This read-write object points to another port whose bandwidth resources will be shared or borrowed by this port, and is applicable only for VM Server ports. An administrator uses this to link a virtual-machine server port's bandwidth allocation to that of a physical or reference port rather than provisioning it independently. For example, pointing a VM Server port's bandwidth resource object at a specific host-facing port lets that VM port draw from the same bandwidth pool the operator has already sized for that host connection.