SmartSDR 3.0.19 - No-Go over VPN

Rick - W5FCX

I have been running SmartSDR 3.0.19 locally at both home and my remote station site for weeks without incident. Today, I decided to do some remote SSB from home to the remote station...

The 3.0.19 SmartSDR client with Multi-flex absolutely craters my VPN connection (similar to how DAX does). My VPN connection has just 540Kb of (DSL) upload bandwidth available. Something in 3.0.19 is abusing upload bandwidth, making this version unusable over the VPN.

As a result, I have dropped back to 2.4.9, which works perfectly across the VPN and has for years.

I suspect it may have something to do with Multi-flex, but unable to determine for sure what's chewing up so much bandwidth.

Mike-VA3MW

Hi Rick I have a question for you. Are you running the same frame for second and rate settings as you were on version two? Please let me know Mike

Rick - W5FCX

Yes. 3 FPS and 45 rate.


It appears the uplink from remote station is saturated, as link latency goes from 30 ms (no load) to more than 3,000 then SmartSDR disconnects. Normal operation with v2 bounces between 30 and 120 ms.


Using iperf, I see 540 Kbps from remote site and 1.5 Mbps to radio at remote site. It’s DSL, which isn’t great, but it’s always worked well for SSB on v2 and v1.

Mike-VA3MW

I have had this happen to be when some other laptop I had forgotten about also had a DAX stream running. Is there any chance another client might be connected?

You got me thinking, so I went to measure mine, and this is what I see with 1 slice, FPS about 25% and Rate about the same on my Maestro.

Is there anyway you can dig deeper and see if it is all going to the same client?

This is on V3.

 

Rick - W5FCX

I only have the single client running on Windows 7 at home, with the 6700 remote through the VPN connection. V2 works perfectly, V3 does not.

Mike-VA3MW

I talked to Engineering

The audio is set to compressed only when using SmartLink.  It is uncompressed when operating on a LAN (which VPN simulates).  This is a change between v2 and v3.

Mike

Rick - W5FCX

Is there a way to configure and control this? It's making v3 unusable.

Mike-VA3MW

Not that I am aware of.  Are you able to run SmartLink at all?

Mike-VA3MW

Rick, assuming you are using SmartEther, in the client settings, there is a flag for compression.  Can you give that a try?

Rick - W5FCX

Yes, compression is on. I have noted that in V2 compression is already required to minimize the data transfers and avoid excess latency due to overrunning the 540 Kbps limited upload bandwidth. Thanks for the idea - it's a good one.

Doug Hall

Mike,

Why did Flex make this change? I also use a VPN from time to time. There are situations where it is preferable to SmartLink. I have not upgraded to 3.0, and I am concerned that doing so would hamper my ability to operate from some of the places I currently do.
73,
Doug K4DSP

Mike-VA3MW

Hi Doug

They removed the compression for a standard LAN connections since there was no requirement to have it compressed.  For none LAN and remote connections we have SmartLink, so that remains compressed.

Mike

Doug Hall

Disappointing.

Rick - W5FCX

Agreed. We need an option to configure Compressed or not for LAN (VPN) operation; otherwise, all of us (many) VPN users are stuck on 2.x. We have other reasons for using the VPN beyond SmartSDR (rotators, amplifiers, remote desktops, etc.) and one cannot use both SmartLink and VPN at same time (due to routing conflicts in /16 CIDR block).

Please provide a way to configure compress/decompress.

Mike-VA3MW

I will pass on your comments to engineering.  

That being said, having run remote for about 15 years, I did find that leaving all the controls on a local PC less painful.    There was years that I remoted everything back to my home qth, it worked but I found it really limiting.  I did this long before starting to work for FRS.


About 6 years ago, I went back to a local PC with all the antenna, amp and everything else control on a Local PC and then I RDP'd to that computer for normal computer work and then I use my Maestro to do all the audio work on SmartLink.  In fact, my SoftEther PI that was on the Maestro died about November last year and I never rebuilt it as I went to SmartLink for 100% of my usage.  

The benefit was that I only had 1 computer to keep updated and it was very very easy to use my remote from anywhere in the world from a PC, MAC or even an iPad.   Just RDP to the local PC using what ever RDP solution you like. 

A side benefit was that it was also easy to lend my station to a few friends and they didn't have to worry about configuring anything.  This is how I contest as well.  N1MM runs on the local PC and this keeps more streaming data off the internet.

I also run WSJTx for 6M work on the local PC and no chance of any audio stream corruption or latency due to the internet part, something I can't control (bad internet).  

What drove me down this path was my 1mb/sec upload and everything that got streamed out got measured.  Internet upstream had to go on a diet.    Rick, you may want to seriously consider this solution with your 500kb/sec upload.

It was by far the best remote setup ever and I physically don't see my remote station for months at a time.  

Is it 100% perfect?  No.  But, given the tools we have available, I am very happy with it.  

Mike 

ctate243

Rick - W5FCX

ctate243

Ya it sounds like you may need to do some net slinging to get yourself an environment where V3 will work for you given the local dsl capability..  probably split those networks up.  sorry.. wish I had a better answer..

Doug Hall

In my case it's not *my* upload speed I am worried about. It's the quality of the connection at the hotel or convention center or wifi hotspot that I might be using to VPN back to my hamshack. Having compression off when not using SmartLink simply reduces the number of places where my VPN connection will work properly.

I have web interfaces for my rotator, my antenna switch, and my amplifier. I do not wish to expose these devices to the Internet. Using a VPN they simply appear as web interfaces on my LAN, and only on my LAN. So does the Flex. There is only one port to forward (to the RasPi running the VPN) and no PC to worry about.

I think it was a poor decision on the part of Flex to quietly make a change that could allow existing connections on 2.4.9 to fail (or perform poorly) on 3.x. I don't need MultiFlex capability, but it's generally nice to be on the latest code base, and my plan was to upgrade to 3.x after it had been out for a while. That is no longer my plan.
73,
Doug K4DSP

Rick - W5FCX

Eric-KE5DTO

Rick - W5FCX

Thank you

Cedric HB9HFN

Tom - N3VM

Hi Eric - I'd like to encourage Flex engineering to expose controls in the UI to enable or disable audio compression. Yes, I know it's a continuous goal to keep the user experience pleasant (and uncluttered). This one option has such an important impact on guys that operate using remote stations, which Flex Radio IS the defacto market leader.  Thanks and 73, tom

Cal N3CAL

Mike-VA3MW

I did ask engineering about this.  Yes, 2.5 will have the compression turned off on so this will affect VPNs at this time as discussed earlier.

The VPN and compression is still on engineering's radar as Eric  mentioned above.

Cedric HB9HFN

Ok. Then 2.5 is a no go for me as I must have a VPN as my mobile provider is using double NAT at the transceiver site :-(

Cedric HB9HFN

I can confirm this. I'm behind a double NAT and the bandwidth is not that much...

Cal N3CAL

2.5 is also a no go for me! 

Cal/N3CAL

Asher - K0AU

Eric,

Is there a supported SmartLink approach to control a Green Heron rotator, an AntennaGenius switch or an Alpha amp? Asking for a friend... A serial pass-through CAT mode would be a big help along with a local agent for the AG.

Mike-VA3MW

Hi Asher

Short story, no.  

The story that I presented at Dayton Forum on Sunday was to have a small Windows PC local to the radio that you do an RDP session to to run all those applications.   

Personally I think this is about the easiest idea today as you are not then dependent on a vendor at all and you then have full control of your station.  Once I get caught up on sleep, I'll record my presentation on why I think this works so well and allows the operator to easily scale their remote operation.

Mike