Network Connectivity - How do I run a loopback test on a Sangoma E1/T1 card?

With the system powered off, confirm that the board jumpers are set appropriately for E1 mode or T1 mode.

(Refer to the user's manual for the interface card.)

Power on the system and backup the Dahdi configuration file (/etc/dahdi/system.conf)

For T1 mode:    

1. Modify your Dahdi configuration according to the type of Digital Sangoma card:

2. Restart Dahdi and make sure the necessary modules load properly.

3. Connect the loopback plug(s) to the ports and check that the span(s) shows OK in dahdi_tool.   See "How do I make an E1/T1 loopback connector?" for details. Alternatively, use the dahdi_maint tool to loop the card in software:

               dahdi_maint --span 1 --loopback localhost

               dahdi_maint --span 2 --loopback localhost

               dahdi_maint --span 3 --loopback localhost

               dahdi_maint --span 4 --loopback localhost

              Note that using dahdi_maint will mask any physical problems in the spans (such as bent contact pins).

4. Compile patlooptest

              # cd <dahdi source direcory>/tools/
              # make patlooptest

5. Run patlooptest:

             on span 1:     #./patlooptest /dev/dahdi/1 -t 300 -v
             on span 2:     #./patlooptest /dev/dahdi/25 -t 300 -v
             on span 3:     #./patlooptest /dev/dahdi/49 -t 300 -v
             on span 4:     #./patlooptest /dev/dahdi/73 -t 300 -v

If no errors occur, you will see "Going for it..." and there will be no further output.  If there are errors, you will see "Unexpected result."  Please report these to your Sangoma technician for possible causes.
 

For E1 mode:    

1. Modify your Dahdi configuration according to the type of Digital Sangoma card:

2. Restart Dahdi and make sure that the modules load properly.

3. Connect the loopback plug(s) to the ports.  See "How do I make an E1/T1 loopback connector?" for details.  Alternatively, use the dahdi_maint tool to loop the card in software:

               dahdi_maint --span 1 --loopback localhost

               dahdi_maint --span 2 --loopback localhost

               dahdi_maint --span 3 --loopback localhost

               dahdi_maint --span 4 --loopback localhost

              Note that using dahdi_maint will mask any physical problems in the spans (such as bent contact pins).

4. Compile patlooptest            

              # cd <dahdi source direcory>/tools/
              # make patlooptest

5. Run patlooptest:

             For Span 1:     ./patlooptest /dev/dahdi/1 -t 300 -v
             For Span 2:     ./patlooptest /dev/dahdi/32 -t 300 -v
             For Span 3:     ./patlooptest /dev/dahdi/63 -t 300 -v
             For Span 4:     ./patlooptest /dev/dahdi/94 -t 300 -v

If no errors occur, you will see "Going for it..." and there will be no further output.  If there are errors, you will see "Unexpected result."  Please report these to your Sangoma technician for possible causes.

The first parameter to patlooptest is the channel on which to run the test (e.g., /dev/dahdi/1 ). The test should be run on the first channel of the span in question. The second parameter (-t) is an optional timeout (e.g., 300), measured in seconds.  The third parameter is the verbose option, so the errors will be printed to the screen.  Without -v, the only indication that errors occur is in the summary at the end of the patlooptest session.

Patlooptest should complete without displaying any errors. If there are errors, it may indicate that the card or port is bad. However, errors could also be caused by interrupt misses or a faulty loopback plug. If patlooptest does not terminate after the timeout interval, then the card is probably not taking any interrupts.