Dr. Jain obtained a Ph.D. in Applied Mathematics (Computer Science) from Harvard University, Cambridge, Massachusetts in 1978, an M.E. in Automation from Indian Institute of Science Bangalore, India in 1974, and a B.E. in Electrical Engineering from Awdhesh Pratap Singh University, Rewa, Madhya Pradesh, India in 1972.

Until 2005 he was the Chief Technology Officer and Co-Founder of Nayna Networks, Inc. – a next generation telecommunications systems company in San Jose, CA. Prior to that he was a professor of Computer and Information Sciences at the Ohio State University in Columbus, Ohio and a Senior Consulting Engineer at Digital Equipment Corporation in Littleton, Massachusetts. He was also a visiting scientist at Massachusetts Institute of Technology in 1983, 1985, and 1987. He has been a professor at Washington University in St. Louis, Missouri since 2005.

Dr. Jain is the co-inventor of the DECbit scheme for congestion avoidance in computer networks^[1] 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).

He is also the co-inventor of the Additive Increase Multiplicative Decrease (AIMD) principle used for traffic management in computer networks and Jain's fairness index.^[2][3]

His work on timeout based congestion control influenced the design of the slow start algorithm in TCP/IP networks.^{[4] [5]}

He is author of four books. His second book The Art of Computer Systems Performance Analysis published by Wiley Interscience won the 1991 Best Advanced How-to Book, Systems award from Computer Press Association.^[6]