There are a lot of cable modems on the market these days. Well, there are a lot of DOCSIS 2.0 cable modems today. There don’t appear to be many that are the new DOCSIS 3.0 ones yet, though.
When cable television companies first started delivering Internet services over their cable systems, there were several competing proprietary systems. As usually happens, a standard was born.
DOCSIS (Data Over Cable Service Interface Specification)is the standard for cable modems. DOCSIS version 2.0 has been around for a few years (since 2001) and is still widely supported by cable Internet service providers. DOCSIS 3.0, released in 2006, is beginning to replace DOCSIS 2.0 because of its increased capabilities.
That was my challenge when I decided to upgrade to a much faster Internet connection package from my Internet Service Provider.
I really didn’t need to go to the DOCSIS 3.0 modem. However, I’ve noticed as I’ve replaced switches and routers over the years that the later models were simply faster. Even if they weren’t advertised to be faster than the earlier models, if I could notice that the network was snappier, then that was a good thing.
The DOCSIS 3.0 modem I bought was the Motorola SB6120 SURFboard DOCSIS 3.0 eXtreme Broadband Cable Modem.
One of the great things about the SB6120 is that it has a Gigabit port, which is used by the Ethernet cable. You connect the other end of the Ethernet cable to your cable/DSL router. You can also connect it to a Ethernet switch, if you are going to arrange with your ISP for the ISP to supply IP addresses for each of your computers. Finally, you can hook the other end directly to a computer.
I strongly recommend that anyone using a cable Internet service should also use a cable/DSL router. If you use the router’s DHCP services (which are usually turned on by default), the router will get an IP address from your ISP, but it will provide IP addresses to your computers, using a range of IP addresses that are reserved for private networks.
Effectively, anyone on the Internet side who tries to initiate connections to your computers gets blocked at the router! Web sites, email servers, game servers and more can respond to your program’s connections to them, but they can not initiate communications with your computers. That’s because the router’s main function is to act as a bridge between the network known as the Internet and the local area network (LAN) created for your computers.
How about some information about the Motorola SB6120?
The modem is small, 5.7 inches by 5.7 inches by 1.5 inches (146mm x 146mm x 38mm). Input is the standard cable F-connector. Output to the computer/network is via 10/100/1000 Base-T Ethernet (RJ-45) (Gigabit Ethernet). Its power requirement is 9 watts, which is provided by the included power adapter.
Although it’s often pictured in the vertical orientation, the SB6120 can be used either horizontally or vertically. It also has three mounting slots on its right side so that you can mount it to a desk or wall.
Configuration is simple — you have to call your cable ISP to provide them the MAC address from the modem. Mine asked for a couple other numbers, e.g. the serial number, from the same tag on the modem.
Activation was almost instant — it went live while I was on the phone with customer service. This was a big improvement over my very first cable modem, in 1998, which took about 15 minutes to push the configuration information downstream from the ISP to my cable modem.
Did I see any benefits? I sure did. With the new Motorola SB6120 cable modem, my top download speed went about 4 Mbps higher than with my older Motorola SB5100 model.