NETGEAR Nighthawk D7000 User Manual page 291

Nighthawk AC1900 WiFi VDSL/ADSL Modem Router Model D7000
router restores the original address information replaced by NAT and sends this reply message to
your computer.
7. When your modem router receives the incoming message to destination port 113, it checks its session
table and finds an active session for port 113 associated with your computer. The modem router
replaces the message's destination IP address with your computer's IP address and forwards the
message to your computer.
8. When you finish your chat session, your modem router eventually senses a period of inactivity in the
communications. The modem router then removes the session information from its session table, and
incoming traffic is no longer accepted on port numbers 33333 or 113.
Manage Port Forwarding and Port Triggering
291