Lucent Technologies MERLIN LEGEND Release 6.0 Network Reference Manual page 181

MERLIN LEGEND Communications System Release 6.0
Network Reference 555-660-150
5 System Management
General Programming in Networks
"Facility Restriction Levels and Remote Access" on page 4–5
interactions among FRLs in greater detail. For procedures that allow you to assign
ARS FRLs to extensions, see System Programming, Chapter 3, "Common
Administrative Procedures."
Remote Access with Barrier Codes
When non-local users access the PSTN facilities connected to your local system
or network calls are routed through your system, you use this procedure to specify
default COR settings for all tie trunks (that is, all networked tandem tie trunks,
analog or T1) and/or all non-tie trunks (that is, all tandem PRI trunks). Be sure to
specify that remote access calls on these trunks do require barrier codes.
!
SECURITYlALERT:
Networked systems require special attention to security issues. Follow the
rules below when setting up and planning your system for network use.
The barrier code setting is ignored for UDP and ARS calls on tandem trunks, but
applies to remote access calls that arrive from the PSTN on DID, PRI dial-plan
routed, or tandem facilities for those UDP calls that are dialed using a Remote
Access code included in the non-local dial plan. In a network, these types of
remote access calls should have restrictions applied to barrier codes and should
not be restricted by default COR settings. In addition, barrier codes should be
required for dial-in and dedicated/shared remote-access trunks used by remote
access users on your own system. Do not assign private networked trunks for
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
called system is compared to the UDP or ARS route FRL on the
called system. See the Feature Reference and
Default Class-of-Restriction Settings" on page 4–6
Extension and ARS FRLs should be carefully and stringently
assigned in order to prevent unauthorized trunk-to-trunk transfers to
local PSTN facilities.
this feature in a networked system.
5
Table 4–1, page 4–3
Issue 1
February 1998
Page 5-5
discusses the
"Remote Access
for details.
explains the operation of