The present disclosure is directed generally to systems and methods for Diameter load balancing. In some embodiments, an intermediary device may receive a diameter connection request from a client that includes a CER. The intermediary device may initiate a connection with a server of a plurality of servers and place the server protocol control block in a reuse pool. Responsive to opening the connection with the server, the intermediary device may forward the received CER. The intermediary device may then receive a CEA message from the server and establish an AVP-based persistent connection. The intermediary device may modify the received CEA message, and then forward the message to the client. When the intermediary device receives a diameter message from a client, the intermediary device may match an AVP of the message with an AVP associated with a persistent server connection, and forward the diameter message to the corresponding server.