Specifications

7-90
Cisco MGX 8850 (PXM45) and MGX 8950 Software Configuration Guide
Release 3, Part Number 78-14788-01 Rev. C0, January 2004
Chapter 7 Switch Operating Procedures
Configuring a line loopback
Once your physical line is connected, you can perform a loopback test using the following procedure.
Step 1 Connect a single line to the appropriate transfer and receive ports on the backcard you want to test.
Step 2 Establish a configuration session with the active AXSM card using a user name with SERVICE_GP
privileges or higher.
Step 3 Enter the dsplns command to display the configuration for all lines on the current card.
Step 4 Enter the addchanloop <ifNumber> <vpi> <vci> <loopback mode> command. Table ** describes the
possible options for each AXSME card type.
In the following example, the user adds a connection loopback in the ingress direction on logical port 4.
The connection loopback has a VPI of 1 and a VCI of 50.
pop20two.1.AXSM.a > addchanloop 4 1 50 1
Step 5 Enter the dspchanloop <ifNum> command to verify the that the appropriate line is in the specified
loopback state.
8850_NY.10.AXSME.a > dspchanloop 1
Loop Back Connection on Interface 1
Index Conn LCN ifNum Vpi Vci
4
Before you can change the loopback type for an existing loopback, you must first delete the loopback by
executing dellnloop, or you can just enter the addlnloop command with the -lpb 1 (No loopback) option.
Table 7-45 addchanloop Command Parameters
Parameter Description
-ifNumber The logical port number. The ranges for AXSM
are as follows:
• AXSM: 1-60
• AXSM-E: 1-32
VPI Specifies the VPI of the connection. The range is
0-4095.
VCI Specifies the VCI of the connection. The range is
1-65535.
loopback mode Specifies the direction of the loopback line.
• 1 = ingress direction
• 2 = egress direction