MHEARD Function

Name

MHEARD -- "Monitor Heard".

Description

The MHEARD facility lists recently heard stations, and may be enabled or disabled for any port. It records callsigns in reverse order of reception, with the most recent at the top of the list, along with other useful information, such as the date/time, position, type, and the number of frames heard.

This allows sysops and users alike to discover who else the node can hear, to aid the search for suitable digipeaters, and to diagnose problems.

Even on linking-only ports, where there is only usually one partner, it provides a useful indication when the frequency is being encroached upon, either by deliberate squatting, unauthorised attempts to link, or lift conditions.

It is therefore recommended that you enable MHEARD on all ports, and indeed this is the default. The ability to disable MHEARD (to save memory) was necessary in DOS XRouter, but memory is not an issue in XRPi.

If you have set your LOCATOR, or have included an APRS-style position report in your ID beacon, XRPi will know its own position and will display position, distance and bearing for any stations which broadcast APRS positions. This is a great aid to network mapping, and it would be nice if everyone were to add APRS positions to their ID beacons.

If a station was heard via a digipeater, the digipeater call is also shown, and the letter "D" is shown in the "type" field. If the heard station is a node, the letter "N" is displayed. If it is sending IP traffic, "I" is shown, and if it is sending ARP traffic, "A" is shown.

Within XROUTER.CFG, the "MHEARD=n" directive is used in each PORT definition block to enable or disable the MHEARD facility and to set the size of the list. For example "MHEARD=50", enables it and sets the table size to record a maximum of 50 callsigns. If the directive is omitted, the default size is 15 callsigns.

You can control which types of station are recorded in the MH list using the "MHFLAGS=n" directive. The default value for n is 255 (show everything), and the number is formed by adding the numbers representing the desired options as follows:

	1    Show directly heard stations
	2    Show directly heard digipeaters
	4    Show digipeated stations

For example "MHFLAGS=3" would show directly heard stations and digipeaters, but not the stations heard via digipeaters.

The MHEARD list is available to sysops and users alike, using the MH command (see command reference section).

A port's mheard list may be cleared by using the "MHCLEAR <port-number>" command. You may clear all MH lists by specifying port 0.

See also

MHCLEAR(2) -- Clear MH list
MHEARD(1) -- List recently heard stations.
XROUTER.CFG(8) -- Main Configuration File.