My home network - cable

August 1, 2013

After over 10 years with DSL from Century-Link (Qwest), I got fed up with problems they were unwilling and unable to fix and made the switch to cable (in the summer of 2013).

I have heard any number of horror stories about Cox. Century Link seems less evil even if vastly less competent. I am hoping that the cable hookup just works and I don't need to try to persuade them to fix problems.

In the past, their phone representatives have always tended to be unpleasant and pushy, but the guy I talked to when I actually signed up for Cable in August, 2013 was decent and didn't ignore my questions and try to sell me services I didn't want.

As always, there are lots of confusing "bundles" and there are always "promotions" - which you can typically get extended if you call them when the promotion expires. Some will include a modem. Some will include a phone line that I don't want. And of course they also want to drag you into Cable TV....

The installer showed up on time. They commit to a 2 hour window (so you don't have to wait around half the day like you do for Century-Link). He reterminated cables, reconnected a protective ground and testing everything, including in the house and was not going to leave until I had verified that my computer was getting on the internet. Quite a change from Century-Link, who I begged to come into the house to test my wiring, and would never do it, even when I agreed to pay if any problems were my fault.

Cox (circa 2013) does offer several speeds, as follows:

They charge either $19 or $41 to hook you up, and you have to buy a modem.

If you are a complete idiot you can buy (or worse lease) a modem from them. Alternately, you can go online and shop for a modem (and you can find approved brand new ones at Amazon.com for example for about $80). Their price for a new DOCSIS 3.0 modem was $130 at the time I investigated. Once you have a modem (let's say you decide to upgrade or replace a modem), you call them and give them the serial number an MAC id of the new modem.

In general it seems that there are "deals" available if you shop online. Do a google search for "Cox free install promo code" or something similar. It seems that you get better deals if you order service online. Perhaps they save enough if you don't use their phone agents to offer things like a free modem or free install. Self install charges are $19.99 and they say they give you full instructions (and I feel confident). Or you can pay $49 for a professional install.

What is DOCSIS

It stands for Data Over Cable Service Interface Standard. Docsis 2.0 is being phased out. The big advantage of Docsis 3.0 is that it allows channel bundling, which even at lower speeds makes service more consistent and reliable. It is essential to get higher speeds (speeds above 25 Mb/s).

What about the Motorola sb5120 modem?

I bought one of these for $12.90 (including shipping!) on Amazon in July of 2013. It seems to work just fine. This is a discontinued model and does only DOCSIS 2.0.

A recommended DOCSIS 3.0 modem

The guy who did my install says he favors the motorola modems. He has a "boxy" modem with initial digits "61", which is probably the 6120 (which is available from Amazon for around $85). Beware the modems being sold by Digital Media Source on Amazon, as they are used modems in various states of repair. Many people have been burned by them.

My Netgear MR814 router

Unlike my old DSL setup where I had one box that combined a DSL modem, an ethernet switch, router, and a wireless access point, my cable modem is a modem and nothing more. This means I can hook up a single computer to it, or I need a router. What happens with a single computer is that a DHCP request from that computer gets answered by some entity (perhaps the cable modem, but more likely a server on the Cox network somewhere), then the cable modem acts somewhat more or less like a bridge. My single computer gets an address on the cox network (something like 67.222.29.13) and I see lots of broadcast traffic (in particular ARP packets) on that wire. A second computer trying to do DHCP just gets ignored. So we need a router.

I dug up my old Netgear MR814 router. This thing has a WAN port, an embedded ethernet switch with 4 ports, and a wireless access point, all in one handy package! There are a couple of problems though with the wireless. It is only 802.11b (11 Mbit/s). This isn't good - but it ain't all that bad. The bad part is that the wireless security is only WEP -- which if you don't know was found to have serious issues back around 2001 and has essentially been abandoned. I realized that something was up when I tried to set up wireless security using a simple passphrase. What I wanted to do was to set up this wireless access point just like my old setup so the rest of the folks in my family won't have to give me their MAC addresses or install arcane keys. Well, that just ain't happening with this unit, and the latest firmware (which I have installed circa 2004) does not support WPA for this unit and never will.

So I will use this as a router and abandon the wireless. I don't find an option to just turn off or disable the wireless, so I set it up to accept only one MAC address and move on.

I set this up as 10.0.0.1, and use my w9h password.

My Linksys WAP54

I just happen to have one of these laying around. This is a pretty nice wireless acess point with two antennas that does 802.11g (54 Mbit) and supports modern WPA authentication with a single passphrase. This means that it is faster, more secure, and the change will be transparent to the rest of my family. There are lots of alternative firmwares available. In particular, should I want it, folks have figured out how to get the wireless radio transmitting with 84 mw instead of the default 22 mw. There is a good chance that this voids any (long expired and forgotten) warrantees, not to mention may violate FCC regulations. Well, I haven't installed the new firmware or enabled any of the high power options - not at this point of time anyway.

It is running 3.04 firmware (whatever that is). This unit comes with no user name and password "admin" (which I change to my w9h password). It fires up on 192.168.1.245. As soon as I get into it I restore factory defaults, then change its IP to 10.0.0.2. I configure it to use WPA2-personal.

Incidently I use a linux "trick" to access the unit initially: 

ip addr add 192.168.1.5/24 brd + dev em1 label em1:linksys
This sets up a route to that subnet and an alternate interface so that I can access its web interface and configure it the way I want it. Seems to be a simple well made unit.

The Linksys WRT54GL

This is a router and wireless access point combined, and available from Amazon for $49. It would (as it seems) nicely replace my MR814 and WAP54 with a single unit. Interestingly a new WAP54 sells for $160 -- wow!
Feedback? Questions? Drop me a line!

Tom's Computer Info / tom@mmto.org