 Now that we understand the agents the peers the client server relationship the message net let's now look at What interesting? Process takes place in the form of an algorithm using interesting Lookup tables, which are used in diameter protocol so the Routing of diameter messages is actually well defined in the diameter standard document The information which is used for Consulting in the routing table is on the basis of the application ID That is definitely going to be diameter in this case and then the destination host application value pair it actually means that the depending upon the Source destination and other preferences Lookup will be made and that particular agent will be consulted and appropriate diameter server would be contacted So there are essentially two kinds of tables the first one is known as the peer table it maintains the identity of each peer and Keeps the updated list of all its neighbors of that peer Which is connected to this particular peer The information about the peers Available on this particular table is the current state of the peer whether it is up or down Or if it is not functioning at the moment Then is the peer information statically Provided in the table or it has it is dynamically being updated using some Watchdog mechanism then these peer entities are actually a time bound. So Is the peer Discovery going to take place dynamically and in that case cashier-based soft timer mechanism can be implemented and What is going to be the transport mechanism and if it is going to incorporate security Between two peers so this kind of peer table is important to discover the relationship of a peer with its neighbors Then we have the routing table which is used for the message to travel from the client to the server This is similar to the lookup Table which is maintained in IP routers So the real entries are actually the ones which are compared against the destination application value pair So the first thing is actually the real name that is What domain from which the request is coming from and where it is going to do it is primarily a key which is maintained between the Sender and destination as the primary key. It is the most important thing Then the next important thing is which application is being used again This is going to be consulted after the real name has been verified that is if the domains actually are discovered then the Application ID or the diameter protocol is verified Then what action has to be taken if it is going to be a local action or it is going to be a redirection action and Then which server is eventually going to be contacted the server identifier as the particular IP address or the URL or The fully qualified domain name. So with all this information, let's look at the overall routing algorithm which takes place If the destination host APV is Equal to the local identity It means this is a local phenomenon and it does not need to be sent to or another domain Or if it is peer entity then this has to be sent from one relay agent to the other or one Proxy agent to the relay agent or vice versa or if it is not working It means that it's not a local phenomenon and there's no peer to which it can be forwarded So in that case the message is delivered with an error code back to the sender