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SBG6580 wifi speeds are absolutely atrocious now. What changed?

Regular Contributor

SBG6580 wifi speeds are absolutely atrocious now. What changed?

I'm just curious if maybe Comcast pushed through another defective firmware for the Motorola SBG6580 modem/router combo since I haven't had issues like this since they pushed through an update a few years back that would cause my internet to be out for 6-12 hours at a clip completely. (usually in the overnights).

 

Long story short I was checking my network using the networking section of file explorer on Windows 10 on my PC and I kept seeing two devices using my wifi. One being an Amazon tablet and the other was some sort of Android phone.  Anyway everything I had read said that those were phantoms and to get rid of them I needed to fully reset my modem/router. Done and done. Now those devices no longer show up and I hid my network from broadcasting it's SSID at all. 

 

Anyway I started out getting 4-5 MBps down and about 2-3 MBps up on the wifi all the way at the other end of my house. But over the last month it's gone down steadily from that to as low as 300 Kbps down. I've tried switching channels as I did a scan and found out there's a TON of devices around me using channel 1 and another one using channel 6. In the end I think I set it up on channel 8 and it seemed to fix it. 

 

Yet now I'm back down to DSL or worse speeds again on my wifi. Really wish Comcast would allow you to use separate modems for upstairs and downstairs and not consider it two accounts as I'd just use a basic Docsis 3.0 modem I got cheap a while ago and run a 50-75 foot ethernet line to my one device I want to connect upstairs.

 

Any ideas on what could've changed on my home network outside of maybe me hiding the network as it worked decently when it was broadcast, but then I ended up with those other devices (whether phantoms or not) on it.

Regular Contributor

Re: SBG6580 wifi speeds are absolutely atrocious now. What changed?

Hopefully somebody has some idea of what's causing this sudden drop in speed as I am at a loss. I've tried power cycling a few times and that doesn't help. I've tried everything short of moving the gateway upstairs and just using one port on the router on that and then just running a line back down to my TV room and using a second router for my devices down there, which is what I really DON'T want to have to do.

 

I did that for long enough with Verizon and their 'wonderful' base speed DSL, which this wifi is actually giving me LESS than the speed of at this point.

 

Any ideas short of redoing my whole network would be welcomed. As it is our contract is up in February and we're looking for a deal to keep this service and heavily leaning towards eliminating our second TV outlet whilst renting a Comcast gateway so that way whenever an issue like this pops up it's THEIR responsibility to figure it out.

New Poster

Re: SBG6580 wifi speeds are absolutely atrocious now. What changed?

You've identified interference from your neighbors on 2.4 Ghz as a likely cause:

"I've tried switching channels as I did a scan and found out there's a TON of devices around me using channel 1 and another one using channel 6. In the end I think I set it up on channel 8 and it seemed to fix it."

 

The Arris/Motorola SBG6580 gateway (combination cable modem, router, four-port switch, and wifi gateway) supports 2.4 Ghz OR 5 Ghz radios  - not both simultaneously like recent wifi access points.   If your client devices have 5 Ghz radios, I recommend switching to 5 Ghz.

 

The 2.4 Ghz range is used by 802.11b, g, and n protocols, and has greater range, lower throughput, and greater penetration than 5 Ghz.  While the SBG6580 shows channels 1 through 11 on the 2.4 Ghz radio,  there really are only three usable channels in 2.4 Ghz (see https://en.wikipedia.org/wiki/List_of_WLAN_channels) - typically 1, 6, and 11.  If you have more than two neighbors using 2.4 Ghz, you likely have contention on one of the usable channels.    From the details on that wiki page, you can see that you may have fewer usable channels if you or your neighbors are using wider 40 Mhz channels in 802.11n.

 

The 5 Ghz range is used by 802.11a, n, ac, and other newer wifi protocols.   Yes, '802.11n' is listed for both 2.4 Ghz and 5 Ghz because the protocol specifies use of bandwidth, not specific frequencies.   That's why you find some cheap '802.11n' wifi devices that only have a 2.4 Ghz radio.  In the 5 Ghz range, there are at least two or three times as many usable channels.   Combined with the greater throughput and weaker penetration, you are less likely to encounter interference with your neighbors.

 

The likely downside is the 5 Ghz radio may not be usable throughout your house, and you'll need to use one of many solutions to extend your 5 Ghz radio throughout the house.

