100Mbps Fiber Ports, Sc Connectors; Frame Buffering And Latency - GarrettCom Magnum P62F Series Installation And User Manual

Magnum P62F-Series Ethernet Switches
screw-lock plug provides a secure connection to the P62F-5V Ethernet Switch unit.
See Section 3.3 for detail description of the PSX-A and PSX-T external power sources.
2.3 Fiber port, SC Connectors
Ethernet fiber switched ports on the Magnum P62F operate at fixed 100Mb speed and full-
duplex mode for the best performance. The P62F's fiber ports are factory-built as either a
multi-mode or single-mode SC connectors. A yellow label on the fiber port connector will
indicate if it is single-mode . . . otherwise it is a multi-mode port. The 100Mbps fiber ports
are each a switched port and perform as a domain, providing a high bandwidth backbone
connection and supporting long (up to 20km single-mode, or 40km special "long-reach")
fiber cable distances for installation versatility.
each of the RJ-45 switched ports. The F/H indicates full-
duplex when ON; when it is OFF, operation is half-duplex.
One (LK/ACT) is steady ON to indicate LINK, and blinking
indicates the port is transmitting / receiving. The 10/100 LED
is ON for 100Mbps and OFF for 10 Mbps (when LINK is
made). For fiber ports, the LEDs are the same except no F/H
(and 10Mb is not possible).
port's cable and a proper link (LK lit) must be made with the device at the other end of the cable
in order for each LINK LED to provide a valid indication of operating conditions.
2.4

Frame Buffering and Latency

The Magnum P62F is a store-and-forward switch. Each frame (or packet) is loaded
into the Switch's memory and inspected before forwarding can occur. This technique ensures
that all forwarded frames are of a valid length and have the correct CRC, i.e., are good packets.
This eliminates the propagation of bad packets, enabling all of the available bandwidth to be
used for valid information.
While other switching technologies such as "cut-through" or "express" impose minimal
frame latency, they will also permit bad frames to propagate out to the Ethernet segments
connected. The "cut-through" technique permits collision fragment frames, which are a result of
late collisions, to be forwarded to add to the network traffic. Since there is no way to filter
frames with a bad CRC (the entire frame must be present in order for CRC to be calculated), the
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Installation and User Guide (11/01)
The Fast
On Magnum P62F units, there are three LED's for
A device must be connected to the other end of a
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