GarrettCom Magnum Quad-Series Installation And User Manual page 38

Magnum Quad-Series Fiber Switches
converters mostly do not support auto-negotiation properly, and require that the switched
port to which they are connected be at 100Mb fixed speed. Attachment to 10/100 auto-
negotiation ports typically will not work properly. The Quad-Switch's RJ-45 ports
handle this situation by changing the internal jumper settings. (see S
When Quad-Switch's RJ-45 copper ports are set for auto-negotiation and
connected to an another auto-negotiating device, there are 4 different speed and F/H
modes selection depending on what the other device supports. These are: (1) 10
full-duplex, (2) 100Mb half-duplex, (3) 10 Mb full-duplex and (4) 10 Mb half-duplex.
The auto-negotiation logic will attempt to operate in descending order and will norma
arrive at the highest order mode that both devices can support at that time. (Since auto-
negotiati on is potentially an externally-controlled process, the original "highest order
mode" result can change at any time depending on network changes that may occur). I
the device at the other end is not an auto-negotiating device, the Quad-Switch's RJ-45
ports will try to detect its idle signal to determine 10 or 100 speed, and will default to
half-duplex at that speed per the IEEE standard.
General information -
Auto-negotiation per-port for 802.3u-compliant switches occurs when:
the devices at both ends of the cable are capable of operation at either 10
Mb or 100Mb speed and/or in full- or half-duplex mode, and can
send/receive auto-negotiation pulses, and . . .
-- when the second of the two connected devices is powered up*, i.e.,
when LINK is established for a port, or
-- when LINK is re-established on a port after being lost temporarily.
•
NOTE – some NIC cards only auto-negotiate when the computer system
that they are in is powered up. These are exceptions to the "negotiate at
LINK – enabled" rule above, but may be occasionally encountered.
When operating in 100Mb half-duplex mode, cable distances and hop-counts
may be limited within tha
account f or all devices and cable lengths within that domain. For Magnum Quad-Serie
Fast Ethernet switched ports operating at 100Mb half-duplex, the bit time delay is 50BT.
www GarrettCom com . .
t collision domain. The Path Delay Value (PDV) bit-times must
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Installation and User Guide (06/03)
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