Origin-Based SCCP Routing

The Origin-Based SCCP Routing feature provides additional options for routing SCCP messages. Without the Origin-Based SCCP Routing feature enabled, the routing of SCCP messages is based only on the called party address fields in the message. With the Origin-Based SCCP Routing feature enabled, SCCP messages can be routed based on the called party address (CdPA), the calling party address (CgPA), CgPA point code, CgPA subsystem number, or originating point code (OPC) fields in the message.

Origin-Based SCCP Routing provides three modes of global title translation:

• CdPA global title translation
• CgPA global title translation
• Advanced CdPA global title translation

The CgPA global title translation and Advanced CdPA global title translation modes are performed only if the Origin-Based SCCP Routing feature is enabled and turned on. The CdPA global title translation mode is performed whether or not the Origin-Based SCCP Routing feature is enabled and turned on.

The CdPA global title translation mode is based on the CdPA global title address, translation type, and global title indicator in the incoming message. If the global title indicator value in the message is 4, the CdPA numbering plan and nature of address indicator is also used in the CdPA global title translation mode.

The CgPA global title translation mode is based on this criteria.

• CgPA global title address, translation type, global title indicator, and subsystem number in the incoming message. If the global title indicator value in the message is 4, the CgPA numbering plan and nature of address indicator is also used in the CgPA global title translation mode.
• CgPA point code, translation type, global title indicator, and subsystem number in the incoming message. If the global title indicator value in the message is 4, the CgPA numbering plan and nature of address indicator is also used in the CgPA global title translation mode.

The Advanced CdPA global title translation mode is based on this criteria.

• The CdPA global title address
• The CgPA global title address, or CgPA point code, or Selector ID. If the Selector ID is used in the Advanced CdPA global title translation mode, the CgPA translation type and CgPA global title indicator are also used in the Advanced CdPA global title translation mode if the CgPA global title indicator value is not 0. If the CgPA GTI value is 0, then the CGPC GTT set name shown in the rtrv-sccpopts output is used to determine the global title translation performed on the message.
• The CgPA subsystem number
• The OPC from the MTP Routing Label
• The CdPA translation type
• The CdPA global title indicator
• If the global title indicator value in the message is 4, the CdPA numbering plan and nature of address indicator is also used in the Advanced CdPA global title translation mode and in the CgPA global title translation mode

GTT Mode Hierarchy

The GTT mode hierarchy determines the preference of GTT modes used by the global title translation process on an incoming message. The global title translation process starts with the first GTT mode of the GTT hierarchy. If the translation was found there, the global title translation process is stopped. If the translation was not found in this first GTT mode, the global title translation process tries to find a translation in the next GTT mode of the hierarchy. The GTT mode hierarchies are shown in the following list.

1. CdPA only
2. Advanced CdPA, CdPA
3. CgPA, Advanced CdPA, CdPA
4. Advanced CdPA, CgPA, CdPA
5. Advanced CdPA, CdPA, CgPA
6. CgPA, CdPA
7. CdPA, CgPA
8. CgPA only

For example, GTT hierarchy 3 (CgPA, Advanced CdPA, CdPA) is selected for the global title translation process. When an incoming message is processed, the CgPA global title translation information is searched first, starting with a search in GTT selector table for CgPA selectors. If no match is found, the advanced CdPA global title translation information is searched next, including a search in GTT selector for CdPA selectors. If no match is found, the CdPA global title translation information is searched. If a match is still not found, the message is handled as a failed GTT lookup and the appropriate action is taken. When a match is found, the global title translation process is stopped and the message is processed according to the global title translation routing data.

The GTT mode hierarchy can be configured on a system wide basis and on a per linkset basis. The system wide option is configured using the dfltgttmode parameter of the chg-sccpopts command and is used to define the default GTT mode hierarchy value for all linksets by default. Each linkset can be configured to use one of the GTT mode hierarchies using the gttmode parameter of either the ent-ls or chg-ls command. The linkset option overrides the system default GTT mode value for only that linkset. If the gttmode parameter is not specified for a specific linkset, the system default GTT mode hierarchy is assigned to the linkset.

