In this episode of the History of Networking, Raj Jain joins us to talk about his early work with TCP/IP, DECnet, Frame Relay, and congestion control mechanisms. He is the co-inventor of the DEC-bit scheme for congestion avoidance in computer networks which has been adapted for implementation in Frame Relay networks as forward explicit congestion notification (FECN), ATM Networks as Explicit Forward Congestion Indication (EFCI), and TCP/IP networks as Explicit Congestion Notification (ECN).