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A R 7 2 0 R O U T E R Q U I C K S T A R T G U I D E
CONFIGURING ISDN DIAL ON DEMAND
A PPP interface that uses an ISDN call as its physical interface
can be configured for dial on demand operation. The ISDN call
is activated only when there is data to be transmitted, and is
disconnected when the link has been idle for a period of time.
To configure ISDN dial on demand operation, follow these steps:
1
Complete steps 1 to 5 of
Configuring Basic Rate ISDN
, or
steps 1 to 4 of
Configuring Primary Rate ISDN
above.
2
Create PPP interfaces to use the ISDN calls and enable the
IDLE timer. Using the example in step 6 of
Configuring Basic Rate
ISDN
above, on the Head Office router create PPP interface 0
to use the ISDN call ROHO:
CREATE PPP=0 OVER=ISDN-ROHO IDLE=ON
On the Remote Office router, create PPP interface 0 to use the
ISDN call ROHO:
CREATE PPP=0 OVER=ISDN-ROHO IDLE=ON
Setting the IDLE parameter to ON enables the idle timer
and sets the timeout period to 60 seconds. ISDN calls will be
disconnected if there has been no data transmitted over the
link for 60 seconds. To enable the idle timer with a different
timeout period, specify a time in seconds instead of the
value ON.
PPP interface 0 is now configured for dial on demand operation
and any routing protocols such as IP and IPX that are
configured to use PPP interface 0 will automatically inherit the
dial on demand functionality.
CONFIGURING ISDN BANDWIDTH ON DEMAND
A PPP interface can be configured to use up to two B channels
on an ISDN Basic Rate interface, to provide bandwidth on
demand. PPP activates additional ISDN channels when the
bandwidth exceeds an upper threshold, and deactivates ISDN
channels as bandwidth falls below a lower threshold.
To configure an ISDN connection for bandwidth on demand
operation, follow these steps:
1
Complete steps 1 to 5 of
Configuring Basic Rate ISDN
, or
steps 1 to 4 of
Configuring Primary Rate ISDN
above.
2
Create a second ISDN call on each router, identical to the
call ROHO but with the name DEMAND.
3
Create PPP interfaces to use the ISDN calls, enable the
IDLE timer and add a second demand channel. Using the
example in step 6 of
Configuring Basic Rate ISDN
or step 5 of
Configuring Primary Rate ISDN
above, on the Head Office router
create PPP interface 0:
CREATE PPP=0 OVER=ISDN-ROHO IDLE=ON
ADD PPP=0 OVER=ISDN-DEMAND TYPE=DEMAND
On the Remote Office router, create PPP interface 0:
CREATE PPP=0 OVER=ISDN-ROHO IDLE=ON
ADD PPP=0 OVER=ISDN-DEMAND TYPE=DEMAND
PPP interface 0 is now configured for bandwidth on demand
operation and any routing protocols such as IP and IPX that are
configured to use PPP interface 0 will automatically inherit the
bandwidth on demand functionality.
