Cisco NCS 2000 series Troubleshoot Manual

Terminal Loopback SignalCard/Port
BridgedAR_XP/AR_MXP trunk ports
Important notes about loopback on MXP and TXP trunk and client ports:
• For SONET or ANSI TXP and TXPP cards with a client-side terminal loopback, the client port is in the
OOS-MA,LPBK & MT service state and trunk port must be in IS-NR service state.
• For SONET or ANSI MXP and MXPP cards with a client-side terminal loopback, the client port is in
the OOS-MA,LPBK & MT service state and the remaining client and trunk ports can be in any service
state.
• For ADM-10G cards with Client Terminal Loopback on a SONET Client port, AIS-P is sent forward on
client for the circuits on that port.
• For ADM-10G cards with a Terminal Loopback on a GE Client port, the client port is squelched.
• In SONET or ANSI MXP or TXP trunk-side terminal loopbacks, the trunk port is in the OOS-MA,LPBK
& MT service state and the client ports must be in IS-NR service state for complete loopback functionality.
A terminal loopback affects all client ports because it is performed on the aggregate signal.
• For ADM-10G cards with a Facility Loopback on the Trunk port, AIS-P is sent forward on all the SONET
client ports.
• For ADM-10G cards with a Facility Loopback on the Trunk port, all the GE client ports is squelched
• For ADM-10G Terminal Loopback on the Trunk port, the signal is anyway sent downstream (drop and
continue).
• For SDH or ETSI TXP and TXPP client-side facility loopbacks, the client port is in the
Locked-enabled,maintenance & loopback service state and the trunk port must be in Unlocked-enabled
service state.
• For SDH or ETSI MXP and MXPP cards with a client-side terminal loopback, the client port is in the
Locked-enabled,maintenance & loopback service state and remaining client and trunk ports can be in
any service state.
• In SDH and ETSI MXP or TXP trunk-side terminal loopbacks, the trunk port is in the
Locked-enabled,maintenance & loopback service state and the client ports must be in Unlocked-enabled
service state for complete loopback functionality. A facility loopback affects all client ports because it
is performed on the aggregate signal.
The loopback itself is listed in the Conditions window. For example, the window would list the
LPBKTERMINAL condition or LPBKFACILITY condition for a tested port. (The Alarms window would
show the AS-MT condition, which indicates that all alarms are suppressed on the port during loopback testing
unless the default is set to alarm for loopback while in AS-MT.)
Troubleshooting MXP, TXP, XP, or ADM-10G Circuit Paths With
Loopbacks
Facility loopbacks and terminal loopbacks are often used together to test the circuit path through the network
or to logically isolate a fault. Performing a loopback test at each point along the circuit path systematically
Cisco NCS 2000 series Troubleshooting Guide, Release 11.0
7
General Troubleshooting
Troubleshooting MXP, TXP, XP, or ADM-10G Circuit Paths With Loopbacks

Cisco NCS 2000 series Specifications

General

Brand	Cisco
Model	NCS 2000 series
Category	Network Hardware
Language	English