Disclosed are methods and apparatus for managing a registration state of
an endpoint node in a network address port translation environment. A
registration message is received from a first endpoint node located
within a local network. The registration message is sent from the first
endpoint node to a gatekeeper node, and the registration message includes
a local source address of the first endpoint node, a local source port of
the first endpoint node, and local call signaling information to be used
by another endpoint node to initiate a data connection with the first
endpoint node. The local source address of the first endpoint node is
translated into a first global address. A first binding that associates
the local source address with the global source address is created. The
local call signaling information is translated into global call signaling
information. A registration state of the first endpoint node is
maintained, and the first binding is maintained based on the registration
state (e.g., by using "registration doors").