StarTech 10' DB9 RS232 Serial Female to Female Null Modem
How To Install A Cable Modem On Your Home Network - YouTube
NETGEAR DOCSIS 3.1 Multi-Gig Cable Modem with 4 Ethernet Ports. Max download speeds of 6.0 Gbps, For XFINITY by Comcast, Spectrum, and Cox (CM1200) - Newegg.com