Lucent Technologies MERLIN LEGEND Release 6.0 Network Reference Manual page 71

MERLIN LEGEND Communications System Release 6.0
Network Reference 555-660-150
2 Call-Handling Scenarios
Networking Guidelines
UDP routing applies FRLs to calls over specific routes for pools of tandem
trunks. A different set of FRLs is programmed for ARS routes. However, an
extension's FRL applies to both UDP routes and ARS routes. An
extension's FRL is applied only to local tandem and PSTN calls and is not
carried across the network when the caller uses ARS to direct a call to
PSTN facilities on another switch. As you read the scenarios in this
chapter, pay attention to the following rules:
— Within a system, ARS FRL restrictions compare the local extension FRL
— For intersystem calling, the system compares the local extension FRL to
— When a Remote Access code is included in the non-local dial plan of the
— When a UDP or ARS call is routed into a system over tandem trunks and
— When a PRI dial-plan routed or DID call is routed across systems in a
!
SECURITYlALERT:
Networked systems require special attention to security issues. Follow the
rules below when setting up and planning your system for network use.
to the route FRL. To use a route for a call, the extension FRL must be
equal to or greater than the route FRL.
the UDP route FRL. To use a route for a call, the extension FRL must be
equal to or greater than the UDP route FRL.
calling system, the caller's barrier code FRL on the called system is
compared to the UDP or ARS route FRL on the called system.
then out of it again, the route FRL on the local receiving system is
compared to the FRL assigned locally to the default COR for all-tie or all
non-tie trunks.
network, the system receiving the call from the PSTN searches the local
dial plan and then the non-local dial plan for the destination extension
number. If the number is in the non-local dial plan, the call is routed out
using the UDP routing pattern for the specified extension range. For a
call to be routed out of the next receiving system, that system's COR
FRL must be equal to or greater than the UDP route FRL.
Ensure that barrier codes are required for incoming remote access
calls received on PSTN PRI dial-plan routed and DID facilities, as
well as those calls that are made from the local system by dialing
the Remote Access code (889, for example). When you program the
default COR, turn the barrier code requirement on. This setting is
ignored for ARS calls and calls to non-local extensions across the
network. However, it is still applied to DID and PRI dial-plan routed
remote access calls as well as to calls received on a tandem trunk
and routed to a Remote Access code. Because the COR Calling
Restriction must be set to unrestricted for network calling, using
barrier codes on these facilities is essential in order to apply security
measures. When a Remote Access code is included in the non-local
dial plan of the calling system, the caller's barrier code FRL on the
Issue 1
February 1998
Page 2-11