Noted author Jim Metzler reports on one of the major impacts of virtualization: the emergence of vWOCs , or virtual WAN Optimization Controllers. In the majority of data centers, VMs already exist that can be used to host a vWOC.  In a branch office, a virtualized server - or even a router with server blades - could host a vWOC as well as other virtual appliances forming what is sometimes referred to as a Branch Office Box (BOB).  Virtual appliances can therefore support branch office server consolidation strategies by enabling a single device to perform multiple functions typically performed by multiple physical devices.