Two nodes on one server, audio issues

App_rpt-users
1

Greetings,

I am running Asterisk 2.0.0-beta 3/24/2021 GIT a4245fb (recently downloaded sd image) on a Raspberry Pi 4B rev 1.5 with 8 gigs of ram. The Pi is connected to two radios via CM119B modules. One is a module from Repeater Builders going into a VHF Maxtrac, and the is the ARA-1+ from “TechnoByGeoge”, connected to a 900 MHz Spectra.

Initially I only had one module, the VHF system, connected, and everything seemed fine. I was able to use this to basically add a VHF system to my existing 70cm repeeater (which is a completely separate asterisk server).

When I added the second radio, the 900 MHz one, I followed this guide, which seems to be the only guide of its kind on the internet: Two Nodes on One Server - AllStarLink Wiki

I made some changes due to using simpleusb versus usbradio, and added an entry into extensions.conf under [iaxrpt] for the second node number.

It all went pretty smooth and seemed to work, but, when both the VHF and 900 nodes connect over to the same other node, transmitted audio would periodically drop. I only observed this personally on the 900 MHz system but I was told it happened on the VHF one as well. I checked all the connections and even threw the scope on the CM119. But the end conclusion was that Asterisk was actually muting the audio for some reason. It seemed to happen typically a few seconds into each transmission. During this “glitch”, the radio continues to transmit, only there is no modulation, just silence.

If only one node is connected (and that is, the second node is not connected to anything), the sole connected node works just fine without any audio issues.

I don’t see any unusual messages or warnings in the log files.

Any suggestions on where I can look for clues? Should I just get an sd card and download ASL3?

Thanks for any suggestions,

–Elliott
de W6EL

2

If I am reading you correctly? you have 2 URI’s on a Pi4.
This has a bug in the software that is suppose to be remedied in the ASL3 software.
So, yes, give that a try.

3

Hi Mike,

Yes, basically. I’m using less-expensive CM119B modules than the URI but it probably looks the same to the software.

ASL3 looks intimidating, I was getting quite used to things. But I suppose it will be worth it for all the fixes!

Thanks,

–E
de W6EL

4

Ok, I am rocking ASL3, nice job team! So many improvements!

To add the second node, is it essentially the same procedure as the link I mentioned before, except that the simpleusb audio config is now all one file? Is there a way to add the second node with the asl-menu?

Thanks very much, excellent work on ASL3,

–E
de W6EL

1 Like
5

Oh! I see “Add node” in asl-menu.

I will try it.

Thanks all,

–E
de W6EL

6

Hi Mike,

I have upgraded to ASL3 and both nodes are configured.

I am having the same problem :frowning:

I played around with it some more and I can summarize it as follows (let’s pretend node1 and node2 are the nodes on this server, for the sake of simplicity):

If node1 or node2 are connected to some other node on some other server:

If Node1 keys, the transmit audio for Node2 is muted.
If Node2 keys, the transmit audio for Node1 is muted.

I can simulate this situation by calling from Node1 to a repeater (on another server), and then issuing these commands within asterisk:
(note, node2 is not connected to anything)
susb active node2
susb key
(the transmit audio on node1 now is muted)
susb unkey
(the transmit audio on node1 is not unmuted).

Both node1 and node2 are half-duplex simplex nodes using simpleusb.

If I connect node1 to node2, it works intermittently. Sometimes we get no-audio keyups on the transmitting node, sometimes we get the audio as expected.

Any ideas?

I am running very stock ASL3, haven’t gotten around to customizing anything yet with this new install.

Thanks,

–E
de W6EL

7

Another way to replicated this behavior is to be using Node1, connected to any other system, and then, for Node2 to play the CW ID. When Node2 keys up to play the CW ID, transmit audio on Node1 is muted.

Would it help if one of the nodes used the usbradio driver? Or is there a change we can make to place them in different context?

Thanks,

–E
de W6EL

8

Some of your statements did confuse me.
But I will say that each node is independent.
If you want them to work a bit in unison, you need to connect one to the other by command.

If you were trying this with ASL2b on Pi4, you likely had a response that is not normal and should not be expected otherwise.

Clear your thinking and start over. Somewhat.

9

Hi Mike,

I’m going for independent nodes on one Pi.

I cannot understand why when my two nodes are NOT connected each other, if both nodes happen to need to transmit (perhaps during a QSO, playing a regular CW ID, or susb key), the second node to key up will cause the first node to mute and transmit an empty carrier.

