Your omnibox box will have a splitter in it, one cable to upstairs and one downstairs. If you get a new splitter from VM then the upstairs connection will need a terminator on it otherwise you are likely to feed spurious signal into the cable, VM should supply this. An alternative is to remove the splitter from th omnibox and replace it with an female to female F joiner. You can then put the splitter in the downstairs room for the two devices.
Tudor
There are 10 types of people: those who understand binary and those who don't and F people out of 10 who do not understand hexadecimal c1a2a285948293859940d9a49385a2