Distributed keepalive support from Packet Forwarding Engine to LNS PPP tunneled sessions

Junos OS supports client-initiated and server-initiated Point-to-Point Link Control Protocol (PPP LCP) echo request and reply packet handling from the Packet Forwarding Engine to the L2TP Network Server (LNS) PPP tunneled sessions on an MPC. Keepalive aging timeout is defined as the product of the keepalive interval and down-count values at the LNS. If the keepalive aging timeout is greater than 180 seconds, the keepalive packets are handled at the Routing Engine. If the aging timeout is less than or equal to 180 seconds, the packets are handled at the Packet Forwarding Engine.