Method and device for providing priority access to a shared access network

Abstract

An interface that provides priority access to a network is disclosed. The interface includes several ports. Preferably the ports are Ethernet compliant ports. At least one of the ports transmits high priority frames in advance of lower priority frames. High priority frames are preferably buffered. Buffered high priority frames pre-empt transmission of lower priority frames at the port. If the port is operating half duplex using CSMA/CD, transmission of high priority frames pre-empts re-transmission of lower priority frames for which a collision has been detected. Additionally, in the case of frames to be broadcast to multiple ports, buffered frames may be transmitted at varying times at the ports at which the frame is to be broadcast. The interface may further buffer frames received at each port. As the buffer fills, flow of frames into the interface is preferably limited on a per-port basis, based on the number of frames already buffered for a particular port. The interface is particularly well suited for providing priority access to a shared access network to a high priority appliance such as an Ethernet phone. As such the interface may be integrated with such a phone.