HP X.25/9000 Programmer's Guide

Chapter 5 75
Receiving and Transmitting Out-of-band Information
Building a Signal Handler
OOB_VC_CLEAR
A CLEAR INDICATION packet was received on the VC. The VC is closed
and can no longer send or receive data. The OOB_VC_CLEAR is always the
last event in the out-of-band queue.
You can use the recv(MSG_OOB) call to read out-of-band data that
arrived before the CLEAR INDICATION packet. You can also use the
ioctl(X25_RD_USER_DATA) (described below) to read cleared user data,
if any exists. In addition, a CLEAR INDICATION packet may contain a
facilities field that can be examined with the
ioctl(X25_RD_FACILITIES) call (see “The ioctl(X25_RD_FACILITIES)
Call” in Chapter 6 for more information).
You can get information on the state of the interface with the
ioctl(X25_GET_IFSTATE) call.
The first byte contains the length of the buffer and the second byte
contains the clear indication. The third byte buf[2] contains the cause
code. The fifth byte byte[4] always contains 0 (zero).
OOB_VC_DBIT_CONF
The D bit confirmation was received on a socket in nonblocking mode.
This event can only be received on sockets in nonblocking mode, because
a send() or write() with the D bit set blocks until confirmation is
received. For more information on D bit usage, see “Using the D
(Delivery Confirmation) Bit” The first byte of the buffer contains the
length and the second byte contains the event code.
OOB_VC_INTERRUPT_CONF
Confirmation to a previously-sent INTERRUPT packet was received on a
socket in nonblocking mode. This event can only be received on socketsin
nonblocking mode because send(OOB_MSG) blocks until interrupt
confirmation is received.
The first byte of the buffer contains the buffer length and the second byte
contains the event code.
Table 5-1 Controlling call acceptance when establishing an SVC
Value Reason
0 CLEAR INDICATION packet sent by network provider, subsystem,
or X.25 device driver.
36960-90061.bk Page 75 Friday, November 10, 2000 3:42 PM