs

and deployment delays.

Overview 2

Different approaches to

pre-deployment assessment: 2

Other considerations

for VoIP pre-deployment 3

The consequences of ignoring

pre-deployment assessments 4

A solution to meet your VoIP

assessment needs 4

Conclusion 5


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Fluke Networks www.lukenetworks.com2

OverviewOver the past several years as enterprises have been deploying voice over IP (VoIP) with more requency, many have learned the hard

way that the rst step in the VoIP liecycle process should be a complete assessment o network readiness. Too oten, IT organizations

all into the stereotype o lets put it on the network and see what happens.

As convergence grows, the lets see what happens approach with VoIP will almost certainly not be successul. While it is a data

application at the core, VoIP does not act like traditional data applications. In addition, or most enterprises, VoIP will be the highest

prole application on the inrastructure, meaning i the phones do not work, everyone will know.

With early VoIP deployments many enterprises had major issues with initial rollouts. One key reason was a lack o pre-deployment

assessment. When there were initial problems, there was nger-pointing between the enterprise, VoIP equipment vendors and service

providers.

Today, most VoIP equipment vendors, who took most o the blame or poor perormance, are now requiring network assessments even

beore they will sell or service the IP PBX and phone systems. While this is a good rst step, many enterprises still do not perorm com-

prehensive assessments.

This white paper will reinorce why readiness assessments are key or successul VoIP deployments. Pre-deployment assessments are the

rst step in a successul VoIP deployment, which also must include monitoring, management and optimization.

Different approaches to pre-deployment assessment:

Polling-based analysis

One approach uses the quantiable usage o VoIP to estimate readiness. For example, an enterprise plans to use the G.711 codec and sets

up the quality requirements. With these assumptions, each VoIP call might require 64 Kbps o bandwidth (actually, it is closer to 80 Kbps

with the header inormation). Thereore, i a location is expecting ve concurrent calls maximum, there should be at least 320 Kbps o

bandwidth available just or VoIP.

With this approach, a polling-based solution will ocus on using the existing inrastructure and polling standard MIBs which to trend

utilization on each device. With this inormation, the enterprise can attempt to calculate how much bandwidth is available and/or

needed or each location. Problems with this approach are the limited granularity o the inormation, the polling interval can skew and

fatten the bursty nature o data applications, and the trac is not broken down by application so there is no correlation o perormance.

An example o this is monitoring two locations. Location A has a consistent 50% usage over the ve-minute polling period. Location

B has usage o 100% the rst hal o the period and 0% the second hal (data trac typically is bursty and has big spreads). A polling

solution would say both locations have a 50% average. The skewing o the data could set a alse sense o security because Location A

may have plenty o bandwidth but Location B is bursting to maximum usage hal o the time. I you deployed VoIP to Location B, there

is a great likelihood o perormance impact to both voice and data trac.

The polling requency can be increased, but there is a cost or this as well because it adds overhead to the network each time the poller

requests data and the device responds. There is a ne line between getting more granular with polling and overburdening your network

with management trac.

Business case for VoIP Readiness

Network Assessment


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Granular converged perormance

Another approach, granular converged perormance uses the quantiable aspect o VoIP listed earlier, but with a dierent tactic. Instead

o polling and averaging usage every 1 to 15 minutes, this approach ocuses on detailed monitoring o the network and provides up to a

1-second level o granularity. For example, instead o one data point every 5 minutes with a polling based solution, 1-second granularity

gives you 300 data points in the same 5-minute period so you are able to see peaks and valleys with bursty applications.

The benet associated with this solution is the deep granularity it provides by actually monitoring and measuring every packet goingacross the network. One disadvantage with this approach is the requirement o a device or appliance at each location. It is impossible

to collect this level o data and granularity without a dedicated appliance.

