MDTCP: towards a practical multipath transport protocol for telco cloud datacenters

The next-generation networks (5G) aims to support services that demand strict requirements such as low-latency, high throughput, and high availability. Telecom operators have adopted Network Functions Virtualization (NFV) to virtualize the network functions and deploy at distributed cloud datacenters. Deploying virtual network functions (VNFs) close to the end-user can reduce Internet latency. However, network congestion in telco cloud datacenters can result in increased latency, low network utilization and a drop of throughput. The existing protocols are not capable of utilizing the multiple paths offered by datacenter topologies e.g., DCTCP; require a major architectural change and face deployment challenges e.g., NDP; or increase flow completion times of short flows e.g., MPTCP. To address this, we propose a multipath transport for telco cloud datacenters called coupled multipath datacenter TCP, MDTCP. MDTCP evolves MPTCP subflows to employ ECN signals to react to congestion before queue overflow, offering both reduced latency and higher network utilization. The evaluation of MDTCP with simulated traffic indicates comparable or lower flow completion times compared with DCTCP and NDP for most of the studied traffic scenarios. The simulation results imply that MDTCP could give better throughput for telco traffic and at the same time be as fair as MPTCP in datacenters.