Bandwidth isolation is achieved in FlowVisor by maximizing the VLAN priority code point, which is a 3-bit field in a frame ranging from 0-7 and can be used to prioritize different classes of traffic. OpenFlow protocol allows VLAN tags such as the PCP field to be managed, which makes it possible to give certain priority to packets in a flow.

Implementing bandwidth isolation involves modifying the flow table of all slices in the network as well as setting the VLAN priority field by FlowVisor. Traffic from every slice is then mapped to one of the eight priority groups, granting the network administrator capability to prioritize the bandwidth per slice.