GarrettCom P80C - Manual (Page 23)

Magnum P80F & P80C Personal Switches Installation and User Guide (07/03)
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4.0 OPERATION - the function and operation of the Magnum P80F and P80C switches.
4.1 Dual-Speed Functionality, and Switching
The Magnum P80F and P80C Personal Switches provide eight switched
ports, one of which may be 100Mb fiber on Model P80F. The architecture supports a dual speed
switching environment, with a built-in full-duplex “future-proof” fiber port on the Model P80F.
The Model P80C has RJ-45 copper on all the ports with auto-negotiation capability.
The switched RJ-45 ports are full-duplex and auto-sensing for speed. (See section 2.2).
When the connected device is 10 Mbps, the P80F obeys all the rules of 10 Mbps Ethernet
configurations. The 10 Mbps users share a 10 Mbps traffic domain, and can “communicate with”
100Mbps users as well as 100Mbps domain. Similarly, the 100Mbps traffic obeys the rules of
100Mbps Ethernet, and can communicate with 10 Mb domain too.
Magnum P80F and P80C units are plug-and-play devices. There is no software
configuring to be done at installation or for maintenance. The only hardware configuration
settings are user options for UP-LINK on RJ-45 port # 1. Half / Full duplex mode selection for
the switched fiber port and FF/AN can be done through a switch accessed from the front of the
unit for P80F and P80C. The internal functions of both are described below.
Switching, Filtering and Forwarding
Each time a packet arrives on one of the switched ports, the decision is taken to either
filter or to forward the packet. Packets whose source and destination addresses on the same port
segment will be filtered, constraining them to one port and relieving the rest of the network from
processing them. A packet whose destination address is on another port segment will be
forwarded to the appropriate port, and will not be sent to the other ports where it is not needed.
Packets needed for maintaining the operation of the network (such as occasional multi-cast
packets) are forwarded to all ports.
The Magnum P80F and DP80C Personal Switches operate in the store-and-forward
switching mode, which eliminates bad packets and enables peak performance to be achieved
when there is heavy traffic on the network.
Switching, Address Learning
The Magnum P80F and P80C units have address table capacity of 16K node addresses,
and are suitable for use in large networks. They are self-learning, so that as nodes are added or