Dynamic Cac; Enabling Dynamic Cac And Setting Maximum Bandwidth - Avaya G250 Administration

Dynamic CAC

Dynamic Call Admission Control (CAC) provides enhanced control over WAN bandwidth. When
Dynamic CAC is enabled on an interface, the G250/G350 informs the MGC of the actual
bandwidth of the interface and tells the MGC to block calls when the bandwidth is exhausted.
Dynamic CAC is especially useful in situations where a primary link is down and a backup link
with less bandwidth than the primary link is active in its place. Without dynamic CAC, the MGC
is unaware that the interface has switched over to the backup link. Thus, the MGC is unaware of
the resulting changes in network topology and bandwidth available for the interface.
Consequently, the MGC might allow calls through the interface that require more than the
currently available bandwidth.
Note:
Dynamic CAC works in conjunction with the Avaya Communication Manager Call
Note:
Admission Control: Bandwidth Limitation (CAC-BL) feature. A related feature is
Inter-Gateway Alternate Routing (IGAR), which provides a mechanism to re-route
bearer traffic from the WAN to the PSTN under certain configurable conditions.
For more information on CAC-BL and IGAR, see Administrator Guide for Avaya
Communication Manager, 03-300509.
You can enable dynamic CAC on the following interface types:
Fast Ethernet
●
Serial (PPP or frame relay)
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GRE Tunnel
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VLAN
●
Note:
Since VLAN interfaces are always up, configuring dynamic CAC on a VLAN
Note:
interface provides a means to have a default dynamic CAC bandwidth.

Enabling dynamic CAC and setting maximum bandwidth

Use the dynamic-cac bbl command in interface context to enable dynamic CAC on the
interface and set the maximum bandwidth for the interface. The dynamic-cac bbl command
includes the following parameters:
bbl — The bearer bandwidth limit (kbps). The MGC enforces this as the maximum
●
bandwidth for the interface. If you set the bbl to 0, the interface can only be used for
signalling.
Dynamic CAC
Issue 3 February 2007 255