Use of the Character “c” for the NI, NC, NCM, ZONE, AREA, ID, NPC, MSA, SSA, and SP Parameters
The character
“
c
”
is used in the
blocked OPC or DPC screens (for parameters
ni
,
nc
,
ncm
,
zone
,
area
,
id
,
npc
,
msa
,
ssa
, and
sp
) to allow the screening process to
continue for messages with point codes that do not match any point codes in the
blocked OPC or DPC screens. The character
“
c
”
is used this way.
When screening for a blocked OPC or DPC and the point code being screened does
not match any of the point codes in the blocked OPC or DPC screens, the message
is not rejected and the screening process continues. To allow the screening
process to continue, the blocked OPC and blocked DPC screens must have at least
one entry consisting of a screening reference, a point code, a next screening
function identifier, and a next screening reference. The point code is in the
form of
ni=c
,
nc
=c
,
ncm
=c
(for ANSI point codes),
zone=c
,
area=c
,
id=c
(for ITU international point
codes),
npc=c
(for 14-bit ITU national point codes),
and
msa=c
,
ssa=c
,
sp=c
(for 24-bit ITU national point
codes). When the character
“
c
”
is specified, the
next screening function identifier and next screening reference must be
specified, unless the next screening function identifier is stop (nsfi=stop
). Then the next screening reference cannot be
specified.
When the point code does not match any entries in the
blocked OPC or DPC screens, the screening process is directed to the screening
reference with the point code
c
-c
-c
or
npc=c
. The next screening function
identifier and next screening reference in this entry are examined to determine
the next step in the screening process.
When a blocked OPC or DPC screen is created, the first
entry for the
ni
-nc
-ncm
,
zone-area-id
, or
msa-ssa-sp
must be
c
-c
-c
, or the
npc
must “c
.” Subsequent entries can be specific point codes.
If the character
“
c
”
is specified for
any parameters
ni
,
nc
,
ncm
,
zone
,
area
,
id
,
msa
,
ssa
, or
sp
, it must be specified for all three
parameters. No other values can be used. For example, a point code
c
-c
-255 is not allowed. The point code must be
c
-c
-c
. The “*
” (asterisk) value cannot be used with the character
“
c
”
(for example, a
point code
c
-c
-*
is not allowed).
ANSI, ITU international, or 24-bit ITU national point
codes using the value “c
” can be entered by
specifying only the
ni=c
parameter (for ANSI point codes),
zone=c
parameter (for ITU
international point codes), or
msa=c
parameter (for 24-bit ITU
national point codes), and the
nc
,
ncm
,
area
,
id
,
ssa
, and
sp
parameters can be omitted.
The
pcst
and
npcst
parameters, for specifying the
ITU international and 14-bit ITU national spare point codes, cannot be used
with point codes containing the character “c
”.