Contemporary Control Systems Compact Managed Switches Software Manual for Web Browser - Manual (Page 16)

TD020851-0MG
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4.3.2 Port Frame Statistics
These numbers will remain static until the Refresh option is used to provide an update.
The displayed values are the total number of these events from when the switch was
last powered-up, its IP address was redefined or its parameters were reset to their
default values. Recycling power, redefining the IP address or resetting parameters to
their default values will reset the Port Frames Statistics to zero.
Port Frame Statistics are available for the following counts:
Unicast Frames Received This counts unicast frames received by the switch.
Unicast Frames Sent This counts unicast frames transmitted by the switch.
Multicast Frames Received This counts multicast frames received by the switch.
Multicast Frames Sent This counts multicast frames transmitted by the switch.
Broadcast Frames Received This counts broadcast frames received by the switch.
Broadcast Frames Sent This counts broadcast frames transmitted by the switch.
Dropped Frames This counts the frames dropped on transmission due to
an excessive number of collisions.
Oversize Frames This counts the frames dropped on reception because
they exceeded 1518 bytes — often due to faulty drivers.
Undersize Frames This counts “runt” frames dropped on reception because
they were under 64 bytes with no valid CRC/FCS. Runt
frames are usually created by collisions.
Fragments This counts the number of fragmented frames.
Jabbers These frames exceed 1518 bytes, have invalid CRC/FCS
values and are due to constant transmissions from a
network interface card which likely is faulty.
Collisions This counts the collisions on a half-duplex segment —
most often due to physical-layer issues.
Deferred Transmissions This counts the frames delayed on the first transmission
attempt because the media was busy.
(Figure 11, lower panel)