Implementation And Application Of The VLAN Switch Technology On Router

In the recent years, the network technology, especially the Ethernettechnology develops fast ,pushing the metropolitan area network, campusnetwork, Troops network and the enterprise network to advance rapidly. Thedeveloping trend of the way organizing network, From the star and tree typeto flat, flexible and individual. And what the network providers pursue is thehigh ratio of performance and price, and the services that can bring profit. thefunction of network equipment that the customers required is not just foraccess .the ways organizing network using only router or switch can notsatisfy the requirements of metropolitan area network and the networkproviders.The 10G port is put into use, which satisfies the requirement of themetropolitan area network and WAN about higher bandwidth. People needthe services of High-speed Internet, VPN( IP or LAN) etc. The three-layerswitch works in flow module and can be attacked easily by the network virus,so it will appear abnormal and can't work stably. the types of port that theswitch has are few and the services that it supports are weaker than router, soit can't satisfy the way organizing network that the telecommunicationrequired. The services that metropolitan area network supported are inabundant, so people require the network equipments have stronger abilities todeal with services, especially for the equipments that will be put at the edgeof public network. for example abundant two-layer functions, the IP VPN, theIP multicast, VoIP, IPTV, QoS, NAT, IPV6 etc. these request the metropolitanarea network equipments have the abilities to deal with many services and tosupport the newer services . It is the developing trend that the paper putsforward the vlan switch technology.The paper will explain the predicaments of the way organizingnetwork that the network providers faced now, then put forward the solutionVLAN switch technology. Design the vlan forward table, tell the basicfunction that it need to carry out and the performance that it should attain. Itwill also tell how The VLAN switch module deal with different packets withdifferent strategies and analysis how to test the VLAN switch module. byperformance contrast it will explain the advantage of VLAN switchtechnology . The followings will introduce the main work of the paper fromseveral aspects .1. The first problem that the network providers faced is how to send thePPPOE packets to BAS without changing the content of the packets in theway of "router+BAS".2.the second problem that the network providers faced in the way of"switch+router+PE" is in the following explanations.(1) the networkproviders require that the IP services can be recognized in security, the mostefficient way to recognize the customers is by VLAN ID ,but the number ofVLAN ID is only 4095,so the access network will be restricted within narrowlimits.(2) and sometimes the VLAN ID that the customers required is thesame ,so the public network can not recognize the data with the sameVLAN ID from different customers .3.facing the above two problems , the paper puts forward the VLANswitch technology. Firstly, we can send the PPPOE packets belonged todifferent VLANs to the BAS without changing the content of the packets inthe way of "router+BAS" by configuring the vlan forward table . Secondly,we realize the function of QinQ by adding the outer VLAN ID and divestingit for the packets ,solving the limit of access network because of the lack ofVLAN ID and the public network can not recognize the data with the sameVLAN ID from different customers ,the security of network is enhanced andthe scope of VLAN is extended from 4095 to 4095×4095.4.The paper will put forward the key factor of the VLAN switchtechnology, that is the VLAN forward table. then it will explain the necessaryfactors that the VLAN forward table should compose, they are the identifiersof port, equipment , VLAN ID and QoS.5.The paper will analysis the basic functions that the VLAN switchtechnology should realize. they should support the communications of thesame link layer and different link layer by BCP. They should support LACPfor increasing the bandwidth and strengthing the stableness of the linklayer .they should support QoS in order to satisfy different requirements fornetwork resource by different services .they can restrain the broadcast stormby arp agent, consequently they also can avoid betaking more link layerresource by PPPOE packets.6. The paper will write how to look up the vlan forward table and howto deal with many kinds of packets with different strategies in detail .7.The paper will introduce the knowledge of software test .take whitebox and black box test for example, they will be used in different phases.during the course of test we should perform function test, performance testand system test. at last it will analysis that the function of VLAN switchmodule can be tested by simulation.8.The paper will tell the advantage of VLAN switch with the chart . theanalysis is in the following, if the router uses VLAN switch technology thenthe port will look up in the vlan forward table by VLAN ID that the packetsbring and send the packets without changing the content of them if it find theforward item . whereas if the router uses the IP technology then the port willdeal with the packets it received by divesting the header of frames ,then lookup IP route in route table ,at last the port will send the packets to the next hopby adding the newer header of frames .so we can see that using the VLANswitch technology can fasten the rate of forwarding packets and can decreasethe loss of frame. So it can improve the performance of router.In a word , the paper describes the above aspects , it puts forward theVLAN switch technology and realizes it . by contrasting the data that I testusing VLAN switch and IP technology we can see the advantage of VLANswitch technology. The VLAN switch technology satisfies both therequirements of network providers and the performance of router just likekilling two birds with one stone.