This file has information specific to vat ATM version (only available
on Linux platform as of Nov 1997). The version number for this ATM
mutation is 4.0b2-atm0.2 and it is based on vat 4.0b2 source code.


Requirements:
=============
o Linux 2.0.29 (for Linux ATM version 0.31, check Linux ATM package
  to verify which kernel is needed for the latest ATM software)
o Linux-ATM 0.31 or later (http://lrcwww.epfl.ch/linux-atm/)
o Tcl 7.6 and Tk 4.2
o ATM NIC and ATM network


Building ATM vat:
=================
o Install Linux ATM package according to the instructions that come with it
o For convenience the GSM package is bundled into this distribution
  of vat source. Build the GSM library by (cd gsm-1.0-pl10; make)
  before running the vat configuration script.
o Run configure script: ./configure
o Build the vat binary: make
(o Optionally make install)


Using ATM vat:
==============
ATM mode is turned on by command line option '-z'. (If you don't specify
'-z', vat runs in normal IP mode.) Before you can use vat with ATM, you
must be running an ATM signalling daemon (that implements UNI3.1) so that 
opening and closing ATM streams would be possible. See the ATM package on 
details.

Unlike IP mode, vat can open only point-to-point connections in ATM mode
and furthermore the roles of the parties are asymmetric: the other end
must have a vat process running in listen mode before you can initiate
a call. Listen mode is specified by command line option '-w' in which
case vat block until an incoming call is received.

As with normal vat, one must specify an address at the command line.
When making a call to the remote end, the ATM address of the remote
party must be given. You don't have to specify port number, because
the ATM version of vat uses an internally defined SAP.

When you have resolved all the details with ATM addresses, running
signalling daemons (that are compatible with your switch, or, in
back-to-back configuration, with each other) etc. you can make an
ATM vat call by running 'vat -z -w <ATM address>' at the other end
and 'vat -z <ATM address> at the other. If nothing happens, signalling
trace of the signalling daemons might become useful.


Shortcomings:
=============
The window of the listening vat doesn't get updated until an incoming
call arrives. This would require modifications to the user interface,
because the operation is different from reqular vat.

The ATM vat doesn't seem to exit until the signalling daemon is killed.