CdPA GTT Mode

The GTT functionality in previous releases of the EAGLE is now the CdPA GTT mode. The CdPA translation type and global title indicator in the incoming messages are used to select the GTT table (GTT set) used to process the message. If the global title indicator value in the message is 4, the CdPA numbering plan and nature of address indicator are also used to select the GTT table used to process the message. Once the GTT table is selected, the CdPA global title address determines how the message is translated.

Advanced CdPA GTT Mode

The Advanced CdPA GTT mode provides greater flexibility to route SCCP messages. CdPA GTA translation, along with either one or both of the following types of translations:

• CgPA GTA or CgPA point code translation identified by a pre-provisioned GTT set in the CdPA translation or by a search in GTT selector table using the SELID value from the CdPA translation along with other CgPA selectors, with or without a subsequent CgPA subsystem number translation. The CgPA GTA, CgPA point code, and SELID translations are mutually exclusive.
• OPC translation, with or without a subsequent CgPA subsystem number translation.

The translations are executed in a predefined order as displayed in the previous list and cannot be changed.

These additional translations can be applied on top of the mandatory CdPA GTA translation:

• CgPA GTA translation only
• CgPA GTA and CgPA subsystem number translation
• CgPA point code translation only
• CgPA point code and CgPA subsystem number translation
• Translation based on the SELID
• CgPA GTA and OPC translation
• CgPA GTA, OPC, and CgPA subsystem number translation
• CgPA point code and OPC translation
• CgPA point code, OPC, and CgPA subsystem number translation
• SELID and OPC translation
• SELID, OPC, and CgPA subsystem number translation
• OPC translation only
• OPC and CgPA subsystem number translation

  Note:

  The CdPA global title indicator is always validated before GTT starts processing SCCP messages. The CgPA global title indicator is not validated, which means, that when a subsequent lookup in the Advanced CdPA GTT mode is based on the SELID value, the attempt to find a CgPA GTT set in GTT selector table may fail because of an invalid or unsupported CgPA global title indicator in the incoming message.

CgPA GTT Mode

The CgPA GTT mode offers two options for translating and routing SCCP messages, the CgPA GTA translation with or without a subsequent CgPA subsystem number translation, or the CgPA point code translation with or without a subsequent CgPA subsystem number translation search. The CgPA GTA and CgPA point code are mutually exclusive.

When CgPA global title translation performs a lookup in the GTT selector table, two new selectors, the CgPA subsystem number and SELID, are always members of the selectors. If CgPA global title translation performs a lookup in the GTT selector table as a part of Advanced CdPA global title translation because the SELID is specified in the CdPA entry, the only GTT selector match that will be found is the entry with this particular SELID. If CgPA global title translation performs a lookup in the GTT selector table in the CgPA GTT mode, the only GTT selector match that will be found is the entry with the SELID value equal to NONE.

The CgPA subsystem number for GTT selector lookups is used differently. If the MSU contains a CgPA subsystem number, then the first and the best match that will be found is the entry with this particular CgPA subsystem number. If the MSU does not have a CgPA subsystem number or if the match for a specific CgPA subsystem number was not found, CgPA global title translation attempts to find a GTT selector entry with the CgPA subsystem number equal to ANY, along with the rest of the selectors.

Note:

The CdPA global title indicator is always validated before global title translation starts processing SCCP messages, even when the GTT mode is CgPA and the CdPA data is not used by global title translation. The CgPA global title indicator is not validated, which means, that the attempt to find a CgPA GTT set in the GTT selector table may fail because of an invalid or unsupported CgPA global title indicator in the incoming MSU.

