VoIP testing
- an overview or tutorial of the different test requirements for VoIP and
techniques used in VoIP testing.
IP networks carrying VoIP traffic are very complicated. They
carry both voice and data traffic and this results in a variety of traffic with
different requirements being carried and this presents many challenges. In order
to ensure that all the requirements are met and the network operates to its
maximum efficiency can present many challenges. Obviously the design must be
correct, but once implemented testing of the network is needed to ensure that it
is able to operate correctly when installed, and then maintained correctly
ensuring that its performance is maintained or optimised to provide the
performance meets the needs of the network provider and the user. For VoIP,
testing is an essential element of any network. However specialised VoIP testing
techniques are required.
VoIP network architecture
The structure of a VoIP network comprises many entities and
this means that VoIP testing is essential to ensure that the network is
operating satisfactorily. A typical VoIP network will include many different
entities:
- Signalling gateways
- Media gateways
- Gatekeepers
- Class 5 switches
- SS7 network
- Network management system
- Billing system
This variety of different entities within the VoIP network
all communicate with each other using a variety of protocols. To perform
correctly it is necessary to ensure that they communicate efficiently and that
no bottlenecks are created. Analysing the performance of a VoIP network is not
always easy. However it can be achieved and significant improvements in
performance can be achieved if the VoIP testing scenarios are carefully chosen
and planned, and the data analysed to reveal any problems.
VoIP testing fundamentals
When considering VoIP testing, it is first necessary to
categorise the different applications or different types of VoIP testing that
may be employed. There are three areas into which VoIP testing (and other types
of testing) may be categorised:
- VoIP functionality or pre-deployment testing
- VoIP standards compliance testing
- VoIP performance testing
Each element within the overall VoIP testing regime is of
importance as it will ensure that the network is able to perform properly. A
problem in any one element will result in the whole network not performing
properly. These tests can be of the form of a functional test in the laboratory
before deployment. VoIP testing of the individual elements is essential to make
sure that any problems do not manifest themselves during deployment. Isolating
the problem, and fixing it at this stage is considerably more costly.
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