The DSR MAP-Diameter Interworking Function feature allows the DSR to support bi-directional interworking between Diameter and SS7-MAP messages. This functionality is carried out by two applications: DM-IWF and MD-IWF.
DM-IWF is a DSR application that runs on each DA-MP. It manages Diameter transactions received from the Diameter network via DRL and MAP transactions received from SS7-MPs.
MD-IWF is a TCAP application which runs on each SS7-MP. It manages MAP transactions received from the SS7 network (via TCAP) and Diameter transactions received from DA-MPs.
The MAP-Diameter Interworking assumes the following things regarding the relationship between the two applications.
- All MAP-Diameter message and parameter interworking is performed on the SS7-MP.
- DM-IWF and MD-IWF exchange Diameter messages using ComAgent. No SS7/MAP message are exchanged between DA-MPs and SS7-MPs.
- When a transaction is initiated by either a DM-IWF or MD-IWF instance, it creates a Transaction ID which is unique to the DM-IWF/MD-IWF instance which is initiating the inter-MP transaction. The Transaction ID is sent that correlates the messages/responses exchanged between DM-IWF and MD-IWF associated with a transaction. When DM-IWF or MD-IWF sends a response to the request, it echoes the transaction ID from the Request to allow the recipient to correlate the response with the request it had previously sent.
- DM-IWF and MD-IWF will use ComAgent's Enhanced Routed Service for load sharing Request messages to MD-IWFs and DM-IWFs respectively. ComAgent Enhanced Routed Service self learns about the topology changes and enables deployment of transparent, elastic and scalable solutions.
- In this document, any reference to DM-IWF Routed Service or MD-IWF Routed Service implies ComAgent's Enhanced Routed Service for internal message exchange. It also indicates that the growth/degrowth of SS7-MPs and DA-MPs is non-impacting to MD-IWF and DM-IWF application instances and ensures guaranteed delivery.
Note: DM-IWF Routed Service and MD-IWF Routed Service is displayed as "DMIWFSvc" and "MDIWFSvc" respectively on the ComAgent maintenance screens. Each DM-IWF instance acts as a service provider for the DM-IWF Routed Service and as a service user for the MD-IWF Routed Service, and vice versa.
Note: Service users and providers can now dynamically register against the Routed Service. Service Providers publish their own provider status. ComAgent Routed Service accounts for each registered service provider's status and congestion level when selecting service providers to distribute Requests.