This reports which interface, Ethernet, labeled 'other', or Satellite, the traffic for this multicast group is arriving from. This tells an admin the direction a given multicast stream is flowing through this unit, useful for confirming a hub is correctly sourcing a feed from its Ethernet-side content source rather than unexpectedly receiving it from the satellite side, which would indicate a routing loop or misconfiguration. A hub site expecting to originate a multicast video feed locally should see this report other(1) for that group; seeing sat(2) instead would indicate the feed is unexpectedly coming in over the satellite link, a sign of possible misrouting.