General Tips and Troubleshooting ISDN PRI Service

If the dial tone at your location is supplied via ISDN PRI service, it is essential that the trouble is reported against the circuit and not individual telephone numbers. Each ISDN PRI is composed of (3) elements: T1, D Channel, and (23) B Channels.

Below is a chart with a list of “symptoms” and the level of service to place the trouble ticket against. By reporting the correct issue, it helps to restore your service faster.

Cannot make or receive calls
All calls have a popping or cracking noise
Smart jack shows an alarm or has no lights

Can receive, but cannot make calls
Can make calls, but cannot receive
Cannot call long distance

Specific channels on the T1 not working




The answering party will need the following information:

Provide the circuit ID, location o f the Smart jack, customer contact & telephone number, and hours of operation (or special hours you will be available to accommodate technician site visit)

Problem: Voice – Is it the telephone equipment or the phone lines/circuit?

How to Troubleshoot: It is easiest to look at the equipment first. Pick up your phone and see if the display is showing characters or if lights are on. Next, try making an internal intercom call. If those two don’t work…look at the phone equipment “box” and see if there are any lights on. If none of the above, it is almost certain that the problem lies with the equipment.

If the phone system is working as described above, contact your voice provider immediately and let them know you have tested your phone system and it works.

Problem: I’m having intermittent problems with making and/or receiving phone calls.

How to Troubleshot: This may seem like adding insult to injury in terms of adding time to solve the issue, but the following is vital:

Depending on inbound, outbound or both- you must document the following information on multiple calls with issues:

  • Time of Day the call was (tried) to be placed or received
  • The number called outbound or attempted from inbound
  • Result of call- Examples: A recording played, and it said…….; or the person calling received a fast busy. Be as detailed as possible
  • Document details of more than one problematic call
  • Report the details immediately to your phone provider

The above procedure will absolutely minimize your telephony problem.

Problems with Long Distance- Start with a 711 and 1010 tests

If you are having problems making long distance calls, you must start by finding out who the the carrier of record is. Call 1-700-555-4141. You will get a recording that will give you the name of your underlying long distance carrier is. Please note if there ais a number sequence as well. The recent volume of mergers has led to a confusing number of LD carriers.

When you have this information, report it to your service provider (who you get your invoice from)> This will give them a huge head start into fixing your problem.

Your service provider might give you a three or code and have you try a long distance call that will be10-10-(code)-1- (area code & number). This will allow the provider to see if your number is active in the carrier’s data base.

Commtrol is the perfect choice for your business. We help you manage the most frustrating part of your business – your connection to the outside world. Plus, we have the best customer support around, but don’t take our word for it, ask our customers!