Yes, three non-overlapping 2.4ghz channels, I am quite familiar. Double channel width allows for greater bandwidth as well as greater exposure to noise/interference. I've picked up a few tidbits working on a 20,000 client wifi network in Minneapolis. The problem is not just my own networks utilization, which can be problematic on its own, but also neighbors wifi (eg, poor channel selection) as well and of course the non-wifi conforming rf using devices. If you have two clients that both associate to the same ap but can't see each other (rf-wise) then they step on each other when tx'ing which is more likely to happen when you have random transients on your ap connecting from random locations that are more likely to be further away. And of course increasing TX power on the ap doesn't help this specific condition as it is the clients' TX power that matters. My point being there are more possible causes of issues as you add more variables and more clients. Inviting more rf usage to your vicinity strikes me as only increasing the possibility of issues. As for the comcast specific component I don't have any experience directly with what they have or how it works as I don't use comcast. <div>-------- Original message --------</div><div>From: Ryan Coleman <ryan.coleman at cwis.biz> </div><div>Date:02/01/2015 9:16 PM (GMT-06:00) </div><div>To: TCLUG Mailing List <tclug-list at mn-linux.org> </div><div>Subject: Re: [tclug-list] More weird Comcast problems </div><div> </div>An additional item of note: I must operate under the presumption you don’t know this … There are 13 channels in the US available for 2.4GHz: 1-13. Each channel is 10MHz apart. But each channel is 20MHz wide. Therefore if you have something on channel 11 you can use channel 6 free and clear. Same with 1. But if you have anything strong on 2-5 and you’re on 1 or 4-9 and you’re on 6 you’re SOL. You will be bleeding and conflicting and upsetting your transceiver (aka AP). — ryan On Feb 1, 2015, at 8:59 PM, Ryan Coleman <ryan.coleman at cwis.biz> wrote: If you’re worried about it do a scan. Look where it is (1 6 or 11) and pick a different frequency. Your RF concerns aren’t really that big, trust me, as you’re never going to push so much data over wifi that you need it. I’ve been designing, installing and configuring large-capacity private networks for years and residential usage (even by me - where my laptop does a lot of data and always on wifi) never comes close to utilizing the spectrum capabilities. Wi-Fi on it’s own is flawed, even beam-forming AC and N isn’t really full duplex - that’s not a spectrum issue but a design flaw. Some are better than others but most APs you would buy off the shelf don’t come with them. The best I’ve ever gotten off a 300Mbit link is about 110Mbit/sec (13MB/sec) and that was a dual-radio system (2 unique radios operating) going 75 feet over unobstructed space on 6GHz. If you need speed Wi-Fi is not the way to go. If you need convenience and backup systems definitely. On Feb 1, 2015, at 8:20 PM, Justin Krejci <jus at krytosvirus.com> wrote: I can't imagine the electricity cost is really noteworthy, especially if nobody is actually using it but even if they are, still I doubt it's too significant. I'd personally be more concerned with the rf spectrum usage. If someone is using more of the 2.4ghz bandwidth that might affect my own 2.4 ghz usage, that then directly affects my experience, regardless of the cable side of the bandwidth. Just my own opinion / $.02 -------- Original message -------- From: Ryan Coleman Date:02/01/2015 5:09 PM (GMT-06:00) To: TCLUG Mailing List Subject: Re: [tclug-list] More weird Comcast problems On Feb 1, 2015, at 2:17 PM, Saul Alanis <sdalano at gmail.com> wrote: I later learned about that whole BS which other Comcast customers could connect to my access point, and that's where I drew the line to a point. No, they couldn’t. I’m afraid you’ve remembered the wrong end of the setup being BS. Trust me - I use the xfinity_wifi SSIDs all the time. It’s a private pipe, you cannot talk to others… but they could sniff your traffic and you theirs. That’s the problem with unsecured Wi-Fi. The part that is BS is that you have to PAY for the electricity at no discount in service. It doesn’t take away from your internet connection speed - just draws off your power bill. But you should also have a line-item discount on your serbice for hosting this extra configuration. You could have turned it off easily. I bought a used modern off Craigslist and my performance problems where dissolved. I had the Comcast technicians out which said they need to be present during the issue, but when you call technical support all they can do is reset your modem :( This doesn’t surprise me. The only hardware