Lucent Technologies 555-661-150 manual SECURITYlALERT

MERLIN LEGEND Communications System Release 6.1	Issue 1
Network Reference 555-661-150	August 1998

2Call-Handling Scenarios

Networking Guidelines Page 2-13

■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 private 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 to the route FRL. To use a route for a call, the extension FRL must be equal to or greater than the route FRL.

—For intersystem calling, the system compares the local extension FRL to 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.

—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 called system is compared to the UDP or ARS route FRL on the called system.

—When a UDP or ARS call is routed into a system over tandem trunks and then out of it again, the FRL assigned to the default COR for all-tie or all non-tie trunks is compared to the FRL assigned to the outgoing UDP or ARS route on the called system. The default COR’s FRL must be greater than or equal to the FRL of the outgoing route on the called system.

—When a PRI dial-plan routed or DID call is routed across systems in a private 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.

—In Release 6.1 and later, when an integrated VMI calling group is used for routing calls to a centralized VMS/AA, assign an FRL of 0 to the UDP route for the VMI conversion number. The pattern for the VMI conversion number should not be used for any other routing.

!SECURITYlALERT:

Networked systems require special attention to security issues. Follow the rules below when setting up and planning your system for private network use.

■Ensure that barrier codes are required for incoming remote access calls received on PSTN dial-plan routed and tandem facilities that route to 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 private network. However, it is still applied to DID and PRI dial-plan routed remote access calls as well as to calls received