Dialing Plans

As organizations with multiple locations focus on integrating telephone systems across the enterprise and even centralizing call flow, one area often overlooked is dialing plans.  Through expansion or acquisition, no one has paid attention to the extensions and potential overlap across locations.  It really has never been a concern.  Users at the same location would just dial a predefined number of digits and their call was connected.  And, some locations may use three digits while others may use four.  Many times, these digits are combined with direct inward dial (DID) numbers to keep things simple internally and externally.

As these locations start to become integrated, there is a high likelihood that these extensions will no longer be valid as sites have conflicts with these extensions.

Some Helpful Hints

  • Thoroughly examine the current dialing plans of all your locations as well as any association with DID numbers.
  • Consider a dialing plan that can support as many of your locations as possible. This may be as easy as adding another digit or incorporating site codes as a prefix to the extension.
  • Depending on future expansion plans, try to make your new plan flexible as new users and/or locations are added.
  • Remember that obtaining DID numbers in the future can be limited based on availability. So, plan on receiving more DID numbers that you need to allow for expansion.

As your project progresses to integrate calling within your enterprise, make sure that you are including the aggregate dialing plan that will support this project.  Leaving this step for later in the project can cause you needless delays and expense.