Lucent Technologies MERLIN LEGEND Release 6.1 Feature Reference page 557

MERLIN LEGEND Communications System Release 6.1
Feature Reference 555-661-110
Features
Primary Rate Interface (PRI) and T1
Fractional Use Support. You can tailor your use of PRI B-channels with
drop-and-insert equipment that allows fractional use of B-channels for non-
MERLIN LEGEND data/video communications between sites at 64 kbps
per channel, while keeping the remaining B-channels for MERLIN
LEGEND PRI voice/data traffic. The PRI D-channel must remain active.
The system also allows this type of fractional use of T1 circuits
programmed as T1-emulated tie and tandem trunks.
Tandem PRI Trunk Programming
In Release 6.0 and later systems (Hybrid/PBX mode only), two PRI Switch Type
options allow you to set up a PRI tandem trunk that connects two MERLIN
LEGEND Communications Systems or a MERLIN LEGEND Communications
System and a DEFINITY ECS or DEFINITY ProLogix Solutions system. The two
additional programming options are LEGEND-Ntwk and LEGEND-PBX. One
system is specified as operating in PBX mode and the other as operating in
networked mode. When both systems are MERLIN LEGEND Communications
Systems, it is not significant which system is assigned which switch type, only that
they are opposites. When you program this switch type, it is important to specify
the type of switch at the other end of the PRI trunk, not the local switch.
DEFINITY ECS and DEFINITY ProLogix Solutions systems do not have a Switch
Type setting. The Interface field on such a system identifies the type of the
DEFINITY ECS or DEFINITY ProLogix Solutions system, not the type at the other
end of the tandem trunk as on MERLIN LEGEND Communications Systems. If the
Interface field specifies Network , as it typically might, the connected MERLIN
LEGEND Communications Systems specify LEGEND-Ntwk. If the Interface field
specifies User , the connected MERLIN LEGEND Communications Systems are
programmed with the LEGEND-PBX setting.
NOTE:
DEFINITY ECS and DEFINITY ProLogix Solutions features and operations
are beyond the scope of this guide. For information about these systems,
consult their documentation.
When you specify one of these two switch types at a MERLIN LEGEND
Communications System, the system's automatic assignment algorithm performs
the following actions to set up the PRI tandem trunk:
A single unused B-channel group number is automatically assigned with all
23 B-channels on the trunk; B-channels may be removed or added
subsequently. To find an unused group, the system starts at group 80 and
searches backward.
PRI dial plan-routing does not apply for incoming calls on the trunk.
Instead, incoming routing is automatically set to Route Directly to UDP; this
cannot be changed as long as the LEGEND-PBX or LEGEND-Ntwk switch
type is in effect.
Issue 1
August 1998
Page 508
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