Communication between Neighboring Peers

This chapter describes in detail the principles of both transport and Diameter‐level connectivity between two adjacent Diameter nodes, known as peers. It covers how the peers discover each other, how the peers connect and maintain connections, and how transport failures are handled. There are two types of peer discovery: static discovery, in which connection information for adjacent peers is configured into the Diameter node, and dynamic discovery, in which a Diameter node uses Domain Name System (DNS) to find its adjacent peers. Each Diameter node has a DiameterIdentity, which is a fully qualified domain name. The chapter also covers advanced transport topics such as multi‐homed connections, head‐of‐line blocking, and multiple connection instances. It provides an overview of how Diameter uses DNS. Since Diameter is a peer‐to‐peer protocol where either end of the communication can be a server or a client or both, either end can initiate peer connections.