Specifications

Installation and Operation Manual Chapter 4 Troubleshooting and Diagnostics
MPW-1 MP-4100 Ver. 2.0 Diagnostic Functions 4-19
4.5 Diagnostic Functions
The MPW-1 modules support the following diagnostic function:
• Loopbacks on selected timeslots of the internal DS1 ports:
 Local loopback per timeslot
 Remote loopback per timeslot
• Ping test, which enables checking the IP connectivity between MPW-1 packet
ports and the pseudowire destination IP address.
The following sections explain the loopbacks and tests supported by MPW-1
modules.
Note that the activation of a loopback disconnects the local and remote equipment
served by the corresponding pseudowire. Therefore, when you initiate a loopback,
you have the option to limit its duration to a selectable interval in the range of 1
through 30 minutes. After the selected interval expires, the loopback is
automatically deactivated, without operator intervention. However, you can always
deactivate a loopback activated on the local Megaplex-4100 before this time-out
expires.
Local Loopback on Selected Internal DS1 Port Timeslots
The local loopback on timeslots of an MPW-1 internal DS1 port is used to return
the transmit payload carried by selected timeslots of the tested port through the
same timeslots of the receive path. The timeslots looped back remain connected
to the transmit path of the port, but the corresponding timeslots received from
the remote end are disconnected.
This test is recommended for testing signal paths between the I/O port of the
other local module which uses the pseudowire, and the MPW-1 port.
The loopback is activated within the MPW-1 pseudowire cross-connect matrix,
and only on the timeslots specified by the user during the activation of the
loopback. As a result, there is no disturbance to services provided by means of
the other timeslots (pseudowires) of the same port: only the flow of payload
carried by the specified timeslots is disrupted.
The signal paths for a local loopback on timeslots are shown in
Figure 4-1 .
The user can activate the loopback on any individual timeslot, or on several
arbitrarily selected timeslots.
When the loopback is activated on timeslots of a port which is part of a
redundancy pair, the CL module automatically activates the loopback on the same
timeslots of the other port of the pair. The same is true for timeslots assigned to
the same pseudowire.
This convenience feature is also available for loopback deactivation: the
deactivation command can be issued to either one of the ports of the
redundancy pair (even if it has been activated by a command to the other port).