ISDN Problems ISDN problems can be troublesome. Normally these occur during ISDN line installation. ISDN problems can also occur with long distance carriers.
Some carriers have extensive clear channel trunks around the world.
Some only have 56 kbps restricted trunks to certain regions or countries. And sometimes, during busy hours, you may be routed over a restricted 56 kbps trunk even if you have in the past made 64 kbps connections using this same carrier. Testing your local loop. Testing the far end local loop. For the following examples, we show screen shots taken from the Planet Control Panel.