Magnum 6KM Mobile Ethernet Switch Installation and User Guide
07/10
22
www GarrettCom com
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4.2
Auto-Cross(MDIX) and Auto-negotiation, for M12 ports
The M12 ports independently support auto-cross (MDI or MDIX) in auto-
negotiation mode and will work properly with all the other connected devices with
RJ-45 ports whether they support Auto-negotiation (e.g 10Mb Hub, media converter)
or fixed mode at 10Mb or 100Mb Half/Full Duplex(managed switch) or not. No
cross-over cable is required while using the 6KM’s copper port to other devices.
Operation is according to the IEEE 802.3u standard.
The Managed 6KM’s Fast Ethernet copper ports can be set for either fixed 100Mb speed
or for 10/100 F/H N-way auto-negotiation per the IEEE802.3u standard. The selection is
made via MNS software. The factory default setting is for auto-negotiation. At 10Mb or
100Mb-fixed speed, the user may select half- or full-duplex mode by MNS Software for
each M12 port separately. For detail information
See Section 2.3 of this manual for
information to access the “6K-MNS Software user guide”
One frequently-used application for the Managed Magnum 6KM Switch
copper ports is to connect one of them using a fiber media converter to another Switch in
the network backbone, or to some other remote 100Mb device. In this case, it is
desirable to operate the fiber link at 100Mb speed, and at either half- or full duplex mode
depending on the capabilities of the remote device. Standard commercially available
Fast Ethernet media converters mostly do not support auto-negotiation properly, and
require that the switched port to which they are connected be at the 100Mb fixed speed.
Attachments to a 10/100 auto-negotiation port typically will not work properly. The
6KM Switch’s M12 ports handle this situation by configuring the ports as per desired
through MNS software port settings and can check the port status of each port after the
change.
When Magnum 6KM (M12) copper ports are set for auto-negotiation and are
connected to another auto-negotiating device, there are 4 different speed and F/H modes
possible depending on what the other device supports. These are: (1) 100Mb 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 normally
arrive at the highest order mode that both devices can support at that time. (Since auto-
negotiation is potentially an externally controlled process, the original “highest order
mode” result can change at any time depending on network changes that may occur). If
the device at the other end is not an auto-negotiating device, the 6KM’s M12 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
10Mb or 100Mb speed and/or in full- or half-duplex mode, and can
send/receive auto-negotiation pulses, and . . .
