Cautionary tale before taking a free DOCSIS 3.1 modem upgrade
I work in IT and my client called because Cox sent them a new Arris CM8200 cable modem. I asked if they upgraded to a higher speed plan that would require it, but they hadn't made any changes to their services with Cox. It seemed odd, but since it was provided at no charge and the modem was essentially an updated version of their current SB6183 modem we went ahead and installed it. I explained the differences between DOCSIS 3.0 and 3.1 to my client and that 3.1 is more efficient with how it uses the available spectrum on the cable lines. (QAM256 vs. QAM 4096) Now the bad part....
After upgrading, they started to notice problems with call quality on their VoIP phones. I wasn't made aware of it initially as they contacted the VoIP vendor for help. After being made aware, I ran some ping tests to see if there was any obvious problems. Sure enough, pinging the gateway on the Cox side along with Google and Cloudflare DNS showed packet loss. We contacted tech support to see what could be done about it. We were informed that the node we were using was noisy, overloaded and experiencing capacity problems. Since speed was not a factor and reliability was more important we decided we should try to switch back to the old cable modem. With the problematic and noisy node we were on, running the older, but less efficient QAM256 modem might help alleviate their problems. After all, they hadn't experienced any problems before installing the newer modem. Also, the previous SB6183 is still a modem on the Cox business compatibility list.
So we called tech support to swap the old modem back, but we were informed that wasn't possible. I was told upgrading to DOCSIS 3.1 was a one way street and we could not reinstall our old modem. Installing the DOCSIS 3.1 modem offered little benefit to my client, but benefited Cox by helping them avoid a costly node split. So now they are stuck with poor quality internet and have no other option other than to repeatedly call tech support and complain. After more than a dozen phone calls with no resolution I was referred to the customer retention department. This is an unacceptable situation to put a business in. So beware that Cox may send your a new modem, but make sure that you will benefit from it before installing. There is no going back once you've upgraded, even if it results in a connection of worse quality.