Work progresses on gigabit Ethernet

Gigabit Ethernet starts with the well known and widely implemented CSMA/CD (carrier sense multiple access with collision detect) protocol specification and will include several enhancements: carrier extension, which will pad out short frames from 512 bits (minimum packet size) to 512 bytes (eight times the minimum data size) so that CSMA/CD can operate over a 100 meter radius network; packet bursting, which will let a station that has acquired the network after contention keep starting new packets until a timer expires-this timer is set to the length of time it takes to transmit a maximum length packet and thus some of the efficiency lost with carrier extension is reclaimed; and full duplex operation with in-band flow control, which will coordinate operations between receiver and transmitter. This was included in P802.3x, just approved by the IEEE Standards Board and added to the 802.3 family of standards. Most Gigabit Ethernets are expected to operate in full duplex mode, especially in initial implementations. In addition, Gigabit Ethernet will maintain the plug and play simplicity that Ethernet users have come to expect through the use of link configuration. This is similar in concept to auto negotiation, which was standardized along with 100BASE-T. With these tools, a broad range of products with multiple speeds and the ability to configure themselves can work at the best speed they have in common with their link partner.