3Com SuperStack II, NETBuilder SI manual Configure the ports for loopback testing by entering

134APPENDIX A: TROUBLESHOOTING

To perform a loopback test on the built-in ISDN port, follow these steps:

1Assign each path to separate ports, if necessary, by entering:

ADD !3 -PORT PAths 3.1

ADD !4 -PORT PAths 3.2

2Set the rate adaption parameter to automatically detect the speed of the sending interface using:

SETDefault !<connectorID.channelID> -PAth RateAdaption = Auto

In the example shown in Figure 9, the test originates from path 3.2 and targets 3.1. To specify path 3.2, enter:

SETDefault !3.2 -PAth RateAdaption = Auto

3Configure the ports for loopback testing by entering:

SETDefault !3 -PORT OWNer = Loopback

SETDefault !4 -PORT OWNer = Loopback

4Add the phone number of path 3.1 to the dial number list of port 4 using:

ADD !4 -PORT DialNoList “<phone no>” Baud=64 Type=Bri Pos=1

5Establish a connection between the two B channels by dialing out on one channel and dialing into the other using:

DIal !<path>

To dial path 3.1 from path 3.2, enter:

DIal !3.2

Path 3.2 places a call to the number configured in step 4, which is the number for path 3.1. It is not important which port originates or answers the call as long as the port does not try to call itself.

6When the connection is successfully established, select the loopback testing mode by entering:

DLTest TestMode Loopback

7You can specify the number of seconds the test should run. Enter this value any time before entering the DLTest START command. If a value is not specified, an infinite time duration is assumed. To run the test for a specific number of seconds, use:

DLTest TestDuration <seconds>

Use caution when running for a specified test duration. The test ends abruptly as soon as the time duration expires and a discrepancy between the number of packets transmitted and the number received may result.