1. Feature Guide
  2. DSR Features and Functions
  3. Routing and Transaction Related Parameters in the DSR
  4. Diameter Peer Discovery

2.6.10 Diameter Peer Discovery

The base Diameter protocol specification RFC6733 mandates that both dynamic Diameter agent discovery and manual configuration mechanisms be supported by all Diameter implementations; and either or both may be used in the network deployment.

From the DSR signaling point of view there are three basic use-cases for dynamic Diameter peer discovery.

  • initiator mode: DSR discovering the last-hop Diameter peers.
  • initiator+responder mode: DSR discovering Diameter (Edge) Agent for further handling of a Diameter operation. It is combination of the above 2 uses cases between two end-points.

The DSR supports the above listed deployment use-cases. The support for Dynamic Peer Discovery provides:

  • the capability to configure realms that are dynamically discovered using RFC 6733 extended NAPTR methods.
  • For a DNS Client Application instance that performs dynamic discovery.
  • OAM functions that update/create the managed objects that are used for Diameter signaling.
  • The ability to accept connections from configured realms.

Figure 2-13 Dynamic Diameter Peer Discovery: Example


Dynamic Diameter Peer Discovery: Example

In the above example for ‘initiator’ mode, each DSR node does the following:

  • Monitors configuration changes.
  • Creates tags required for Diameter extended NAPTR (S-NAPTR) query.
  • Invokes DNS Client Application Interface for query resolution towards configured DNS Servers.
  • Provides DNS Client Application Interface, processes the DNS responses and resolves NAPTR, SRV, A, AAAA lookups
  • Performs target server resolution mapping to Diameter peer attributes for specified realm.
  • Invokes OAM interface to update discovered Diameter peer attributes in DSR configuration managed objects.
  • Replicates DSR configuration managed objects to DA-MPs. The signaling functions become aware of the required peer attributes and initiates connection establishment and Diameter capabilities exchange.

In the above example for ‘initiator+responder’ mode, ‘Initiator+responder’ mode for peer discovery is possible using one ‘initiator+responder’ connection.