Magnum 10ETS / 10XTS Installation and User Guide
06/12
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4.2
Auto-Cross (MDIX) and Auto-negotiation, for Ethernet RJ45
ports
The RJ45 ports independently support auto-cross (MDI or MDIX) in auto-
negotiation mode and will work properly with all the other connected devices with
RJ45 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 10ETS/XTS’s copper port to other
devices. Operation is according to the IEEE 802.3u standard.
The Managed 10ETS/XTS 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 RJ45 port separately. For detail information
See
Section 2.3 of this manual for information to access the “MNS-DX Software user
guide”
One frequently-used application for the Managed Magnum 10ETS/XTS 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 10ETS/XTS RJ45
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 10ETS/XTS RJ45 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 10ETS/XTS RJ45 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.