Comcast has ever supplied that was worth the price (of free) is the business class equipment. And the customer service… Holy cow it makes a difference. Sorry this is more of a rant than anything else. I really hope for alternative service providers in Dakota County. I guess since not enough people are willing to speak up we'll always be undeserved for the services we pay with our hard earned money. That’s not how contracts and bidding works… What you need to do is convince a commissioner who needs to reach out to other providers. If they want competition you will end up paying for it in property taxes because the county will be footing the bill to get the prices lower… Wonderful, right? On Feb 1, 2015 2:01 PM, "Ryan Coleman" <ryan.coleman at cwis.biz> wrote: Which model modem did they bring? On Feb 1, 2015, at 1:44 PM, Olwe Bottorff <galanolwe at yahoo.com> wrote: Looking at the modem admin page, I saw that the errant T410 was only listed as its MAC address. Also, it was not listed as DHCP but always listed with a "Reserved IP" of 172.16.0.145 --which will not allow itself to be changed, even when I repeatedly try to choose DHCP and save. On a hunch, I changed (Ubuntu/Gnome) in the "IPv4 Settings" tab from "Automatic (DHCP) to "Automatic (DHCP) addresses only". Now it works . . . after a whole weekend of hair-tearing-out! Can anyone tell me why it wants to default to (won't change from) "Reserve IP"? And what did my changing to ". . . addresses only" do exactly? Thanks. On Sunday, February 1, 2015 1:43 PM, Olwe Bottorff <galanolwe at yahoo.com> wrote: I want to blame Comcast because these problems on the T410 don't appear when I use it on any other Wifi connection (I'll test again to make sure) -- and they don't even happen when Comcast gave us a loaner modem a few weeks ago! The new box is a dual 2.4/5.0 GHZ, while the loaner box was just 2.4 GHZ. On the new (and previous) 2.4/5.0 box I can't get any Internet logging into the 2.4, and the 5.0 connection gives me the aforesaid weirdness. There has been sporadic weirdness with other things too: Android devices tend to act up occasionally; an older Kindle has trouble getting online. I also tested this with the T410 on a straight ethernet connection to the modem -- same problems. To make it even more confusing, I tried Win8.1 on the T410 -- and it worked just fine. So if my T410/U14.10 works elsewhere AND with a different Comcast modem, gosh, it must be some very weird clash with the 2.4/5.0 Comcast modem and my T410/U14.10. Also, my Thinkpad X201 used to have weirdness, but it settled down and seems to work now. That's another wrinkle to this, problems come and go. For a long time we'd get Internet AFTER we waited 10 minutes or so after Wifi login, sometimes even with ethernet. But again, like I say, my older T61/U14.10 works fine. The only explanation I can think of is that the Comcast 2.4/5.0 modem and U14.10's network software don't like each other when U14.10 is installed on my T410. Just for laughs, I should get a non-Debian Linux version or even BSD for my T410 and see what happens. On Sunday, February 1, 2015 11:32 AM, Ryan Coleman <ryan.coleman at cwis.biz> wrote: My Thinkpad T61 (also Ubuntu 14.10) works fine with no weirdness. So it’s your laptop not Comcast. It’s amazing who quickly people blame their ISP when only one device on the network has issues. I suspect something is RFU with your firewall (UFW). On Feb 1, 2015, at 9:47 AM, Olwe Bottorff <galanolwe at yahoo.com> wrote: Still having problems with my Comcast Internet service. Now it looks like my U14.10 Thinkpad 410 connection (wire or w-less) won't do ssh (no route to host), won't give me most web pages, but, amazingly, will connect with gmail, YouTube, and Wikipedia. Also, I can do software updates and synaptic. My Thinkpad T61 (also Ubuntu 14.10) works fine with no weirdness. LB Grand Marais (in spirit) _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota tclug-list at mn-linux.org http://mailman.mn-linux.org/mailman/listinfo/tclug-list _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota tclug-list at mn-linux.org http://mailman.mn-linux.org/mailman/listinfo/tclug-list _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota tclug-list at mn-linux.org http://mailman.mn-linux.org/mailman/listinfo/tclug-list _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota tclug-list at mn-linux.org http://mailman.mn-linux.org/mailman/listinfo/tclug-list _______________________________________________ TCLUG Mailing List - Minneapolis/St. Paul, Minnesota tclug-list at mn-linux.org http://mailman.mn-linux.org/mailman/listinfo/tclug-list -------------- next part -------------- An HTML attachment was scrubbed... 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