
Using ISDN and DDR to Enhance Remote Access Connectivity • Chapter 5 161
Interesting Traffic
The mechanism that allows DDR to function is the definition of interesting
traffic. Interesting traffic is defined as traffic the router deems important
(based on access lists); all other traffic is deemed uninteresting. When
interesting traffic enters the router destined for a remote network, the
router establishes a call to the remote network and sends the data (see
Figure 5.7). Once the circuit is connected, all traffic (including uninter-
esting traffic) can flow through the circuit. In the event of uninteresting
traffic coming into the router destined for a remote network, ...