Timers

Cisco HDLC (cHDLC) has two timers associated with the protocol, the keepalive interval and the timeout interval. The keepalive interval sends periodic keepalive packets. The receiver process expects to receive a keepalive packet at the rate specified by the keepalive interval. The link is declared down if the receiver process does not receive a keepalive within the timeout interval. The link is declared up when the number of continual keepalive packets received equals the up-count.

It is recommended that the nodes at the two endpoints of the cHDLC link are provisioned with the same values.