Apparent packet loss in RX and TX audio - any thoughts

arwhite

Hello,
I've searched around the forum and can't find a thread that directly addresses the issues that I'm encountering, apologises in advance if I've missed the glaringly obvious.

I'm commissioning a remote station using a Flexradio 6400.


Set up, Remote radio:
Flex 6400 with latest software.
Fibre broadband 80Mbps down/10Mbps up (based on BT Openreach FTTP product).
Smartlink working correctly.
Draytek 2860 router.
Traffic from Flexradio configured to enter the internet from the remote site, i.e. Smartlink can reach the Flex ports.
Subnet 192.168.70.x
LAN-to-LAN IPsec VPN to Operating station.


Operating station:
Full fibre broadband 400Mbps up/ 400Mbps down (using a UK ALTNET, not BT Openreach).
Windows SmartSDR V3.4.23, using Smartlink.
Draytek 2860 router.
LAN-to-LAN IPsec VPN to Remote station
Subnet 192.168.1.x


Everything works 'almost perfectly', latency is reported as around 15-25ms. Normally green, but occasionally (every minute/couple of minutes) drops to amber/red. Every now and then I'm experiencing drop outs in the RX and TX audio. In my first few QSOs, it's been reported that my TX audio has noticeable drop outs.

(Normal VoIP services, TEAMS/Zoom/Skype/VoIP all work just fine from both sites.)

Is there a how to improve your Flex's QoS / Latency guide?

Any suggestions welcome ....

73

Andrew
G1RVD

Lee, N2LC

Following.

Was told a few days ago that my audio sounded like it was cutting out during an fldigi conversation. Seems similar to the cutouts many of us observed in earlier SSDR versions although the RX cutouts and red network bars are few to non-existent now with 3.4.23; need more observation. Can't even say for sure which radio I was using.

Lee N2LC

David Decoons, wo2x

I’d try with just SmartLink. Keep the VPN connection disabled. The VPN is going to use a LOT of data.

If you can use SmartLink, what do you use the VPN for? If only for controlling auxiliary equipment, think about moving to something like Node Red which can run on a Raspberry Pi at the radio location then use TailScale to access the Node Red dashboard without opening ports and restricting access to only devices on the TailScale list.

73

Dave wo2x

arwhite

Thanks for the replies.

NodeRed (RPi at remote site) controls the remote station, there are a number of IP connected devices on the remote site (PC, power switches, cameras, etc).

I believe that the current configuration routes all of the Flexradio packets out to the Internet at the remote site. I'm going to test turning off the VPNs and check how well Smartlink works.

Is TailScale similar to Ethersoft?

73, Andrew

David Decoons, wo2x

Not familiar with Ethersoft. You install TailScale of all devices you want access to and from (PC, MAC, Pi, laptop, tablet, phone). TailScale provides a VPN network with IP addresses for each device.

Check your Node Red to radio connections. If something tries to send TCP commands to the radio during TX, you will get a “pop” or dropout of audio. This is best seen if you enable the TX in waterfall on Flex and during FT8 transmissions.

I’ve rewritten my Node Red flows to only send sub commands to the radio once on connection. Try disabling Node Red if the VPN is not the culprit.

73

Dave wo2x

arwhite

Thanks Dave,
I've made quite a bit of progress.
Slightly reconfiguring the remote router and VPNs seem to have made things much more stable.

Now, the Flex/SmartSDR is using Smartlink and everything seems to be working well.

You touch upon my next issue. I have Node Red happily 'discovering' the Flex. The flexradio-meter nodes show the IP address and port 4992. However, the meter nodes aren't generating any output. I'm sure that I missing something obvious ... any suggestions?

Thank you for your thoughts.

73

Andrew
G1RVD

David Decoons, wo2x

If you are using my Flexradio v16_4 flow, check the ping node is set to the IP address of your radio.

73

Dave wo2x

arwhite

Thanks Dave,
I have now worked out how to subscribe to meters correctly! Am I correct in observing that the meters put a fair bit of CPU load on the RPi?

BTW, have you uploaded your dashboard flow. The "beam" (rotator) group looks very good.

73

Andrew

David Decoons, wo2x

A Pi 3b or higher should be sufficient for minimum of 6 flows. My Pi 400 with 4 GB ram has 26 flows loaded and runs about 25% CPU and 35% RAM.

There are several rotor flows in the file section on the Node Red for Ham Radio site. Look in the !Flows by Type!/Rotors. The one I use is the RT21 to Pi. I have the Green Heron RT21 direct to the Pi.

73 Dave wo2x