Is it necessary a Diameter node should have information of its possible peer even before getting CER message ?

Question

In one Diameter blog, I saw a statement in which mentioned, if a Diameter node receive CER from unknown peer it responds back to that peer with Result-Code AVP set to "DIAMETER_UNKNOWN_PEER".
Now my query, Does a Diameter node keep its potential peers information in advance ?

Answer 1

Yes the information is needed to establish a TCP connection. Other node should have prior info from where it has to receive a message. Also we know TLS is supported with DIAMETER so in that case also it will help

Comments

Thanks Peeyush for your input but my question is "Does the sever has information of client like  "Orgin-Host" or "Origin-Realm" in advance ?". For the transport connection  I agree TLS will be used. My question is more about Diameter level rather than transport level.

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Yes, server has the information about the client like its realm and hostname.

Answer 2

There are two methods how diameter peers can configured:

1. Diameter Peer entries are manually configured for peers.
2. Service aware peer discovery.

In first method, peers are configured manually so that they would know each others identity.

In the second method, a peer broadcast SVC enquiry to identify the peers and respective services supported by them. After getting information about the peers, diameter peer initiate usual CER flows.