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1. Hop control

Starting with version 1.13 there is simple hop control available on a per node basis. Also it is possible to isolate a network completely so that you get all the benefits of being on that network, but can't pass on information from it to any other networks you may be connected to (or vice versa).

1.1 Basic hop control

In /spider/data you will find a file called hop_table.pl. This is the file that controls your hop count settings. It has a set of default hops on the various PC frames and also a set for each node you want to alter the hops for. You may be happy with the default settings of course, but this powerful tool can help to protect and improve the network. The file will look something like this ...

# 
# hop table construction
# 

package DXProt;

# default hopcount to use
$def_hopcount = 5;

# some variable hop counts based on message type
%hopcount = 
(
 11 => 10,
 16 => 10,
 17 => 10,
 19 => 10,
 21 => 10,
);


# the per node hop control thingy


%nodehops = 

 GB7ADX => {            11 => 8,
                        12 => 8,
                        16 => 8,
                        17 => 8,
                        19 => 8,
                        21 => 8,
                   },

 GB7UDX => {            11 => 8,
                        12 => 8,
                        16 => 8,
                        17 => 8,
                        19 => 8,
                        21 => 8,
                   },
 GB7BAA => {
                        11 => 5,
                        12 => 8,
                        16 => 8,
                        17 => 8,
                        19 => 8,
                        21 => 8,
                   },
};

Each set of hops is contained within a pair of curly braces and contains a series of PC frame types. PC11 for example is a DX spot. The figures here are not exhaustive but should give you a good idea of how the file works.

You can alter this file at any time, including whilst the cluster is running. If you alter the file during runtime, the command load/hops will bring your changes into effect.

1.2 Isolating networks

It is possible to isolate networks from each other on a "gateway" node using the set/isolate <node_call> command.

The effect of this is to partition an isolated network completely from another nodes connected to your node. Your node will appear on and otherwise behave normally on every network to which you are connected, but data from an isolated network will not cross onto any other network or vice versa. However all the spot, announce and WWV traffic and personal messages will still be handled locally (because you are a real node on all connected networks), that is locally connected users will appear on all networks and will be able to access and receive information from all networks transparently. All routed messages will be sent as normal, so if a user on one network knows that you are a gateway for another network, he can still still send a talk/announce etc message via your node and it will be routed across.

The only limitation currently is that non-private messages cannot be passed down isolated links regardless of whether they are generated locally. This will change when the bulletin routing facility is added.

If you use isolate on a node connection you will continue to receive all information from the isolated partner, however you will not pass any information back to the isolated node. There are times when you would like to forward only spots across a link (maybe during a contest for example). To do this, isolate the node in the normal way and put in a filter in the /spider/filter/spots directory to override the isolate. This filter can be very simple and consists of just one line ....

$in = [
        [ 1, 0, 'd', 0, 3]      # The last figure (3) is the hop count
];

There is a lot more on filtering in the next section.


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