European Advanced Networking Test Center
VoIP Services: Winning Strategies
How to AchievePSTN Scalability and Reliability
Carsten RossenhoevelManaging Director
European Advanced Networking Test Center (EANTC AG)
European Advanced Networking Test Center
About EANTC
§ Test and certification of network components for manufacturers
§ Proof of concept evaluation,acceptance tests and network design consultancy for service providers and large enterprises
§ Research and development of test methods and analysis tools
EANTC, Berlin, Germany
The European Advanced Networking Test Center offers vendor independent network quality assurance since 1991.
European Advanced Networking Test Center
U.S. VoIP service provider outage in August 2004:
Ø 90 mins failure
Ø Small number of subscribers affected
Ø Reduces service quality to 99.98% - still quite good
European Advanced Networking Test Center
Consequences of a FailureVoIP carrier services are under observation
Ø Technical press, analysts
Ø Customer blogs
Small outages can quickly lead to huge brand damages, specifically for established carriers:
VoIP service providers need to focus high quality service maybe even more than PSTN carriers!
European Advanced Networking Test Center
DefinitionInternet voice solutions:Ø Voice over IP service offered by a full-service
operator (controlling the last mile and Internet access to the VoIP soft switch and bordergateways)
Ø Net Centrex full-service solution (all the above, plus a virtual PBX)
Ø Internet telephony service offered by an application service provider (controlling only the VoIP soft switch and border gateways)
Ø Peer-to-peer Internet telephony
European Advanced Networking Test Center
Risk AnalysisWe identify six main groups of
potential risks for a VoIP carrier service:Ø Scalability
Ø Availability
Ø Speech Quality
Ø Management and Accounting
ØWarranty Claims
These risks can be managed by careful proof of concept and acceptance testing
European Advanced Networking Test Center
Scalability TestingVoIP networks grow fast
Ø Residential networks may reach millions, business networks 10,000s of customers
Growth is not linear:Ø High call volume at
New Year‘s EveØ New customers added
in a short time following marketing activities
Ø Many voice boxes in use during holiday season
Emulate any future traffic conditions with call generators to ensure scalability
0
20
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60
80
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120
An
zah
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UnexpectedCall Load
European Advanced Networking Test Center
Scalability Testing (2)Untested software often doesn‘t scale
Ø Example: Customer growth can slow down operational speed of databases, interfaces, etc. disproportionally
Ø Generic vendor tests do not substitutecarrier tests becausespecific configurationsoften scale differently
Verify scalability of all call types and situations
Hardware Investment System Performance
European Advanced Networking Test Center
Availability TestingAny service component will fail eventually
Ø Many fatal outages are caused by erroneous switch-over procedures
Ø Network behavior can onlybe predicted with realisticproof of concept tests under load
Ø Pure functionality tests are not representative at all!
Emulate failure of all components and services, eliminate single points of failure
European Advanced Networking Test Center
Speech Quality
Customers should "feel" VoIP call quality to be similar or better than PSTN
Components:Ø Network jitter
Ø Packet loss
Ø CODEC quality
Ø Echo cancellation
Network quality measurements and automated MOS tests help to assess subjective call quality
54321
GSM
SevereImpairment
ISDN G711
G.723/9
MO
S
European Advanced Networking Test Center
Don‘t Forget ManagementManagement plane needs to keep up with network
growthØ Customer self-service provisioning interfaces are subject
to peak loadsØ Fault monitoring needs to scale to many subscribers
(alert errors with short delay)Ø Accounting must report correct call usage under any
conditions (otherwise not all calls are charged, or claims can be expected if too much is charged)
Include all system interfaces in scalability tests, including the management plane – even improveslegal position in case of accounting tests
European Advanced Networking Test Center
Warranty ClaimsCarrier equipment is typically used 3-5 yearsWarranty periods are often only 6-12 months
Ø Full scale not reached within warranty period
Ø Lack of scalability can‘t be claimed in time
Careful acceptance tests anticipating the max. scalability help to raise flaws within warranty period, saving money
100%
Sca
le
Time1 5 yrs
With acceptance tests… without
European Advanced Networking Test Center
SummaryØ A well-performing service is a mandatory
prerequisite for a successful paid VoIP carrier service
Ø Network reliability and maintenance of service levels will be one of the main differentiating factor for VoIP service providers
Ø Serious proof of concept and acceptance tests can improve VoIP scalability and reliability considerably
European Advanced Networking Test Center
Thank you for your interest!
For further information, please contact us:
EANTC AG Einsteinufer 17 D-10587 BerlinGermany
Phone: +49.30.318 05 95-0Fax: +49.30.318 05 95-10E-mail: [email protected]
www.eantc.de