US Patent 7782869 Network traffic control for virtual device interfaces

Processes for the control of traffic and Quality of Service (QoS) over a switch fabric network comprised of application servers and virtual I/O servers. In the embodiment, an application server includes virtual device interfaces, a QoS module, and a network port controlled by a packet scheduler. When the QoS module receives a packet from a virtual device interface, the QoS module stores the packet in a queue. The QoS module removes the packet from the queue and transmits it to the packet scheduler, in accordance with a hierarchical token bucket that allocates bandwidth for the port among the virtual device interfaces in the application server. In the embodiment, the port is the root of the hierarchy for the hierarchical token bucket and the virtual device interfaces are the leaves. The packet scheduler uses round-round arbitration to transmit the packet it receives to the port.