Comtech EF Data SLM-5650B, Installation And Operation Manual

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SLM-5650B Satellite Modem
Revision 2
Network Processor (NP) Interface 8–45 MN-SLM-5650B
Selection Description / Setting
IGMP Select IGMP as Enabled or Disabled.
Query Interval
This is the interval between general queries sent by the modem. By varying the query
interval, a modem administrator may tune the number of IGMP messages on the subnet;
note that larger numbers cause the IGMP queries to be sent less often.
Enter a value, in seconds, from 1 to 60 (default = 1 second).
Response Interval
This is the maximum response time inserted into the periodic general queries. By varying
the Response Interval, a modem administrator may tune the “burstiness” of
IGMP messages on the subnet; note that larger values make the traffic less “bursty” as
host responses are spread out over a large interval.
Enter a value, in seconds, from 1 to 25 (default = 10 seconds).
Note: The number of seconds assigned to the Response Interval must be less than what
is assigned to the Query Interval.
Last Member Query
Interval
This is the maximum response time inserted into group-specific queries that are set in
response to Leave Group messages, and is also amount of time between group-specific
query messages. This value may be tuned to modify the "leave latency" of the network; a
reduced value results in reduced time to detect the loss of the last member of a group.
Enter a value, in seconds, from 1 to 25 (default = 1 second).
Robustness
The Robustness Variable allows tuning for the expected packet loss on a subnet. If a
subnet is expected to be lossy, the Robustness Variable may be increased. IGMP is
robust to (Robustness Variable-1) packet losses.
Enter a value from 2 to 10 (the default value is 2). Note that the Robustness Variable
MUST NOT be 0, and SHOULD NOT be 1.
Version Version – Enter 1 for IGMPv1 or 2 for IGMPv2.
Click [ Submit] to save the desired IGMP configuration changes on this page.