[Cluster-tech] PC92

[Dirk Koopman]

Lee Sawkins wrote:
> Hi Dirk
> 
> I can connect to you and get the PC93 stuff ok.
> After a while your node issues a disconnect to me.
> Do I need to send something to keep the link alive?
> What does the PC93 data mean?  I have looked all over for info on the
> PC93 sentences.  There are ^A^ ^C^ and ^D^.  What are these?
> 

You mean PC92.

Lets take an example:-

PC92^GB7TLH^78031^C^5GB7TLH:5454^1G1TLH-2^5GB7DJK:5454^H99^

The first bit, up to the '^C^', you know about.

The rest is a combination of PC19 and PC17. Each 'thingy' is made up
like this:-

5GB7TLH:5454

5 is a bit map which is made up like this:-

Bit 1 - here/not here
Bit 2 - external, traditional PC protocol node
Bit 4 - Node

GB7TLH is obviously a callsign

:5454 is the version number. In principle other things could be tacked
on later, separated with commas. This only appears on C records. The
first slot after the 'C', 'A' or 'D', is always reserved for the node
call. At some point in the future, this slot will be empty (as in
...^A^^1G1TLH^... as opposed to ..^A^5GB7TLH^1G1TLH^..) if the node is
the same as the node call after PC92. Any software must be able to cope
with this empty slot.

You should note that DXSpider converts PC16/17/19/21 from *directly*
connected PC only nodes into PC92 that look like:-

PC92^GB7TLH^78042^C^7GB7DJK-1:5453^1G1TLH-1^H99^

This means that GB7TLH has PC node GB7DJK-1 with user G1TLH-1 attached
to it.

The C record stands for 'current configuration'. At the moment these are
sent once an hour and are designed to override any fanciful notion that
another node might have of this node's config.

'A' records add nodes or users
'D' records delete nodes or users.

The principle being used here is similar to protocols like OSPF. A node
*only* sends records that either come from it or PC nodes that it is
"responsible" for. Nodes do *not* splurge out their local view of the
network to cause even more confusion...

Dirk