said by rody_44: Comcast doesnt write the firmware. They simply send the newest firmware after testing it. So yea firmware issues on customer owned modems is between the owner of the modem and the manufacturer
From the Motorola website:
Upgrading Firmware on my Motorola Cable Modem
Published 03/22/2007 12:23 PM | Updated 01/18/2013 02:16 PM
Can I upgrade the Firmware on my Motorola Cable Modem?
We apologize about the inconvenience, but your Motorola modem does not support manual upgrades. Motorola is not allowed to control the upgrades of DOCSIS devices, per the standards specification. Any firmware or software changes must be implemented via the cable network. Your cable provider can update the firmware based on what they have approved for their network distribution. Because of that Motorola is not capable of installing firmware for cable modems. Please contact the cable operator to obtain information on upgrading firmware on the cable modem.
I understood that to mean the firmware was specific to Comcast.