User guide

Physical and Layer 2 Interfaces 61
Software Release 2.4.1
C613-02021-00 REV B
Setting the IDLE parameter to ON enables the idle timer and sets the
timeout period to 60 seconds. ISDN calls are disconnected no data is
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
You can configure a PPP interface 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 follow these
steps
The following steps are required:
1. Configure BRI or PRI ISDN.
2. Create a second ISDN call.
3. Create PPP interfaces.
1. Configure BRI or PRI ISDN.
Complete steps 1 to 5 of “Configuring Basic Rate ISDN” on page 55, or steps
1 to 4 of “Configuring Primary Rate ISDN” on page 58.
2. Create a second ISDN call.
Create a second ISDN call on each router, identical to the call ROHO but
with the name DEMAND.
3. Create PPP interfaces.
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” on page 55, on the Head Office router create PPP interface
0, enter the command:
CREATE PPP=0 OVER=ISDN-ROHO IDLE=ON
ADD PPP=0 OVER=ISDN-DEMAND TYPE=DEMAND
On the Remote Office router, to create PPP interface 0, enter the command:
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.
For more information about ISDN, including LAPD, Q.931, Call control, Call
Logging, DNS, AODI, X.25 and Data over voice, see the Integrated Services
Digital Network (ISDN) chapter in the AR400 Series Router Software Reference.