Nortel RLC Installation And Administration Manual page 220

Configuring the RLC
Network Port Configuration field descriptions
Field
PSTN Number
Allocation
194
Description
Enter the port's DN in the PSTN Number field. (This is the
DN programmed on the switch that the remote unit uses to
contact the RLC.)
The allocation setting refers to the connection status of the
port being configured.
Click on the Permanent option button if you want
connections established over the port you are
configuring to remain up until the remote unit goes
offline.
Click on the On Demand option button if you want
connections established over this port to go down when
they are no longer needed. Connections over ports
configured as On Demand remain up until the
minimum call duration timer expires.
When using the PSTN, call-establishment takes longer in
On Demand mode than in Permanent mode. This is
because, in On Demand mode, the Remote Gateway 9100
Series unit or RLC must establish a new connection for the
call. In Permanent mode, the connection already exists.
RLC Installation and Administration Guide
Standard 4.0