Connecting to other Clusters

Dirk Koopman G1TLH

Last modified: Sun Sep 2 22:02:36 BST 2001

At the moment, anybody can connect inwards at any time from outside, either by ax25 or by telnet (assuming you have followed the instructions in installation instructions. However, in order to connect outwards, you will need to create connect scripts.

Connect scripts live in the /spider/connect directory and are simple ascii scripts that are written using a normal editor. There are a couple of examples in the issue directory.

The first example is a simple telnet (TCP/IP) connect to port 7000 of WR3D (this will actually work if you have or make an arrangement to connect to WR3D)[oh, and substitute x1xxx for your real node callsign].

The colouration will be explained later on in this page, you don't have to try to emulate the colours!

    timeout 15
    # this is a comment
    connect telnet 7000
    'login' 'x1xxx'
    client wr3d telnet

If you put the above script in a file called: /spider/connect/wr3d then you can leave out line: client wr3d telnet.

For a connect that requires a login and execution of the programs from a normal shell, do:-

    timeout 15
    connect telnet
    'login' 'gb7djk'
    'word' 'gb7djk'
    '\$' 'cd /spider/perl'
    # set the line to prevent echoing, leaving this out will
    # confuse whole networks for hours!
    '\$' 'stty -echo raw'
    # tell GB7DJK that you are GB7DJK-1
    '\$' '/spider/src/client gb7djk-1 telnet'
    # tell GB7DJK-1 that it is connected to GB7DJK
    # you can leave this out if you call this script 'gb7djk'
    client gb7djk telnet

An ax25 example (connecting from GB7DJK, to GB7DXM via my local BPQ node and one X1J intermediate node):-

    timeout 60
    abort (Busy|Sorry|Fail)
    # don't forget to chmod 4775 netrom_call!
    connect ax25 /usr/sbin/netrom_call bbs gb7djk-0 g1tlh-0
    'Connected' 'c np7'
    '*** Connect' 'c gb7dxm'
    'Connect' ''

The -0 ssid is important if you want it to work reliably. Obviously if you are using a different ssid then you would use that. You can use the Netrom alias instead if it it is in the machines node table.

The line: "'Connected' ''" means: wait for the string Connected and when that is seen, then move onto the next line without sending anything. The reason you do this (in this case) is to wait for the final "connect" string from the BPQ node that directly connects you to the cluster node itself.

An AGW Engine example would be very similar and look like this:-

    timeout 60
    abort (Busy|Sorry|Fail)
    connect agw 2 g1tlh
    '*** Connect' 'c np7'
    'Connected' 'c gb7dxm'
    'Connect' ''

A connection is started manually by typing in connect <scriptname> on a sysop enabled session. For example:-

    G1TLH de GB7DJK 13-Dec-1998 2041Z > connect gb7djk-1
    connection to GB7DJK-1 started
    G1TLH de GB7DJK 13-Dec-1998 2043Z > 

Consider the following specific example, it is located in the file /spider/connect/gb7djk-1 :-

    timeout 15
    connect telnet
    'login' 'gb7djk'
    'ssword' 'gb7djk'

You can watch the progress of the connection (if you have connect debugging enabled [set/debug connect]) on the screen and you should see something like this:-

    <- D G1TLH connect gb7djk-1
    -> D G1TLH connection to GB7DJK-1 started
    -> D G1TLH G1TLH de GB7DJK 13-Dec-1998 2046Z >
    timeout set to 15
    CONNECT sort: telnet command:
    CHAT "login" -> "gb7djk"
    received "
    Red Hat Linux release 5.1 (Manhattan)
    Kernel 2.0.35 on an i586
    received "login: "
    sent "gb7djk"
    CHAT "word" -> "gb7djk"
    received "gb7djk
    received "Password: "
    sent "gb7djk"
    Connected to GB7DJK-1, starting normal protocol
    <- O GB7DJK-1 telnet
    -> B GB7DJK-1 0
    GB7DJK-1 channel func  state 0 -> init
    <- D GB7DJK-1 
    <- D GB7DJK-1 Last login: Sun Dec 13 17:59:56 from dirk1
    <- D GB7DJK-1 PC38^GB7DJK-1^~
    <- D GB7DJK-1 PC18^ 1 nodes, 0 local / 1 total users  Max users 0  Uptime 0 00:00^5447^~

I have coloured the commands in an attempt to make it clear as to what goes on, where and why. Lines that are coloured thus are miscellaneous setup commands. Lines that are this colour are lines that make the initial connection to the first hop. The things that are this colour are the strings I am looking for (what I am "expecting") and the things that are this colour are the commands I am going to send when I see the "expect" strings in the input.

The script starts by setting the timeout to 15 seconds, then starts the connection. It is important to note that, in the case of an ax25 connection (usually) this will be the callsign of the first hop along the route that you are going to take to the destination, so this will be typically the callsign of your local node.

You will notice that the script waits until it sees the left hand string of the pair and only then does it send the string on the right hand side. This is called a State Machine.

A state machine "walks" through a conversation (in this case) looking for "states" (in this case particular strings) and then performs some "action" (usually some kind of connect command for the type of system you are trying to navigate). When one "state" "fires" (detects the string are looking for), it sends the command associated with that state and then moves onto the next "state", in our case: the next line.

PLEASE NOTE: the colouration in the above example is for illustrative purposes only, the debug output is all one colour.

The connect scripts consist of lines which start with the following keywords or symbols:-


Copyright © 1998 by Dirk Koopman G1TLH. All Rights Reserved
$Id: 4a4eaa3cd86dadb7e583a7e3b9d7b6b58964982c $