Do I need to upgrade my modem to DOCSIS 3.0?

Recently, Comcast has been pestering me by mail and phone to upgrade my modem to a DOCSIS 3.0 model.

I currently own a Toshiba DOCSIS 2.0 modem that works fine. I subscribe to an 8MB/s plan. Since DOCSIS 2.0 can handle roughly three times this speed, I'm curious as to why Comcast is pushing me on this.

Their claim is I'll need a DOCSIS 3.0 for the all digital service coming soon to my neighborhood.

Do I need to replace the cable modem solely due to the digital upgrade if I don't plan on upgrading my service plan above 8MB/s? Nobody at Comcast is willing to provide a straight answer. I suspect this is a ploy to switch me back to renting a cable modem ($8-$15/month) and/or convince me to sign up for their new 100+MB/s service for three times the monthly rate of my current 8MB/s service - something I don't plan on doing.

Any thoughts or advice would be appreciated. Thanks.

 

DOCSIS 3.0 is a fairly new technology (about 3 years old) in the Cable Internet industry. It employs a technology they call Channel Bonding. This means that you are essentially making multiple connections at the same time. Comcast currently bonds 4 channels for the download but is still only using a single channel for the upload. The DOCSIS 3.0 spec actually has the ability to bond 8 channels up and down with a maximum speed well in excess of 300mbps. Even on the 8mbps service you should see an improvement in reaction time on the Internet though your download speeds would probably remain about the same through the throttling of your ISP.

The DOCSIS 2.0 spec will remain for a long time to come so the upgrade is not essential but you will see an improvement in performance with a DOCSIS 3.0 Modem.

 

I forgot to mention that there are also differences in the DOCSIS 3.0 modems.

I use Motorola Cable Modems so that's where my knowledge lies so that's what I'll use for examples. The Motorola SB6121 has some enhancements over the SB6120. It has a "power" switch which isn't really a power switch, it just disconnects the modem from the internet without powering it down. Most of the SB5xxx DOCSIS 2.0 modems had this also.

Most important is the MoCA filter that is built in to the SB6121. Although it operates at a much higher frequency, MoCA generates a fair amount of noise on your coax. If your using MoCA (Multimedia over Cable Alliance) in your home, this can improve performance by filtering the MoCA noise from the data connections. This would only be relevant if you are streaming video on your local network.

 

Thanks for the info.

Currently, things are fine with my 2.0 modem. Running the speakeasy speed test (http://www.speakeasy.net/speedtest/), I'm actually getting speeds up to 12MB/s. Since I live alone (and don't do Pirate Bay :-D), my current speed is more than enough for downloads and streaming HD video.

If or when my current modem dies, I'll invest in a 3.0.

 

Yeah, I would certainly purchase a Modem over renting one.

I have to say though that I saw a big difference in how quick the Internet responds after upgrading from an SB5100 to the SB6120. My download speed didn't change much, the pages just load faster because of the 4 channel stream instead of a single channel stream. I bought the SB6120 used on CraigsList for $50, well worth the money.