Ethernet Interfaces; Ethernet Dual 10Base-T/Aui Interfaces - Allied Telesis AR Series Hardware Reference Manual

Hardware Reference
C613-03031-01 REV C
data, while asynchronous modems don't require a clock and rely on the
inherent framing provided by the start and stop bits. Normally, any modem
9600 bps or faster will be synchronous. The router can be connected to other
remote routers to form a wide area network (WAN), using synchronous
modems connected to the synchronous interfaces on the router's rear panel.
WAN links faster than 9600 bps are normally provided using Network
Terminating Units (NTUs), which are always synchronous. The interface to
these devices is generally X.21 or V.35.
Good quality data grade cables should be used for all cables, particularly X.21.
This must be made from paired cable with an overall foil shield. Ideally,
metalised backshells should also be used. Poor quality cables will limit the
maximum speed or the maximum length of the cable, or both.

Ethernet Interfaces

10BASE-T Interfaces
All AR300 Series routers have at least one 10BASE-T Ethernet LAN port. The
AT-AR330 has two 10BASE-T Ethernet LAN ports. A rear panel slide switch
(labelled MDX) allows the user to configure the LAN port for a direct
connection to either a hub or personal computer. The same RJ-45 cable
(supplied with the router) may be used in either situation.
The LAN ports can easily be tested using a simple external loopback plug. See
"Cables And Loopback Plugs" on page 63 for details of how to construct a
loopback plug.
10BASE-T/100BASE-TX Interfaces
The AT-AR026 4ETH PIC has four 10BASE-T/100BASE-TX ports with RJ-45
connectors. Port characteristics such as speed, flow control, half/full duplex,
and auto-negotiation can be set by configuring links on the PIC's PCB. See the
PIC Hardware Reference for more information. If your router has a PIC bay, the
PIC Hardware Reference is included on the Documentation and Tools CD-ROM
that shipped with your router, or it can be downloaded from
www.alliedtelesyn.co.nz/documentation/documentation.html.

Ethernet Dual 10BASE-T/AUI Interfaces

The AT-AR022 ETH PIC has a dual 10BASE-T/AUI Ethernet interface. Only
one Ethernet interface type can be active at any one time. The PIC auto-senses
which Ethernet interface type is in use.
The AUI interface is able to supply the required +12 Volts to attached transceivers. The
+12 Volts is fused to prevent any transceiver faults from causing problems with the
router. See the description of the appropriate router series in this Reference for the
location of the fuse. The fuse must be a 500 mA type. If the fuse fails, LEDs on any
attached transceiver will not be lit. The AUI cable should be checked for continuity
problems if the fuse blows.
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