Replaces Cisco ADSL & 1841 router as this is a Fast Ethernet only router, the 1921 is a similar router but with Ge0/0 and Ge0/1 interfaces and two hwic slots. I have a EHWIC-1GE-SFP-CU card as well because in the foreseeable future I will need to bring the internet in from the ISP ONT. Note this is NOT a direct fibre from the ISP, it is fibre to the ONT, then a Ethernet to fibre converter and on to the 1941 SFP fibre in a different building.