It is appropriate that the Bell System broke up in January - the month named for Janus, two-faced Roman god of doors and of beginnings. The divestiture - the spinoff of local phone companies from AT&T - has shown two faces in New England during the past month. The breakup has meant confusion and additional expense for telephone users. But its smiling face, so to speak, has been new opportunities for the region's high-tech entrepreneurs and consultants.
On one hand:
* Some residential customers worry they will not be able to afford the anticipated rate increases for local phone service.
* Businesses are having to shop around to find the best telephone services to meet their needs.
* And the independent phone companies, which serve parts of all six New England states, are under ''a real strain'' to deal with the Bell divestiture, says William Stafford, president of the New Hampshire Telephone Association.
On the other hand, much of high-tech New England is bullish on the breakup. Telecommunications manufacturers are looking forward to selling to the seven newly divested regional holding companies, which will be free to go into the equipment business.
But some people are afraid they might have to give up their phones, particularly if the controversial long-distance access charge is imposed. These concerns surfaced during last week's press conference of the Massachusetts Coalition for Affordable Phones.
In a high-ceilinged hearing room under the gold State House dome on Beacon Hill, a young woman, obviously unaccustomed to public speaking and nervous under the intense TV lights, was one of several consumer representatives who expressed concern about the costs of divestiture, particularly for the poor.
''We're already hurting,'' she said. ''The telephone has become a necessity - a contact with the outside world.'' She took nervous gulps of air between sentences as she pushed on through her prepared statement. She spoke of being alone with four small children and needing the telephone as a lifeline to schools, to doctors, and other services.
But down in Newington, Conn., at TeleConcepts Inc., where this reporter visited a few days later, things look brighter. TeleConcepts makes ''decorator'' phones for the residential market, and claims the largest range of styles of any phonemaker in the United States. Many of their phones have sophisticated extra features such as automatic callback of busy numbers.
Myra Winkler, vice-president for design, showed off some of the firm's creations, including a phone that comes in a special acrylic case adorned with a museum-quality Oriental print and real gold leaf. This sort of thing retails at stores like Bloomingdale's and Saks for several hundred dollars.
Frank Manning of Zoom Telephonics in Boston, which makes automatic dialers, is another telecommunications entrepreneur bullish on divestiture. ''The local phone companies are a $5 billion-a-year market, and a lot of that is going to be our stuff.''
William M. Brown of Acton, Mass., president of a new firm called Teltec, predicts New England will change its long-term technology orientation from defense to communications, and sees particular opportunities in the small-business market.
Optimists predict tumbling long-distance rates and equipment prices, as well as sophisticated services, such as electronic grocery shopping, available in even the humblest of homes.
''But only 12 to 20 percent of all consumers have communications needs sophisticated enough for them to benefit from the divestiture,'' argues Robert Rebitzer, a utility researcher with Massachusetts Fair Share Inc., a consumer advocacy group in Boston.
He sketches out three principal consumer concerns:
* Access charges. The Federal Communications Commission (FCC) mandated charges (initially set for $2 a month) on residential phones to pay for part of the fixed cost of long-distance service. This cost had been offset by subsidies to local phone companies from the old AT&T Long Lines Division, but no more. AT&T has also promised, however, that the access charge will enable it to cut long distance rates 10 percent. But, Mr. Rebitzer says, the access charge and rate cut don't even balance unless one's long-distance calls come to $20 a month. Most residential customers simply don't make that many long-distance calls, he says.
The FCC has postponed the access charges until mid-1985 - well after the elections, consumer groups note with a certain cynicism. In November, the US House passed a bill canceling residential access charges altogether, but companion legislation in the Senate was tabled late last week, despite active consumer lobbying.
* ''Unbundling'' or ''de-averaging'' of long-distance rates. Hitherto, rates for long-distance calls between major cities have subsidized the rates for calls to rural areas, which are expensive to serve in relation to the revenue they generate. Now that is to change: Rural customers will ultimately pay relatively more for long distance than city dwellers.
* Local measured service. New England Telephone estimates the average economic cost of a telephone line at $25 a month. But the average consumer is paying about half that for unlimited local dialing. The telephone operating companies, arguing that ''cost-causers should be cost-payers,'' want to push their customers toward paying per call - measured service, with ''message units.''
Consumer groups are concerned local phone companies will hike flat rates to the point that poorer customers have two choices: measured service or no service. And they say the national goal of ''universal service'' is not met when customers have a telephone they can't afford to use. Elderly shut-ins, for example, need to be able to make local calls without worrying about message units.
But many observers argue that the number of people likely to be driven off the telephone system is very small. A $10-per-month basic service, they say, is not guaranteed in the Bill of Rights. And they point out that the prices of other staples - notably oil - have multiplied, and people have coped.
Teltec's Mr. Brown says the telephone companies have too much of a social-service ethic to leave great numbers of people cut off from the system, but he calls the additional costs of divestiture ''something we have to do for posterity'' to inject competition, with all its advantages, into the telecommunications marketplace.
What's critical, industry observers say, is that NYNEX Corporation - the new regional holding company comprising New York Telephone and New England Telephone - avoid ''bypass.'' If NYNEX prices are too high, its big customers will bypass the system and establish a telephone network of their own. All parts of the country face this problem. But it is especially acute for NYNEX because of its dependence on a few big customers in New York City and, to a lesser extent, in Boston.
NYNEX recently announced that if the $2 monthly access charge for residence and single-line business phones is defeated, NYNEX could lose 25 percent of its toll revenues to bypass - resulting in a $7.17 monthly rate increase for remaining customers.