While reviewing some API documentation on network programming I was alerted to the fact that TCP and UDP are not the only transport protocols in use (as defined by IETF). I did a little bit of reading on SCTP, or Streaming Control Transmission Protocol, which allows a multi-homed host to establish a stream or session with another host. The big picture scenario here is that a multi-homed host can establish a session that will allow it to use any number of it's interfaces throughout the communication, allowing for one or more of it's interfaces to fail. As long as one interface remains, the host can continue the communication.
More documentation can be found in the RFCs which describe it: