The Design And Implementation Of Multicast Igmp In Epon System

With the rapid development of multimedia broadband services,the demand for the access network bandwidth requirements are also increasing.Traditional access network has been unable to meet user demand for bandwidth,as an emerging access network technology,EPON(Ethernet Passive Optical Network)can effectively improve the access speed of the entire access network.Thanks to its tree topology and up to1G bandwidth characteristics,EPON can transfer the multicast data(IPTV,Internet Protocol Television)very well.IP multicast is an emerging key technology to the multimedia broadband services transmission in recent years,which relies on related IGMP(Internet Group Management Protocol)for point-to-multipoint transmission and transmits data to a group of destinations from the source in"best-efforts"mode.It can run on any network with different structures,and is one of the main implementations to optimize the bandwidth of system.The author combines the design with the internship work of the OLT project in the internship company,discusses the related technologies of multicast in EPON system and analyzes the insecurity of the protocol multicast and data delaying issue,meanwhile,on the basis of this,controllable multicast and multicast pre-joined have been put forward.This paper first discusses the background of implementing multicasting in EPON systems,then analyzes the existing Layer two multicast protocol,adopts IGMP Snooping and IGMP Proxy in connection with the characteristics of EPON itself to achieve the protocol multicast program.Finally,it analyzes in detail how Optical Line Terminal and Optical Network Unit support multicast services.At the same time,the paper provide the design ideas and implementation of controllable multicast to solve the multicast security issues,it makes OLT control ONU more efficiently by sending down forwarding table from OLT to ONU.Then,in view of the time-lapse multicast data forwarded, puts forward the function of multicast pre-joined the group to receive the data at once.At last,in a lab environment,we applies the network equipment testing instrument IXIA and video player VLC to test the design of the multicast scheme by referring to China Telecom multicast test network program,and provide the detailed procedure of test for multicast, verifying the feasibility and reliability of multicast.