Ethernet Switches Eaps System Design

The Ethernet is gradually developed to the MAN and even WAN, which is taken as core network by more and more costomers.The Ethernet Switch is now being developed to multifunction and multi-level orientation.The 2000 series Ethernet Switch was designed by ZTE corporation up to date, which was located in the core networking. And it also could be used in WAN and MAN.In practical networking, there is "Broadcast storm(the network is blocked by too many broadcast packet)"as a result of ethernet ring, which seriously effect the network cap- ability. Although the STP(Spanning Tree Protocol) which is constituted by IEEE can solved "Broadcast storm", but its convergence is so slow that can not adapt the requirement of core network.EAPS( Ethernet Automatic Protection Switching) is the subsystem of ring auto-detect and protection in the system of the 2000 series Ethernet Switch, which is used in enterprise networks. With EAPS subsystem, 2000 series Ethernet Switch, could avoid the emergence of broadcast storm", and its convergence speed can be controlled within 50 milliseconds.This thesis will introduce the EAPS design in combine of 2000 series Ethernet Switch software system. We will expatiate the design roof,the system structure and the total design in detail. We also discuss the Ethernet theory, Vlan technology,etc. In Ethernet ring, using the principle of EAPS, the "broadcast storm" can be avoid through message pass,port block and domain. Its convergence speed could fit the requirement of the core network.