Simulated VoIP calls

With simulated VoIP call testing, trac agents are used to generate simulated RTP (Real time Transport Protocol) trac between them-

selves and measure the perormance across the network. This approach provides detailed results o mean opinion score (MOS), jitter,

packet loss and latency or delay or each call. From these results, the maximum number o calls (above a user dened MOS threshold)

will be calculated. Then, the network perormance is urther validated to ensure the deployment can support the VoIP requirements under

normal and peak situations by generating the maximum number o calls at specied intervals to ensure the voice trac is not aected by

data applications. The simulated calls need to be generated simultaneously rom selected areas throughout the network and should also

ensure that the additional voice trac does not aect the perormance o exiting applications. This process is typically run or two ormore weeks and i there are no problems, the network is deemed ready and the assessment is over.

However it is necessary to consider the ollowing:

Howlongwillittakefromassessmenttoactualfulldeployment?

Whatchangescouldaffectyourorganizationinthemeantimenewusers,newapplications,increasedusage,newlocations?

These variables highlight why a single assessment is not sucient.

I the calls are below quality metrics, then changes in the inrastructure should be made and another assessment perormed prior

to deployment. However, beore making changes to the inrastructure, it is necessary to ascertain exactly what is contributing to the

degradation in voice quality without knowing whether the degradation is a result o jitter, delay or lost packets, it is impossible to

determine where the changes need to be made. Consequently, enterprises require additional troubleshooting products to determine the

root cause o the problem.

Other considerations for VoIP pre-deployment

In addition to perorming an assessment to estimate the number o simultaneous calls and the expected call quality on the network, it

is essential to assess the network topology to determine how devices are interconnected at both layer 2 and layer 3 and to veriy VLAN

congurations and device membership within those VLANs.

Inrastructure devices also need to be evaluated to ensure they are capable o handling voice trac and are correctly congured espe-

cially with regards to Quality o Service (QoS) policies or Class o Service (CoS) settings.

There are also other considerations outside the scope o this paper such as:

PoweroverEthernet(PoE)support

Adequatecoolingforthedevices

SufcientCPUandmemorycapacityininfrastructuredevices

Another major issue in todays converged world is that many enterprises are combining applications and networks, but are not bring-

ing the voice, data, application, IT and inrastructure groups together. All too oten the voice group needs to replace the legacy phone

system and begins the migration to VoIP. The data or networking group may not be aware o impending change or the potential impact,

and o course, everyday business continues where new applications and increased usage occurs.


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The consequences of ignoring pre-deployment assessments

In addition to the obvious increase in costs caused by the need to perorm post deployment troubleshooting which also results in ull

deployment delays, many enterprises understand that the network and applications are constantly changing. I the organization is paying

several thousand dollars per site or a consulting assessment, they are not likely to do continuous assessments (assessments can range

from$2,000(US)totensofthousandsofdollars,dependingonsize,complexityandlengthofevaluation).Additionally,severalvendors

will void assessments they completed, i changes like new applications occur on the network. In todays dynamic world, changes in

the network happen requently and now the enterprises costly assessments are no longer valid and they must decide whether to reassess

at the same cost.

So, organizations that want a successul rst-time deployment must nd a way to not only do an initial assessment or VoIP, but they

must nd a cost-eective and user-riendly way to continuously monitor readiness or VoIP in the bursty and high-demand converged

networking area. Since VoIP deployments typically occur over a period o months or quarters, enterprises must consider how to carry

out dynamic and on-demand assessments without raising the cost several times.

A solution to meet your VoIP assessment needs NetAlly Assessment and

Troubleshooting Software

Whether you are planning a new VoIP deployment or an expansion to an existing deployment, it is essential you can determine:

WhetheryourLANandWANcircuitscapableofhandlingtheincreasedtrafcfromtheVoIPdeployment

AreQualityofService(QoS)policiescorrectlyimplemented

TheMeanOpinionScore(MOS)callqualityyouexpect

Themajorfactoraffectingvoicecallqualitydelay,packetloss,jitterorCodec

ThenumberofconcurrentVoIPcallscanthenetworkhandlewithoutimpactingexistingapplicationperformance

The NetAlly Network Assessment and Troubleshooting Sotware quickly and automatically determines the network readiness or VoIP

deployment and provides tools to identiy and resolve service and readiness problems across the entire network.

