And just as a disclaimer, most regular RJ11 phone cords like this will have the pins reversed at one end, so you'll need to crimp a new 4P4C connector on to make it straight-through like this:
And just as a disclaimer, most regular RJ11 phone cords like this will have the pins reversed at one end, so you'll need to crimp a new 4P4C connector on to make it straight-through like this: