The present invention concerns a modem box, a splitting module, and an integrated access device.The modem box comprises upside communication means for coupling with central equipments through central signals, the latter being modulated for at least one of the central equipments, downside communication means coupling the modem box with terminal equipments through terminal signals, transfer means between the upside and downside communication means, and modem means for doing transformation between the modulated central signals and demodulated signals among the terminal signals.The modem box comprises an outer contact surface receiving a splitting module, which does transformation between the central signals and grouped signals formed with a multiplexing of the latter, and the upside communication means comprise at least one connection element arranged with that contact surface, in contact with at least one respective connection element of the splitting module.