HP X.25/9000 User's Guide HP-UX 11i v3 (5900-1523, August 2011)

6 PAD services
Introduction
This section describes X.25/9000 PAD (Packet Assembler/Disassembler) Services which enable
HP 9000 computers to connect and communicate with remote systems over a Packet Switching
Network (PSN).
NOTE: Refer to “Configuring PAD services” (page 55) in Chapter 3 for information on configuring
PAD Services with SMH.
PAD Services include the following commands and functions:
• x29server – for PAD support for remote terminals:
A daemon process that allows a local HP 9000 system to function as a host for (real or
emulated) terminals attached to a remote PAD.
• x29printd – for remote PAD printer support:
A daemon process that allows local HP 9000 computers to print at printers attached to a
remote PAD.
• x29uucpd – for PAD-UUCP connectivity:
A daemon process that allows HP 9000 computers to originate UNIX-to-UNIX copy services
over an X.25 Switched Virtual Circuit (SVC).
• padem – for local PAD emulation:
A user command that allows a local HP 9000 system to emulate both a terminal and a PAD
for connection with remote systems over a PSN.
CCITT recommendations
X.25/9000 PAD Services are compliant with the X.25, X.28, X.29, and X.3 CCITT
Recommendations of 1984.
Recommendation X.28 defines the exchange of messages between PAD terminals and the PAD.
A superset of the commands defined by this protocol are performed by padem.
Recommendation X.29 is the protocol for the exchange of messages between the host and PADs.
Recommendation X.3 defines a set of parameters that control PAD operation. The following
illustration shows the relationship between each of these recommendations.
Figure 22 PAD support protocols
94 PAD services