So instead of doing things unilaterally (or at least without UN approval), they got a resolution to do one thing (a no-fly zone)...
Two things: Create/enforce the no-fly zone and prevent Gaddafi from attacking civilians or civilian population centers.
There's some question as to whether the language was intended to allow for attacks on additional forces not related to air operations in order to accomplish that though.
But you agree that there was a resolution for more than one thing. Great. That was my point. In fact, the protection of citizens is its own section and comes before the portion declaring a no-fly zone. There's no confusing that these are two separate things.
And dropping missiles and bombs onto (non-air) military bases and command and control locations in Tripoli? That would kinda be outside the mandate as well, right?
Given that knocking out Libyan communications was Step One? No, probably not outside the mandate.