The Diameter protocol involves transactions in the form of requests and answers exchanged between clients and servers. These clients and servers may be peers, that is, they may share a direct transport (e.g., Transmission Control Protocol (TCP) or Stream Control Transmission Protocol (SCTP)) connection, or the messages may traverse one or more intermediaries, known as Diameter Agents. Diameter nodes use Transport Layer Security (TLS), Datagram Transport Layer Security (DTLS), or IPsec to authenticate peers, and to provide confidentiality and integrity protection of traffic between peers. Nodes can make authorization decisions based on the peer identities authenticated at the transport layer.