As another example, codes 00100 and 00101 are used when a particular time slot address is to be assigned to a particular device, that address being is identified to the device via paths RB and/or SB. Yet another pair of codes, 01000 and 01001, cause an addressed port to convey, over paths RB and/or SB, such information about itself as its generic type (access module, application module, modem or D