Multipath Transport Challenges and Solutions

Multipath transport is a promising new paradigm that enables the concurrent use of different paths and resource pooling of their capacity. Ongoing research and standardization activities extend the Transmission Control Protocol (TCP) towards a Multipath TCP solution. The objective of the MPTCP protocol [1] by the IETF Multipath TCP is to aggregate multiple subflows between two endpoints into a session that can be accessed by an application like a TCP connection. Promising use cases include mobile devices with multiple interfaces or bandwidth aggregation inside data centers. This contribution analyzes the capacity sharing implications of multipath transport. We analyze the resulting challenges and present selected solutions. As an alternative to MPTCP we developed Multi-Connection TCP (MCTCP) [2][3]. We will present our solutions for some of the multipath transport challenges and compare it to existing ones. Finally, we will discuss remaining open capacity sharing issues.