Playing with ISDN

As I work on the current big project at $work, I’m getting more exposure to ISDN (otherwise called It Still Does Nothing by my boss), and the tools used to diagnose ISDN connectivity issues. We’ve got a few bits of kit lying around here, including handsets that can emulate a PBX or monitor an ISDN channel, and something called a Siemens K1197 ISDN Protocol Tester. No longer made, and around 20 years old, it just fired up and ran today. Dan hooked it up, tapped on the keyboard a few times, and I made a test call. We were all amazed to see it displaying call information – right first time.

Well, almost right. The information we were after wasn’t displaying, and no amount of fiddling with short vs comprehensive output would show it. There was a slight smell of smoke, and then Dan tapped in a few more instructions, and I made another test call. Hey presto, full ISDN session setup information, flags indicating the type of call and number types and all sorts of other information.

Very, very nice tool. Quite expensive too.

Now to run a series of test calls to get the information I need, and then contact our ISDN supplier to see if they can’t sort a few things out for us.

ISDN protocol tester