Specifications

Engineering Guidelines
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bandwidth is shared. You may need to specify alternative routes where multiple routes go
through a common bottleneck, or where bandwidth is shared between a primary and secondary
controller for resilient operation in the event of a controller failure.
Call Admission Control and re-routing applies to normal calls. Emergency calls, certain priority
calls and established calls being re-routed, for example, calls on hold, do not need to negotiate
access. The use of the resource will be noted and subsequent (non-emergency) calls from the
same extension may be restricted.
More details on programming and defining zones are highlighted in the System Administration
Tool Help for MiVoice Business. Some typical network deployments are shown below, along
with how they would be realized using the tree topology information.
There are some important points to consider with the Call Admission Control in place.
• For Call Admission Control and Bandwidth Management to be effective, call setup must
pass through all the bandwidth managers responsible for monitoring the bandwidth along
the entire path taken by the call's audio stream.
• Available bandwidth can be allocated across multiple bandwidth managers (up to 6 with
single level mapping). Bandwidth managers need routing lists to link to each other so the
bandwidth can be shared dynamically.
• Mitel recommends multiple bandwidth managers and multiple zone access paths for resil-
ient operation so that bandwidth control is maintained if a single unit fails.
• Integrate the bandwidth manager with the controller hosting the phones. This will allow you
to monitor the bandwidth of remote phones hosted from a central call server.
• Bandwidth managers should be logically located with the bandwidth pipe to be monitored,
either upstream, or downstream, that is, the call should monitored as it exits or enters
through a router connection.
Determining the position of the root node in meshed and non-meshed WAN
When building up the connection tree, the most important point to recognize is the location of
the root zone. Often this is the WAN (as shown in Figure 22), but this may not always be the case.
Fully meshed WAN connections
In a fully meshed network where the WAN can switch data, or where VPNs exist from every
access point to every access point, then the root node is the WAN. In the case with multiple
nodes, this can lead to many VPN connections.
Figure 22 shows a deployment example of a fully meshed WAN network. In this example, a
distributed sales organization is linked using an MPLS network.