LTTP: An LT-Code Based Transport Protocol for Many-to-One Communication in Data Centers

TCP has been widely adopted in current data centers to ensure reliable data delivery. However, recently TCP Incast was found to occur in many-to-one communications with barrier-synchronized requirement, where the TCP goodput drops dramatically. Previous solutions to TCP Incast either require updating the OS/hardware to support fine-grained timers, or smartly control utilization of the switch buffer to reduce the probability of buffer overflow and packet loss. In this paper we explore a different approach to support many-to-one communication in data center networks, which we call LTTP (LT-code based Transport Protocol). LTTP improves LT (Luby Transform) code to achieve reliable UDP-based transmission by exploiting data redundancy, and employs TFRC (TCP Friendly Rate Control) to adjust the traffic sending rates at servers. NS-2 based simulation shows that the goodput of LTTP never degrades with the increase of the number of servers in many-to-one communications, and LTTP significantly outperforms DCTCP when the number of servers is large. Simulation results also demonstrate that LTTP flows can fairly share bandwidth with TCP flows.