The IEC 60870-5-104 protocol standard is officially named “Network access for IEC 60870-5-101 using standard transport profiles”. The protocol is based on existing IEC 61870-5-101 application and transport layer profiles while also including a network link layer specification for Ethernet/TCP communication. Sometimes IEC 60870-5-104 is referred to as IEC 60870-5-101 over Ethernet/TCP.