Measure Intranet Qos; Qos Evaluation Process Overview - Nortel 1000 Description, Installation And Operation Manual

Measure intranet QoS

QoS evaluation process overview

End-to-end delay and error characteristics of the current state of the intranet
can be measured. These measurements help set acceptable QoS standards
when using the corporate intranet to transmit voice services.
There are two main objectives when dealing with the QoS issue in an IP
Trunk 3.01 (and later) network:
1 to predict the expected QoS
2 to evaluate the QoS after integrating IP Trunk 3.01 (and later) traffic into
the intranet
The process for either case is similar; one is without IP Trunk 3.01 (and later)
traffic and one is with. The differences are discussed in this section.
In the process, it is assumed that the PING program is available on a PC, or
some network management tool is available to collect delay and loss data and
access the TLAN subnet that connects to the router to the intranet.
1 Use PING or an equivalent tool to collect round-trip delay (in ms) and
loss (in%) data.
2 Divide the delay by 2 to approximate one-way delay. Add 93 ms to adjust
for ITG processing and buffering time.
3 Use a QoS chart, or Table 34 on
excellent, good, fair or poor.
4 If a customer wants to manage the QoS in a more detailed fashion,
re-balance the values of delay compared to loss by adjusting IP Trunk
3.01 (and later) system parameters, such as preferred codec, payload size,
and routing algorithm, to move resulting QoS among different
categories.
5 If the QoS objective is met, repeat the process periodically to make sure
the required QoS is maintained.
ITG engineering guidelines
page 201, to predict the QoS categories:
IP Trunk Description, Installation, and Operation
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