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                                                                     Exhibit 4.6

                             CMC INDUSTRIES, INC.
                          1990 EQUITY INCENTIVE PLAN

  Amended and Restated as of the Date of the 1996 Annual Shareholders Meeting

                                  1. Purpose.
                                     -------

    (a)   The purpose of this Second Amended and Restated 1990 Equity Incentive
Plan (the "Plan") is to provide a means by which selected key employees,
directors and consultants of CMC Industries, Inc. (f/k/a/ Cortelco Holdings,
Inc. and f/k/a International Telecommunication Corp.) may be given an
opportunity to benefit from increases in value of the stock of the Company. It
is intended that this purpose will be effected through the granting of (a)
incentive stock options, (b) nonstatutory stock options, (c) stock bonuses, and
(d) purchases of restricted stock. The Plan was originally adopted by the Board
of Directors of the Company on August 30, 1990, and the First Amended and
Restated Plan was adopted by the Board as of June 1, 1992. The Second Amended
and Restated Plan was adopted by the Board as of October 2, 1993. The Second
Amended and Restated Plan was adopted to reflect certain changes in the
Company's name, capitalization and corporate structure and to reflect the public
offering of shares of the Company's common stock. The Plan was amended and
restated a third time effective as of the date of obtaining shareholder approval
of the Plan amendments in 1996.

    (b)   The work "Affiliate" as used in the Plan means any parent corporation
or subsidiary corporation of the Company, as those terms are defined in Sections
424(e) and (f), respectively, of the Internal Revenue Code of 1986, as amended
from time to time (the "Code").

    (c)   The Company, by means of the Plan, seeks to retain the services of
persons now employed by or serving as consultants or directors to the Company,
to secure and retain the services of persons capable of filling such positions,
and to provide incentives for such persons to exert maximum efforts for the
success of the Company.

    (d)   The Company intends that rights granted under the Plan ("Stock
Awards") shall, in the discretion of the Board of Directors of the Company (the
"Board") or any committee to which responsibility for administration of the Plan
has been delegated pursuant to subparagraph 2(c), be either (i) stock options
granted pursuant to paragraph 5 hereof, including incentive stock options as
that term is used in Section 422 of the Code ("Incentive Stock Options"), or
options which do not qualify as incentive stock options ("Supplemental Stock
Options") or (ii) stock bonuses or purchases of restricted stock granted
pursuant to paragraph 6 hereof.


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                              2. Administration.
                                 --------------

     (a)  The Plan shall be administered by the Board unless and until the Board
delegates administration to a committee, as provided in subparagraph 2(c).
Whether or not the Board has delegated administration, the Board shall have the
final power to determine all questions of policy and expediency that may arise
in the administration of the Plan.

     (b)  The Board shall have the power, subject to, and within the limitations
of , the express provisions of the Plan:

          (i)    To determine from time to time which of the persons eligible
under the Plan shall be granted Stock Awards; when and how Stock Awards shall be
granted; whether a Stock Award will be an Incentive Stock Option, a Supplemental
Stock Option, a stock bonus, a purchase of restricted stock, or a combination of
the foregoing; the provisions of each Stock Award granted (which need not be
identical), including the time or times when a person shall be permitted to
purchase or receive stock pursuant to a Stock Award; and the number of shares
with respect to which Stock Awards shall be granted to each such person.

          (ii)   To construe and interpret the Plan and Stock Awards granted
under it, and to establish, amend and revoke rules and regulations for its
administration. The Board, in the exercise of this power, may correct any
defect, omission or inconsistency in the Plan or in any Stock Award, in a manner
and to the extent it shall deem necessary or expedient to make the Plan fully
effective.

          (iii)  To amend the Plan as provided in paragraph 11.

          (iv)   Generally, to exercise such acts as the Board deems necessary
or expedient to promote the best interests of the Company.

     (c)  The Board may delegate administration of the Plan to a committee
composed of not fewer than two (2) members (the "Committee"). To the extent that
the Board determines it to be desirable to qualify Options granted hereunder as
"performance-based compensation" within the meaning of Section 162(m) of the
Code, the Plan shall be administered solely by a Committee of two or more
"outside directors" within the meaning of Section 162(m) of the Code. To the
extent desirable to qualify transactions hereunder as exempt under Rule 16b-3
promulgated under the Securities Exchange Act of 1934, as amended, the
transactions contemplated hereunder shall be structured to satisfy the
requirements for exemption under Rule 16b-3. If administration is delegated to a
Committee, the Committee shall have, in connection with the administration of
the Plan, the powers theretofore possessed by the Board, subject, however, to
such resolutions, not inconsistent with the provisions of the Plan, as may be
adopted from time to time by the Board. The Board may abolish the Committee at
any time and revest in the Board the administration of the Plan.
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                        3. Shares Subject to the Plan.
                           --------------------------

