Chapter 18: DID (direct inward dialing)

Note: DID is an optional feature and requires an additional hardware purchase.

What is DID?

Direct Inward Dialing (DID) requires a separate piece of hardware that operates between the Central Office (CO) DID trunk lines and the voice board in your system. A DID interface allows the voice board to accept Client line identification signals (unique phone numbers) that are sent by a CO on the DID trunk. These signals are typically the last 3,4, or 5 digits of the phone number, and would correspond to Access Boxes or Mail Boxes. This allows your system to identify the number that was dialed and route calls using the DID information.

For example, assume Dr. Smith's office number is 555-1212. DID replays the 1212, which takes the caller to an Access Box or Mail Box which says, "Thank you for calling Dr. Smith's office...". If it weren't for the automatic replaying of the digits your customer base would be limited to the number of phone lines your system can handle. With DID, dozens of different phone numbers can come in through a few phone lines. You will want to have a default greeting on each line just in case the digits from the DID hardware are not valid for any reason.

You should be aware that DID service can be quite expensive. Be sure to consider all costs before attempting to implement DID. If

you want to go ahead with DID lines, you will need to purchase optional DID hardware. In addition, you will need to contact your phone service provider to verify that they can provide you with a "trunked" line and DID phone numbers.

You would set the initial box on each line to an Access Box with Tweaks set to Accept Tones. Then, in the Access Box keys display you would define destination boxes where callers will be sent based on the DID digits captured in the Access Box.

Note: For proper operation of DID you will need to change the Off-Hook Delay to 100. This can be found in the Switch command in the MAINTAIN menu. Once you are in the Switch Information window, click on the Technical Info button and enter 100 in the Off-Hook Delay field.