LCP keepalive intervals are configured in the PPPoE client policy. While the regular PPPoE control plane is initiated from the CPM, keepalives are handled directly on the ISA. Because the ISA is aware of any traffic, this handling is optimized so that echo requests are not sent if active traffic is received from the BRAS. The keepalive timer is reset upon each received echo-request. These two mechanisms significantly reduce PPP keepalive messages without compromising liveness detection. Incoming echo requests are always responded to, if LCP is in the LCP Opened state.
LCP PPPoE packets are always sent within the NC forwarding class and dot1p 7. Egress remarking can be used to change dot1p values.