DDR types

Depending on how DDR calls are triggered, DDR includes packet-triggered DDR and auto-dial DDR.

You can define packets on a dialup interface as interesting and uninteresting by configuring access control rules. Only interesting packets trigger outgoing calls and reset the link idle-timeout timer.

Before a dialup connection is established, uninteresting packets will be dropped. After a dialup connection is established, uninteresting packets can be forwarded. When the link idle-timeout timer expires, DDR disconnects the connection.

For more information about interesting and uninteresting packets, see "Associating a dial rule with a dialup interface."

DDR automatically initiates a dialup connection to the remote end upon router startup without requiring a triggering packet. If the connection cannot be established, it will retry at the auto-dial interval. The established connection will not disconnect due to the idle-timeout timer expiration.