As a network engineer responsible or VoIP deployment projects and network troubleshooting, NetAlly quickly identies most o your

network issues so that when VoIP deployment is started you are condent that you will not be aced with dissatised users complaining

o poor call quality.

The NetAlly network pre-deployment assessment is specically designed to assess the readiness o the network, and certiy the peror-

mance or supporting VoIP applications prior to deploying VoIP trac. The assessment process is divided into three dierent phases,

each o which has a denite objective in the overall assessment scheme.

The Network Conguration phase checks aspects o the network and consists o three dierent tests

Connectivity

VoIPtrafcprecedence(QoSpolicy)

Routequalityandutilizationmeasurements

The readiness assessment provides the most accurate picture o VoIP readiness or the network that is being tested by

Identifyingthemaximumcallcapacity

Identifyingmajorcontributorstocallqualitydegradation

Validatingexistingcapacityplanningassumptions


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End-to-endcallqualityismeasuredusingtheMOSscoringmethod.Syntheticcallscanbemixedwithrealdatatrafcduringnormal

production hours to get a real world assessment o service quality or scheduled or o-hours operation when critical business applications

are not in use.

The perormance certication test phase veries the accuracy o the Readiness Assess-

ment test data by emulating a xed number o calls over an extensive period o time.

This test makes it possible to assess VoIP perormance according to time o day andday o week, under varying network trac conditions.

Comprehensive reports are generated or each phase o the assessment process.

In addition to the analysis o primary measurements or VoIP trac such as delay,

jitter, loss and throughput, NetAlly is also capable o perorming a variety o special-

ized troubleshooting tests with customized attributes to assist in identiying network

and application perormance issues. Troubleshooting tests can be perormed between

trac agents or between trac agents and application servers or hosts.

For in-depth troubleshooting during the pre-deployment assessment and during actual VoIP deployment, the OptiView Network Analyzers

can provide additional inormation by perorming network topology discovery, switch congurations, VLAN congurations and switch port

membership as well as being able to monitor the simulated voice trac and identiy the root cause o call quality degradation.

To complete the VoIP liecycle process, post deployment monitoring can be provided by Visual Perormance Manager, a network manage-

ment solution that provides broad visibility and analysis into your network by consolidating views rom multiple network sources into one

seamless view tailored or each users needs.

Conclusion

The success o VoIP deployment relies on many individual components and when one is not perorming eciently call quality will be

degraded. The key to having a successul voice deployment is to build a strong oundation across the distributed enterprise. VoIP will

raise the level o attention o poor perormance because in the best-eort world o data applications, most users will never notice or

complainifanEmailtakes10extrasecondstosendorwebapplicationsarealittleslow.However,withVoIP,userswillimmediatelynotice degradation and most likely complain. This increases the exposure and risk to your IT organization. This exposure adds to the

criticality o ongoing perormance management or both voice and data applications.

Dont take the risk o starting a live VoIP deployment without rst conducting a network assessment VoIP is just not another

application on your network, VoIP has a number o unique requirements.

N E T W O R K S U P E R V I S I O N

Fluke NetworksP.O.Box777,Everett,WAUSA98206-0777

Fluke Networks operates in more than 50 countriesworldwide. To nd your local oce contact details, go towww.fukenetworks.com/contact .

2009FlukeCorporation.Allrightsreserved.PrintedinU.S.A.5/20093473080D-ENG-NRevA

VoIP Resources:

NetAlly Product Information:

www.fukenetworks.com/netally

NetAlly Free Trial:

www.fukenetworks.com/netallytrialVoIP Featured Topic:

www.fukenetworks.com/voip

OptiView product information:

www.fukenetworks.com/optiview

Contact Fluke Networks: Phone 800-283-5853(US/Canada)or

425-446-4519 (other locations). Email: [email protected].

business case for voip assessment

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