3Com NBX 100 Administrator's Manual page 139

Table 24 Maximum Bridged Extensions
System Device Limit
NBX V3000 250
NBX V3000 More than 250
SuperStack 3 NBX 250
SuperStack 3 NBX More than 250
NBX 100 200
There are no restrictions on the number of secondary telephones or the
number of bridged extensions on secondary telephones.
Provided that you do not exceed the limits shown in
configure the maximum number of bridged extensions using any
combination of primary telephones and bridged extensions. For example,
on a SuperStack 3 NBX system, you can configure 400 primary
telephones with three bridged extensions each or 300 primary telephones
with 4 bridged extensions each to reach the limit of 1200.
You can configure a different number of bridged extension buttons on a
primary and an associated secondary telephone. For example, if a primary
telephone has 5 bridged extensions, one of the secondary telephones can
be configured to have fewer (1 through 4) bridged extensions. However,
if all of the primary bridged extensions are in use, the person at the
secondary telephone will not be able to see all of the calls.
You can define any one telephone as either a primary telephone or a
secondary telephone, but not both. If the telephone has an Attendant
Console associated with it, the bridged extension functions for the
telephone extend to the Attendant Console. For example, an NBX 2101
Basic Telephone with an associated Attendant Console, can be
configured as a primary telephone with up to 11 bridged extensions on
Attendant Console buttons.
You can configure bridged extensions on the same buttons that are used
for the telephone's extension or on non-extension buttons. Before you
can create a bridged extension on a telephone, you must unlock the
button settings in the telephone group button mappings dialog box for
the telephone group to which the telephone belongs.
Creating and Managing Bridged Extensions
Maximum
Number of
Primary
Telephones
250
400
250
400
100
139
Maximum Number
of Bridged
Extensions on
Primary Phones
1200
1200
1200
1200
300
Table 24, you can