HP X.25/9000 Programmer's Guide

116 AppendixA
X.25 Packet Formats
CALL ACCEPTED/CONNECTED Packet
CALL ACCEPTED/CONNECTED Packet
A CALL ACCEPTED/CONNECTED packet establishes a VC with a
remote host. A CALL ACCEPTED packet is sent in response to a CALL
INDICATION packet. Typically, the X.25 subsystem sends a CALL
ACCEPTED packet immediately in response to a CALL INDICATION
packet when an accept system call is issued on a listen socket. However,
if the ioctl(X25_CALL_ACPT_APPROVAL) call has been issued on the
listen socket, X.25 waits for the ioctl(X25_SEND_CALL_ACEPT) call to be
issued on the socket descriptor returned in the accept() system call.
Access to the fields in the CALL ACCEPTED/CONNECTED packet is
described below:
Figure A-2 CALL ACCEPTED Packet
General Format
Identifier
Indicates D bit usage and packet sequence count. This field cannot be
read by an X.25 application. The D bit cannot be read or written by an
X.25/800 application. The packet sequence count (modulo 8 or modulo
128) is set at configuration time and cannot be read or written by the
application. However, the application can read the configuration file
Logical Channel Identifier
Called DTE Address Length
DTE Addresses
Facilities
87654321
1
2
3
4
Bits
Called DTE Address Length
Facility Length
Packet Type Identifier
General Format Identifier
Octets
Call User Data
36960-90061.bk Page 116 Friday, November 10, 2000 3:42 PM