     (a)  Subject to the provisions of paragraph 10 relating to adjustments upon
changes in stock, the stock that may be issued pursuant to Stock Awards granted
under the Plan shall not exceed in the aggregate One Million Two Hundred Twenty-
Four Thousand Four Hundred Seventy- Nine (1,224,479) shares of the Company's
common stock, increased annually on the first day of each of the Company's
fiscal years during the term of the Plan (and subsequent to the 1996 amendment
and restatement of the Plan) in an amount equal to 5% of the Company's common
stock issued and outstanding at the close of business on the last day of the
immediately preceding fiscal year (the "Annual Replenishment"), with only the
initial 1,224,479 shares and subsequent annual increases in an amount equal to
the lesser of (i) 1,224,479 shares, or (ii) the number of shares subject to the
Annual Replenishment to be available for issuance as Incentive Stock Options,
with any amounts in excess of such amount to be available for issuance as
Supplemental Stock Options or as other awards hereunder. If any option or right
granted under the Plan shall for any reason expire or otherwise terminate
without having been exercised in full, the stock not issued under such option or
right shall again become available for the Plan.

     (b)  The stock subject to the Plan may be unissued shares or reacquired
shares, bought on the market or otherwise.

                                4. Eligibility.
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     (a)  Incentive Stock Options may be granted only to employees (including
 officers) of the Company or its Affiliates. A director of the Company shall not
 be eligible to receive Incentive Stock Options unless such director is also an
 employee (including an officer) of the Company or any Affiliate. Stock Awards
 other than Incentive Stock Options may be granted only to directors, officers
 or employees of or consultants to the Company or its Affiliates.

     (b)  No person shall be eligible for the grant of an Incentive Stock Option
  under the Plan if, at the time of grant, such person owns (or if deemed to own
  pursuant to Section 424(d) of the Code) stock possessing more than ten percent
  (10%) of the total combined voting power of all classes of stock of the
  Company or of any of its Affiliates unless the exercise price of such option
  is at least one hundred ten percent (110%) of the fair market value of such
  stock at the date of grant and the term of the option does not exceed five (5)
  years from the date of grant.

     (c)  The following limitations shall apply to grants of awards hereunder:

     (i)  No person shall be granted, in any fiscal year of the Company, options
          or other rights to acquire more than 250,000 Shares.
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     (ii)  However, in connection with his or her initial service, a person may
be granted options or other rights to acquire up to an additional 250,000 Shares
which shall not count against the limit set forth in subsection (i) above.

     (iii) The foregoing limitations shall be adjusted proportionately in
connection with any change in the Company's capitalization as described in
Section 10.

     (iv)  If an Option is canceled in the same fiscal year of the Company in
 which it was granted (other than in connection with a transaction described in
 Section 10), the canceled Option will be counted against the limits set forth
 in subsections (i) and (ii) above. For this purpose, if the exercise price of
 an Option is reduced, the transaction will be treated as a cancellation of the
 Option and the grant of a new Option.


     5.    Terms of Stock Options. Each option shall be in such form and shall
           ----------------------
contain such terms and conditions as the Board or the Committee shall deem
appropriate. All options shall be separately designated Incentive Stock Options
or Supplemental Stock Options at the time of grant, and in such form as issued
pursuant to this paragraph 5. An option designated as a Supplemental Stock
option shall not be treated as an incentive stock option. The provisions of
separate options need not be identical, but each option shall include (through
incorporation of provisions hereof by reference in the option or otherwise) the
substance of each of the following provisions:

     (a)   The term of any option shall not be greater than ten (10) years from
the date it was granted.

     (b)   The exercise price of each Incentive Stock Option shall be not less
than one hundred percent (100%) of the fair market value of the stock subject to
the option on the date the option is granted. The exercise price of each
Supplemental Stock Option shall be not less than eighty-five percent (85%) of
the fair market value of the stock subject to the option on the date the option
is granted.

