A DiaPeerDef clause defines describes and defines a Diameter peer this Radiator instance can be connected to. A Diameter connection can be initiated by Radiator or by the peer.

A minimal Radiator configuration requires one DiaPeerDef clause in addition to any AuthBy DiaPCRF, DiaPCEF, DiaRelay or other Diameter based AuthBys. When there is no ServerDIAMETERTelco clause, the DiaPeerDef clauses must be configured with the Initiator flag to connect to the Diameter peers.

A ServerDIAMETERTelco clause allows accepting incoming Diameter connections. When a ServerDIAMETERTelco is configured, Radiator will act as a Diameter responder. The settings for the connecting peers are looked up from DiaPeerDef clauses. The clauses are matched against the incoming CER (Capabilities Exchange Request) from the peer.

If a ServerDIAMETERTelco clause is configured but there are no DiaPeerDef clauses, the incoming CER messages are rejected by Radiator. A DiaPeerDef is required to form a successful CEA (Capabilities Exchange Answer) back to the peer.

Here is an example of configuring DiaPeerDef clauses. The first clause defines a Diameter peer that Radiator connects to. The connection is made to the IP address and port configured within the clause. An IP address and port are only needed when Initiator flag parameter is set.

The second DiaPeerDef clause defines a peer that must initiate a connection. When a Diameter peer connects to Radiator, the transport layer responder parameters, such as use of TLS, are defined within a <ServerDIAMETERTelco> clause. When the transport layer is successfully set up, the peer sends a Diameter Capabilities-Exchange-Request (CER). If the CER has Origin-Host with value epdg.epc.mnc001.mcc001.3gppnetwork.org , it matches the first DiaPeerDef and defines how Radiator responds to the CER.

# Our DRA requires that Radiator initiates the connection
<DiaPeerDef Origin-Host=dra.mnc001.mcc001.3gppnetwork.org>
    Identifier example-dra

    SupportedVendorIds 3GPP
    AuthApplicationIds 3GPP SWx, 3GPP SWm, 3GPP S6b

    ProductName Radiator 3GPP AAA Server

    Peer 172.16.172.80
    Port 3868
    Initiator

    OriginHost radiator-3gpp.aaa.mnc001.mcc001.3gppnetwork.org
    OriginRealm aaa.mnc001.mcc001.3gppnetwork.org
</DiaPeerDef>

# Definition of direct peering our ePDG initiates
<DiaPeerDef Origin-Host=epdg.epc.mnc001.mcc001.3gppnetwork.org>
    Identifier example-epdg

    SupportedVendorIds 3GPP
    AuthApplicationIds 3GPP SWm

    ProductName Radiator 3GPP AAA Server

    OriginHost radiator-3gpp.aaa.mnc001.mcc001.3gppnetwork.org
    OriginRealm aaa.mnc001.mcc001.3gppnetwork.org
</DiaPeerDef>

# Listen to incoming Diameter connections
<ServerDIAMETERTelco>
    Identifier diameter-server

    Port 3880
    # TLS and other settings
</ServerDIAMETERTelco>