Augmenting flows for the consistent migration of multi-commodity single-destination flows in SDNs

Updating network flows in a real-world setting is a nascent research area, especially with the recent rise of Software Defined Networks. While augmenting s-t flows of a single commodity is a well-understood concept, we study updating flows in a multi-commodity setting: Given a directed network with flows of different commodities, how can the capacity of some commodities be increased, without reducing capacities of other commodities, when moving flows in the network in an orchestrated order? To this extent, we show how the notion of augmenting flows can be efficiently extended to multiple commodities for applications with a single logical destination. We also show that our methods induce stronger consistency settings than previous work. Lastly, we prove the consistent migration to new demands to be NP-hard for unsplittable flows, and discuss extensions for the case of multiple source–destination pairs.