     (c)   The purchase price of stock acquired pursuant to an option shall be
paid, to the extent permitted by applicable statutes and regulations, either (i)
in cash at the time the option is exercised, or (ii) at the discretion of the
Board or the Committee, either at the time of the grant or exercise of the
option, (A) by delivery to the Company of other common stock of the Company
which, in the case of common stock acquired from the Company, has been owned by
the optionee for more than six months on the date of exercise, (B) according to
a deferred payment or other arrangement (which may include, without limiting the
generality of the foregoing, the use of other common stock of the Company which,
in the case of common stock acquired from the Company, has been owned by the
optionee for more than six months on the date of exercise) with the person to
whom the option is granted or to whom the option is transferred pursuant to
subparagraph 5(d), or (C) in any other form of legal consideration that may be
acceptable to the Board or the Committee.
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       (d)   Unless otherwise expressly stated in the option, an option shall
  not be transferable except by will or by the laws of descent and distribution,
  and shall be exercisable during the lifetime of the person to whom the option
  is granted only by such person.

       (e)   The total number of stock subject to an option may, but need not,
  be allotted in periodic installments (which may, but need not, be equal). From
  time to time during each of such installment periods, the option may become
  exercisable ("vest") with respect to some or all of the shares allotted to
  that period, and may be exercised with respect to some or all of the shares
  allotted to such period and/or any prior period as to which the option was not
  fully exercised. During the remainder of the term of the option (if its term
  extends beyond the end of the installment periods), the option may be
  exercised from time to time with respect to any shares then remaining subject
  to the option. The provisions of this subparagraph 5(e) are subject to any
  option provisions governing the minimum number of shares as to which an option
  may be exercised.

       (f)   An option shall terminate three (3) months after termination of the
   optionee's employment or relationship as a director of or consultant to the
   company or an Affiliate, unless (i) such termination is due to such person's
   permanent and total disability, within the meaning of Section 422(c)(6) of
   the Code, in which case the option may, but need not, provide that it may be
   exercised at any time within one (1) year following such termination of
   employment or relationship as a director or consultant; or (ii) the optionee
   dies while in the employ of or while serving as a director of or consultant
   to the Company or an Affiliate, or within not more than three (3) months
   after termination of such relationship, in which case the option may, but
   need not, provide that it may be exercised at any time within eighteen (18)
   months following the death of the optionee by the person or persons to whom
   the optionee's rights under such option passes by will or by the laws of
   descent and distribution; or (iii) the option by its terms specifies either
   (a) that it shall terminate sooner than three (3) months after termination of
   the optionee's employment or relationship as a director or consultant, or (b)
   that it may be exercised more than three (3) months after termination of the
   relationship with the Company or an Affiliate. This subparagraph 5(f) shall
   not be construed to extend the term of any option or to permit anyone to
   exercise the option or to permit anyone to exercise the option after
   expiration of its term, nor shall it be construed to increase the number of
   shares as to which any option is exercisable from the amount exercisable on
   the date of termination of the optionee's employment or relationship as a
   consultant or director.

       (g)   The option may, but need not, include a provision whereby the
  optionee may elect at any time during the term of his or her employment or
  relationship as a director or consultant to the Company or any Affiliate to
  exercise the option as to any part or all of the shares subject to the option
  prior the stated vesting date of the option or of any installment or
  installments specified in the option. Any shares so purchased
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  from any unvested installment or option may be subject to a repurchase right
  in favor of the Company or to any other restriction the Board or the Committee
  determines to be appropriate.

         6. Terms of Stock Bonuses and Purchase of Restricted Stock. Each stock
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  bonus or restricted stock purchase agreement shall be in such form and shall
  contain such terms and conditions as the Board or the committee shall deem
  appropriate. The terms and conditions of stock bonus or restricted stock
  purchase agreements may change from time to time, and the terms and conditions
  of separate agreements need not be identical, but each stock bonus or
  restricted stock purchase agreement shall include (through incorporation of
  provisions hereof by reference in the agreement or otherwise) the substance of
  each of the following provisions as appropriate:

            (a)  The purchase price under each stock purchase agreement shall be
  not less than eighty-five percent (85%) of the fair market value of the stock
  on the date the stock purchase agreement is authorized by the Board of the
  Committee. Notwithstanding the foregoing, the Board or the Committee may
  determine that eligible participants in the Plan may be awarded stock pursuant
  to a stock bonus agreement in consideration for past services actually
  rendered to the company or for its benefit.

            (b)  No rights under a stock bonus or restricted stock purchase
  agreement shall be assignable by any participant under the Plan, either
  voluntarily or by operation of law, except where such assignment is required
  by law or expressly authorized by the terms of the applicable stock bonus or
  restricted stock purchase agreement.

