Cabletron Systems CyberSWITCH CSX400 Installation Manual

Also see for CyberSWITCH CSX400: Setup guide Configuration guide User guide User guide User guide

Contents

Chapter 2: About the CSX4002-14CyberSWITCH CSX400 and CSX400-DC Installation GuideThe Designated Router is chosen from the list of eligible routers. If a one or more routers havedeclared itself to be the DR in their Hello packets, the one with the highest Router Prioritybecomes the DR. If no routers have declared themselves to be DR, then the router with the highestpriority becomes DR.Backup Designated RouterBackup Designated Routers (BDR) are used for each multi-access network. The BDR is adjacentto all routers on the network and becomes the Designated Router if the existing Designated Routerfails. The BDR does not generate network link advertisements and is also elected by the HelloProtocol.The Backup Designated Router is chosen from those routers who have not declared themselves tobe the Designated Router. If a one or more routers have declared itself to be the BDR in their Hellopackets, the one with the highest Router Priority becomes the BDR. If no routers have declaredthemselves to be BDR, then the router with the highest priority becomes BDR.Detailed information on the OSPF protocol is documented in RFC 1247.HDSLHigh-bit rate Digital Subscriber Line (HDSL) technology uses existing copper twisted pair cablesdesigned for conventional analog voice transmission from a telephone carrier servicing area as alow-cost alternative to the quality and speed of fiber optic cables, and provides high-speedfull-duplex digital transmission links of up to 1.544 Mbps. The WPIM-HDSL is easy to install inyour network over existing telephone lines, and it is a portable investment if a business, orindividual user plans to relocate.HDSL is a direct connection technology that allows connections to be made for distances of up to12,000 feet over 24 American Wire Gauge (AWG) unconditioned Twisted Pair wire. To obtain theFull T1 line Rate of 1.544 Mbps, two wire pairs are necessary (four wires). If one pair of wires isused (two wires), then data rates of 772 Kbps are supported, which is equivalent to one-half of aT1 line.