IBM 8260 Switch User Manual


 
or hub, you might want to consider offloading the task
to an external monitoring device.
Octets The total number of octets of data in good frames
received on the network in non-MAC packets
(including the FCS octets but excluding the framing
bits). An octet represents an integral collection of
eight bits of information.
Packets The total number of non-MAC packets in good frames
received on the network.
Broadcast Packets The total number of good non-MAC frames received
that were directed to an LLC broadcast address
(0xFFFFFFFFFFFF or 0xC000FFFFFFFF). Broadcasts are
normal in all networks. For example, when an
X-terminal is powered up, it generates some
broadcast packets to locate the server station.
Excessive broadcasts, known as broadcast storms,
can greatly deteriorate network performance.
Multicast Packets The total number of good non-MAC frames received
that were directed to a local or global multicast or
functional address. This does not include packets
directed to the broadcast addresses.
Packet Size Statistics The probe keeps individual counters for counting the
number of frames detected with the following frame
lengths:
18-63 octets
64-127 octets
128-255 octets
256-511 octets
512-1023 octets
1024-2047 octets
2048-4095 octets
4096-8191 octets
8192-18000 octets
Greater than 18000 octets
This information can be used to fine-tune your network
buffers to accommodate the appropriate traffic loads.
It can also be used to determine what packet sizes are
commonly used. Some applications can be modified
to use a different frame size. This can help in tuning
the network.
You can also use this information for acquiring
bridges, routers, and hubs that are better suited for
your network environment. Bridges or routers or hubs
offer varying performance throughputs based on
different packet sizes. Some of this equipment works
well with large packet sizes while others dont. So
armed with the knowledge of what packet sizes
occupy your network, you can make a better purchase
decision.
Chapter 10. 8260 RMON Support 207