            (c)  The purchase price of stock acquired pursuant to a stock
  purchase agreement shall be paid either (i) in cash at the time of purchase,
  or (ii) at the discretion of the Board or a Committee to which administration
  of the Plan has been delegated, (A) according to a deferred payment or other
  arrangement (which may include, without limiting the generality of the
  foregoing, the use of other common stock of the Company which, in the case of
  common stock acquired from the Company, has been owned by the optionee for
  more than six months on the date of purchase) with the person to whom the
  stock is sold, or (B) in any other form of legal consideration that may be
  acceptable to the Board or the Committee in its discretion. Notwithstanding
  the foregoing, the Board or the Committee to which administration of the Plan
  has been delegated may award stock pursuant to a stock bonus agreement in
  consideration for past services actually rendered to the Company or for its
  benefit.

            (d)  Shares of stock sold or awarded under the Plan may, but need
  not, be subject to a repurchase option in favor of the Company in accordance
  with a vesting schedule to be determined by the Board or the Committee.

            (e)  In the event a person ceases to be an employee of or ceases to
  serve as a director of or consultant to the Company or an Affiliate, the
  Company may repurchase or otherwise reacquire any or all of the shares of
  stock held by that person which have
<PAGE>

  not vested as of the date of termination under the terms of the stock bonus or
  restricted stock purchase agreement between the Company and such person.

                         7. Covenants of the Company.
                            ------------------------

          (a)    During the terms of any Stock Awards granted under the Plan,
  the Company shall keep available at all times the number of shares of stock
  required to satisfy such Stock Awards.

          (b)    The Company shall seek to obtain from each regulatory
  commission or agency having jurisdiction over the Plan such authority as may
  be required to issue and sell shares of stock upon grant or exercise of Stock
  Awards under the Plan; provided, however, that this undertaking shall not
  require the Company to register under the Securities Act of 1933, as amended
  (the "Securities Act"), either the Plan, any Stock Award granted under the
  Plan or any stock issued or issuable pursuant to any such Stock Awards. If,
  after reasonable efforts, the Company is unable to obtain from any such
  regulatory commission or agency the authority which counsel for the company
  deems necessary for the lawful issuance and sale of stock under the Plan, the
  Company shall be relieved from any liability for failure to issue and sell
  stock upon exercise of such Stock Awards unless and until such authority is
  obtained.

     8.   Use of Proceeds From Stock. Proceeds from the sale of stock pursuant
          --------------------------
  to Stock Awards granted under the Plan shall constitute general funds of the
  Company.

                               9. Miscellaneous.
                                  -------------

          (a)    The Board or the Committee shall have the power to accelerate
  the time during which a Stock Award may be exercised or the time during which
  any option or stock acquired pursuant to a Stock Award will vest,
  notwithstanding the provisions in the Stock Award stating the time during
  which it may be exercised or the time during which stock acquired pursuant
  thereto will vest.

          (b)    Neither a recipient of a Stock Award nor any person to whom a
  Stock Award is transferred under subparagraphs 5(d) and 6(b) shall be deemed
  to be the holder of, or to have any of the rights of a holder with respect to,
  any shares subject to such Stock Award unless and until such person has
  satisfied all requirements for exercise of the Stock Award pursuant to its
  terms and is thereby entitled to receive shares of stock.

          (c)    Nothing in the Plan or any instrument executed or Stock Award
 granted pursuant thereto shall confer upon any recipient any right to continue
 in the employ of the Company or any Affiliate to terminate the employment or
 consulting relationship ro directorship of any eligible employee or recipient
 with or without cause. In the event that a Stock Award recipient is permitted
 or otherwise entitled to take a leave of absence will be treated as a
 termination of employment for purposes of his or her Stock
<PAGE>

  Award, and (ii) suspend or otherwise delay the time or times at which the
  shares subject to the Stock Award would otherwise vest.

             (d) To the extent provided by the terms of any Stock Award, the
  recipient may satisfy any federal, state or local tax withholding obligation
  relating to the exercise or receipt of such Stock Award by any of the
  following means or by a combination of such means: (1) tendering a cash
  payment; (2) authorizing the Company to withhold from the shares of the common
  stock otherwise issuable to the participant as a result of the exercise of
  receipt of the Stock Award cash or a number of shares having a fair market
  value less than or equal to the amount of the withholding tax obligation; or
  (3) delivering to the Company owned and unencumbered shares of the common
  stock having a fair market value less than or equal to the amount of the
  withholding tax obligation.

             (e) In connection with each Stock Award made pursuant to the Plan,
 the Company may require as a condition precedent to its obligation to issue or
 transfer shares to an eligible participant, or to evidence the removal of any
 restrictions on transfers or lapse of any repurchase right, that such
 participant make arrangements satisfactory to the Company to insure that the
 amount of any federal or other withholding tax required to be withheld with
 respect to such sale or transfer, or such removal or lapse, is made available
 to the Company for timely payment of such tax.

