Multicasting messag transmission method base on two layer exchange device

Abstract

This invention discloses a multimessage CC method based on a two-layer exchange device receives IGMP message from the ACC port to judge if there is VLAN head in the message; if not, adding VLANID of the ACC port to the said message to form VLAN head, then to generate an image relationship list of ACC port VLANID and MAC address to IGMP message physical port and generating an image relationship list of up-line port VLANID and MAC address to IG MP message physical port, and finally to the multimessage according to the above image relationship list.

Description

technical field [0001] The invention relates to a message forwarding method in a communication network, in particular to a multicast message forwarding method based on a two-layer switching device. Background technique [0002] Currently, in a broadband network, a user terminal usually accesses the network through a Layer 2 switching device, and the most common Layer 2 switching device is an Ethernet Layer 2 switch (LANSWITCH) supporting the 802.1Q protocol. The following uses LANSWITCH as an example to illustrate the forwarding of multicast packets. All messages sent by user terminals connected to the network by LANSWITCH must be added with a special tag for user terminal identification. In practice, this tag is usually a virtual local area network (VLAN: Virtual Local Area Network) tag. This VLAN The label can uniquely identify the specific physical interface where the user terminal accesses LANSWITCH, that is, the Ethernet format message sent by the user from the access ...

AI Technical Summary

Problems solved by technology

When LANSWITCH generates a Layer 2 forwarding table about the multicast MAC address, its VLAN ID uses the VLAN ID of the access port on the user side that received the IGMP message. For data packets (actually, the sources of multicast programs are all on the network side, and the multicast data packets are all sent from the uplink port of LANSWITCH), LANSWITCH will add a VLAN header composed of the VLANID of the uplink port to the packet, However, the VLAN IDs of the user-side port and the uplink-side port are different, so the generated Layer 2 forwarding table about the multicast MAC address has no function, LANSWITCH will still treat multicast packets as broadcast packets, and forward them according to the physical port corresponding to the VLANID, which will still waste a lot of network resources

Images