Earlier this week, a Charter Communications internet service subscriber in Atlanta reported to the company that he was having problems connecting with his Netgear CMD31T DOCSIS 3.0 modem. On Monday, August 13, a Charter customer support supervisor responded to the customer by reporting that the CMD31T had been "blacklisted"
CMD31T - BLACKLISTED IN 05/24/2012 PER THE BLACKLIST DOCUMENT
In recent months, Netgear had also been dropped from the approved modem list by Comcast XFINITY, due to a problem with IPv6 incompatibility. Comcast now says that they have re-tested the CMD31T post Netgear firmware update, and restored it to their approved device list.
At our request, Charter investigated the issue, and they now say that the blacklisting was "inadvertent". Charter also added that the customer made a "good decision" by upgrading to a DOCSIS 3.0 device.
As you might expect, we do maintain an internal list of non-supported or non-compliant modems, which have been phased out due to older versions of firmware that are unable to receive updates. The Netgear CMD31T was inadvertently added to that list, due to an internal communications error. Our Engineering team has removed that device from the list, and our Customer Care team has changed its classification and will also communicate this change to our front line Advisors. Although we don’t specifically endorse any modem make or model, this customer’s choice to upgrade to a DOCSIS 3.0 modem was a good decision.In the mean time, users of the CMD31T continue to report issues, and a XFINITY customer in Maryland had to return his modem when Comcast was unable to establish a connection after one and a half hours of trying. Netgear's PR firm has promised a report on these issues by early next week.
We do, however, continue to support modems that are no longer receiving updates to the best of our ability. If a modem is classified as unsupported or non-compliant, it will continue to function on our network, although troubleshooting the modem when issues arise may be limited.
-source: Charter spokesperson