Multicast optimization in a VLAN tagged network

发明公开了一种在VLAN标记环境下优化组播业务的方法和设备。由VLAN间交换设备执行的该方法包括：在所述交换设备上配置的多个VLAN内的第一VLAN内接收一个组播信息流，和将该组播信息流内部地分配给在所述VLAN间交换设备上登记接收此组播信息流的基本上所有的组播组成员。根据本发明，仅在所述的一条或多条VLAN标记通信链路上传输组播信息流的单个拷贝，因而避免了当在多个VLAN内存在组播组成员时通常出现的一个或多个复制的组播信息流。 A method and apparatus for optimizing multicast traffic in a VLAN-tagged environment is disclosed. The method, implemented by a cross-VLAN switching device, comprises the steps of receiving a multicast stream within a first VLAN of a plurality of VLANs configured thereon, and internally distributing the multicast stream towards substantially all the multicast group members registered at the cross-VLAN switching device to receive the multicast stream. Distribution of the multicast stream preferably comprises the steps of internally routing the multicast stream from the first VLAN to each VLAN in which there is a multicast group member registered to receive the multicast stream and then switching the multicast stream from each VLAN in which it is present in a cross-VLAN switching device to substantially all of the multicast group members registered to receive the multicast stream. In accordance with the invention, only a single copy of a multicast stream propagates across said one or more VLAN-tagged communications links, thereby avoiding one or more duplicative multicast streams that generally occur when there are multicast group members in a plurality of VLANs.