Storing ISDN telefonie

  • 29 maart 2015
  • 3 reacties
  • 606 keer bekeken

Dear Sir or Madame,

sorry for writing you in English, but my Dutch isn't good enough for writing (I can read and understand quite well).

3rd time within 2 years my ISDN telephone line is just dead. Happend 5 days ago. Internet is still working, so it's either the NT1 or the splitter. ISDN device is operated without a "centraale", and I've tried 2 of them - with same result.

Last time it was the NT1, and the technician replaced it by a used 2-port NT1 (1 port working, one port broken). The "line ok" light is currently on (green). The 230V light is not on, so I guess it's serviced over the line, since there is no cable going to a 230V wall outlet.

I need your assistance.

Besides that I don't need/want ISDN any more, so after fixing my problem I either will switch to a different supplier (like cable) or to a different contract with KPN. As a software developer I need better internet bandwidth and a reliable telephone.

Kind regards,


3 reacties

Reputatie 7
Badge +11
Dear Thomas,

I can send an engineer to fix the ISDN problem. I also understand you're thinking about changing your subscription. If you don't need ISDN anymore, VoIP is a better alternative. If you want a working telephone line on short term, we need to create a trouble ticket for you. Can you send me a https:///t5/notes/privatenotespage/tab/compose/note-to-user-id/227" target="_blank with your zipcode, housenumber and mobile phone number?

It's not always possible for us to deliver faster internet, this depends on your location. On http://www.kpn.com/prive/tv-internet-bellen/service/internetsnelheid/tips.htm" target="_blank it's possible to check the maximum achievable internet speed over our copper network. If you're interested in an upgrade and if it's available, please let me know. 😃
Hi Tim,

thanks a lot for your reply. After posting on the forum, I've had a short chat with a supporter, who measured the line ok. So I guess the NT1 is working, and it only can be the splitter (which dies at least once per year). I was informed that I'd have to pay for a technician, so I'll first get myself a new splitter.

The "Maximaal haalbare internetsnelheid" for my location is shown as 9 Mbit/s (my Router receives a max of 9,57 Mit/s downstream). This would be sufficient, if it would be kind of stable - which it isn't. Nowadays a lot of people are doing strange things on the internet, like watching TV channels, eating up all the bandwidth for decent use. Performance was ok until about a year ago - and then it started to get very unstable.

I'm kind of afraid that moving to VoIp would further reduce my bandwidth, since there must be a QOS for voice services.

I will get back to this thread if a new splitter can't fix my problem.

Thanks again,


Reputatie 7
Badge +11
Hello Thomas,

The Quality of Services (QOS) for VoIP doesn't use much bandwidth. I don't know the exact number but i believe it's only 64Kbps or 128Kbps. In fact, the ISDN carrier is probably eating more bandwidth then VoIP is doing.

It's a good idea to try with another DSL splitter, make sure you'll get the ISDN type!

Please let me know if it did the trick, otherwise I would like to help you.