[pskmail] Re: Aw: Servers syncronization

  • From: Franco Spinelli <frspin@xxxxxxxxx>
  • To: pskmail@xxxxxxxxxxxxx
  • Date: Sun, 16 Dec 2012 22:20:42 +0100

Il 16/12/2012 21:55, Rein Couperus ha scritto:

using several servers on 1 frequency generates a problem called
'hiden transmitter syndrome'. When you send a ping which is heard by
DL9YCS-3, DL4OAH-8 and  EA3GLL,  they will all try to answer.
When the frequency is busy each station will wait until the transmitting
staion is
ready. The problem is that DL9YCS-3 and DL4OAH-8 don't hear each other
because they are too close to each other, so they are in the skip zone.

PSKmail tries to solve the problem by:
* Cloud marshalling (TM). All servers are supposed to be connected to
the cloud
on the internet, to a server called BigEar. Whenever a server activates
is sends the status to BigEar. When other servers want to TX, they wait for
the lock to disappear. Here is an example with DEBUG activated on PI4TUE:

As we have the congestion problem only in EU, the server checks its
before activating the connection....
This afternoon, there were network problems again in the data center which
hosts the BigEar server. The hosting company has been under DDoS attack
for the last 24 hours...

Hi Rein

So, if DDoS attack go away, in next tests I will get more "scattered" signal from different server?. I will try it.

PSKmail is the only system I know which goes to such great length of
effort to
make sure it behaves as a 'good citizen' on our shared bands.
The alternative would be to jam large parts of the bands like winlink
does it...

And this need a frequency list, an interface to prediction program, and a try for each station. If BigEar is working, it is a better solution.

We also have an experimental feature which makes all servers regularly
send their frequency table to a server on pskmail.org. In future you
will be
able to ask any server to list the frequency table of the others.

Meanwhile you can inspect the freq. tables stored by telnetting to
pskmail.org port 8888, and entering the following command:

Again an example:
telnet pskmail.org 8888
Connected to pskmail.org.
Escape character is '^]'.
~info PI4TUE
FREQ:PI4TUE:Version 2.0.8
10148000,10148000,10148000,10148000,10147000, #0

This works provided the server you want to list is version 2.0.8 or
greater, and it is connected...

There is a documentation of commands accepted from this telnet connection?
Now client use a set of files, one for each server, with working frequencies.
Mantaining this set of files is a big and manual work
If there is a possibility to automatically mantain this files I can work on it.


Franco Spinelli

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