That’s my issue.

Can you envision any situation where this would happen, and what might be causing it? I have verified that transmit audio coming out of the URI simply stops when the second node keys. It should not, I should be able to operate the nodes independently, and audio should not discontinue simply because the other node transmits.

I feel like this is a bug in chan_simpleusb or some kind of shared-context error.

Does that make sense? This began as a pretty clean ASL beta, and then I did a fresh install this morning of ASL3, and I am seeing the same behavior.

Thanks for any help or ideas,

–E
de W6EL

10

Ok, I moved one node to usbradio, and left the other on simple usb. There was no change to the odd behavior.

Here is a video showing the behavior: https://youtu.be/8J0RBIcgfbo (since this video is freshly uploaded, you may need to manually set the playback quality to 1080 via the gear menu)

In the video, node1 is connected to 50522, which has some traffic.
Node2 is not connected to anything.

You can hear the audio coming through my radio, which is monitoring node1.

When I manually key Node2 (via radio key), you will note that the audio on Node1 drops out. Node1 does continue to transmit though. When I unkey Node2 (via radio unkey), audio on Node1 resumes.

In my example I use manual keying, but if I were to kerchunk Node2 or if Node2 were to send its CW ID, the same thing happens where Node1 continues to key without audio until Node2 stops transmitting.

Thanks for any advice you have on running two independent nodes from one Pi,

–E
de W6EL

11

Does anything interesting show up in the cli when you key the second node?

Danny

12

Hi Danny,

Nothing shows up, I was running asterisk using -vvv in the video. Nothing in the logs either.

–E
de W6EL

13

If there’s some debug I can do, I’m up for it, I have compiled the beast of asterisk on humble hardware in the past.

Am I correct that each node gets its own thread of app_rpt? Where are the places where these threads share information when the nodes are not connected together?

Or is this the “don’t run two nodes on a Pi 4” bug that I have heard about? How could I tell, is this what the bug manifests itself as?

I’m able and willing to do some work to debug it. Just let me know. Happy to try things.

Thanks both of you for your hard work on ASL, it really is a wonderful gift to the community,

–E
de W6EL

14

Is it possible this is RF related? I know you said node 50522 is linked, but just asking. Any thoughts on that?

15

I had the same thought!

I turned off the radios and observed the same issue (using my portable scope to monitor the audio). So it is not RF (at least, not any RF I’m making!).

–E
de W6EL

16

Did you try making one node dahdi/dummy… a hub node. Then link the hub to another node and key the radio node. Also what are your duplex settings?

Also, I have more than one server (and support other servers) with 2 or nodes. This problem has never existed on any of them since the beginning of time (Limey, DIAL, ASL1, ASL2 and now ASL3) on any hardware. Bad audio, yes on Pi’s but not total muting of linked audio. I’m thinking you’ve been using a bad configuration… I could be wrong but I don’t know what else to think right now.

17

Hi,

That is an interesting idea. I will try it and report back.

Thanks,

–E
de W6EL

18

And you asked about duplex settings.

Both of these nodes are simplex nodes and the duplex is set to 1 in rpt.conf.

–E
de W6EL

19

Ok, this was a very good idea.

I had to use dahdi/pseudo, not dahdi/dummy, but I think that’s just a typo.

I changed one of my nodes (617080) to the pseudo device. Connected this node to 41751 (my local UHF repeater, on a different server). Then I connected the 617080 hub to the WINS system to utilize the 24/7 chatter.

Normal WINS traffic was heard on the 41751 repeater.

Then I keyed the second node on the pi, node 617081. And… the audio on the hub, as heard via the 41751 repeater, remained!! I tried keying via kerchunking the simplex node and also radio key and with either method, the audio was just fine coming out on the repeater which was connected to the 617080 pseudo hub.

So, ideas?

Happy to share my configs if you want them.

–E
de W6EL

20

This isn’t an ASL problem. It’s a rPi4 problem, and isn’t specific to sound fobs.
This may sound silly, but try putting both fobs behind a USB hub, then plugging the hub into the rPi4. This resolved a problem I was having with two USB SATA controllers on an rPi4 rev 1.4 board with 4GB of ram, and also coincidentally did the same for two sound fobs being addressed by ASL2.0 (haven’t tried this on ASL3 yet).