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Posted 2 years ago
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Tim - W4TME, Customer Experience Manager
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Tim - W4TME, Customer Experience Manager
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(Or Tim, does this still get sent via large packets, only fewer of them?)
I can live without waterfall, but it is tough without the panadapter trace!
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I am on a hardwired fibre connection 320 MB/s down, 115 MB/s up and the site of the equipment in Maryland is also hardwired and gets 50 down, 15 or so up which is plenty, but neither of us are using wifi.
I did packet traces and keep getting malformed packets on the vita 49 protocol, which is from my understanding the protocol the waterfall and pan trace would depend on.
I am very surprised at the battle we're having to get this going. It seems so straight forward. What are we missing?

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Well, that was my one good idea.
You certainly have enough bandwidth up and down at both ends of the connection. For sure, There is a clog in the drain somewhere.....
Serious Networking troubleshooting is out of my league. The guys at FRS will sort it out eventually.
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Peter K1PGV, Elmer
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Note that streaming with NetFlix (for one example) is a *far* simpler problem than implementing SmartLink. It's unfortunate that you happen to be one of the folks who are experiencing one of the issues.
That there are some issues showing up here and there speaks to the difficulty of the problem, not to any deficiency in the engineering team.
Peter
K1PGV
(a network protocol architect in a former life, and implementer of some non-Flex related pseduo-real-time streaming code)
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There is a wrench in the works somewhere in your network, obviously. Purely guessing here, to kill time while the experts look into it......perhaps some obscure networking parameter configured on one end or the other of your network connection (router or firewall settings.). Or perhaps even CAT5/6 patch cable problems. Or something the internet provider on either end of the connection is doing. Or some strange deal in the handoff between one provider and the other as it crosses the border?
Peter K1PGV, Elmer
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Yeah... no. Nothing nearly so elegant or interesting, I'm afraid.
Several years back, I wrote a program called ScannerCast that streams "live" scanner audio over the Internet from user PCs to the Radio Reference web site. I learned a lot about Internet streaming on that project.. which was definitely only pseudo-real-time as it buffered several seconds of audio before transmission.
Peter
K1PGV
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Tim - W4TME, Customer Experience Manager
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IF I reboot the local PC or my Flex 6500 and then restart SmartLink it seems to work again.
Tim - W4TME, Customer Experience Manager
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OK, I’m going to start this from the start. I have a 6500, hard wired via ethernet cable to a router. My desk PC, Windows 10, i7, is also hard wired via ethernet cable to the same router. I downloaded 2.0 and installed it on my desk PC. Then booted the 6500. Bought the license, installed 2.0 on the 6500, rebooted all. Started SmartSDR on my desk PC and it works fine. Spectrum scope and water fall working fine. I can unlink the meters on the right and move them to another monitor, real neat.
I then installed 2.0 on my Maestro. The Maestro is connected to WiFi that is on the other (outside) of the router. The Maestro could not see the 6500 direct. Download speeds are over 60mps and upload is around 10mps. When I logged in with SMARTLINK on the Maestro, the Maestro saw my 6500 ready. I connected to it. So, my Maestro is going “over the internet” to come back and connect to the 6500. It connects, shows freq, meters, changes freqs, changes bands, ATU works, get audio, I can key the radio, look at menus etc, EXCEPT no spectrum scope, other than about 1 inch. And no waterfall at all. Rebooted all a couple of times. Same story.
So, I linked my Maestro to my Android phone hot spot. Same story, can connect fine, no spectrum or waterfall.
I then installed SmartSDR on my MS Surface Book, Windows 10, i7. Connected to my home wifi the laptop saw the 6500 and I connected. No waterfall or spectrum scope. Again this was thru the internet and SMARTLINK.
Next I went to McDonalds with the MS Surface Book and connected to McDonalds Wifi. Had a good wifi connection. Started SmartSDR than logged in via SMARTLINK and the laptop saw my 6500 at home... YEA. Connected. Everything seemed to work but the spectrum and waterfall.
An observation. The waterfall area has about a 1 inch square in the middle that is totally black/empty. Odd. I have photos of the screen and the network numbers. below


David Decoons wo2x, Elmer
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Connect to the router and ensure uPNP is enabled (what model router?).
If that does not work then you might need to use manual port forwarding..
Dave wo2x
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Tim - W4TME, Customer Experience Manager
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Eric - KE5DTO, Official Rep
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Call in tomorrow to see if blocking by waterfall traffic. Display is same as others here.
73, Russ K5OA
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If you wish me to demo to you via Teamviewer I can do so. Give me your direct line # and I will call you.
Tim - W4TME, Customer Experience Manager
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So, a couple of things. One. my internet does pass the large packets. Because I could use my wifi and internet to connect and operate the others 6500, and he could connect and operate mine.
Two. But, I cannot get spectrum and water fall with my Maestro or laptop connected to the same wifi and internet provider. How can this be???
Tim - W4TME, Customer Experience Manager
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I even tried using the phone hot spot and Maestro connecting to my friends 6500 across town. EVERYTHING worked, including the scope and waterfall.
Then I tried my MS Surface Pro book thru the phone hot spot, could not see the 6500 spectrum or waterfall. Connect to my friends 6500 and everything worked.
So, my home wifi was not in use for this. My 6500 is hard wired to the router. And my friend can connect to my 6500 and everything works.
