HP X.25/9000 Programmer's Guide

Appendix A 117
X.25 Packet Formats
CALL ACCEPTED/CONNECTED Packet
where this information can be posted.
To read this field on an incoming packet:
This field cannot be read by the application.
To write this field on an outgoing packet:
X.25/800 applications use the ioctl(X25_SEND_TYPE) call to set the D
bit.
Logical Channel
Identifier
Associates a logical channel number with the VC. This field is controlled
by the X.25 subsystem. It can be read using ioctl(X25_RD_LCI) after
the call has been established.
Packet Type
Identifier
Indicates the kind of packet. This field cannot be read or written directly,
but through system calls, CALL ACCEPTED/CONNECTED packets can
be transmitted or detected.
To read this field on an incoming packet:
The application can detect the arrival of this packet when the connect()
system call unblocks or selects writable.
To write this field on an outgoing packet:
The subsystem automatically sends this packet when an accept()
system call has been issued, unless the application is controlling call
acceptance. In that case, this packet is sent only after an
ioctl(X25_SEND_CALL_ACEPT) is issued on a socket that had
ioctl(X25_ACPT_APPROVAL) issued on the listen socket.
Calling DTE
Address (Length)
Indicates the source of the packet.
To read this field on an incoming packet:
This field cannot be read by the application.
To write this field on an outgoing packet:
The X.25 subsystem computes this field.
Called DTE
Address (Length)
Indicates the destination of the packet. This field is accessed through the
x25addrstr structure.
To read this field on an incoming packet:
This field can not be read by the application.
To write this field on an outgoing packet:
36960-90061.bk Page 117 Friday, November 10, 2000 3:42 PM