Multicast (Igmp Configuration) - NetComm NL1901ACV User Manual

Multicast (IGMP Configuration)

The Internet Group Management Protocol (IGMP) is a communications protocol used by hosts and adjacent
gateways on IP networks to establish multicast group memberships.
IGMP is a protocol only used on the network between a host and the gateway. It allows a host to inform the
gateway whenever that host needs to join or leave a particular multicast group. IGMP provides for more efficient
allocation of resources when used with online gaming and video streaming.
F I E L D
Default Version
Query Interval
Query Response
Interval
NL1901ACV Enhanced Hybrid 4G LTE Gateway – User Guide
UG01063 v. 1.0 December 2018
Figure 103 – Multicast
The version IGMP in use by the gateway.
The hosts on the segment report their group membership in
response to the gateway's queries. The query interval timer is also
used to define the amount of time a gateway will store particular
IGMP state if it does not hear any reports on the group. The query
interval is the time in seconds between queries sent from the
gateway to IGMP hosts.
When a host receives the query packet, it starts counting to a
random value, less the maximum response time. When this time
expires, the host replies with a report, provided that no other host
has responded yet. This accomplishes two purposes:
D E F I N I T I O N
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