3Com MSR 50 Series, Configuration Manual

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1184 C
HAPTER
71: PIM C
ONFIGURATION
Configuring PIM-SM
Register Messages
Within a PIM-SM domain, the source-side DR sends register messages to the RP,
and these register messages have different multicast source or group addresses.
You can configure a filtering rule to filter register messages so that the RP can
serve specific multicast groups. If an (S, G) entry is denied by the filtering rule, or
the action for this entry is not defined in the filtering rule, the RP will send a
register-stop message to the DR to stop the registration process for the multicast
data.
In view of information integrity of register messages in the transmission process,
you can configure the device to calculate the checksum based on the entire
register messages. However, to reduce the workload of encapsulating data in
register messages and for the sake of interoperability, this method of checksum
calculation is not recommended.
When receivers stop receiving multicast data addressed to a certain multicast
group through the RP (that is, the RP stops serving the receivers of a specific
multicast group), or when the RP formally starts receiving multicast data from the
multicast source, the RP sends a register-stop message to the source-side DR.
Upon receiving this message, the DR stops sending register messages
encapsulated with multicast data and starts a register-stop timer. When the
register-stop timer expires, the DR sends a null register message (a register
message without encapsulated multicast data) to the RP. If the DR receives no
register-stop message during the register probe time, it will start sending register
messages with encapsulated data again; otherwise, the DR will refresh its
register-stop timer.
The Register-Stop Timer is set to a random value chosen uniformly from the
interval (0.5 times register_suppression_time, 1.5 times register_suppression_time)
minus register_probe_time.
Follow these steps to configure PIM-SM register-related parameters:
n
Typically, you need to configure the above-mentioned parameters on the
source-side DR or the RP only. Since both the DR and RP are elected, however, you
To do... Use the command... Remarks
Enter system view system-view -
Enter public instance PIM view
or VPN instance PIM view pim [ vpn-instance
vpn-instance-name ]
-
Configure a filtering rule for
register messages register-policy acl-number Optional
No register filtering rule by
default
Configure the device to
calculate the checksum based
on the entire register
messages register-header-checksum Optional
By default, the checksum is
calculated based on the
header of register messages
Configure the register
suppression time register-suppression-timeo
ut
interval
Optional
60 seconds by default
Configure the register probe
time probe-interval interval Optional
5 seconds by default