Packet assembler/disassembler
You must add a |reason= parameter to this Cleanup template – replace it with {{Cleanup|September 2005|reason=<Fill reason here>}}, or remove the Cleanup template.
A packet assembler/disasembler, abbreviated PAD was a communications device which provided multiple terminal connectivity to an X.25 network or host computer. It collected data from a group of terminals and placed the data into X.25 packets (assembly). A PAD also did the reverse, it took data packets from an X.25 network or host computer and returned them into a character stream that can be sent to the terminals (disassembly). Since the decline of X.25, PADs have almost become obsolete.
The structure of a PAD is defined by ITU-T (International Telecommunication Union); recommendations X.3, X.28, and X.29.
X.3 specifies the parameters for terminal-handling functions such as line speed, flow control, character echo, et al for a connection to an X.25 host. The X.3 parameters are similar in function to present day Telnet options.
Recommendations X.28 and X.29 specify the user interface or remote host requirements for controlling a PAD.
The following is list of X.3 parameters associated with a PAD:
- 1 PAD recall using a character
- 2 Echo
- 3 Selection of data forwarding character
- 4 Selection of idle timer delay
- 5 Ancillary device control
- 6 Control of PAD service signals
- 7 Operation on receipt of break signal
- 8 Discard output
- 9 Padding after carriage return
- 10 Line folding
- 11 DTE speed
- 12 Flow control of the PAD
- 13 Linefeed insertion after carriage return
- 14 Padding after linefeed
- 15 Editing
- 16 Character delete
- 17 Line delete
- 18 Line display
- 19 Editing PAD service signals
- 20 Echo mask
- 21 Parity treatment
- 22 Page wait