packet assembler/disassembler (PAD)
A packetizer/depacketizer(PAD) is a protocol converter that converts non-packet-oriented protocols into packet-oriented communication protocols.
Data terminal equipment( DTE) that sends or receives its data in a non-packet-oriented manner must be adapted to Datex-P by means of appropriate PAD equipment located at the data packet exchange in the local switch or by subscriber-owned PADs located at the user's premises.