 

 

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Regular Contributor

Re: SBG6580 wifi speeds are absolutely atrocious now. What changed?

2.4Ghz channels actually overlap each other - the only completely non-overlapping set are 1, 6, and 11.  On channel 8, you'll still get interference from the devices on 6.

 

I agree that 5 Ghz is likely to be even better.  It's definitely worth a shot - it penetrates my house just fine and I see very little else on it.

Regular Contributor

Re: SBG6580 wifi speeds are absolutely atrocious now. What changed?

Thank you @tg896w and @strega7 . Sadly from everything I've read the Playstation 4 doesn't really work on 5 Ghz wifi.

 

But it's worth a shot anyway. 

 

New Poster

Re: SBG6580 wifi speeds are absolutely atrocious now. What changed?

Your other option besides running a 50-75 foot ethernet cable is using one of the many HomePlug / PowerLine networking solutions to use your house wiring to extend a wired ethernet connection -- e.g., https://www.amazon.com/TP-Link-Powerline-ethernet-Adapter-TL-PA4010KIT/dp/B00AWRUICG/ref=sr_1_3_acs_... You can also buy kits where the remote end PowerLine plug also has an integrated wifi access point.

 

The Xfinity xFi pods solution is similar and appears to be more simple and seamless, but I believe xFi requires a new router to provide a single solution manageable by the Xfinity xFi app.
https://www.xfinity.com/support/articles/xfinity-xfi-overview
https://www.xfinity.com/support/articles/activate-xfi-pod-with-xfi-app

Regular Contributor

Re: SBG6580 wifi speeds are absolutely atrocious now. What changed?

@tg896w

 

I've thought of the powerline adapters solution before to try and provide a wired connection without having to run a line from downstairs to upstairs.  But at the same time I use a surge protector that covers both nearby power outlets to the device(s) I'd want to use the adapter for so I don't know if the connection would go through the protector AND still be viable. I also don't want to buy Comcast's wifi pod things because this company is one that, if we had other options for both services in my area, we would drop like a hot potato because they're leagues worse than their predecessor in this area(Adelphia).

 

If anything I would like an answer from Comcast themselves, but I guess that's not happening. The connection went from 30-40 Mbps down to bottom tier DSL speeds or worse virtually overnight and the last time I had major connection issues like that it turned out that it was something THEY did on their end with my gateway (bad firmware) that caused the issue.

 

Either way I reset everything AGAIN and even unhid my network again and at best I now get 3-5 Mbps up and 5 or so down, which is far cry from the connection I was getting prior.

Contributor

Re: SBG6580 wifi speeds are absolutely atrocious now. What changed?

You should connect a laptop or pc via ethernet to your modem to determine your download speed there could be some other issue. I own a SBG6580 and the wireless is terrible. I finally purchased a separate Netgear  nighthawk router which supports concurrent 2.4 and 5g.  Much better range and we can now connect tv, roku, tablets and phones via the 5g band leaving the 2.4 band for other devices.  As these devices multiply you are going to find more congestion and interference on 2.4.  

Regular Contributor

Re: SBG6580 wifi speeds are absolutely atrocious now. What changed?


@jw32097 wrote:

You should connect a laptop or pc via ethernet to your modem to determine your download speed there could be some other issue. I own a SBG6580 and the wireless is terrible. I finally purchased a separate Netgear  nighthawk router which supports concurrent 2.4 and 5g.  Much better range and we can now connect tv, roku, tablets and phones via the 5g band leaving the 2.4 band for other devices.  As these devices multiply you are going to find more congestion and interference on 2.4.  


I actually have my one desktop PC hooked up to the SBG6580 via ethernet and the wired speed is pretty bad too on it. Yet I use it for so little that I don't feel like resetting it to get the speed to rebound as it did one time prior. The speed test results on my PS4 and PS3 downstairs are decent though.

 

Yet the wifi was fine until a handful of months ago.  I was regularly getting 25 Mbps down and 4-5Mbps up with no problem. 

 

Just wish I had a spot to centrally locate the gateway in the house and just run lines to whatever I needed to connect as wifi can be so unreliable at times. 

Contributor

Re: SBG6580 wifi speeds are absolutely atrocious now. What changed?

If your download speed is bad when direct connected to the modem your wireless speed will be even worse. Please post the information from your modem.

https://forums.xfinity.com/t5/Your-Home-Network/Information-Requested-for-Connection-Related-Posts/t...