             (f) The Company may, as a condition of transferring any stock
 pursuant to the Plan, require any person who is to acquire such stock (1) to
 give written assurances satisfactory to the Company as to the optionee's
 knowledge and experience in financial and business matters and/or to employ a
 purchaser representative reasonably satisfactory to the Company who is
 knowledgeable and experienced in financial and business matters, and that he or
 she is capable of evaluating, alone or together with the purchaser
 representative, the merits and risks of acquiring the stock; and (2) to give
 written assurances satisfactory to the Company stating that such person is
 acquiring the stock for such person's own account and not with any present
 intention of selling or otherwise distributing the stock. These requirements,
 and any assurances given pursuant to such requirements, shall be inoperative if
 (i) the issuance of the shares has been registered under a then currently
 effective registration statement under the Securities Act, or (ii) as to any
 particular requirement, a determination is made by counsel for the Company that
 such requirement need not be met in the circumstances under the then applicable
 securities laws.

                    10. Adjustments Upon Changes in Stock.
                        ---------------------------------

             (a) If any change is made in the stock subject to the Plan, or
 subject to any Stock Award granted under the Plan (through merger,
 consolidation, reorganization, recapitalization, stock dividend, dividend in
 property other than cash, stock split, liquidating dividend, combination of
 shares, exchange of shares, change in corporate structure or otherwise), the
 Plan and outstanding Stock Awards will be appropriately
<PAGE>

 adjusted in the class(es) and maximum number of shares subject to the Plan and
 the class(es) and number of shares and price per share of stock subject to
 outstanding Stock Awards.

          (b)  In the event of: (1) a merger of consolidation in which the
 Company is not the surviving corporation, or (2) a reverse merger in which the
 Company is the surviving corporation but the shares of the Company's common
 stock outstanding immediately preceding the merger are converted by virtue of
 the merger into other property, whether in the form of securities, cash or
 otherwise, then to the extent permitted by applicable law: (i) any surviving
 corporation shall assume any Stock Awards outstanding under the Plan or shall
 substitute similar rights for those outstanding under the Plan, or (ii) such
 Stock Awards shall continue in full force and effect. In the event any
 surviving corporation refuses to assume or continue such Stock Awards, or to
 substitute similar Stock Awards for those outstanding under the Plan, then,
 with respect to Stock Awards held by persons then performing services as
 employees or as consultants or directors for the Company, as the case may be,
 the time during which such Stock Awards shall vest shall be accelerated and the
 Stock Awards terminated if not exercised prior to such event. In the event of a
 dissolution or liquidation of the company, any options outstanding under the
 Plan shall terminate if not exercised prior to such event.

                          11. Amendment of the Plan.
                              ---------------------

          (a)  The Board at any time, and from time to time, may amend the Plan.
 However, except as provided in paragraph 10 relating to adjustments upon
 changes in stock, no amendment shall be effective unless approved by the
 shareholders of the Company within twelve (12) months before or after the
 adoption of the amendment, where the amendment will increase the number of
 shares reserved for issuance under the Plan.

          (b)  With a view to making available the benefits provided by Section
 422 of the Code and/or Rule 16b-3 promulgated under the Exchange Act, if deemed
 desirable by the Board, the Board in its discretion shall determine at the time
 of each amendment of the Plan whether or not to submit such amendment to the
 shareholders of the Company for approval.

          (c)  It is expressly contemplated that the Board may amend the Plan in
 any respect the Board deems necessary or advisable to provide eligible
 employees with the maximum benefits provided or to be provided under the
 provisions of the Code and the regulations promulgated thereunder relating to
 employee incentive stock options and/or to bring the Plan and/or incentive
 stock options granted under it into compliance therewith.

          (d)  Rights and obligations under any Stock Award granted before
 amendment of the Plan shall not be altered or impaired by any amendment of the
 Plan
<PAGE>

unless (i) the Company requests the consent of the person to whom the Stock
Award was granted and (ii) such person consents in writing.

                  12. Termination or Suspension of the Plan.
                      -------------------------------------

          (a)  The Board may suspend or terminate the Plan at any time. Unless
sooner terminated, the Plan shall terminate ten (10) years from the date the
Plan is adopted by the Board or approved by the shareholders of the Company,
whichever is earlier. No Stock Awards may be granted under the Plan while the
Plan is suspended or after it is terminated.

          (b)  Rights and obligations under any Stock Award granted while the
Plan is in effect shall not be altered or impaired by suspension or termination
of the Plan, except with the consent of the person to whom the Stock Award was
granted.

          13.  Effective Date of Plan. The Amended and Restate Plan shall become
               ----------------------
effective as determined by the Board.