Leaf Example
------------

   A relatively common simple case is a "leaf site", a system which
only calls or is called by a single remote site.  Here is a typical
`sys' file that might be used in such a case.  For full details on what
commands can appear in the `sys' file, see See sys File.

   This is the `sys' file that is used at `airs.com'.  We use a single
modem to dial out to `uunet'.  This example shows how you can specify
the port and dialer information directly in the `sys' file for simple
cases.  It also shows the use of the following:

`call-login'
     Using `call-login' and `call-password' allows the default login
     chat script to be used.  In this case, the login name is specified
     in the call-out login file (see Configuration File Names.).

`call-timegrade'
     `uunet' is requested to not send us news during the daytime.

`chat-fail'
     If the modem returns `BUSY' or `NO CARRIER' the call is
     immediately aborted.

`protocol-parameter'
     Since `uunet' tends to be slow, the default timeout has been
     increased.

   This `sys' file relies on certain defaults.  It will allow `uunet'
to queue up `rmail' and `rnews' commands.  It will allow users to
request files from `uunet' into the UUCP public directory.  It will
also allow `uunet' to request files from the UUCP public directory; in
fact `uunet' never requests files, but for additional security we could
add the line `request false'.

     # The following information is for uunet
     system uunet
     
     # The login name and password are kept in the callout password file
     call-login *
     call-password *
     
     # We can send anything at any time.
     time any
     
     # During the day we only accept grade `Z' or above; at other times
     # (not mentioned here) we accept all grades.  uunet queues up news
     # at grade `d', which is lower than `Z'.
     call-timegrade Z Wk0755-2305,Su1655-2305
     
     # The phone number.
     phone 7389449
     
     # uunet tends to be slow, so we increase the timeout
     chat-timeout 120
     
     # We are using a preconfigured Telebit 2500.
     port type modem
     port device /dev/ttyd0
     port speed 19200
     port carrier true
     port dialer chat "" ATZ\r\d\c OK ATDT\D CONNECT
     port dialer chat-fail BUSY
     port dialer chat-fail NO\sCARRIER
     port dialer complete \d\d+++\d\dATH\r\c
     port dialer abort \d\d+++\d\dATH\r\c
     
     # Increase the timeout and the number of retries.
     protocol-parameter g timeout 20
     protocol-parameter g retries 10