Modem Slowing Down

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  • Updated 8 months ago
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My modem has developed an issue where it continually slows down.    I can reset it and on Speedtest see 25-35 Mb download speed.   Within a couple of hours, it drops to 15Mb.   Eventually, it drops to around .5 (if I wait that long).   If I cut the power for 5 seconds, it will be back to 25-35 Mb.  This cycle usually occurs over 4-5 hours and it has to be processing traffic.   Sitting overnight doesn't cause it to be slow when I start up in the morning.    It reminds me of a program with a memory leak.   I've contacted Viasat and a technician is coming out tomorrow.   Just not sure it is a hardware issue.
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Tom

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Posted 10 months ago

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Bev, Champion

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Wait and see what the tech says, it very well could be a hardware issue.
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GabeU, Champion

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Bev,

Does ViaSat further divide its beams into channels, where the modem connects to the least populated channel at the time it's started?  And, over time, that channel gets more people on it, causing it to slow?  

I ask this because that's what mine is like with HughesNet.  This is why power cycling the modem sometimes helps to improve the speed when it starts to get slow, at least temporarily.  On the subsequent power up it again chooses the cleanest, or least populated, channel.  I didn't know if ViaSat was similar.  
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Bev, Champion

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I dn't know, Gabe but, I'm going to say probably, it only makes sense. VS! and VS 2 might differ on that though being they are very different satellites technology wise.
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Jab

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RE: beams into channels

There were dedicated Tx/Rx channels on original Wildblue's "birds,"  users were assigned a specific channel set. 

WiMax protocol is being used, "flipping channels" is possible via Frequency Selective Scheduling, but Viasat may or may not do this.  Their Tx/Rx equipment would have to be capable, and someone would have to do the required programming.

My uninformed understanding, when aircraft came onboard, Viasat reserved frequencies for them, which means channel flipping did not exist, at least in earlier days.   Channel bandwidth can be resized on VS-1 and later birds, but earlier WB's can't, as I understand.

VS-2 is a different bird...it can downlink data on more than one frequency.  Offhand, I'd say channel flipping is possible, if it is wise to flip frequencies instantaneously; hence, can their TRIAs handle channel flipping in Ka frequency bands.

Here's a WiMax overview, in tech speak.
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Jab

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RE: "...HughesNet...power cycling the modem sometimes...chooses the cleanest, or least populated, channel"

Hughes use to do channel-pair assignments....unless they have stated otherwise, how about the modem reboot just eliminates a modem SNAFU (buffer choke, CPU thermal issues, etc)?

Footnote on Channel Flipping - Be it cellphones, satellite, WISPs, etc., having each CPE unit on frequency is best.  I'm not a geek here, but it would be logical to have a CPE unit "drift" its assigned frequency initially before being engaged.  I know Tx power is evaluated, but I don't know if frequency is evaluated.  Hence, with channel flipping, not channel assignment changes, Tx unit would have to nail freq jumps, perfectly.  Changes in channel assignment is possible, but flipping with consumer grade CPE equipment may be risky.  With aircraft equipment, they go from beam to beam, so polarity would have to be changed, but an unknown about flipping channels.
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GabeU, Champion

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Hughes use to do channel-pair assignments....unless they have stated otherwise, how about the modem reboot just eliminates a modem SNAFU (buffer choke, CPU thermal issues, etc)?
HughesNet does as I stated.    A power cycle or reboot connects the modem to the cleanest channel within the beam. 
(Edited)
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Tom

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Update on problem:   The tech came out yesterday afternoon and replaced the modem.   My speed is much more consistent.   The slowest I've seen is 20mb.   This morning I was around 22 mb and decided to reset the modem to see if it improved and it did.   That was a couple of hours ago and I'm still at 43 mb.   My old modem was also beginning to cycle itself, which never improved the download speed when it came back up.   It always required the power being disrupted to make an improvement.  Another noticeable difference between the modems is this one runs much cooler.   The old modem ran hot from day 1.
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Old Labs (VS1-329-L12FZ)

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Thanks for the feedback - it's rare for folks who experience problems here to come back here with the outcome. 
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Tom

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Update 2 on problem:    The problem is back.   I have to unplug the modem every 2 or 3 hours to get my speed back.   I was at .74 mb download.   Unplugged it for 5 seconds and now I'm at 32 mb.
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Tom

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Update 3 on problem:   The modem continued to give me problems.   I had switched the power off and on and as it was booting up, I logged into the modem.   I saw a message flash that a software update was in progress.   After the modem reset itself a couple of times I tested the speed and it was above 40 mb.    It has stayed in a 30-47 mb range for the last 3 hours.   Modem seems cooler to the touch also. 
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VeteranSatUser, Champion

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What plan are you on? I have my suspicions
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Tom

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25 mb, unlimited.    I think I know your suspicions. 
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Tom

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10 minutes after my last post, my speed went back to normal and the modem is no longer resetting itself every hour.   
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VeteranSatUser, Champion

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Unless they know your MAC address tied to this account profile, even if they wanted to do something they couldn't.
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Tom

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Something was resetting that modem.   I don't mean it was around an hour either.   You could set the second hand on your watch to it.   I'm not running at the same speed I was before this latest episode, but I don't care either.    I only picked 25 mb download because providers seldom meet their advertising.
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Todd P

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It’s now 3 pm and Still getting 17.5
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VeteranSatUser, Champion

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If you are on an 150GB plan, it is early yet :).