Question Long Term Poor Download Speed Issues

FriboRage

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Jan 26, 2016
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Hello everyone!

Read through before you start to come to conclusions, cause I've made progress but Im going to give the whole story.

Just to set up: I've got a pc that my download speeds have been abysmal for years. I made some half hearted attempts at fixing it a few years ago, but just decided to live with it. I begrudgingly accepted it until a few days ago when I had a really painful few days involving multiple days of game updates that had to go over night.

So... Modem is Arris Surfboard 6700AC... Router is Netgear Nighthawk AC1900 R700, 300megabit service... pc is connected via external wifi adapter through USB 3.0. (2.4ghz band). The modem is a 2-in-1 modem/router combo that I just have the radio turned off to function as a standalone modem.

Download speeds from Steam cap out at 1.2megabyte/s, which is horrendous, and internet speed test gets me a pretty consistent 9Megabit/s, which works out mathematically.

I convinced myself the wifi was the issue.. between the bad speeds and I get drops fairly often, so that just reinforced it. Running ethernet through my house would be a huge pain because of the layout, but the old tenants had coax run through the whole house. So I decided to do a moca setup since the infrastructure was already there... cables ended up being very old and bad. The two I needed were testing as open circuit even with the end shorted. Replaced the line from where my router is to my pc location with brand new coax, got the moca connected up, it works.

The issue is, it was only *marginally* faster... like 5megabyte/s instead of 1.2... internet speed test shows 40megabit... so again, that works out. So... improvement over the wifi but not by much, and certainly not to what I should be getting.

So I hunted more. In my router control panel, I found that my wireless connections were shown at 600M(2.4ghz) and 1300M(5ghz) ... LAN1 where the moca line was connected was shown at 1000M, but WAN was shown at 10M... that's the connection into the router directly from the modem. I swapped that ethernet cable out and it bumped to 100M.

Now, my downloads go to 12Megabyte/s, and speed test at 89-90Megabits...which is much better, but still feels very shy of the service I pay for.

Being that the link between the modem and router looks like the bottleneck, and the modem is pretty old... and I know the 2-in-1 router/modem combo units can be pretty poor quality to begin with... Im ready to get a modem upgrade right now if it'll fix this situation. I just want some advice before I go and spend more money on this project and have it be a waste.

Any advice is appreciated, thank you!
 
Hello everyone!

Read through before you start to come to conclusions, cause I've made progress but Im going to give the whole story.

Just to set up: I've got a pc that my download speeds have been abysmal for years. I made some half hearted attempts at fixing it a few years ago, but just decided to live with it. I begrudgingly accepted it until a few days ago when I had a really painful few days involving multiple days of game updates that had to go over night.

So... Modem is Arris Surfboard 6700AC... Router is Netgear Nighthawk AC1900 R700, 300megabit service... pc is connected via external wifi adapter through USB 3.0. (2.4ghz band). The modem is a 2-in-1 modem/router combo that I just have the radio turned off to function as a standalone modem.

Download speeds from Steam cap out at 1.2megabyte/s, which is horrendous, and internet speed test gets me a pretty consistent 9Megabit/s, which works out mathematically.

I convinced myself the wifi was the issue.. between the bad speeds and I get drops fairly often, so that just reinforced it. Running ethernet through my house would be a huge pain because of the layout, but the old tenants had coax run through the whole house. So I decided to do a moca setup since the infrastructure was already there... cables ended up being very old and bad. The two I needed were testing as open circuit even with the end shorted. Replaced the line from where my router is to my pc location with brand new coax, got the moca connected up, it works.

The issue is, it was only *marginally* faster... like 5megabyte/s instead of 1.2... internet speed test shows 40megabit... so again, that works out. So... improvement over the wifi but not by much, and certainly not to what I should be getting.

So I hunted more. In my router control panel, I found that my wireless connections were shown at 600M(2.4ghz) and 1300M(5ghz) ... LAN1 where the moca line was connected was shown at 1000M, but WAN was shown at 10M... that's the connection into the router directly from the modem. I swapped that ethernet cable out and it bumped to 100M.

Now, my downloads go to 12Megabyte/s, and speed test at 89-90Megabits...which is much better, but still feels very shy of the service I pay for.

Being that the link between the modem and router looks like the bottleneck, and the modem is pretty old... and I know the 2-in-1 router/modem combo units can be pretty poor quality to begin with... Im ready to get a modem upgrade right now if it'll fix this situation. I just want some advice before I go and spend more money on this project and have it be a waste.

Any advice is appreciated, thank you!
You still have a bad cable, IMO. The link on the WAN should be 1000 rather than 100.
 
Is it possible that link is so slow because the modem isnt doing well? Whether it's old and failing or just bad to begin with? Like my understanding is that's the rate that the router is detecting from the modem, and reporting it, so it could be the modem itself, the cable between... or potentially even (I really hope not) the service line to the pole? Or am I mistaken, and the router is reporting on the actual link between the two?

The cable I swapped is a brand new cat6 that's only like 4 feet long... I know stuff can be bad right out of the factory but damn..

Edit: Okay, I swapped the cable with a cat5e I had laying around and it's no change, so original cable had me at 10M, swapped it for a new cat6 that got me to 100M... second new cable holds steady at 100M.

Edit2: Also, the modem has 2 ethernet ports on the back, swapped between the two to make sure that Port 1 isnt bad, but it also makes no difference... also want to note that the little LED indicator on the back that indicates port activity is red/orange... at one point it was green while I was swapping and went back to orange. LED's on the front are Green/Blue/Blue/Green which I believe is as good as it gets for those indicators.
 
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Okay, reviewed those documents...

-Downstream-
Signal is good, as per the troubleshooting document, Modulation is QAM256, meaning I should be looking for a power level of - 15 dBmV to + 15 dBmV for each downstream channel.

Each of my channels is lay between 5.5dBmV and 6, so very close to middle of the road... the document says being near the limits is bad, so this seems right on target.

SNR specifies 30dB or greater, every channel is between 41 and 42dB

-Upstream-
Signal seems weak upstream.. minimum for any channel type is 45dBmV and all of my upstream channels are 42 or so.

Well that's surprising, as my upstream speeds seem to be fine, it's the download speeds that are upsetting me.. I guess I'll call the cable company to have someone out?

Thanks for all the help, guys! I'll update when I get something.
 
I guess it depends on where you are seeing the 100m. If it is with something like speedtest then it can be the modem.

You need to see the speed either on the router or the modem port. If the menus do not tell you the lights might indicatre the speed.

Your router and modem have gigabit ports so this should always be 1000mb. The only thing that will make it run at 100m is a bad cable or a bad port. Bad ports are very rare bad cable are fairly common espically with all that fake ethernet cable being sold. Never use those flat cables.
 
USB 3.0 is known to cause interference with the 2.4ghz band. If you have a USB 2.0 port on your motherboard or PC case, I would try that first.

Also, make sure your modem is set to Bridged mode, so it can truly act as a modem and you're not double NAT'd: https://arris.my.salesforce-sites.c...eral_FAQs/SBG6700-AC-v8-6-x-Bridge-Mode-Setup

The Arris SBG6700AC is only recommended for Internet plans up to 100mbps. The max rated spec is 343mbps but Comcast would need to have a profile for that modem which works at that speed and the signal levels would need to be very good. You should get a docsis 3.1 modem if possible. I bought my Arris S33 on Amazon refurbished for $99. I think it would solve alot of your issues.

Also 2.4ghz typical speeds are going to be about 40mbps, so game updates will likely be about 5MB/s max.
 
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