GarrettCom DS80C - Manual (Page 23)

Magnum DS80F & DS80C Dual-speed Stackable Hubs Installation and User Guide (12/01)
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addresses, and is suitable for use in large networks. They are self-learning, so that as nodes are
added or removed or moved from one segment to another, the DS80F and DS80C automatically
keeps up with node locations.
An address-aging algorithm causes least-used addresses to fall out in favor of new
frequently-used addresses. To reset the address buffer, cycle power down-and-up.
4.2 Auto-negotiation and speed-sensing
All eight RJ-45 ports independently support auto-negotiation for speed in 10BASE-T
and 100BASE-TX modes. Operation is according to the IEEE 802.3u standard.
When a RJ-45 cable connection is made, and each time when a LINK is enabled, auto-
negotiation takes place. The DS80F or DS80C advertises it capability for 10 or 100 Mbps speed,
and the device at the other end of the cable should similarly advertise / respond and both sides
will agree to the speed being used. Depending upon the device connected, this will result in
agreement to operate at either 10Mbps or 100Mbps speed.
When the ‘LINK/ACT’ LED is ON, steady ON indicates LINK with no traffic
blinking ON indicates the port is transmitting / receiving. The port has auto-negotiated for
operation. (If a DS80F or DS80C RJ-45port is connected to a non-negotiating device, it will
default to 10Mbps speed and half-duplex mode, per the IEEE 802.3u standard).
4.3 Full or Half - Duplex, manual switch selection for DS80F Models
Ports 1SW and 2SW (the switched ports) have a common “F - H” manual switch
mounted on the front-left of the DS80F personal hub. While in the “F” position, it causes full-
duplex mode to be advertised for the standard 802.3u auto-negotiation session on RJ-45 ports
1SW. For fiber, it forces full-duplex mode at 100Mbps. In the “H” position, it causes half-
duplex mode to be advertised for auto-negotiation on port 1SW, and for fiber it forces half-
duplex mode.
4.4 Full Fixed or Auto-Negotiation, manual switch selection for DS80C Models
Port 2SW have a “FF - A” manual switch mounted on the front-left of the DS80C
Personal Hub. While in the “FF” position, it causes full-duplex mode to be advertised for the
standard 802.3u auto-negotiation session on RJ-45 port 1SW, but for switch 2SW, it causes
100Mbps fixed full duplex, only which can be useful for using Fast Ethernet media converter
(like Magnum 15E).
While in “A” position, the switched port 2SW is set at 10/100 auto-negotiation, that
allow this switched port to connect at 100Mb Full-duplex with any other auto-negotiating
Switches.