[andrewhillman]

I just had comcast to my home last week. I pay for 120 mbps but when connected via cat 5 it only reached 90 max mbps which would fine considering when using a wifi router it only reaches around 30 mbps. I have moved around the wifi router but it doesn't make much of a difference. The technician told me the 120 mbps that I am being charged for is for for direct access and wifi won't reach 120mbps. I complained to customer care saying if I go to the grocery store and pay for 120 items, I expect to get 120 items, not 30 items. I told them they should tell people upfront that 120 mbps is when you are plugged in directly since most people use a wifi router but this still doesn't make sense to me since they can easily downgrade you to, say, 6 mbps without a problem.

Does anyone know if this OpenWRT works? I would love to push my speed to its limits. Comcast pretty much has a monopoly in my city and they are not very helpful.

[icebraining]

I don't see the problem. If you paid for 120 items and you can't carry them in your car, it's not the grocery store's fault, even if "most people" used small cars.

If you want to get a better Wifi connection, get a good router and plug it in to the one installed by Comcast.

[minot]

Personally, I got an Asus router as well so this does not affect me. However, I can understand this from an average customer's point of view. It would be nice for the ISP to give a router that is good enough for the speed that they advertise. The router should not be the bottleneck.

[Dylan16807]

But the port needs to support the full 120. Cabling problems are on him, but if the builtin wifi can't do 120 to anything, then that's misleading advertising. Wifi is entirely capable of 120, and it's not something you can check until it's already delivered and failing.

If the grocery store makes a big deal out of having staff to carry groceries to your car, and how they sell 120 groceries, they had better be able to carry all 120 to cars that support it.

[andrewhillman]

I have a NETGEAR Nighthawk X6 AC3200 Tri-Band Router.

[apenwarr]

It's extremely rare for OpenWRT to magically make your wifi connection's raw speed faster. It's good for many things, but not that.

Wifi is extremely finicky, due to interference and the FCC's limits on legal transmit power levels. But you should be able to get same-room speeds of at least 180 megabits if you have a decent router and a client that supports it. The key things are you need to use a 5 GHz radio and (for distance) channel numbers >100. Many ISPs still give out 2.4 GHz-only radios, so performance will suck.

[lvs]

It sounds like you just may have a few things to learn about how networking works. Comcast is selling you a coax line into your house and, if you rent their modem, giving you an ethernet interface to it. It isn't making any claims about what happens after that. They can't have control over all your networking hardware and how you configure it.

[andrewhillman]

I may have a few things to learn about how networking works. However, I was just stating the facts. A technician came out to re-configure to see if the issues of speed could be resolved. They did, and technician said... speed test is hitting ~93/120 mbps or so when wired in but the speed over wifi was much less while the specs say it is capable of doing 120 mbps without a problem. The tech actually said it isn't going to reach 120 mbps over wifi. If they don't have control, how is it they can "flip a switch" while on the phone to put you at 25 mbps or less, if you ask to downgrade? I believe when you buy 120 mbps that they are advertising they are claiming you will hit this speed if you are paying for it. I didn't see any disclaimer next to the 120 mbps saying "speed will be substantially less if using wifi router."

[phil21]

This isn't a Comcast issue. Their demarc (the divide between where service is delivered and your network) is the cable modem.

You could of course make the argument that you bought some combined cable modem/router/wifi AP box from them and it should "just work" - but you're just going to talk until you're blue in the face. Simply think of them as a pipe provider (not your IT support) and you'll be a lot happier.

What they provide is in general crap, and costing you money you can save off the monthly rental fee by providing your own equipment. This will also generally result in better performance.

I suggest buying a Surfboard 6183 (or lesser, depending on your area), and the wireless router of your choice. I recommend for simplicity sake the Apple Airport extreme or any quality 802.11n (or 802.11ac if your laptop supports it) router. Your network should look something like Cable from wall -> DOCSIS Modem -> Your wifi router. The only time you should be calling comcast is when the actual cable modem cannot obtain a lease and/or internet is in general failing.

Relying on Comcast to manage your CPE is just a plan for disaster. If your wired tests are getting 100Mbps, then the problem is on your end.

[sfont]

30 mbps is about what you would expect over 802.11g. You may want to investigate a driver issue on your PC. Another scenario that may give you poor speed over wireless is interference from neighboring access points. There are utilities available to view the channels used by access points within range. If you are on a channel that is crowded you may benefit from manually specifying the channel in your router.

[getsat]

Cat5 has a max throughput of 100mbps. 802.11g wifi (probably what you're using) has a max throughput of 54mbps.

Either buy a Cat5e/Cat6 cable or change your wifi access point to use 802.11n. I am connected to my 2007 Airport Extreme at 300mbps right now using 802.11n.

[seanp2k2]

Any old cat5 can handle 1000BASE-T. 1000BASE-TX uses 2 pairs (4 conductors) and is pretty rare in the wild, whereas 1000BASE-T uses all 4 pairs (8 conductors). https://www.iol.unh.edu/sites/default/files/knowledgebase/ge...

This has more information on cat5 vs cat5e vs cat6 and their compatibility with different speeds / modes: http://serverfault.com/questions/107172/what-is-the-actual-d...

TL;DR almost any Ethernet cable you buy today will be cat5e or better, which will work just fine. Really old cat5 is technically compatible and should work too, but due to it having slacker tolerances for e.g. crosstalk, it might not work over e.g. longer runs or difficult situations (cable ran next to fluorescent lights, etc).

EDIT: If you want to know what speed your link-level has established, your OS should provide this info. netstat -e on windows or netstat -i on OSX / Linux should show the connection speed. In windows, you could also do WinKey+ r -> ncpa.cpl -> right-click active internet connection -> connection details IIRC.

[Dylan16807]

To add on to that: 100BASE-TX and 1000BASE-T use the exact same symbol rate, 125MHz. Better cables are nice but not critical.

[quanium1337]

Cat5 is suitable even for 1000BASE-T (Gigabit), although at that speed it's just not as good as Cat5e [1]. But it should be enough to handle 120mbps.

[1]: https://en.wikipedia.org/wiki/Category_5_cable