Terminal Loopbacks - Cisco ONS 15454 DWDM Manual

1.1.2 Terminal Loopbacks

When a port terminates a facility loopback signal, the signal only loops back to the originating port and
is not transmitted downstream. When a port bridges a loopback signal, the signal loops back to the
originating port and is also transmitted downstream.
Note In Table
terminated, an applicable AIS is injected downstream.
Table 1-1
Card/Port
TXP_MR_10E/TXP_MR_10E_C/TXP_MR_10E_L client
ports
TXP_MR_10E/TXP_MR_10E_C/TXP_MR_10E_L trunk
ports
TXP_MR_2.5G/TXPP_MR_2.5G client ports
TXP_MR_2.5G/TXPP_MR_2.5G trunk ports
MXP_2.5G_10E_C/MXP_2.5G_10E_L client ports
MXP_2.5G_10E_C/MXP_2.5G_10E_L trunk ports
MXP_MR_10DME client ports
MXP_MR_10DME trunk ports
MXP_MR_2.5G/MXPP_MR_2.5G client ports
MXP_MR_2.5G/MXPP_MR_2.5G trunk ports
The loopback itself is listed in the Conditions window. For example, the window would list the
LPBKFACILITY condition for a tested port. (The Alarms window would show the AS-MT condition
which means that alarms are suppressed on the facility during loopback.)
With a client-side SONET or ANSI facility loopback, the client port service state is OOS-MA,LPBK &
MT. However, any remaining client and trunk ports can be in any other service state. For SONET or
ANSI cards in a trunk-side facility loopback, the trunk port service state is OOS-MA,LPBK & MT and
the remaining client and trunk ports can be in any other service state.
With a client-side SDH or ESTI facility loopback, the client port is in the Locked-enabled,maintenance
& loopback service state. However, the remaining client and trunk ports can be in any other service state.
For MXP and TXP cards in a SDH or ETSI trunk-side facility loopback, the trunk port is in the
Locked-enabled,maintenance & loopback service state and the remaining client and trunk ports can be
in any other service state.
1.1.2 Terminal Loopbacks
The following sections give general information about terminal loopback operations and specific
information about ONS 15454 card loopback activity.
Cisco ONS 15454 DWDM Troubleshooting Guide, R7.0.1
1-4
1-1, no alarm indication signal (AIS) is injected if the signal is bridged. If the signal is
DWDM Card Facility Loopback Behavior
Chapter 1 General Troubleshooting
Facility Loopback Signal
Bridged
Terminated
Terminated
Terminated
Bridged
Terminated
Bridged
Terminated
Bridged
Terminated
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