Click for...

• Tips on Acoustics for Your Home Studio
• Frequently Asked Questions from Voice Talent
• Tips on ISDN, 2 3
• Tips on Wiring Your Home Studio, 2 3 4
• Tips on Selecting and Using a Microphone

• Connecting is one thing; framing is another. In most cases, if you can complete a call to another destination, your ISDN is OK. If your codec isn't framing after the calls are established, ISDN is not your problem. You should try setting your codec to a "decode" or "receive" setting compatible with the sending unit...
• If you experience calls which have errors, try dropping the call and dialing again. If the problem still persists, try having the called party call you. If your LD carrier is AT&T, for example, and the called party uses someone else and the problem is with AT&T, placing the call from the other party will circumvent the issue.
• If you suspect an issue with your LD carrier, you might be able to "PIC" around them and select another carrier. This works well with standard voice calls but might be prohibited with ISDN. Still, it can't hurt to try. Use standard PIC codes to dial though another carrier. To use a pic code, dial it, then 1, the area code and then the number. AT&T is 1010288; Sprint is 1010333; MCI is 1010220.
• The BEST test of your ISDN line is calling the second number with the first. This preempts use of the LD network and only tests your box and your ISDN line. If you can call your second number from your first and frame, the issue is probably the LD carrier. Note: Sometimes when calling 2nd with 1st with Musicam TA301 terminal adapters, the first dial attempt might fail. Let the unit redial.
• The green light on the back of Musicam terminal adapters indicates a "LAYER 1" or physical network connection only. This does NOT mean your terminal adapter is properly programmed. It does not indicate your SPIDs are programmed properly. It merely means your terminal adapter is physically and electrically connected to a circuit it thinks is an ISDN line. If, therefore, your green light is flashing, you have a very basic problem with your ISDN line. It could be something as simple as the line being unplugged or it could be a cut line from the central office or it could be a dead card in the central office. Whatever the case, a flashing green light means no calls in our out until you fix the problem.
• SPIDs entered into your terminal adapter usually take the syntax of AAAEEENNNN0101 or AAAEEENNNN0100 where A is your area code, E is your exchange and N is your number. Very often, LEC installers only give you a SPID with a 2 digit suffix. As this syntax indicates, SPIDs almost always have a 4 digit suffix. (This syntax is relative to National ISDN or DMS-100. If your ISDN is fed from an AT&T switch running 5ESS, your SPIDs will usually have a 3 digit PREfix.)
• Incorrectly entered SPIDs will not prevent you from placing calls on some terminal adapters. If the terminal adapter does not expressly prohibit dialing with bad SPIDs, you can call a number and connect. If you have issues with incoming calls only, it might be a bad SPID entry.