Technical information

DEFINITY ECS, DEFINITY Communications Systems,
System 75, and System 85
Issue 7 June 2001
7-11
ARS Measurement Selection
The ARS Measurement Selection can monitor up to 20 routing patterns (25 for
G3) for traffic flow and usage.
For DEFINITY ECS, DEFINITY G1, G3, and System 75:
 Use change ars meas-selection to choose the routing patterns you want
to track.
 Use list measurements route-pattern followed by the timeframe
(yesterday, today, or last-hour) to review the measurements.
For DEFINITY G2, use Monitor I to perform the same function.
Automatic Circuit Assurance
This monitoring technique detects a number of short holding time calls or a single
long holding time call, both of which may indicate hacker activity. Long holding
times on Trunk-to-Trunk calls can be a warning sign. The ACA feature allows you
to establish time limit thresholds defining what is considered a short holding time
and a long holding time. When a violation occurs, a designated station is visually
notified.
When a notification occurs, determine if the call is still active. If toll fraud is
suspected (for example, aca-short or aca-long is displayed on the designated
phone), use the busy verification feature (see ‘‘Busy Verification’’ on page 7-12) to
monitor the call in progress.
With Remote Access, when hacker activity is present, there is usually a burst of
short holding times as the hacker attempts to break the barrier code or
authorization code protection, or long holding time calls after the hacker is
successful. An ACA alarm on a Remote Access trunk should be considered a
potential threat and investigated immediately. If the call is answered by an
automated attendant, a hacker may be attempting to gain access to the system
facilities using TACs.
For DEFINITY ECS, DEFINITY G1, G3, and System 75:
 Use change system-parameters feature to display the Features-Related
System Parameters screen.
 Enter y in the Automatic Circuit Assurance (ACA) Enabled field.
 Enter local, primary, or remote in the ACA Referral Calls field. If
primary is selected, calls can be received from other switches. Remote
applies if the PBX being administered is a DCS node, perhaps unattended,
that wants ACA referral calls to an extension or console at another DCS
node.
 Complete the following fields as well: ACA Referral Destination, ACA Short
Holding Time Originating Extension, ACA Long Holding Time Originating
Extension, and ACA Remote PBX Identification.