[SOLVED] QoS on xFinity/Comcast Router/Modem

BlueFireAngel

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Jul 15, 2010
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I have xFinity/Comcast as my ISP. So far we use their modem/router. It's an Arris TG1682G. From time to time, and more frequently in the last 3 weeks or so, the internet will cutout for a few minutes to maybe an hour at a time. Sometimes I'll reset the router with the button on the back, sometimes it'll come back on it's own.
I've called Comcast about it, assuming it was something on their end. (I haven't ruled that out yet.) The person I spoke with asked how many devices I had on the network. I said 6, and she said it looks like 17. So I started investigating. I don't think there are 17 typically on at any time, but it's probably around 11 to 13. She had said that we have 150 Mbps service and each device can be allocated a certain amount. If there are too many devices, then it can overwhelm and shut down. So I started researching how to potentially reallocate appropriate bandwidth to each device.
Essentially I learned I'm trying to setup my own QoS specifications on my router. After going to my router and investigating, I don't think that is something that's available to me. So, I'm asking:
  1. if anyone else has had a similar experience with xFinity/Comcast and what they've done about it,
  2. has anyone had success flashing DD-WRT or similar to this router/modem (it's not listed as far as I can tell as a recommended router for DD-WRT),
  3. Should I buy my own router and see if I can successfully configure my own QoS spec for the bandwidth I have (and any tips or pointers on that setup),
  4. or should I upgrade my bandwidth
  5. or both 3 and 4.
Devices that connect to the router include:
3 phones,
1-2 tablets,
1 smart TV
1 roku
1-2 laptops
1 security camera system (wired connection for the base station with HDD)
2 wireless security cameras
1 alarm system (this is the reason I started to know that the internet was down as it would switch from a wired connection to a cellular backup)

Any help, pointers, tips is greatly appreciated. Thanks!
 
Solution
The arris products have a event log. You should be able to get into the router and see if it is actually going down. You have to be careful to not reboot it since the logs are cleared.

You will generally see some random messages but if you get a number within seconds it likely is a problem. There are tables that tell what these messages mean.

This is different that say if you have a wifi radio fail or if the router gets hung and you can't even get into it.

You should be able to run your router at 100% usage and all it will do is be slow. You can with QoS decide which application will be less slow but it does not fix a router or internet connection actually going down.

If large amount of traffic are actually killing the...

kanewolf

Titan
Moderator
That many devices should not be an issue. The more of them you have on wired, the better your performance.

A combo device (modem/router in a single package) is not going to be compatible with second source firmware. If you want flexibility, then you should get a standalone modem and discrete router.
 
There are 2 ways to go about this, (1)Buy as much bandwidth as u can and forget (maybe difficult) QOS implementation for the noob. (2)Enlist geeky cousin Vinny to implement QOS, always nice to have control no matter what the bandwidth.

QOS, as ^he says, u must do it in your own box. I use pfsense myself, I didn't want to be surprised by whatever shortcomings of ready-made boxes, plus pfsense is free and use any ole PC with 2 NICs and BAM! U don't like it, just unplug from the chain and back as u were. I find pfsense QOS WIZARD easy to use and not too complicated but of course u can get complicated if u want to. Pfsense, large installed base, whatever u wanna do, somebody else has done it.
 
The arris products have a event log. You should be able to get into the router and see if it is actually going down. You have to be careful to not reboot it since the logs are cleared.

You will generally see some random messages but if you get a number within seconds it likely is a problem. There are tables that tell what these messages mean.

This is different that say if you have a wifi radio fail or if the router gets hung and you can't even get into it.

You should be able to run your router at 100% usage and all it will do is be slow. You can with QoS decide which application will be less slow but it does not fix a router or internet connection actually going down.

If large amount of traffic are actually killing the router or wifi radio or the internet you have some kind of hardware issue. Since this device has a cable modem in it you do not have the option to update the firmware only the ISP can do that.

My guess is from your description you likely have a hardware issue. The event log should give you a pretty good clue.....than again the ISP can see that also and those messages are sent to their servers so rebooting your modem does not wipe their copy. The tech you talked with may not know how to access those.
 
