DAX Audio over SmartLink choppy...

ok2it

Hello I know this has been asked before but I am struggling a lot. I am network engineer by trade, and I tried everything from IPSec/L2TPv3 , VPNs with low latency but I am not getting anywhere. I am travelling and WPX RTTY is on but I can onsly SWL as my TX signal is just dirty...not dirty TX but audio is distorted, chopped, and it looks like lot of packets are lost, altough if I use Virtual Audio Cables, all works fine. This seems to be somehow bound to DAX Audio only.
https://ctrlv.link/TTtG
That is screenshot and I am also listening to MON and sounds horrible. Tried single tone, two tone test on TX same results, regardless of TX Levels. Works fine locally, but even if I go just to next internet conenction (I have 2 x FTTH 1000mbps lines on my remote QTH) and I go from one to another, with latency bellow 25mS constant, zero jitter buffer needed, it happenes as well.
I saw suggestion to reboot do radio, done that, it helped for a minute or two and then started all over again. I also seem to remember it got worse as I moved up the FW. Currently sitting at 3.6.8 as I tried 4, but didnt work with iOS APPs I am using and I lost Waveforms for FreeDV.

Runnig Flex 6300 baby, v3, using Extreme Networks infrastructure. Any hints?

Thanks Jiri OK2IT

Mike-VA3MW

Does this happen only on a remote connection and not on a local connection? I am guessing this is a remote connection failure.

Can you recreate in on SmartSDR v4.1.5 (which is free)?

Does the same problem happen if using SmartLink? This is critical, as when using SmartLink the radio uses a totally different audio codec than when the radio is on a local LAN (or VPN). In both cases, the VITA49 packets that have the data are a UDP stream. It does sound like your UDP stream is getting throttled at some please.

It can also be related to the DPC Latency in the PC or even windows drivers on the PC if they are old.

The first thing we want to do is see if you can recreate this with a link.local connection to the radio to show if the issue is the radio or the transport layer. Given your background, that should be a simple test.

SmartSDR v4.1.5 does with with iOS Apps. I use it all the time. But, I have also struggled with Audio issues on my iPhone and I have come to the conclusion the problem is in the iPhone network stack. Somedays it works fine, and others, it does not. One time I think I got to the conclusion my audio was bad if location services on the iPhone was turned on. You might want to give that a try.

Let us know what you find.