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

Chapter 3 109
NetIPC Intrinsics
IPCRECVCN
return of the call user data (CUD) field from an X.25
packet. If call user data is present, but this option is
not supplied, the discarded
flag [25] is set. If the
buffer is not long enough to contain the data, the
data is truncated and the discarded flag is set.
• calling node address (code=141, length=8; 8-byte
array) (output). An output parameter that is used to
contain the address of the requestor.
For TCP, the first two bytes of the array contain the
remote socket’s port address and the next four types
contain the remote node’s internet protocol address.
The remaining bytes are unused.
For X.25 protocol access, the X.25 address of the
calling node is returned in this field. The format of
the record is equivalent to 16 nibbles (or BCD digits)
in which the first nibble is the address length
(ranging from 1 to 15), and the following 15 nibbles
contains the calling address. The calling node
address is not available if the call originated from a
PAD.
You can use READOPT to obtain the output of this
parameter.
• protocol flags (code=144, length4; 4-byte buffer)
(output). This option contains 32 bits of
protocol-specific flags. The following flags are
currently defined:
— Fast select (bit 7, output). (X.25 only.) If this flag
is set, the fast select facility has been used in the
connection request.
— Fast select restricted (bit 8, output). (X.25
only.) This flag only has meaning if the previous
flag was set. If this flag is set, the fast select
facility has been used in the connection request
with restriction on response. This means that if
the deferred flag was set, then the connection can
be rejected (only) by using IPCCONTROL (and up
to 128 bytes of CUD can be returned). If this flag
is not set, but the fast select (bit 7) was set, the
connection can be accepted or rejected by using
IPCCONTROL, and up to 128 bytes of CUD can be
returned.
— request from PAD (bit 14, output). (X.25 only.)
This flag indicates that the connection request is
coming from a PAD as opposed to a connection
coming from a host.