Cisco Cisco Expressway Maintenance Manual
Bandwidth Control
This section describes how to control the bandwidth that is used for calls within your Local Zone, as well as calls out
to other zones (Configuration > Traversal Subzone and Configuration > Bandwidth).
to other zones (Configuration > Traversal Subzone and Configuration > Bandwidth).
About Bandwidth Control
The Expressway allows you to control the amount of bandwidth used by calls passing through the system's Traversal
Subzone. This is done by using
Subzone. This is done by using
Bandwidth limits may be set on a call-by-call basis and/or on a total concurrent usage basis. This flexibility allows
you to set appropriate bandwidth controls on individual components of your network.
you to set appropriate bandwidth controls on individual components of your network.
Calls will fail if links are not configured correctly. You can check whether a call will succeed, and what bandwidth will
be allocated to it, using the command
be allocated to it, using the command
xCommand CheckBandwidth
.
.
Configuring Bandwidth Controls
The Bandwidth configuration page (Configuration > Bandwidth > Configuration) is used to specify how the
Expressway behaves in situations when it receives a call with no bandwidth specified, and when it receives a call that
requests more bandwidth than is currently available.
Expressway behaves in situations when it receives a call with no bandwidth specified, and when it receives a call that
requests more bandwidth than is currently available.
The configurable options are:
Field
Description
Usage tips
Default call
bandwidth
(kbps)
bandwidth
(kbps)
The bandwidth to use for calls for which no bandwidth value
has been specified by the system that initiated the call.
has been specified by the system that initiated the call.
It also defines the minimum bandwidth to use on SIP to H.323
interworked calls.
interworked calls.
This value cannot be blank. The default value is 384kbps.
Usually, when a call is initiated
the endpoint will include in the
request the amount of bandwidth
it wants to use.
the endpoint will include in the
request the amount of bandwidth
it wants to use.
Downspeed
per call mode
per call mode
Determines what happens if the per-call bandwidth
restrictions on a subzone or pipe mean that there is insufficient
bandwidth available to place a call at the requested rate.
restrictions on a subzone or pipe mean that there is insufficient
bandwidth available to place a call at the requested rate.
On: the call will be downspeeded.
Off: the call will not be placed.
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