What is GSN:

A new full duplex network technology with transfer speeds of 6400 Mbits/s in each direction.

Gigabyte System Network ( GSN ) is a new technology for switched networks with a transfer rate of 800 MBytes/s or 6.4 Gbits/s. The transfer channel uses four multiplexed channels called the Virtual Channels VC 0-3. Data is transferred in micropackets of 32 Bytes plus a control word. Using small packets and the virtual channels make that very large file transfers can not lock out a switch port for smaller files. Link control and look ahead flow control is done with Admin-micropackets that have the same size as data micropackets

Correct link behaviour is checked by CRC check summing on the link level acting internally only and for data integrity by a second CRC check summing acting over the full data path.

Connections are made by a copper cableor by a parallel fibre connection. The copper cable uses 20 coaxial wires and has a maximum length of 40 m. The parallel fibre cable with 10 multi mode fibres for connections up to 300 m. It will be available during 1998. A single mode fibre connection is planned to cover distances up to 10 Km.

Switches are in development for 32X32 connections and less. Part of the switch specification is a converter box that allows to have up to eight HIPPI-800 connections made into a single GSN node.

The Scheduled Transfer specification ( ST ) gives the possibility to do transparent memory to memory transfers. As it is technology independent it brings the possibility to combine GSN easily with other network technologies as Fibre channel, ATM and Gigabit Ethernet. The ST specification will be compatible with the emerging Via specification.

GSN Specifications

HIPPI-6400-PH 6400 Mbit/s Physical Layer
HIPPI-6400-SC 6400 Mbit/s Switch Control
HIPPI-6400-OPT 6400 Mbit/s Optical Specification
Scheduled Transfer Protocol

This is one of the CERN High Speed Interconnect pages. Last update 24 January 1998 - Arie van Praag