Global Title Translation

Overview

Global Title Translation (GTT) frees originating signaling points from the burden of having to know every potential destination to which they might have to route a message. A switch can originate an SS7 Signaling Connection Control Part (SCCP) query and address it to an STP along with a request to perform GTT. The receiving STP makes a determination of the intended address Destination Point Code (DPC) based on the digits and other Called Party Address parameters of the SCCP message.

GTT is an optional Ribbon STP feature that can be licensed to translate up to 500,000 search records.

An incoming message from the SS7 network is routed through the Message Transfer Part Level 3 (MTP3) and Signaling Connection Control part (SCCP) protocol stacks if the message is destined for a GTT registered PC. The SCCP examines the Called Party's Global Title (GT). If GT Routing is indicated, the SCCP queries the GTT for new routing information for the message.

The GTT application searches for matching GT components or fields of the Called Party and/or Calling Party Address. The most common GTT configuration is to translate on the Called Party Address.

Ribbon GTT supports multiple databases. Most customers use a unique database for each Network Appearance (NA). However, it is possible to have multiple databases within an NA. Each of these databases may register to the STP with a separate PC or with a unique Application ID.

The GTT PC List Record Network Appearance attribute introduced in this release allows a PC List to contain PCs from other networks for backup applications support and other routing flexibility. For detailed description about this feature, refer to Configuring Point Code Lists.

For information about configuring GTT, refer to Configuring the Global Title Translation.

Searchable Values

Searchable fields include the following:

• Digits: Search Digits [Global Title Address Information (GTAI)]

• Global Title Indicator (GTI): 4-bit field that identifies the presence and format of the GT

• Numbering Plan (NP): 4-bit field that identifies the digit format used in the GT
• Nature of Address Indicator (NAI): 7-bit field that identifies the nature of the digits in the GT
• Subsystem Numbering (SSN): 8-bit field that identifies the service to address GT-related special routing cases or MSU service interceptions
• Translation Type (TT): 8-bit field that identifies the GT-related network services

The Digits field uses a range of digits and can include a sub-string. For example, the NPA-NXX range can be used in this search field. In addition, more specific ranges contained within other ranges are also permitted. For example, NPA-NXX may coexist with 10-digit range searches. Searches performed on the GTT table entries return results with the best matching value. If the search is unsuccessful, the system's error handling component processes the message.

If the search is successful and the PC List is found, the message Called Party is translated according to the GT Modification attributes. All the fields of the SCCP party address parameter are modifiable. If applicable, the GT Modification also provides additional translations as found in the associated Command List. GTT uses the PC List to determine the new destination(s) of the resulting SCCP message.

GT Modification Attributes

GT Modification attributes include the following:

Destination Routing

The GTT creates a PC List destination parameter for the SCCP. The SCCP uses the lowest cost destination, also referred to as Lowest Cost Available Point Code, depending on availability, and then forwards the message.

When the Point Code List contains multiple PCs provisioned at the same cost, the application distributes the traffic between these PCs using Signaling Link Selector (SLS) or TCAP Transaction ID (TID).

Routing can also be performed based on the PC/SSN as per the RTI in the Called Party Address.

Batch Operations

To support large volumes of data entry and to avoid manual entry of deletion of records, the GTT supports Batch File operations such as addition and deletion of records from ASCII files. These ASCII files are simple comma separated value (CSV) files that can be generated by most databases and spreadsheet applications.

Advanced Global Title Translation

Operators are requesting to have more control on how messages are routed due to specific business arrangements. Advanced GTT satisfies this requirement by expanding the criteria by which these destinations are determined and, therefore, allows the operator to choose a destination based on the following criteria:

• Called Party Address Digits
  
  
• Called Party Parameters
  
  
  • Numbering Plan (NP)
    
    
  • Translation Type (TT)
    
    
  • Global Title Indicator (GTI)
    
    
  • Nature of Address Indicator (NAI)
    
    
  • Subsystem Number (SSN)
    
    
• Calling Party Address Digits
  
  
• Calling Party Parameters
  
  
  • NP
    
    
  • TT
    
    
  • GTI
    
    
  • NAI
    
    
  • SSN
     
• OPC within the MTP3 header