Title: Fast failover of multicast sessions in software-defined networks,
Abstract: With the rapid growth of services that stream to groups of users comes an
increased importance of and demand for reliable multicast. In this paper, we
turn to software-defined networking and develop a novel general-purpose
multi-failure protection algorithm to provide quick failure recovery, via Fast
Failover (FF) groups, for dynamic multicast groups. This extends previous
research, which either could not realize fast failover, worked only for single
link failures, or was only applicable to static multicast groups. However,
while FF is know to be fast, it requires pre-installing back-up rules. These
additional memory requirements, which in a multicast setting are even more
pronounced than for unicast, are often mentioned as a big disadvantage of using
FF.
We develop an OpenFlow application for resilient multicast, with which we
study FF resource usage, in an attempt to better understand the trade-off
between recovery time and resource usage. Our tests on a realistic network
suggest that using FF groups can reduce the recovery time of the network
significantly compared to other methods, especially when the latency between
the controller and the switches is relatively large.