.TH AAN 8
.SH NAME
aan \- always available network
.SH SYNOPSIS
.B aan
[
.B -d
]
[
.B -c
]
[
.B -m maxto
]
.I dialstring
|
.I dir
.SH DESCRIPTION
.I 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.
.PP
.I Aan 
uses a unique protocol to make sure no data is ever lost even
when the connection breaks.
After a reconnection,
.I aan
retransmits all unacknowledged data between client and server.
.PP
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
.I aan
re-establishes the client's connection automatically.
.PP 
When the server part has not heard from the client in
.I maxto
seconds, the server part of
.I aan
exits.  The default
.I maxto
is one day.
The client side (option
.BR -c )
calls the server by its
.IR dialstring ,
while
the server side listens for connections in the 
already-announced network directory
.IR devdir .
.PP
.I Aan
is usually run automatically through the
.B -p
option of
.IR import (4).
.SH EXAMPLE
Assume the server part of aan is encapsulated in exportfs on the
machine
.B sob
and started through
.B aux/listen
as follows:
.IP
.EX
netdir=`{echo $3 | sed 's;/[0-9]+$;!*!0;'}
exec exportfs -a -A $netdir
.EE
.PP
Then machine
.BR astro6 's
name space can be imported through
.I aan
using this command:
.IP
.EX
import -p astro6 / /mnt/term
.EE
.SH FILES
.TP
.B /sys/log/aan
Log file
.SH SOURCE
.B /sys/src/cmd/aan.c
.SH SEE ALSO
.IR import (4),
.IR exportfs (4)