GE T1000, Technical Manual

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Chapter 4
– Functions
GE Reason Switches
72 REASON SWITCHES-TM-EN-3
Figure 34: Multicast communication
7.2 IGMP Snooping
Internet Group Management Protocol (IGMP) was designed in the end of 1980’s (first
version by RFC 1112) to fulfill the requirement of using multicast transmission over IP
networks (more specifically, IPv4 networks). The second version of the protocol was
defined at RFC 2236 and its last version is the IGMPv3, defined at RFC 3376.
In internet context, common applications that require multicast transmission are
video and audio streaming. When it comes to power systems communication, IGMP
protocol can be used when there is multicast communication between Phasor
Measurement Unit (PMU) and the Phasor Data Concentrator (PDC).
The IGMP snooping mechanism is shown in the figure below.