Figure | Remote PAD Support |
T |
T | PAD |
T |
PAD Services
Remote PAD Support (x29server)
HP 9000 host
|
| User Level |
|
x29server |
| UNIX | |
| Applications | ||
|
|
| |
BSD | Sockets |
| |
X.25 |
| Pseudo- | |
| terminal | ||
Level III | Kernel | drivers | |
|
|
| (PTYs) |
Network
The x29server remote PAD support provides capabilities for:
•Managing call acceptance.
•Launching applications automatically.
•Ensuring system security.
•Monitoring access and data transfers.
When x29server begins execution, it examines the PAD support section (pad_spt) of the /etc/x25/x29hosts file. The PAD support section contains
Call Acceptance Mechanism and System Security
The x29server process operates in conjunction with devices declared in the set of pad_spt (PAD support) entries contained in the x29hosts file. It continually “listens” to the network and initializes communications channels at the user level when a call request is received. x29server can handle a large number of calls because each communication channel is managed by an independent process.
Chapter 6 | 137 |