Aan tunnels traffic between a client and a server through a persistent
network connection. If the connection breaks (voluntarily or due
to networking problems), the aan client re–establishes the connection
by redialing the server.
Aan uses a unique protocol to make sure no data is ever lost even
when the connection breaks. After a reconnection, aan retransmits
all unacknowledged data between client and server.
A connection can be broken voluntarily (e.g. by roaming over IP
networks), or a connection can break when the IP service is unreliable.
In either case, aan re–establishes the client's connection automatically.
When the server part has not heard from the client in maxto seconds,
the server part of aan exits. The default maxto is one day. The
client side (option –c) calls the server by its dialstring, while
the server side listens for connections in the already–announced
network directory netdir.
Aan is usually run automatically through the –p option of import(4).|