2.13.1 Range Based Address Resolution (RBAR)

Range based address resolution is a DSR enhanced routing application which allows the user to route Diameter end-to-end transactions based on Application ID, Command Code, “Routing Entity” Type, and Routing Entity address ranges. A Routing Entity can be a User Identity (IMSI, MSISDN, External Identifier, IMPI or IMPU) or an IP Address associated with the User Equipment (IPv4 or IPv6-prefix address). Charging characteristics are supported for the “Routing Entity” Type as well. Routing resolves to a “Destination” which can be configured with any combination of a Realm and FQDN (Realm-only, FQDN-only, or Realm and FQDN). Prefix filtering is provided with the creation of a user-configurable table filled with invalid IMSI MCC values that is used during IMSI validation prior to using the IMSI value for address resolution. The address resolution application checks against ranges of MCC values which are then used to invalidate an IMSI. The RBAR supports third (tertiary) routing entity search in the priority list for performing Destination lookups for a given application-id and command code. That is, customers can use up to 3 routing entities to perform address Resolution, for e.g. IMSI, MSISDN and External-Identifier in the preferred order of priority.

The RBAR application routes all messages as a Diameter Proxy Agent. Each Routing Entity supports up to two prioritized AVPs that are searched for in the ingress Diameter message resolving to configure Destination node. When a message successfully resolves to a Destination, RBAR replaces the Destination-Host and possibly Destination-Realm AVP in the ingress message, with the corresponding values assigned to the resolved Destination, and forwards the message to the DSR Relay Agent for egress routing into the network. A GUI is provided allowing the operator to provision MCC-MNC combinations of all network operators in the world which includes the country and network name. A list of all the well-known MCC-MNC combinations are pre-populated at installation time but these can be modified/deleted at a later time.