Panadapter suddenly stopped - SSDR 2.0 remote

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I recently upgraded to SSDR 2.0 on my 6300 on Windows 7.  That works fine on the LAN connection.  I brought up SmartLink remote on my Windows 10 laptop and got it working.  Everything worked well until I tried to resize the screen a bit larger and the panadapter/waterfall froze up with only a partial signal trace across the screen.  The audio is working correctly.  I have been unable to get the panadapter to show a trace.

I have restarted the machine and the flex, but to no avail  No signal trace shows on the panadapter or on multiple panadapters and the waterfall is empty.  I don't seem to be able to clear this situation.  I did shut down the firewall on the computer and that didn't help.  If I bring up SSDR on the LAN on either machine the panadapter works perfectly.

Can someone advise a cure to this or why it happened in the first place?

Paul - AA6Z 
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Paul Burton

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Posted 2 years ago

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Paul Burton

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An added symptom is that there is a big black rectangle in the middle of the waterfall.  The network performance indicator is showing 3 yellow bars.  
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Ken Hansen

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Bandwidth.

I upgraded my 6300 to SSDR 2.0 in preparation for an extended vacation. It worked fine locally, and on area wifi connections around town.

Went on vacation, fired up my laptop, got exactly what you described, down to the little squiggle in the upper-left corner of the panadapter display and the black square in the waterfall display area.

After trying everything else, I took my laptop off the hotel wifi and used my phone in hotspot mode. The problem went away.

Conclusion, the issue is a bandwidth issue.... at least adding bandwidth corrected problem.

What do you see in the lower right corner of the screen - what does the network connection icon tell you when you mouse over it's signal bars?

Ken, N2VIP
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Paul Burton

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It says "network: Good, Latency (RTT) 120 ms"
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Mike Hoing

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120 is kind of high or at least highe then I like. I like under 50

Mike
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Paul Burton

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An added sympton is that I had undocked the sidebar causing the panadapter to enlarge, and that seems to be when things failed.  When I redock the sidebar the panadapter starts up again.  But not the waterfall.  It still is full of a big black rectangle.  If I try to expand the size of the SSDR window the panadapter stops.  
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KY6LA - Howard, Elmer

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It's a known bandwidth issue

One solution is to narrow the Band spread of the display so as to minimize the amount of data you are trying to display
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Paul Burton

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Thanks Howard,  Yes, if I expand the physical width (not the bandwidth) of the display it quits.  As long as I keep the screen small I can display the whole 20 meter band.  If I bring the physical width of the dissplay back to the original size the panadapter starts again. But nevertheless, the waterfall is not working at all and is filled with a black box.  

It sounds like the connection is the problem although I have 3 yellow bars and am connected to an XFINITY hotspot which comes from my router 6 feet away.  This is my first excursion into SmartLink so I will be patient.
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Paul Burton

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An added sympton is that I had undocked the sidebar causing the panadapter to enlarge, and that seems to be when things failed.  When I redock the sidebar the panadapter starts up again.  But not the waterfall.  It still is full of a big black rectangle.  If I try to expand the size of the SSDR window the panadapter stops.  
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Mike va3mw

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Official Response
I am dealing with this as well.  It isn't as much a bandwidth issue as it is a firewall / packet reassembling issue.  Even with me, going to 20khz wide didn't solve it.   

This is going to be tough to isolate as it is external to Flex equipment.  

Mike
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Ken Hansen

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I'm confused why the problem manifests itself with a black box in the waterfall, a squiggle in the upper-left corner of the panadapter, and no activity on either.

I can understand low bandwidth, no activity displayed, but the squiggle and black box? It's 100% repeatable, and exactly the same each time.

I wonder if the application is sending some sort of setup/initial display information that doesn't get to the client (remote pc) when sent, and for whatever reason that setup display info is not resent, once it is lost, the server (radio) never sends it again.

Anyway, just a thought.
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Paul Burton

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The  squiggle is a small segment of the signal trace which only extends part way across the screen.
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Paul Burton

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Thanks Mike.  Let me know if I can help.
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Mike va3mw

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Here is one of my findings.  At my house, I have 2 unique networks.  One has a pfSense firewall an the other is the Sagecom as  provided by Bell Canada.

At the far end, I am using an IQRouter (this is the radio end).  BTW, the IQRouter makes my F Bufferbloat look like an A and I am running about 500kb/sec upload.  

On the Sagemon router.  It fails with the blackbox error.

On the pfSense one, it works fine.

This is how I believe it isn't a Flex issue causing this on my Maestro.

BTW, I have dropped 1900 packets out of 6.5M today.  Not bad with only a 1mb/sec upload at the radio end.

Mike 
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Andy M5ZAP

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I think there are various reasons people are getting no display in there panadaptor and only audio.

This is my laymans under standing.

They all stem from the fragmented VITA64 packets that contain the data for the display.

1 - Some modems / firewalls block fragmented packets for historical data attack reasons

2 - Some network providers do the same as above.

3 - Further hypothesis is that quite a few networks use PPPoE. This adds an 8 byte header to the already maxed out 1500 byte packet. So this packet would require fragmenting, but the "do not fragment" flag is set by the software so the oversize packet cannot pass.

"Since Ethernet has a maximum payload size of 1500 octets, the PPPoE header is 6 octets and the PPP Protocol ID is 2 octets, the PPP MTU MUST NOT be greater than 1492."

"on the VITA64 packets from the flex the do not fragement (DF) flag is set, this causes packets to be dropped as they are larger than the MTU size of 1500 on the VDSL infrastructure."

I think the small sized panadaptor keeps the packets lower than 1492.

I might be very wrong and an official comment by flex would be good.

Myself and my son have got around the problem as did Howard by using a VPN out from his QTH in Gibraltar to London.
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Tim - W4TME, Customer Experience Manager

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That is a fairly accurate summarization of the issue.
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John - K3MA

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In my case it is not a bandwidth issue or a firewall issue.  It happens at my station when I am connected over my LAN to the Flex 6500.  I also made the changes recommended to the router and the issue seemed to go away but yesterday resurfaced.  It only happens on a infrequent and irregular basis.  

I originally reported this issue in this thread.
https://community.flexradio.com/flexradio/topics/no-activity-on-spectrum-or-waterfall-upon-restart-v...