Interaction with the Advanced GT Modification Feature

Any kind of SCCP translation (CdPA GTA, CgPA GTA, CgPA PC, OPC, SSN) can be provisioned with Advanced GT Modification data. This Advanced GT Modification data will be applied to a CdPA GTA if it exists, or to a CgPA GTA if it exists. If the CdPA or CgPA part of the message under translation does not contain a GTA, the Advanced GT Modification data from this translation will be ignored. The CdPA GTA is modified only if it is provisioned in a CdPA GTA set. If the CdPA GTA is provisioned in a CdPA GTA set, the CdPA GTA is not modified. The only exception to this is discussed in the Interaction with the ANSI/ITU SCCP Conversion Feature section.

Interaction with the ANSI/ITU SCCP Conversion Feature

When the ANSI/ITU SCCP Conversion feature attempts to perform a global title translation lookup on the CgPA in the message, the GTT hierarchy of the incoming linkset is ignored. The EAGLE performs a CdPA only global title translation using the CgPA data. The selectors from the CgPA part are used to find a CdPA GTA set in the GTT selector table, and the CgPA global title address is used to find a translation in the CdPA GTA set.

Interaction with MPS-based Features

The messages from the MPS-based services are processed by global title translation using the GTT mode assigned to the linkset on which these messages arrived at the EAGLE.

GTT for EAGLE-generated MSUs

UDTS messages and responses generated by the EAGLE and the required global title translation are processed in the CdPA GTT mode only.

Wildcard Provisioning for the OPC and CgPA Point Code

Origin-Based SCCP Routing allows for the use of wildcards (asterisks) as values for an ANSI OPC or ANSI CgPA point code.

For example, the point code value 12-*-* indicates that any ANSI point code containing with the network indicator value 12, regardless of the network cluster and network cluster member values in the ANSI point code, is considered a match.

The point code value 12-34-* indicates that any ANSI point code containing the network indicator value 12 and the network cluster value 34, regardless of the network cluster member value in the ANSI point code, is considered a match.

When searches for ANSI point codes are performed, the search order tries to find the best possible match. For example, the incoming message contains the ANSI point code 12-24-25. The search mechanism first searches for the point code value 12-34-25 in the global title translation tables. If that search fails, the search mechanism searches for the point code value 12-34-* in the global title translation tables. If that search fails, the search mechanism searches for the point code value 12-*-* in the global title translation tables.

An ANSI OPC or ANSI CgPA point code value containing all asterisks is not allowed. Asterisks cannot be used for ITU point codes.

The Cluster Routing and Management Diversity or Network Routing features do not have to turned on to use asterisks for the ANSI OPC or ANSI CgPA point code value.

Provisioning the Origin-Based SCCP Routing Feature

To provision the Origin-Based SCCP Routing feature, perform these steps.

1. Turn the GTT and EGTT features on using the chg-feat command. Add the required E5-SM8G-B or SLIC cards to the database using the ent-card command. Enter the rtrv-card command to verify the cards that are provisioned in the database. Perform the Adding a Service Module procedure.
2. Enable the Origin-Based SCCP Routing feature using the enable-ctrl-feat command. Enter the rtrv-ctrl-feat command to verify the status of the Origin-Based SCCP Routing feature. Perform the Activating the Origin-Based SCCP Routing Feature procedure.

   Note:

   The Origin-Based SCCP Routing feature can be turned on in this step using thechg-ctrl-feat command. If the Origin-Based SCCP Routing feature is not turned on in this step, provisioning for the Origin-Based SCCP Routing feature can still be performed except for provisioning the Origin-Based SCCP Routing GTT mode hierarchy for linksets and system wide default GTT mode option with one of the Origin-Based SCCP Routing GTT mode hierarchies. The Origin-Based SCCP Routing GTT mode hierarchy for linksets and system wide default GTT mode option with one of the Origin-Based SCCP Routing GTT mode hierarchies can be provisioned only when the Origin-Based SCCP Routing feature is enabled and turned on.. When the provisioning is completed, the Origin-Based SCCP Routing feature can be turned on. The Origin-Based SCCP Routing feature will not work until the feature is turned on either in this step or step 8.
3. Change the system wide default GTT mode, if desired, using the chg-sccpopts command. Enter the rtrv-sccpopts command to verify the system-wide default GTT mode value. Perform the Changing the Default GTT Mode Options procedure.
4. Provision the required destination point codes, linksets, signaling links, and routes, by performing these procedures in Database Administration - SS7 User's Guide.
   • Destination Point Codes – Adding a Destination Point Code procedure in Database Administration - SS7 User's Guide. Enter the rtrv-dstn command to verify the destination point codes that are provisioned in the database.
   • Linksets – Perform one of these procedures depending on the type of linkset. Enter the rtrv-ls command to verify the linksets that are provisioned in the database.
     • SS7 Linkset – Adding an SS7 Linkset procedure in the Database Administration - SS7 User's Guide
     • These procedures in Database Administration - IP7 User's Guide
       • IP Gateway Linkset – Configuring an IPGWx Linkset
       • IPSG M2PA Linkset – Adding an IPSG M2PA Linkset
       • IPSG M3UA Linkset – Adding an IPSG M3UA Linkset

