Cabletron Systems ELEMENT MANAGER NB30 Manuale Utente

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Bridge Statistics
3-11
NB-30 Bridging
Device Errors
The total number of frames (either inbound or outbound) containing errors which 
prevented them from being processed by the bridgeÕs interfaces.
Nothing
The selected scale is not currently in use.
For the port level window, you can choose from among the following display 
options. Note that some of these options are available only for the local Ethernet 
port or only for the remote port, as indicated in the Þeld deÞnitions below.
Frames Received
The total number of frames received by the selected bridge interface from the 
other bridge interface, as read from the device after each poll interval.
Discarded Inbound (Ethernet Port Only)
Displays the number of packets which were discarded at the port on reception. 
One possible reason would be to free up buffer space Ñ even though no errors 
were detected in the packet on reception. Discarding good packets often indicates 
a very busy network. If a device routinely discards packets, it usually means that 
network trafÞc is overwhelming the device Ñ perhaps because the deviceÕs 
performance is inadequate for the rate of trafÞc on the network. 
Another reason might be that the incoming packet was not formed correctly for 
use on an Ethernet Ñ for example, it may be too large or formatted according to 
an unknown or unsupported protocol. 
Forwarded Outbound
The number of frames forwarded by the selected bridge interface to the other 
interface on the bridge.
Lack of Buffer Space
The number of frames that were discarded speciÞcally because the NB-30Õs frame 
buffer could not keep up with the rate of trafÞc on the network. 
Trans Exceeded (Ethernet)
The number of frames that were discarded because the maximum time for 
forwarding was exceeded before it could be transmitted by the port.
Collisions (Ethernet Port Only)
The total number of collisions detected in the transmission of frames by the 
selected port. A collision is a natural by-product of a busy network Ñ although an 
extremely high rate might indicate a data loop or a node with a hardware 
problem.
Trans. Aborted (Ethernet Port Only)
The total number of frame transmissions from this port that had to be aborted 
because of an excessive number of collisions.