telcodad Most modems are spec’ed to handle signals in the range of -15 dBmV to +15 dBmV.
At least some manufacturers specs are now -12dBmV to +15dBmV, however, most modems can actually handle power levels outside of that range (as in the real world the levels are not always as good as one would like, and components are not always exactly identical, so you want a bit of wiggle room on the supported levels).
Regardless, most operators prefer to target a delivered range well within those numbers (+/- 10dBmV or better), as the equipment will change performance over the seasons, and they want to not have to be called out due failures due to those changes. As always, deviation from those targets is sometimes (in practice) necessary.
Some operators run on the hotter side because they expect to need to end up using splitters in a residence (and for a 3 three way split that usually means a loss up to 7dBmV on some ports (yes, there are balanced splitters, but few use them)).
