NetIPC 3000/XL Programmer's Reference Manual (5958-8600)

36 Chapter1
NetIPC Fundamentals
Direct Access to Level 3 (X.25)
Figure 1-10 SVC Requestor Processing Example
SVC Server Example
Figure 1-11 shows the order of NetIPC calls used for a server program
and the X.25 packets generated as a result of the calls. The calls
outlined in Figure 1-11 perform the following functions:
1. Create a call socket with IPCCREATE. The call socket descriptor
(
calldesc ) is returned. The socket could be created as a catch-all
and/or bound to a particular protocol relative address.
2. Call IPCRECVCN and wait for an incoming call request packet.
IPCRECVCN will return a VC descriptor (
vcdesc ) when it is
established that the incoming protocol relative address defined in (1)
matches the incoming protocol relative address, or a catch-all socket
was created in (1).
3. As IPCRECVCN completes and returns a
vcdesc , X.25 sends the
requestor process a call accepted packet.
4. Receive a message over the connection with IPCRECV.
5. Send a message over the connection with IPCSEND.
6. Since the server (IPCRECV) in this example waits to receive a
message, you may decide to set a timer to handle the inactivity.
7. (Optional step.) Shutdown the connection with IPCSHUTDOWN after
data has not been received for a period of time. (For example, after a
timeout has occurred.) Note that the X.25 protocol implicitly handles
the incoming clear request by sending a clear confirmation packet.
1) IPCCreate
2) IPCDest
3) IPCConnect 4) IPCRecv 5) IPCSend 6) IPCRecv 7) IPCShutdown
CALL
REQUEST
CALL
CONFIRM
CLEAR
REQUEST
CLEAR
CONF
DATA
DATA
X.25 Protocol