Address Translation

Address Translation is the process by which Diameter routing information is mapped to an SS7 network (for Diameter originated requests) or SS7 signaling data is mapped to a Diameter network (for MAP originated requests).

Diameter requests are mapped to the SS7 network by using the Destination-Host and Destination-Realm AVPs and a series of table look ups to derive an MTP3 layer OPC and DPC as well as the SCCP Called Party Address. The Destination-Host AVP is optional. If the Destination-Host is absent, the IMSI value from the User-Name AVP is used instead. The Origin-Host and Origin-Realm for the Diameter answer are derived from the SCCP Calling Party Address.

Figure 3-1 Diameter to MAP Requests

MAP requests are translated into the Diameter network by using the SCCP Calling Party Address to derive an Origin-Host and Origin-Realm AVP and using the SCCP Called Party Address to derive a Destination-Host and Destination-Realm AVP for the outgoing Diameter request. Address data from the MAP request is stored away for the life of the MAP Dialogue and used for populating the address information in the MAP response.

Figure 3-2 MAP to Diameter Requests