Managing Data Calls
Wideband Switching
468
Administrator’s Guide for Avaya Communication Manager
November 2003
To reduce glare probability, the network needs to be administered so both sides of the interface select
channels from opposite ends of facilities. This is called linear hunting, ascending or descending. For
example, on a 23B+D trunk group, the user side could be administered to select B-channels starting at
channel 23 while the network side would be administered to start selecting at channel 1. Using the same
example, if channel 22 is active but channel 23 is idle, the user side should select channel 23 for re-use.
Blocking prevention
Blocking occurs when insufficient B-channels required to make a call are available. Narrowband calls
require only one channel so blocking is less likely than with wideband calls which require multiple
B-channels. Blocking also occurs for wideband calls when bandwidth is not available in the appropriate
format (that is, fixed, floating, or flexible).
To reduce blocking, Communication Manager selects trunks for both wideband and narrowband calls to
maximize availability of idle fixed channels for H0, H11, and H12 calls and idle floating channels for N x
DS0 calls that require a contiguous bandwidth. The strategy for preserving idle channels to minimize
blocking depends on the channel type. The chances for blocking are reduced if you use a flexible
algorithm, assuming it is supported on the other end.
Administering Wideband Switching
Before you start
You need a DS1 Converter circuit pack. See the Avaya System Description Pocket Reference for more
information on the circuit pack.
Instructions
To administer wideband switching:
1
On the Access Endpoint screen, administer all fields.
See
Access Endpoint
on page 619 for more information.
2
On the PRI Endpoint screen, administer all fields.
See
PRI Endpoint
on page 1109 for more information.
3
On the ISDN Trunk Group screen, administer all fields.
See
Trk Grp(s)
on page 962 for more information.
Channel Type
Blocking Minimization Strategy
H0
Preserve idle quadrants
H11
Preserve idle facilities
H12
Preserve idle facilities
Flexible NxDS0
Preserve idle facilities
Floating NxDS0
Preserve idle facilities as first priority