Technical Summary
Multipath TCP provides the ability to simultaneously use multiple paths between peers. This document presents a set of extensions to traditional TCP to support multipath operation. The protocol offers the same type of service to applications as TCP (i.e., reliable bytestream), and it provides the components necessary to establish and use multiple TCP flows across potentially disjoint paths. This document specifies v1 of Multipath TCP, obsoleting v0 as specified in RFC6824, through clarifications and modifications primarily driven by deployment experience.
Working Group Summary
After creating the Experimental RFC6824, the primary goal of the MPTCP working group has been to create a bis version of the protocol document on the Standards track, incorporating experience from (for example) implementations, interoperability events, experiments, usage scenarios, protocol corner cases, and feedback from TCPM. This process led to several changes, a couple of which make RFC6824bis incompatible with RFC6824. Hence this document obsoletes RFC6824. There is WG agreement to move ahead with publishing the document.
Document Quality
This document has been reviewed by various people. There is one (non-public) implementation and other implementers of RFC6824 have indicated that they will implement against the new RFC. The original MPTCP spec has been widely implemented and deployed and the Linux implementation is publicly available. The bis document has been implemented in Linux, but permission to release this code has not been forthcoming. The WG is OK with publishing the RFC at this stage rather than waiting further, and vendors /implementers have indicated that they will implement against the new RFC.
Personnel
Philip Eardley is the Document Shepherd and Mirja Kuehlewind is the Responsible Area Director