       Note:

       If you wish to use a GTT mode hierarchy for the linkset other than the system default GTT mode hierarchy, specify the gttmode parameter when provisioning the linkset. The gttmodeparameter values for the Origin-Based SCCP Routing GTT hierarchy can be specified only when the Origin-Based SCCP Routing feature is enabled and turned on.
   • Signaling Links – Perform one of these procedures depending on the type of signaling link. Enter the rtrv-slk command to verify the signaling links that are provisioned in the database.
     • A low-speed SS7 signaling link – Adding an SS7 Signaling Link procedure in Database Administration – SS7 User's Guide
     • An E1 signaling link – Adding an E1 Signaling Link procedure in Database Administration – SS7 User's Guide
     • A T1 signaling link – Adding a T1 Signaling Link procedure in Database Administration – SS7 User's Guide
     • An ATM signaling link – Adding an ATM High-Speed Signaling Link procedure in Database Administration – SS7 User's Guide
     • These procedures in Database Administration – IP7 User's Guide
       • IPLIMx Signaling Link – Adding an IPLIMx Signaling Link
       • IPGWx Signaling Link – Adding an IPGWx Signaling Link
       • IPSG M2PA Signaling Link – Adding an IPSG M2PA Signaling Link
       • IPSG M3UA Signaling Link – Adding an IPSG M3UA Signaling Link
   • Routes – Perform one of these procedures in Database Administration - SS7 User's Guide depending on the type of route. Enter the rtrv-rte command to verify the routes that are provisioned in the database.
     • A route containing an SS7 DPC – Adding a Route Containing an SS7 DPC procedure
     • A route containing a cluster point code – Adding a Route Containing a Cluster Point Code procedure
     • A route containing an IPGWx Linkset – Adding a Route Containing an IPGWx Linkset procedure
5. Provision the required GTT sets using the ent-gttset command. Enter the rtrv-gttset command to verify the GTT sets that are provisioned in the database. Perform the Adding a GTT Set procedure.
6. Provision the required GTT translations using the ent-gta command. Enter the rtrv-gta command to verify the GTT translations that are provisioned in the database. Perform the Adding Global Title Address Information procedure.

   Note:

   The command line on the terminal can contain up to 150 characters. If the parameters and values specified with theent-gta command are too long to fit on theent-gta command line, perform thechg-gta command to complete adding the GTA entry. If the parameters and values specified with thechg-gta command are too long to fit on thechg-gta command line, perform thechg-gta command as many times as necessary to complete the GTA entry.
7. Provision the required GTT selectors using the ent-gttsel command. Enter the rtrv-gttsel command to verify the GTT selectors that are provisioned in the database. Perform the Adding a GTT Selector procedure.

   Note:

   Performing this step is not required depending on how the GTT sets in Step 5 and the GTA entries in Step 6 are configured.
8. Turn the Origin-Based SCCP Routing feature on using the chg-ctrl-feat command. Perform the Activating the Origin-Based SCCP Routing Feature procedure.

Note:

If the required database entity is shown in the output of the retrieve command for that database entity, the procedure for provisioning the database entity does not need to be performed.