Optional) Adjusting Conditions Of The Spt Switchover - Huawei Quidway S7700 Configuration Manual - Multicast

Quidway S7700 Smart Routing Switch
Configuration Guide - Multicast
In PIM-SM forwarding, each multicast group corresponds to an RPT. At first, all multicast
sources encapsulate data in Register messages, and send the messages to the RP in the unicast
mode. The RP decapsulates the messages and forwards the data along the RPT.
Forwarding multicast data by using the RPT has the following disadvantages:
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The solution to the preceding disadvantages is that:
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Pre-configuration Tasks
Before adjusting control parameters for the SPT switchover, complete the following tasks:
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Data Preparation
To adjust control parameters for the SPT switchover, you need the following data.
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13.10.2 (Optional) Adjusting Conditions of the SPT Switchover

You can configure SPT switchover conditions on the DR at the group member side. The DR
then checks the forwarding rate of multicast data. If finding that the rate exceeds the threshold,
the DR triggers the SPT switchover immediately.
Issue 01 (2011-07-15)
The DR at the source side and the RP need to encapsulate and decapsulate packets.
The forwarding path may not be the shortest path from the source to receivers.
Heavy data traffic increases the load of the RP, and may cause a fault.
SPT switchover triggered by the RP: The RP sends a Join message to the source, and
establishes a multicast route along the shortest path from the DR at the source side to the
RP. The subsequent packets are forwarded along the path.
SPT switchover triggered by the DR at the receiver side: The DR at the receiver side checks
the forwarding rate of multicast data. If the DR finds that the rate exceeds the threshold,
the DR triggers the SPT switchover immediately. The DR sends a Join message to the
source, and establishes a multicast route along the shortest path from the DR at the source
side to the DR at the receiver side. The subsequent packets are forwarded along the path.
NOTE
switchs under the control of default values can work normally. In the S7700, users can adjust related
parameters according to the specific network environment. If there is no special requirement, default values
are recommended.
Configuring a unicast routing protocol
Configuring Basic PIM-SM (IPv6) Functions
Data
Forwarding rate threshold that the DR at the receiver side switches packets from the
RPT to the SPT
Group filtering policy and sequence policy for the RPT-to-SPT switchover
Interval for checking the forwarding rate threshold of multicast data before RPT-to-
SPT switchover
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13 PIM-SM (IPv6) Configuration
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