CowboyRobot writes: The Internet relies heavily on two protocols. In the network layer, IP (Internet Protocol) provides an unreliable datagram service and ensures that any host can exchange packets with any other host. Since its creation in the 1970s, IP has seen the addition of several features, including multicast, IPsec (IP security), and QoS (quality of service). The latest revision, IPv6 (IP version 6), supports 16-byte addresses. The second major protocol is TCP (Transmission Control Protocol), which operates in the transport layer and provides a reliable bytestream service on top of IP. TCP has evolved continuously since the first experiments in research networks. MPTCP is a major extension to TCP. By decoupling TCP from IP, TCP is at last able to support multihomed hosts. With the growing importance of wireless networks, multihoming is becoming the norm instead of the exception. Smartphones and data centers are the first use cases where MPTCP can provide benefits.