3Com Switch 4800G 24-Port Configuration Manual page 650

650 C 47: PIM C
HAPTER ONFIGURATION
n
Configuring PIM-SM
Register Messages
To do...
Enter system view
Enter PIM view
Configure the C-RP-Adv
interval
Configure C-RP timeout time
The commands introduced in this section are to be configured on C-RPs.
■
For the configuration of other timers in PIM-SM, refer to "Configuring PIM
■
Common Timers" on page 656.
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 enters the register suppression state.
In a probe suppression cycle, the DR can send a null register message (a register
message without multicast data encapsulated), a certain length of time defined by
the probe time before the register suppression timer expires, to the RP to indicate
that the multicast source is active. When the register suppression timer expires, the
DR starts sending register messages again. A smaller register suppression timeout
setting will cause the RP to receive bursting multicast data more frequently, while a
larger timeout setting will result in a larger delay for new receivers to join the
multicast group they are interested in.
Follow these steps to configure PIM-SM register-related parameters:
To do...
Enter system view
Enter PIM view
Use the command...
system-view
pim
c-rp advertisement-interval
interval
c-rp holdtime interval
Use the command...
system-view
pim
Remarks
-
-
Optional
60 seconds by default
Optional
150 seconds by default
Remarks
-
-