Synchronous Interface; Ethernet Interface; Basic Rate Isdn Interface - Allied Telesis AT-AR020 PRI E1/T1 Hardware Reference Manual

20 Port Interface Card

Synchronous Interface

The AT-AR023 SYN PIC provides a synchronous interface with a single
AMPLIMITE 50-way port. The AMPLIMITE port is wired as a universal
connector for RS-232/V.28, V.35 and X.21 interface standards in both DTE and
DCE modes. A transition cable is required to convert the AMPLIMITE to the
correct physical interface for the standard required (e.g., DB15 for X.21). The
transition cable can be ordered from your supplier, or you can construct your
own cable.
The transition cable does more than simply change the physical connector. The
interface hardware reads the cable type from the AMPLIMITE plug and
enables or disables the internal driver electronics as required. To function
correctly, the cables must be identical to the cables described in "Cables and
Loopback Plugs for PICs" on page 23.
The DCE cable type reverses the direction of the data lines as well as the clock
lines. This cable is intended to be used when the switch or router supplies the
clock for the attached device. This is commonly used when the switch or router
is connected to the synchronous interface of another device or a host, without
using an intermediate modem or NTU (Network Terminating Unit). Therefore,
the DCE cable must only be connected to a switch or router interface that is set
to generate the clock. For more information, see the Interfaces chapter of the
®
AlliedWare Operating System Software Reference for your switch or router.
The transition cable can be changed at any time. It is not necessary to power-
down the switch or router.
When an RS-232 DCE transition cable is connected to a synchronous interface
configured to generate clocks, the maximum clock speed is 38400 bps. When an
X.21 DCE or V.35 DCE transition cable is connected to a synchronous interface
configured to generate clocks, the maximum clock speed is 2 Mbps.

Ethernet Interface

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 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
"AT-AR026 4ETH PIC" on page 14 for more information.
For performance reasons, the AT-AR022 and AT-AR026 PICs should not be
installed in the AT-AR040 NSM.

Basic Rate ISDN Interface

The AT-AR021(S) BRI-S/T and AT-AR021(U) PICs provide Basic Rate ISDN
(BRI) interfaces. In both cases the connecter type is RJ-45. The interfaces
support two 64K B channels and one D channel. Table 12 on page 21 shows the
pinout of the BRI interface.
C613-03023-00 REV N