MESSAGE BASED PACKET SWITCH BASED ON A COMMON, GENERIC BUS MEDIUM FOR TRANSPORT

摘要

A packet switch has a switching unit (SU) forswitching packets between network links and a computing unit(CU) connected to the SU through a network link forimplementing software control functions over the SU. The SU isformed of different functional components interconnected bygeneric buses. The components communicate with one anotherusing program data units (PDUs) that are formatted andtransmitted according to a shared device protocol. Thecommunication between the components occurs by placing PDUs inbus frames that are passed from component to component.Information is exchanged between the components by addinginformation to or dropping information from the fields of thePDUs, or by concatenating new fields to the PDUs, as the framespass from component to component. By using a generic bus toimplement PDU-based interconnections within the SU, all thecomponents are forced to support a common interface. Changesto the implementations of any component's interface can thus beaccommodated by changing the PDU format as opposed to changingthe interfaces of connected components. The new packet switcharchitecture decouples the components on the switch so thatthey can be upgraded or otherwise modified independently of oneanother.