Direct Inward Dialing (DID) and Virtual Numbers

You may or may not have heard of Direct Inward Dialing, also referred to as DID. But, I will bet that even if you’ve never heard that exact term or acronym, you are aware of what this technology is. That’s because DID often masquerades as a feature of a different technology or offering. This little nuance can make finding information about DID and fully understanding it something of a conundrum, leaving you feeling like you need to pull out your old Nancy Drew or Hardy Boys costume from however many years ago.

Luckily, you found this article so you can leave your old costumes safely in the storage vault. Read on and let the mystery of Direct Inward Dialing unfold in addition to understanding how this technology allows for the creation of virtual numbers.

DID and Virtual Numbers

The Lowest Common Denominator

Stripped down to its most basic form, Direct Inward Dialing is simply the assignment of a particular phone number to a particular device. The name is actually very logical. Let’s break it down like this:

  • Direct - a DID is a direct connection between a number and a device.
  • Inward - inbound calls can be made to a DID number from any other calling device.
  • Dialing - people dial (or in today’s world touch to dial) the number.

This is the simple part of DID. How DID is actually manifested is where the complication can enter the stage.

DID and Physical Phone Lines

While Direct Inward Dialing numbers are virtual, they can be setup to interface with a Private Branch Exchange (PBX). For businesses, this provides the ability to dramatically simplify telephony traffic, management and costs. A company can select 50 phone numbers to be routed to 10 different phone lines. In this example, each phone line would share 5 phone numbers.

Each phone number can be assigned to a specific employee. This makes the caller experience easier and more personal as it avoids the need to go through a switchboard or navigate a complex phone tree. Instead, they can dial directly to the person they want to reach.

With legacy telephony solutions such as in the case of a company using an analog PBX, only a single call path will be available to a person that calls a particular DID number. This system works fine until a second call comes in while the initial call is still in progress and the second caller gets a busy signal. In this day and age of high customer expectations, it is almost unforgivable to have anyone call a company phone number and receive a busy signal. The good news is that newer low cost services are widely available that enable multiple options to handle external calls. These include features such as call queuing, call busy transfers, hunt groups, call groups, busy call forwarding and automated attendants. If your current office phone system cannot perform any or all of these functions then it is definitely time to start looking for an alternative telephone service.

DID numbers can of course also be used for fax as well as voice transmissions.

DID, VoIP and Virtual Numbers

Direct Inward Dialing is an essential part of what VoIP is - virtual numbers set up to map to a particular device or person. Each 10 digit phone number assigned via a VoIP provider is in fact a DID number.

When paired with VoIP, the ultimate customizability of Direct Inward Dialing can be realized. Call forwarding, call parking, voice mail, local and international numbers and more are just some of the options available with a VoIP solution. In contrast to DID via PBX systems, DID VoIP solutions are not always a direct 1:1 relationship between a phone number and a device or person.

Some companies may choose to have only one phone number - one DID - but utilize multiple extensions as a way of reaching other people or departments. Other companies may wish to obtain phone numbers with area codes in different locations to better serve a greater number of areas under the guise of a “local” business. The potential configurations are virtually limitless. If you are interested in this, be aware that these are typically referred to as virtual phone numbers.

Costs for DID numbers with VoIP range just as dramatically. Many VoIP providers will provide a DID as part of a base service while others will charge up to $5 per number per month. Phone number porting is typically offered so that when a business moves to a new location or changes service providers, it can easily take its phone numbers with it without any interruption of service.

For people interested in free DID options, Google Voice does offer this. Keep in mind that Google Voice is really just another type of VoIP solution. Instead of assigning a number to a device, however, it assigns a phone number to a person. That number can be aligned with multiple devices. Users can access voicemail, text and other features via phones, tablets and computers. Google Voice is free in most cases although some calls may be charged depending upon location.

What about Toll Free Numbers?

If a phone number begins with 888, 800, 866, 877, 855 or 844 then it is a toll free number. If you make a call to a toll free number you are never charged for the call, as it is the owner (called party) of that number that is charged. Providing a toll free number instead of a local number has become the norm for most businesses as it offers a free and convenient way for people to contact that particular business. These numbers are available on a first come first served basis and typically cost around $5 per month plus usage fees. Vanity toll free numbers can also purchased with widely varying prices depending on specific requirements. A Vanity number is a number such as 1-888-888-8647 which can also be presented as 1-888-888-VOIP.

When You Want a DID Number

In almost all cases, if you already have a DID number, it effectively belongs to you and you can port it to any other service provider at will. If you are going to need to purchase one or more new numbers then you should contact your existing phone service provider to get a cost estimate. If you either need a new phone service provider or are unhappy with your existing service, then you should first find  a new provider and during that process inquire about the cost and availability of DID numbers.

The availability question is important as different providers have access to different pools of numbers and they may or may not have the area code or number combination that you are looking for. Additionally it is important to know that this pool of available numbers is shrinking fast due to the incredible growth in cell phone users. If you already have a phone number you like, then don't give it up. If you are not ready to port it then you can still forward or park the number until you decide what to do with it.

To be successful in business it is extremely difficult to avoid being constantly connected to the office. That being said, many professionals are now leveraging their Smartphones as an extension of their office phone system, and frequently take and make calls from these personal devices. Forwarding an office phone number to a mobile number will certainly give the perception that you are still in the office and you will be able to answer business calls with ease. The challenge is that when you want to make a business call on your cell phone, the person you call is going to see your personal caller ID and may not take the call if they do not associate you or your company with that number. To get around this, we highly recommend considering a mobile business app that is an extension of your office phone system. Using this type of app almost always enables the use of your office number as your caller ID and effectively associates your assigned business DID number to your mobile device, in addition to your office phone. To learn more about this type of solution please read our in depth article on on virtual business phone number services.


Author: Anthony

Published: by WhichVoIP

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