The data plane creates RTOs for UDP and TCP sessions
and tracks state changes. It also synchronizes traffic for IPv4 passthrough
protocols such as GRE and IPsec.
RTOs for synchronizing a session include:
Session creation RTOs on the first packet
Session deletion and ageout RTOs
Change-related RTOs, which include:
TCP state changes
Timeout synchronization request and response messages
RTOs for creating and deleting temporary openings in the
firewall (pinholes) and child session pinholes
