Transparent flow migration through splicing for multi-homed vehicular Internet gateways

We propose a technique, called FloMiS, by which a flow can be migrated from one network to another without requiring any changes to the endpoints (Internet-based servers or mobile clients). Our work is motivated by the needs of our vehicular Internet service, calledWiRover, through which we provide WiFi connectivity in public transit vehicles - city buses as well as long distance buses operating in and around Madison, WI - using multi-network gateways. In our vehicular environment, we have observed that each cellular path experiences stalls and failures resulting in outages to network traffic. To provide robust and uninterrupted experience for these flows, we implement the FloMiS mechanism in the gateways alone, through which the gateways re-initiate a request for the contents of the interrupted flow and splice them back to the original flow in a manner that is transparent to the mobile clients. FloMiS is designed to optimize the majority of network traffic, which our analysis (of about 6 million real user flows) indicates that FloMiS is capable migrating a flow in as little as two round trip times for more than 93% of the traffic volume. Clients left to their own mechanisms would typically recover after several minutes of disconnectivity.