ACC X.25 Protocol User's Guide

ZX25D X.25 Protocol Driver
Virtual Circuit Definitions
Chapter 352
Select Word for X.25 SVC Configuration
VC Device Option Word Definition
The option word for the X.25 logical channel (VC) terminal defines
whether the channel is to be a permanent or switched virtual circuit
(PVC or SVC), the type of SVC, and other operational characteristics to
be used between the application and the X.25 protocol driver. Note that
the number of VCs of each type (PVC, IN, OUT, IO) should match the
subscription parameters specified in the X.25 link terminal definition.
The format of the X.25 logical channel (VC) terminal option word is as
follows:
OUT If set, then outgoing calls are allowed on this SVC. If
both the OUT and IN bits are set, this is a two-way
SVC.
RSET If set, then the application will confirm inbound VC
Resets using the zx25reset_conf() routine. If clear, then
the X.25 protocol driver will automatically send a Reset
Confirm packet when a VC Reset Request is received.
CNT If set, then all applications setup as receivers for this
VC ZLU will be notified through unsolicited status
messages when Call, Call Accept, Reset Request, Reset
Confirm, Clear Request, and Clear Confirm packets are
received. Note that the status message will also contain
the pertinent data from the X.25 level 3 protocol
packet. If the application needs to receive facility, call
user data, called and calling addresses, etc., then this
bit must be set. If this bit is clear, then the application
will not be notified.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Not Used (default to 0)
1
5
1
4
1
3
1
2
11 10 9 8 7 6 5 4 3 2 1 0
Not Used (0) O
ut
RSE
T
CN
T
AC
K
VC
T
I
N
CL
L
NL
L
DE
A
AP
D
INT
C
0