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Solution
Jul 18, 2019
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That many devices should not be an issue. The more of them you have on wired, the better your performance.

A combo device (modem/router in a single package) is not going to be compatible with second source firmware. If you want flexibility, then you should get a standalone modem and discrete router.

I missed the printer but it's wired. The latest additions, the cameras and the alarm system are wired too, and since it's the alarm system that's let me know there's an issue (during school year, no one was home for roughly 8 hours a day, so we didn't know or care if the internet cut out), it makes me think this is a hardware issue to some degree.
I was pretty sure the combo wouldn't let me flash a different firmware to it.
Do you know if the Arris device can be used solely as a modem or would it be better to get my own? Thanks for the reply!
 
Jul 18, 2019
6
0
10
There are 2 ways to go about this, (1)Buy as much bandwidth as u can and forget (maybe difficult) QOS implementation for the noob. (2)Enlist geeky cousin Vinny to implement QOS, always nice to have control no matter what the bandwidth.

QOS, as ^he says, u must do it in your own box. I use pfsense myself, I didn't want to be surprised by whatever shortcomings of ready-made boxes, plus pfsense is free and use any ole PC with 2 NICs and BAM! U don't like it, just unplug from the chain and back as u were. I find pfsense QOS WIZARD easy to use and not too complicated but of course u can get complicated if u want to. Pfsense, large installed base, whatever u wanna do, somebody else has done it.

So is pfsense a firewall software or a router or a system you can customize out of other parts?
 
Jul 18, 2019
6
0
10
The arris products have a event log. You should be able to get into the router and see if it is actually going down. You have to be careful to not reboot it since the logs are cleared.

You will generally see some random messages but if you get a number within seconds it likely is a problem. There are tables that tell what these messages mean.

This is different that say if you have a wifi radio fail or if the router gets hung and you can't even get into it.

You should be able to run your router at 100% usage and all it will do is be slow. You can with QoS decide which application will be less slow but it does not fix a router or internet connection actually going down.

If large amount of traffic are actually killing the router or wifi radio or the internet you have some kind of hardware issue. Since this device has a cable modem in it you do not have the option to update the firmware only the ISP can do that.

My guess is from your description you likely have a hardware issue. The event log should give you a pretty good clue.....than again the ISP can see that also and those messages are sent to their servers so rebooting your modem does not wipe their copy. The tech you talked with may not know how to access those.

I will definitely look at the logs. I don't know how far back they'll go because it seems I have to reset the router about 10% of the time this happens because after an hour or more and after getting rid of some of the deivices temporarily, it's still not connecting. I should have about a weeks worth though.
Then I'll call comcast while the system is up and talk to them about the logs. Thanks for the response!
 
Jul 18, 2019
6
0
10
General follow up question:
The data enters the house at the opposite corner (of course). From the box outside, the coax runs down, gets spliced (straight union connector) to a long run across the house (roughly 50' probably) and to a three way splitter: one to modem/router, one to HD cable box, and one to separate cable box downstairs. I think there's an in and an out for the coax on the cable box but I don't see the advantage of using that as opposed to the three way splitter. My question is, am I potentially losing too much signal across the house with the connections? Should that matter for the data service? When I run speed tests from my phone, I'm getting an average of 140Mbps to 175Mbps on 150 Mbps service. That is when I get the service. Thoughts?
 
The cable and the splitters all reduce the signal levels.

This also is information you can see in the cable modem. There should be a screen that shows all the signal levels for the up and down stream channels. Many times there is also a error count on each channel.

What numbers are considered good vary a big based on how the ISP is encoding the data...ie docsis levels. I really don't want to duplicate that data here but you can find it if you search recommended cables modem levels.

The one that tend to cause the most issues is the when you see upstream power levels near or above 50.

You could temporarily move the modem to the point the cable comes into the house to see if your in house cabling is degrade the signals. in general the in house cabling makes only a very tiny difference.

That said it only takes a tiny bit of water or dirt in the connection cause major issues.