Multicast Vlan Replication Overview; Multicast Vlan Replication Supported By The S3700 - Huawei Quidway s3700 series Configuration Manual

Quidway S3700 Series Ethernet Switches
Configuration Guide - Multicast

3.1 Multicast VLAN Replication Overview

After multicast VLAN replication is configured on a switch, the upstream router only needs to
transmit multicast data to a multicast VLAN. This function saves bandwidth because the
upstream router does not need to send a copy of multicast data to each user VLAN.
In traditional multicast transmission mode, the upstream router must copy multicast data for
each user VLAN and send all copies to the switch when users in different VLANs request the
program provided by the same multicast source. This mode wastes network bandwidth and adds
workload on the router.
When users in multiple VLANs require the program of the same multicast source, you can
configure the VLANs as the user VLANs of a multicast VLAN on the switch. The upstream
router only needs to send multicast data to the multicast VLAN and does not need to send a copy
to each user VLAN. When the switch receives multicast data packets from the upstream router,
it distributes multicast data packets to the user VLANs that have multicast receivers.

3.2 Multicast VLAN Replication Supported by the S3700

This section describes the multicast VLAN replication features supported by the S3700.
Multicast VLAN Replication Based on User VLANs
and reduces workload of the router
Figure 3-1
HostC in different VLANs join the same multicast group, the Layer 3 device (router) must copy
multicast data for each VLAN and send all copies to the Layer 2 device (switch). This wastes
bandwidth and burdens the router.
Figure 3-1 Traditional multicast data transmission
Source
Issue 01 (2011-10-26)
shows the traditional multicast data transmission mode. When HostA, HostB, and
Multicast Packet
VLAN 2
VLAN 3
VLAN 4
Router
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
3 Multicast VLAN Replication Configuration
VLAN 2
Switch
VLAN 3
VLAN 4
Receiver
HostA
Receiver
HostB
Receiver
HostC
37