Info about Computers
Packet assembler/ disassembler (PAD)
It is a device that connects computers and other networking equipment to an X.25 packet-switched network.
Packet assembler/disassemblers (PADs) are telecommunications devices that break down binary data streams into individual packets suitable for asynchronous transmission over X.25 networks. PADs also format packets by adding suitable headers to enable packets to reach their destination. When receiving data, a PAD also accepts packets from the network and translates (reassembles) them into a data stream that the computer can understand. The PAD's function is thus to assemble data such as strings of characters into packets to transmit over the X.25 network to the remote host and to disassemble packets that are received.
PADs were originally developed to enable remote dumb terminals to communicate over X.25 networks with mainframe computers. They were needed because such terminals lacked the processing capability to implement the X.25 protocol on them directly. The PAD thus acted as an intermediary between the terminal and the mainframe and buffered data received from the terminal and assembled or disassembled it into X.25 packets depending on whether it was transmitting or receiving.
Although early PADs required external data communications equipment (DCE), most PADs now have integrated DCE to allow them to be directly connected to asynchronous data terminal equipment (DTE) such as terminals, computers, routers, and access servers.