Huston: Multipath TCP
For many scenarios there is little value in being able to use multiple addresses. The conventional behavior is where each new session is directed to a particular interface, and the session is given an outbound address as determined by local policies. However, when we start to consider applications where the binding of location and identity is more fluid, and where network connections are transient, and the cost and capacity of connections differ, as is often the case in todays mobile cellular radio services and in WiFi roaming services, then having a session that has a certain amount of agility to switch across networks can be a significant factor." (See also: LWN's look at the Linux multipath TCP implementation from 2013).