Fallback Threshold; Setting The Qos Threshold For Fallback Routing; Post-Installation Network Measurements - Nortel 1000 Description, Installation And Operation Manual

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Fallback threshold

Setting the QoS threshold for fallback routing

Post-installation network measurements

553-3001-363 Standard 2.00
ITG engineering guidelines
There are two parameters, the receive fallback threshold and the transmit
fallback threshold, which can be set on a per site pair basis.
"Set QoS expectations" on
page 187 sections describe the process of determining the appropriate QoS
level for operating the IP Trunk 3.01 (and later) network. Site pairs can have
very different QoS measurements if some traffic flows are local, while other
traffic flows are inter-continental. Consider setting a higher QoS level for the
local sites compared to the international sites, thus keeping costs of
international WAN links down.
Normally, the fallback threshold in both directions is set to the same QoS
level. In site pairs where one direction of flow is more important, set up
asymmetric QoS levels.
The QoS thresholds for fallback routing are configured in OTM 2.1 (and
later). A threshold is configured for the "Receive fallback threshold" as well
as the "Transmit fallback threshold." The available thresholds are Excellent,
Good, Fair, and Poor.
The design process is continual, even after implementation of the IP Trunk
3.01 (and later) network and commissioning of voice services over the
network. Network changes in the following – IP Trunk 3.01 (and later) traffic,
general intranet traffic patterns, network policies, network topology, user
expectations and networking technology – can render a design obsolete or
non-compliant with QoS objectives. Review the design periodically against
prevailing and trended network conditions and traffic patterns, at least once
every two to three weeks initially, then eventually on a quarterly basis.
It is assumed that the customer's organization already has processes in place
to monitor, analyze, and re-design both the system network and the corporate
intranet, so that both networks continue to conform to internal QoS standards.
September 2004
page 188 and "Measure intranet QoS" on