Comcast Buisness Class has a list of approved cable modems at https://business.comcast.com/help-and-support/internet/comcast-business-cable-modem-device-compatibility.
Today a technician replaced my old cable modem with a new (for negative values of current models) Cisco DPC3941B.
Cisco has this is as discontinued device (https://www.cisco.com/c/en/us/obsolete/video/cisco-dpc3941-wireless-residential-gateway-with-digital-voice.html with a content date of 25 June 2017). That means no updates to the firmware from Cisco. Does Comcast support leaving insecure devices on their network?
Should I decide on dropping the overpriced leased equipment is there any bonding of signaling, or specific configurations that is done by Comcast on leased modems that could be done on a customer supplied cable modem to improve bandwidth perfomance.