Nortel RLC, Installation And Administration Manual

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66 RLC Installation and Administration Guide
Planning for RLC installation Standard 4.0
Trunks and dialing plans
To obtain an outside line on the local PSTN, users dial local trunk-access SPRE
codes. The SPRE codes configured for remote sites must not conflict with the
dialing plans used by the host PBX. Conflicts result in end-users not being able
to place outgoing calls through the local PSTN.
Call blocking
The voice processing capacity of a remote system depends on the number of
DSP application and trunk interface modules installed at the host and remote
sites. Voice processing capacity defines the number of calls that can be active
simultaneously and the amount of bandwidth the site can access.
Reducing call blocking in PSTN mode
Remote Gateway 9150 units use ISDN BRI trunks in PSTN mode. To reduce
call blocking in the PSTN mode at the host location, you must increase the
number of trunks available to the RLC.
Reducing call blocking in Voice over IP mode
One DSP application module provides the ability to support eight simultaneous
Remote Gateway 9100 Series calls. To reduce call blocking for Voice over
Internet Protocol (VoIP) calls, increase the number of DSP resources in your
system. Do this at the host (RLC) site and, if the remote unit is a Remote
Gateway 9150 unit, at the remote site. You can install up to four DSP application
modules on a Remote Gateway 9150 unit and up to four DSP application
modules on an RLC.
Calculating system requirements
For help in determining how many DSP application modules you need to install
to reduce or eliminate call blocking, refer to “DSP requirements” on page 49 and
the RLC System expansion worksheet on page 345.