Horizons 1500WR Wireless 4-Port Router
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ParkerVision
5.6
Multicast
Traditionally, IP packets are transmitted in one of either two ways -
Unicast (1 sender -1 recipient)
or
Broadcast (1 sender - everybody on the network)
. Multicast delivers IP packets to a group of hosts on the
network - not everybody and not just 1.
IGMP (Internet Group Multicast Protocol)
is a network-layer protocol used to establish membership in a
Multicast group - it is not used to carry user data.
IGMP version 2 (RFC 2236)
is an improvement over ver-
sion 1 (RFC 1112) but IGMP version 1 is still in wide use. If you would like to read more detailed information
about interoperability between IGMP version 2 and version 1, please see sections 4 and 5 of RFC 2236.
The class D IP address is used to identify host groups and can be in the range 224.0.0.0 to
239.255.255.255. The address 224.0.0.0 is not assigned to any group and is used by IP multicast comput-
ers. The address 224.0.0.1 is used for query messages and is assigned to the permanent group of all IP
hosts (including gateways).
All hosts must join the 224.0.0.1 group in order to participate in IGMP. The address 224.0.0.2 is assigned to
the multicast routers group.
The 1500WR Wireless Router supports both IGMP version 1 (IGMP-vl) and IGMP version 2 (IGMP-v2).
At start up, the 1500WR Wireless Router queries all directly connected networks to gather group member-
ship. After that, the 1500WR Wireless Router periodically updates this information. IP multicasting can be
enabled/disabled on the 1500WR Wireless Router LAN and/or WAN interfaces in the web Web Configura-
tion Utility (LAN; WAN). Select
None
to disable IP multicasting on these interfaces.
5.7
Configuring the LAN IP Screens
Click
ADVANCED
and then
LAN
to open the
IP Screen
.
This screen’s options are described on the next page.