基于VLAN的组播方案在EPON系统中的设计与实现

A Novel Implementation of VLAN-Based Multicast Carried on LLID in EPON

提出一种新型的EPON(Ethernet Passive Optical Network)系统中基于VLAN(Virtual Local Access Network,虚拟局域网)的组播实现方案.该方案在OLT(Optical Line Terminal)和ONU(Optial Network Unit)上同时部署监听(Snooping)和代理(Proxy)功能,大大减少了组播控制报文的带宽开销;并且改进了ONU设备的功能与结构,通过逻辑链路标识(LLID)承载着与IP组播地址相对应的组播VLAN ID,实现了在RS(Reconcitiation Sub-layer)子层准确过滤转发数据.并且详细论述了方案的基本思想与实现细节,给出了验证方案的实验过程与结果.

This paper presents a novel implenlentation of VLAN-based nluhicast in EPON system. In the implementation, OLT and ONU have all IGMP snooping and proxy capability, greatly reducing the bandwidth required for multicast control message. It also improves ONU＇s functions and structures. Using logical link identifier （LLID） to carry multicast VLAN that is mapped with IP muhicast address, RS sub-layer can exactly filter and distribute muhicast data frames. The basic idea and process of implementation are given in detail, verification procedure and tesl results are provided.