Fiber Optic Ports; General Guidelines - Allied Telesis FS970M Series Installation Manual

Fiber Optic Ports

General
Guidelines
 The 10/100/1000Base-T ports must be set to Auto-Negotiation, the
default setting, to operate at 1000Mbps.
 The default duplex mode setting for the ports is Auto-Negotiation.
This setting is appropriate for ports connected to network devices
that also support Auto-Negotiation for duplex modes.
 The default duplex mode setting of Auto-Negotiation is not
appropriate for ports connected to network devices that do not
support Auto-Negotiation and have a fixed duplex mode. You
should disable Auto-Negotiation on those ports and set their duplex
modes manually to avoid the possibility of duplex mode
mismatches. A switch port using Auto-Negotiation defaults to half-
duplex if it detects that the end node is not using Auto-Negotiation,
which can result in a mismatch if the end node is operating at a
fixed duplex mode of full-duplex.
Here are the guidelines to cabling the 100Base-FX fiber optic ports:
 The cable specifications for the 100Base-FX fiber optic ports are
listed in Table 4 on page 27.

Do not remove the dust covers from the fiber optic ports until you
are ready to connect the fiber optic cables. Dust contamination can
adversely affect the operations of the ports.
 The connectors on the cables should fit snugly into the ports, and
the tabs should lock the connectors into place.
These guidelines apply to both the twisted pair and fiber optic ports:
 If the switch will have a static or an LACP port trunk, you should
create the trunk first using the switch's management software
before connecting the cables of the trunk. Otherwise, a network
loop will result which can adversely affect network performance.

If your network topology contains a loop where two or more
network devices can communicate with each other over more than
one network path, do not connect the network cables that form the
loop until after you activate one of the spanning tree protocols on
the switch. Data loops can adversely affect network performance.
For background information on the spanning tree protocols, refer to
the FS970M Series AlliedWare Plus Command Line Interface
User's Guide.
FS970M Series Installation Guide
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