Tim - W4TME, Customer Experience Manager
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Thanks!
Sam
Tim - W4TME, Customer Experience Manager
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That is one possibility. The VITA-49 spectrum data (yes, it is UDP) can be larger than the 1500 byte payload of an Ethernet frame, but this is OK because the network stack in the radio is responsible for fragmenting the data into 1500 byte payloads and the network stack on the client end does the re-assembly. This is a tried and true feature of TCP/IP because not all data quanta fit nicely in 1500 byte chunks. So we are sending full sized Ethernet frames (1518 bytes).
I have run into this MTU problem before in a previous life where an MTU on a piece of equipment (I'll refrain from rating out the offending manufacturer) was set for 1500. But a "full" Ethernet frame is actually 1518 bytes (payload + MAC header+ CRC). Most devices interpret a 1500 MTU as 1538 bytes. However, in this situation, this was not the case. Needless to say, when we started streaming full-size data frames from one host to the other, nothing got through. Packets that had data payloads of 1482 bytes made it through.
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Assuming that's the issue, If we are very close to a limit (that is imposed by some significant number of networks out there), could the packet size be reduced slightly to accommodate this?
If there are other troubleshooting actions that you think might address this issue (no Panafall at remote user site), I would greatly appreciate a summary of them.
Thanks
Sam
Tim - W4TME, Customer Experience Manager
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Peter K1PGV, Elmer
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What's the (max) Interface MTU on the radio? Can we gain some perf in the local LAN case by enabling Jumbograms on our LAN and end system? Increasing our local MTU to, say, 9K?
Peter
K1PGV
Eric - KE5DTO, Official Rep
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Eric - KE5DTO, Official Rep
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Peter K1PGV, Elmer
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(To be clear: For me, this is really of academic interest. I don't see myself playing SmartLink anytime soon, due to the lack of decent IP infrastructure where I live.)
Peter
K1PGV
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Let me add that ... in this case of no panafall, both ends are wired. One with fiber (300 Meg down and a flock of speed uplink) the other is coaxial system testing at 90 down and ~15 up. So it is not a WiFi issue for us.
sl
Tim - W4TME, Customer Experience Manager
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Tim - W4TME, Customer Experience Manager
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Tim - W4TME, Customer Experience Manager
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David Decoons wo2x, Elmer
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Just trying to think outside the. Oz.
Dave wo2x
Peter K1PGV, Elmer
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IF the radio generates JumboGrams (we don't know if it does, I actually doubt it) then having a router on the LAN that handles these without fragmentation would only be a good thing, wouldn't it?
Peter
K1PGV
Tim - W4TME, Customer Experience Manager
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I tested again a few hours ago and it still doesn't make any difference here that I have noticed. Perhaps the router and modem have different settings?
Anyway, it is back off again for good.
Tim - W4TME, Customer Experience Manager
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I notice that DAX is NOT streaming the audio. I have channel 2 selected on the Slice for DAX but nothing streaming. I've logged out of Smart CAT and logged back in and it seems connected, but DAX still shows nothing streaming. Going to to play with it some more and see. Will try resetting the hardware at home when I get back and maybe try it again.
..............Bob W4PG
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Tim - W4TME, Customer Experience Manager
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Jul 28 15:28:59 Whole System ACK Flood Attack from WAN Rule:Default deny<br>
D-Link router 3 or 4 years old.
David Decoons wo2x, Elmer
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Dave wo2x
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In an early post to this thread, Tim mentioned fragmentation ... that was the answer for me and VO1IDX. My cable modem firewall had an option to block fragmented packets. I unchecked it and the panafall works fine in Newfoundland. We re-enabled the blocking feature and the panafall goes away. So, you need to be allowing fragmented packets through any firewall involved.
73
Sam K3KLC
and
Chris VO1IDX
Ken - NM9P, Elmer
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The fun starts now!
Enjoy...
Ken - NM9P
Peter K1PGV, Elmer
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This WILL help MANY people.
>My cable modem firewall had an option to block fragmented packets
There are third-party firewall/AV products that also block fragmented packets... so knowing that you must DISable this blocking will be very helpful to folks going forward.
I very pleased to hear you found the solution.
(Having SAID that, it would be nice if the MTU was discovered by SmartLink and this was not necessary... but, maybe that will happen in some future release).
Peter
K1PGV
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Peter K1PGV, Elmer
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It doesn't matter: If the radio is generating 1500 byte packets... or even 1200 byte packets... it is *extremely* likely that on the path from SSDR to the radio over the Internet there will be SOME intermediate system that can't handle a packet that large.
You can check this out by looking at the WireShark/Ethereal trace and seeing the largest IP packet you receive.
There's really very little risk to passing fragmented IP packets, and allowing fragmented packets to pass is extremely common. Anybody doing gaming will need to allow fragmented IP packets, for example. There *are* some very basic IP fragmentation exploits, but they are pretty mundane and easily countered by any good system or piece of network equipment.
Peter
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Peter K1PGV, Elmer
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Peter
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Tim - W4TME, Customer Experience Manager
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David Decoons wo2x, Elmer
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I never have jumbo frames enabled on any of my networking equipment but figures I'd ask so I understand if it would affect other users who may have it enabled in the router..
73
Dave wo2x
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Thanks, Russ K5OA
Tim - W4TME, Customer Experience Manager
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