This object specifies how often, in seconds, an OAM F5 loopback cell is generated from the channel, with a value of 0 disabling generation of these cells. An administrator uses this setting to control how frequently the channel proactively tests end-to-end ATM connectivity using OAM loopback cells. For example, setting this to 30 would cause the channel to send an OAM F5 loopback cell every 30 seconds to continuously verify the PVC is still reachable.