Abstract: Network interface systems are disclosed comprising a bus interface system, a media access control system, a memory system, a security system for selectively encrypting outgoing data and decrypting incoming data, a checksum system for generating and verifying checksum values, and a segmentation system for selectively segmenting outgoing data, where the network interface system may be fabricated as a single integrated circuit chip. Methods are also provided for interfacing a host system with a network, in which checksum information is obtained from the host system, which is used to generate checksum values for outgoing data while the data is being stored in a network interface memory system.

Abstract: One aspect of the invention relates to a network interface system for interfacing a host system with a network. The network interface system includes a bus interface system, a media access control system, a memory system, and a security system. The media access control system comprises one or more local buffers and is adapted to read a second data frame from the memory system while a first data frame is being transmitted to the network. The invention is particularly useful when the memory system has a single memory sharing several clients. When a memory has several clients, there can be instances where a read of the memory by the media access control system is delayed because the memory is busy with a request from another client. The invention helps ensure that such delays do not result in transmission errors and reduces the effect of such delays on overall transmission speed.