5 Allowed Translation Type (TT) Screen Configuration
Chapter 5, Allowed Translation Type (TT) Screen Configuration, contains the procedures necessary to configure allowed translation type screens.
Introduction
The allowed translation type (TT) screen is used to screen all SCCP messages which have the specified translation type value in the called party address. The gray shaded areas in Figure 5-4 shows the fields of the SS7 message that are checked by the TT screening function.
Gateway Screening Actions
If a match is not found, the message is discarded.
If a match is found, the nsfi is examined to determine the next step in the screening process. If the nsfi value is any value other than stop, the next screening reference (nsr) is identified and the screening process continues to the next screen identified by the nsfi and nsr parameter values.
nsfi is equal to stop, the screening process stops and the message is processed. If a gateway screening stop action set is specified with the screen, shown by the actname parameter value, the message is processed according to the gateway screening stop actions that are assigned to the gateway screening stop action set.
- If the
rdct(redirect) gateway screening stop action is specified,the message is diverted from the original destination and sent to another destination with the Database Transport Access feature, specified by global title translation, for further processing. - If the
cncfgateway screening stop action is specified, the PIP parameter in the incoming ISUP IAM message is converted to the GN parameter. The GN parameter in the incoming ISUP IAM message is converted to the PIP parameter. The message is then sent to the node specified by the DPC in the routing label in the message. For more information on the Calling Name Conversion Facility feature, see Calling Name Conversion Facility (CNCF) Configuration. - If the
tlnpgateway screening stop action is specified, ISUP IAMs that pass gateway screening are processed either by the ISUP NP with EPAP feature (if the ISUP NP with EPAP feature is enabled and turned on) or by the Triggerless LNP feature (if the Triggerless LNP feature is turned on). The ISUP NP with EPAP feature is discussed in more detail in G-Port User's Guide. The Triggerless LNP feature is discussed in more detail in ELAP Administration and LNP Feature Activation Guide. - If the
tinpgateway screening stop action is specified, ISUP IAMs that pass gateway screening are intercepted by the Triggerless ISUP based Number Portability (TINP) feature and converted to include the routing number (RN) if the call is to a ported number. The TINP feature is discussed in more detail in G-Port User's Guide. - If the
tif,tif2, ortif3gateway screening stop actions are specified, TIF processing is applied to the message. - If the
sccpgateway screening stop action is specified, MTP routed SCCP UDT/XUDT are forwarded to the service modules for further processing.
Allowed TT Screening Actions
Figure 5-1 through Figure 5-3 show the screening actions of the allowed TT screen.
Figure 5-1 Allowed TT Screening Actions - Sheet 1 of 3
Figure 5-2 Allowed TT Screening Actions - Sheet 2 of 3
Figure 5-3 Allowed TT Screening Actions - Sheet 3 of 3
Figure 5-4 Allowed Translation Type Screening Function
Adding an Allowed Translation Type Screen
This procedure is used to add an allowed translation
type (TT) screen to the database using the
ent-scr-tt command. The parameters
used by the
ent-scr-tt command are shown in the
Gateway Screening Attributes
section. The general rules that apply to configuring gateway screening entities
are shown in the
Gateway Screening Configuration
section.
The examples in this procedure are used to add the allowed TT screen data shown in Table 5-1 and based on the example configuration shown in Figure 2-5.
Table 5-1 Example Gateway Screening Allowed TT Configuration Table
| Screening Reference | TYPE | NSFI | NSR |
|---|---|---|---|
| gw16 | 250 | cdpa | gw18 |
The allowed TT screen can only reference an allowed CDPA
screen and the allowed CDPA screen being referenced must be in the database.
This can be verified using the
rtrv-scr-cdpa:all=yes command. If the
desired allowed CDPA screen is not in the database, perform one of these
procedures to add the required screen to the database or change an existing
screen in the database.
Specifying a Range of Values
A range of values can be specified for the
type parameter. The range of values
specified for the
type parameter cannot include any
values currently provisioned for the screen reference name.
For example, screening reference name
scr1 contains these entries:
SR TYPE NSFI NSR/ACT
scr1 110 STOP ------
scr1 125 STOP ------Another entry for screening reference
scr1 cannot contain a range of values
that would include the
type parameter values 110 or 125.
Figure 5-5 Add an Allowed Translation Type Screen - Sheet 1 of 3
Figure 5-6 Add an Allowed Translation Type Screen - Sheet 2 of 3
Figure 5-7 Add an Allowed Translation Type Screen - Sheet 3 of 3
Removing an Allowed Translation Type Screen
This procedure is used to remove an allowed translation
type (TT) screen from the database using the
dlt-scr-tt command. The parameters
used by the
dlt-scr-tt command are shown in the
Gateway Screening Attributes
section. The general rules that apply to configuring gateway screening entities
are shown in the
Gateway Screening Configuration
section.
The example in this procedure removes the allowed TT
screen
iec, with the translation type 016
from the database.
The allowed TT screen can be referenced by the Allowed
CGPA screen. Enter the
rtrv-scr-cgpa:nsfi=tt command to
verify that this screen does not reference the allowed TT screen being removed
from the database.
To change the NSFI of any of these screens, perform the Changing an Allowed Calling Party Address Screen procedure.
Figure 5-8 Remove an Allowed Translation Type Screen
Changing an Allowed Translation Type Screen
This procedure is used to change the attributes of an
allowed translation type (TT) screen in the database using the
chg-scr-tt command. The parameters
used by the
chg-scr-tt command are shown in the
Gateway Screening Attributes
section. The general rules that apply to configuring gateway screening entities
are shown in the
Gateway Screening Configuration
section.
The example in this procedure is used to change the
translation type 016 for the allowed CGPA screen
iec to 210 and change the NSFI to
stop.
The allowed TT screen can only reference an allowed CDPA
screen. This can be verified using the
rtrv-scr-cdpa:all=yes command. If the
desired allowed CDPA screen is not in the database, perform one of these
procedures to add the required screen to the database or change an existing
screen in the database.
Specifying a Range of Values
A range of values can be specified for the
type parameter. The range of values
specified for the
type parameter cannot include any
values currently provisioned for the screen reference name.
For example, screening reference name
scr1 contains these entries:
SR TYPE NSFI NSR/ACT
scr1 110 STOP ------
scr1 125 STOP ------Another entry for screening reference
scr1 cannot contain a range of values
that would include the
type parameter values 110 or 125.
Figure 5-9 Change an Allowed Translation Type Screen - Sheet 1 of 3
Figure 5-10 Change an Allowed Translation Type Screen - Sheet 2 of 3
Figure 5-11 Change an Allowed Translation Type Screen - Sheet 3 of 3