The SB6121 is made by Arris.
This is no longer licensed under the Motorola Brand.
If you have a modem or device model beginning with "SB" or "SurfBoard" please call Arris Support at: 1-877-466-8646
Other models supported by Arris :
SB6141, SB6183, SB6190, SB8200, SB6121, SB5101, SB6120,
SB6180, SB6182, SBG6782, SBG6782, SBG901, SBG941,
SBM1000, SBR-AC1200P, SBR-AC1750, SBR-AC1900P, SBR-AC3200P