Dealing with numbering plan nonsense.

Next time you watch an old movie of the 1930s or '40s, see how many numbers are dialed on the telephone. It wasn't that long ago that four, five, and six digits were the norm. In time, we evolved to the present 10-digit numbering arrangement, and life was good. For a while, at least.

Let's face it. In 1993 we ran out of phone numbers. Thank to explosive growth in facsimile and wireless communications, among various number-eaters, the U.S. is faced with a serious crisis in capacity.

The North American Numbering Plan (NANP) is our numbering standard. Until recently, Bell Communications Research (Bellcore) was responsible for administering the NANP. Bellcore has since been replaced by another group, since numerous organizations felt Bellcore was not going even-handed with number assignments.

Rising to the occasion was the Federal Communications Commission (FCC), whose docket 92-237 is the blueprint for revamping the NANP. Among the planned changes is the elimination of "1" as the identifier for certain toll calls. This small, of(en un(oticed element of the network infrustructure has been with us for quite a few years. But life moves on.

New Rules

New phone numbers will be made possible through "interchangeable numbering plan area codes" or INPAs. As you know, the current NPA rules state that the middle digit of an area code is either a "1" or "0." The new rules state that the middle digit can be "0" through "9." The designation for that is "NXX." "N" means 2 through 9, but not 0 and 1. "X" means the numbers 0 through 9, inclusive. This, of course, is the same pattern we currently use for central office codes.

Instead of the current 160 area codes currently in use, we will have about 640 area codes. The change will add several billion (with a B) additional phone numbers. Enough, we hope, to last a few more years, at least to the year 2000.

1995 deadline

The important transition is expected to take place on Jan. 1, 1995. Prior to the Jan. 1 date, every LEC central office will be modified to accept the NXX format for area codes. Under certain circumstances, the "1" prefix before a 10-digit number will still be required, according to Bellcore.

Overseas callers will still need to dial 1 + for calls into the U.S.

However, use of the "1" prefix will be limited to calls outside one's home numbering plan area (HNPA). Specifically, the Bellcore plan calls for seven-digit dialing (no "1" prefix) for all calls within an NPA. All other calls crossing into another NPA will require the following pattern: 1-NPA-NXX-XXXX, the same as it is today. With the new arrangement, however, NPA codes will also be "NXX", as is the case with central office codes.

As might be expected, a variation of this has been proposed by another organization--in this case, the Ad Hoc Telecommunications Users Committee. Local calls within an HNPA will require seven digits, but no "1." Local calls crossing to a different NPA will also not require a "1." An example of this is the Washington, D.C., area. Calls passing between area codes 202 (Washington) and 703 (northern Virginia) are considered local calls. Toll calls of any type--either within the HNPA or to a different NPA--will require users to dial a "1" first.

Costly changes

Some important--and costly--changes will need to be made to PBXs and other switching systems. Reprogramming of switch databases and automatic route selection (ARS) features will probably be quite costly for users. Most older PABXs and key telephone systems cannot be reprogrammed to handle INPAs. Companies with private networks will also have to get their networks (which use seven-digit and 10-digit dialing) to work properly using the new scheme.

Does all this mean that older (and not fully depreciated) systems should be scrapped? And what about all the current AT&T Definitys, NTI Meridian 1s, Rolm 9751s and Fujitsu F9600s? What's the tab going to be for all the reprogramming that will be needed?

Estimates totaling well over a billion dollars have been suggested.

Perhaps the answer is some good old Yankee ingenuity. Someone should build a universal black box that has all the codes, route commands and other pertinent data necessary to handle the post-1995 NANP. It simply plugs into a switch's universal card slot. Maybe this solution should be implemented as a single plug-in board that can be used on a standard PC.

As managers, what can you do? Start by talking to your vendors now. Same for your distributors. Call up LECs that provide you with centrex service. Find out their plans for upgrading current and older systems. Read COMMUNICATIONS NEWS to see who has emerged with the "ultimate" solution.