Nedded Bandwith on Remote

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  • Updated 1 year ago
What is the needed throughput BW (up and down) of my internet connection when running remote? Is there any differncies between using a VPN and 1.16 or SmartLink V2.0?

Looking at tne numbers in SSDR and Maestro these do not add up, SSDR shows the same number, no matter what I do. Maestro shows a lot more than SSDR, but varies when I alter number of slices and framerate. What is the best way of reducing the amount of data?
How low can it go and still work?

Latency, how much can SSDR tolerate before shutting down? Is a varying latency worse than a very high but constand number?

/Lasse SM5GLC
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Lasse Moell

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Posted 1 year ago

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Mike va3mw

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Here is what i have seen.

I can safely run with about 400kb/sec on 1 slice and just over 500kb/sec if I turn off the waterfall or reduce it as far as I can.  This is the upstream data rate.

You are correct that the numbers do not add up and there is a bug open for that.  The best way to measure it is at  your firewall.

Many alpha testers have used both a VPN and SSDR with pretty much the same performance, but your mileage may very.   For me, my average is about 52m/sec but with some long pauses to almost 2 seconds over the period of 24 hours.

I don't have an answer on your last question as we have never tested it for an actual breakdown point.  Since the IP communications is handled by Windows your the operator end, that amount may very.  

No idea on the threshold before failure.  Sorry.

Doing QOS tuning on your outbound packets in your routers does make a difference.  Making them a higher priority is very helpful.
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Ken - NM9P, Elmer

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Lasse and Michael,

As an Alpha Tester I have tested SSDR/Win with both VPN and SmartLink over the past several months and have tested SSDR-IOS for a couple of days.

My UPLOAD from the shack is via ATT UVerse varies from 500-700 Kb/sec.
Remote access is at my Office with ATT UVerse with about 12 Mb Down and about 800 Kb UP.

My impressions:

First SSDR/Win:  to a desktop in my office.  

VPN Connection via Softether on my Shack Computer vs. Smartlink.   
The Smartlink Connection is certainly easier to establish and run from my office.  It seems a bit smoother, too, and doesn't seem to be affected as much when I am doing other work online with my office computer.  I have been able to run one or two pans with one slice in each, or one pan with two slices.  HOWEVER, I need to keep the waterfall rate below about 50 and the Display FPS at about 5-7 on each slice.  If I go much higher, I begin to get stuttering.

Now SSDR-IOS: on my iPad Air or iPhone 6.

VPN Connection via OpenVPN on my ASUS RT-AC66U Router. (Because it was easier to set up on the iPad when I did it.)

As with the Windows version, the Smartlink connection was easier to establish, (once I solved a silly licensing problem caused by having changed my Apple-id account shortly after beginning initial alpha testing of the first version of SSDR-IOS over a year ago.)

With the VPN connection I had a SLIGHT bit more stuttering than with the SmartLink connection.

With either mode of connection, I needed to keep Waterfall rate below about 40-50 and Display FPS at about 5 for best performance.

Sometimes I even needed to turn the Waterfall OFF.  BTW, if you DO turn the waterfall OFF, you also need to turn the rate down to Zero, because it still pumps out data that consumes bandwidth.  

I attribute the slight performance in both situations to the fact that SmartLink doesn't encrypt the audio to and from the rig, whereas a VPN connections encrypt everything, whether it needs it or not.


To my surprise, I am actually able to maintain a more stable connection with the Desktop than the iPad.  Perhaps it is because the Windows Desktop is connected to the Office router with CAT6 cables and the iPad is connected through the Wifi in the Secretary's office across the hall.  Or perhaps the iPad Air could be a little under powered, or I have some apps running in the background consuming processing power.

I still have a lot of testing to do, but these are my initial impressions.

Have fun!

Ken - NM9P
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Larry Loen WO7R

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I have run SSdr remotely for several years. I will not run 1.2 until I upgrade my 6300 to a 6400.

Biggest bandwidth hog is the panadapter or panafall display which I access over a VNC. That runs the bandwidth up to about 500 kbits. SmartSDR really should let you turn it off. One of the many things powersdr had right.

But if I plop (say) a JTDX window over it, bandwidth drops to about 170 kbits, about what my remote rig audio takes. (This is also what Flex should measure itself against).

Latency can be a killer, especially in the early evening. No consumer ISP sells latency. You buy bandwidth Instead.

My long ago network class said you want 10x what you actually consume to deal with latency. I have cheaped out and run about 4 to 6x. Works well enough most of the time.

I would expect remoting the IQ stream would have bandwidth in the 150 to 300 kbits range. I hope we can "prefilter" to take less than the whole available slice if we wish. For good CW performance, this may prove more than a nice to have. My current remote rig CW works well, but in bad latency environments can make CWX an effective requirement.

The ability to minimize bandwidth, ideally to the 50 to 150 kbits range, at need, will be a key measure of success.

In good times, 500 kbits or even 750 (beware things like WSJTX waterfalls) can be managed comfortably.
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Ken - NM9P, Elmer

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You can effectively turn the waterfall off by dragging the panadapter/waterfall window divider down to nothing, and then turn the waterfall rate down to 0.

A while back, I used network monitor to test bandwidth and turned various DAX channels on and off and it was amazing to see the change in bandwidth consumed.  The same for the Waterfall rate and display FPS.  I could tune from about 3 MB/sec down to under 500Kb/sec quite quickly.

Some of the hidden "wasters" is leaving DAX Mic Stream turned on at the station when running from the remote site, as well as DAX TX.  Or leaving DAX IQ turned on.

Usually I close DAX at the home station when running remote.  And I check to make sure that I don't have DAX turned on on the remote site client either.

I look forward to the day when FRS finds ways to reduce DAX bandwidth usage.

Ken - NM9P