Specifications

30 Rapier Series Switch
C613-03020-00 REV N
Loopback Plugs for Testing Switch Interfaces
Loopback plugs are used in conjunction with the Test Facility in the AlliedWare
operating system to test the physical interfaces on the switch, Network Service
Modules (NSMs) and Port Interface Cards (PICs). For more information about
the Test Facility, see “Test Facility” on page 47, and the Test Facility chapter of
the Rapier Series Switch AlliedWare
®
Operating System Software Reference.
A loopback plug connects the output pins on the interface to the input pins so
that any data transmitted over the interface is looped back (hence loopback
plug) and received at the same interface.
On interfaces with control signals, these are also looped back. The data
received on the interface is compared with the data transmitted to determine
whether or not the interface is functioning correctly. In order to produce a
comprehensive test report for the interface being tested, most tests performed
by the Test Facility require a loopback plug to be inserted.
Figure 28 shows how to wire a loopback to test Ethernet 10/100 switch ports.
Gigabit copper interfaces cannot be looped back. Use a four-pair crossover
cable between two ports and enter the enable test interface=all command.
Figure 28: Ethernet twisted pair (TP) loopback plug
For information about testing WAN interfaces on NSMs and PICs, see the
Network Service Module Hardware Reference and the Port Interface Card Hardware
Reference. These documents can be downloaded from
www.alliedtelesis.com/support/software.
Not
connected
Not
connected
•Not
Twisted Pair (TP) Loopback Plug (RJ45 connector)
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Switch end view
of plug
TX+
TX-
RX+
RX-
RTPLOOPsw