[arm-allstar] Split-site Repeater Questions

[Chuck Munro]

Hello folks :-)

I have an intriguing problem getting a split-site 10 Meter repeater 
configured using a pair of Pi-3's with Pi hat boards designed with the 
ubiquitous CM-119 chip.  The hat is similar in design to the URI dongle 
for the PC.  I am using private unregistered node numbers on 
non-routable IP addresses within a VPN.

The two end nodes, one for RX and the other for TX, are communicating 
well, using a WireGuard VPN over the Internet. There is tons of 
bandwidth between nodes.  The RX receive-only node will be connected to 
an Alinco DR-03T 10M FM transceiver, and the TX transmit-only node to an 
identical radio.

Part of early testing how well the nodes work is with announcements of 
repeater ID ... playing a GSM voice announcement file on the hour and a 
GSM morse file on the half hour.   I do this by simply putting asterisk 
'rpt playback .....' commands in a Linux cron job, aimed at the TX node 
number.  Example:

   /usr/bin/asterisk -rx "rpt playback 1900 
/etc/asterisk/local/ve7skyID_Voice"   (The documentation says to omit 
the '.gsm' part of the filename)

where 1900 is the TX node number.  The Voice file has a .gsm filename.  
The GSM codec is specifically allowed everywhere in the config files.

The Asterisk CLI shows the following at the TX node when the above 
command is issued locally on that node:

     -- <DAHDI/pseudo-1065208769> Playing 
'/etc/asterisk/local/ve7skyID_Voice' (language 'en')
     -- Hungup 'DAHDI/pseudo-1065208769'

My problem ... when I monitor the CM-119 audio output (LOL and LOR pins 
30 and 32), I hear nothing.

I have tried playing the files on both the RX and TX nodes, in both 
cases aimed at the TX node number.   When I do this locally on the TX 
node, the Asterisk CLI application shows the file is being played (as 
shown above).

When I issue the same command on the RX node aimed at the TX node, 
nothing seems to happen at either node.  I do know the RX node makes a 
very short UNIX connection to the TX node as indicated by debug 
statements at the RX.

I am clearly missing something.  Does there have to be a COR signal at 
the TX node to allow audio thru the adapter's chip?  Is there a 
configuration setting I am missing somewhere?  On restarting the RX 
node's Asterisk server, it does connect with the TX node as indicated by 
the trace from the TX node's Asterisk CLI client.  The RX node is at  
10.6.0.7 :

     -- Accepting UNAUTHENTICATED call from 10.6.0.7:
        > requested format = ulaw,
        > requested prefs = (ulaw|g726aal2|ilbc|gsm),
        > actual format = ulaw,
        > host prefs = (ulaw|gsm),
        > priority = mine
     -- Executing [1900 at radio-secure:1] Rpt("IAX2/10.6.0.7:4569-242", 
"1900") in new stack
   == Spawn extension (radio-secure, 1900, 1) exited KEEPALIVE on 
'IAX2/10.6.0.7:4569-242'

Sorry for the long-winded question, I want to provide as much info as 
possible.

Any advice will be welcomed.
73!   Chuck    VA7UL