User`s guide

Setting up Meridian Mail security 6-55
Network Class of Service—Facility Restriction Level
Standard 1.0 System Administration Guide January 1998
Network Class of Service—Facility Restriction Level
Description
A Network Class of Service (NCOS) designation is a group of
calling privileges you can assign to a station, TIE trunk, DISA
DN, or authorization code.
How NCOS works
The Meridian 1 system uses the NCOS to determine caller
treatments and eligibility for outgoing calls that use the Least
Cost Routing (BARS/NARS) software. By partitioning stations,
TIE trunks, DISA DNs, and authorization codes into unique
NCOS groups, you can track the normal calling patterns of each
group (TFN002). You can then promptly detect variances which
can indicate fraudulent activity, and take action.
Within the NCOS, you can assign the user to one of eight
Facility Restriction Levels (FRL). The FRL is compared to the
minimum FRL requirement assigned to each entry in a route
list. The entries in the route list are trunk routes that are able to
place calls to the NPA, NXX, or special number. The routes are
listed in the order the system searches them when trying to
complete an external call. Callers are eligible to complete a call
on an entry in the route list when their FRL is equal to, or higher
than, the entry’s FRL level.
In conjunction with
TGAR
The BARS/NARS database can be configured to ignore Trunk
Group Access Restrictions (TGAR) or to use them. When
TGARs are ignored, the BARS/NARS software assesses the
Class of Service and the FRL to determine which call facilities
are eligible for a particular call. This configuration allows
flexibility in using a given trunk group while forcing users to
place calls through BARS/NARS. You can base trunk access
for each call on the FRL requirements for the number dialed
rather than basing it on the TGAR.
You can also configure the BARS/NARS database to assess
TGAR assignments in determining how the system can route a
call. In this case, the BARS/NARS software will use the COS,
TGAR, and FRL to determine which call facilities are eligible
to process a particular call.