NE Loopback

In this user interface, you can loop back all ports and query loopback ports on an NE. Figures in the upper pane display the loopback type and signal directions for the selected port. The loopback is a common and effective way to locate equipment faults.

Navigation Path

In the NE Explorer, select the NE and choose Diagnosis&Maintenance > NE Loopback from the Function Tree.

NOTE:

If the check box for selecting a loopback type is dimmed for a port, the port does not support the corresponding loopback function.

NOTICE:

As a loopback interrupts services, it is only used for fault location and must be released after the fault is removed.

Buttons

Button	Description
Expand All	Expands all ports on all boards of the NE.
Collapse All	Collapses all ports on all boards of the NE.
Only Loopback Interface	Displays only loopback ports. This function enables users to view loopback ports conveniently.

Parameters

Field	Value	Description
Unit	For example: 1(IF-1)(IF Loopback)	Indicates the loopback ports and loopback types sorted by board.
Inloop	Checked, Unchecked	The inloop processes the signal at the local end. Within the board, the signal that is transmitted from the cross-connect unit is looped back to the cross-connect unit after being processed. In this way, you can check whether the service processing module and the cross-connect board are normal.
Outloop	Checked, Unchecked	The outloop does not change the signal structure. Within the board, the signal that is transmitted from the receive port is directly looped back to the corresponding transmit port before being processed. In this way, you can check whether the interface and the external cable of the board are normal.
MAC Inloop	Checked, Unchecked	The Ethernet service is looped from the MAC layer of the Ethernet port. At the local equipment, the outgoing services of an Ethernet port are looped back at the MAC layer and input to this Ethernet port.
Physical Inloop	Checked, Unchecked	The Ethernet service is looped from the physical layer of the Ethernet port. At the local equipment, the outgoing services of an Ethernet port are looped back at the physical layer and input to this Ethernet port.
MAC Outloop	Checked, Unchecked	The Ethernet service is looped from the MAC layer of the Ethernet port. At the local equipment, the incoming services of an Ethernet port are looped back at the MAC layer and output to this Ethernet port.
Physical Outloop	Checked, Unchecked	The Ethernet service is looped from the physical layer of the Ethernet port. At the local equipment, the incoming services of an Ethernet port are looped back at the physical layer and output to this Ethernet port.