User manual

Quality of service is the ability to provide different priority levels to different applications, users, or data, or to guarantee a certain level of
performance for data. Real time applications benefit the most when a system of QoS is employed. Examples are for voice and video over IP.
In Ethernet, QoS is dependent on VLAN tagged packets. This is because the QoS priority bits (3 bits) are included in the VLAN tag. Without
VLAN tags, there are no priority bits, and no way to set QoS Priority. In FRM220-1000MS, QoS Priority is enabled by default, but if there are
no VLAN tagged packets, the enabled setting is meaningless.
Broadcast Storm is a condition where either a loop exists on the network or an Ethernet transceiver is bad and exhibiting jabber. In
addition there are the deliberate attempts to bring a network down through virus and denial of service routines. When enabled, the Broadcast
Storm Filter will recognize and block the forwarding of these broadcasts.
Multicast storms happen when application participants request retransmits of information they have missed in the multicast stream. There
are many applications, like video streaming, IP based punch clocks, IP based surveillance trackers and camera, that come with multicast or
some broadcast based protocol turned on by default. The Multicast Storm Filter can be enabled to filter these unwanted effects.
The Unknown DA Unicast Storm Filter can be used to filter the Unicast broadcasts whose objective is to cause deny-of-service. Some
Trojans and virus start scanning multicast IP ranges causing excess broadcasts and reducing network performance.
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