EXHIBIT 10.15


                           MEMORANDUM OF UNDERSTANDING

         This Memorandum of Understanding (MOU) is entered into this lst day of
April, 1998 by and between Summa Four, Inc., with principal offices at 25
Sundial Avenue, Manchester, New Hampshire 03109 (Summa Four), and e-NET, with
principal offices at 12800 Middlebrook Road, Germantown MD 20874.

         WHEREAS, Summa Four is in the business of manufacturing open
programmable switches for the telecommunications industry, and

         WHEREAS, e-NET is in the business of manufacturing proprietary data
telephony (voice over data network) products, including a product known as
Telecom 2000, and applicable Voice Over IP (VOIP) algorithms, and

         WHEREAS the parties presently desire to formally document their desire
to work together to deliver VOIP solutions to Network Operators, and

         WHEREAS both parties agree that the next steps include: 1.) completion
of the Business Plan, and 2.) to promptly engage in a joint design review which
shall culminate in a mutually agreed upon development plan/schedule and Product
Requirements document for the Summa Four/e-NET integrated product and 3.) upon
completion of the above, entering into a comprehensive Strategic Technology
Sales and Licensing Agreement which shall have as a goal, deployment of the
integrated product before the end of calendar 1998, in accordance with the
Business Plan.





   NOW THEREFORE, the parties agree as follows:

   1.     It is intended that the e-Net Business Plan shall be completed within
          30 days of the executed MOU. Such Business Plan shall generally
          provide the basis upon which e-NET shall distribute, market and resell
          the integrated Summa Four/e-Net system ("Telephony Switch") to
          its customers, worldwide. Summa Four shall assist e-NET in the
          completion of such Business Plan, which shall include a.) an
          assessment of the market opportunities for the Telephony Switch
          product, and b.) the identification of the preferred sales and
          distribution channels therefore, and c.) a determination of commercial
          terms for product deployment including pricing, warranty, and support
          terms, and d.) e-NET's projected annual purchase commitment for Summa
          Four switch products for the initial 24 months following product
          introduction.

   2.     As soon as practicable, but in no event later than the completion of
          the Business Plan, both parties shall initiate a Product Design and
          Engineering Development Plan (Plan) to determine the specifications of
          the Telephony Switch in light of market requirements (i.e. the
          Business Plan) and the present capabilities of the products of the
          respective parties. It is anticipated that such Plan shall culminate
          in a high level Product Requirements Specification which shall include
          the 





          anticipated specifications and performance requirements of the desired
          Telephony Switch, any anticipated adjustments, alterations and/or
          modifications which may be required to each party's presently
          available (and/or under development) products to achieve the timely
          development and deployment of the Telephony Switch. Such Plan shall
          also include each party's best estimate(s) with regard to the
          anticipated product development schedule as well as all costs,
          resource allocations and expenses which may reasonably be anticipated
          to be incurred by the parties

   3.     Upon completion of the Plan, the parties shall determine the most
          feasible development plan to proceed with the mutual development of
          the Telephony Switch product. At that time, the parties shall enter
          into a formal Product Development Agreement, setting forth in greater
          detail the respective obligations of the parties. Throughout the term
          of that agreement, it is understood that both parties will use
          reasonable, commercially practical, best efforts to design and develop
          the Telephony Switch product in accordance with the schedule as
          agreed.

   4.     Notwithstanding the above, the parties recognize that unforeseen
          circumstances may exist which, in the course of the product
          development effort, lead the parties to conclude, jointly or
          individually, that it is no longer in their best interests to continue
          the 





          product development effort. In the event of any such decision, neither
          party shall be obligated or liable to the other, other than for any
          such cost or obligation which it may have incurred to the other under
          the terms of such development agreement as of the date of such
          termination.

   5.     Summa Four acknowledges that it has already agreed upon an internal
          development schedule which will address and resolve (prior to
          December, 1998) two technical issues which have been raised by e-NET:
          a.) the integrated product shall be engineered to be capable of
          performing packet communication across the Time Division Multiplex
          (TDM) bus structure which currently exists between the ICC and the SPC
          at a rate adequate to allow reasonable performance parameters to be
          achieved for a product handling 960 simultaneous IP telephony calls,
          and b.) the integrated product will support ethernet capabilities
          greater than 7 Mbps.

   6.     In order to facilitate the development process, e-NET shall,
          simultaneously with the execution of this agreement, purchase a VCO 4K
          lab switch from Summa Four, the configuration of which shall be as
          determined by the parties.

   7.     Summa Four shall provide e-NET with Sigma Pricing as soon as it is
          available. E-NET, within ten business days of receipt of Sigma






          pricing, will issue Summa Four a purchase order for a Sigma Lab Switch
          to be delivered as soon as available in Beta format. For this
          consideration, Summa Four will give e-NET the first Sigma lab switch
          for any Voice over IP customer and Summa Four will provide the Sigma
          Lab Switch at list price less: a) appropriate discount per signed
          Volume Purchase Agreement between e-NET and Summa Four, Inc., and b)
          100% trade in credit for the VCO 4K Lab Switch purchased by e-NET upon
          return of such switch in working condition. In no event shall the
          Sigma Lab Switch net purchase price be less than zero.

   8.     Summa Four may from time to time decrease its published prices and
          volume discount standard schedule. Should Summa Four issue a new
          standard price list and discount schedule for its Sigma Products for
          Voice Over IP customers with volume commitments equal to e-NET's, from
          that time forward Customer may have the lower of the net prices that
          are (i) calculated by reference to the new price list, using the new
          volume discount schedule at Customer's then volume of purchases or
          (ii) the prices that are calculated using the prices and discounts
          found in their current Volume Purchase Agreement.

 -   Entire Agreement This agreement constitutes the full and complete
     agreement of the parties with respect to the subject matter hereof.





 -   Applicable Law This agreement and the rights and obligations of the
     parties hereunder shall be governed by and interpreted, construed and
     enforced in accordance with the laws of the State of New Hampshire
     applicable to agreements made and to be fully performed therein.

IN WITNESS WHEREOF, the parties have signed and sworn to this agreement as of
the date written above.

e-NET, Inc.                                          Summa Four, Inc.
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By:                                                  By:
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