EXHIBIT 10.1 (i)

                   AMENDED AND RESTATED INVESTMENT AGREEMENT

         This Amended and Restated Investment Agreement (this "Agreement") is
entered into as of this 3rd day of January, 2002, by and between ADTRAN, Inc.
(the "Borrower"), a Delaware corporation, and FIRST UNION NATIONAL BANK
(successor-in-interest to First Union National Bank of Tennessee) (the
"Bondholder"), a national banking association.

                                 WITNESSETH

         WHEREAS, the State Industrial Development Authority for the State of
Alabama (the "Issuer") issued its Taxable Revenue Bond, Series 1995 (ADTRAN,
Inc. Project) in the principal amount of Fifty Million and No/100 Dollars
($50,000,000.00) (the "Bond") to the Bondholder pursuant to that certain First
Amended and Restated Financing Agreement (as amended from time to time, the
"Financing Agreement") dated as of April 25, 1997 among the Issuer, the
Bondholder and the Borrower; and

         WHEREAS, the Borrower and the Issuer entered into that certain First
Amended and Restated Loan Agreement (as amended from time to time, the "Loan
Agreement") dated as of April 25, 1997, and the Issuer assigned to the
Bondholder all of the rights of the Issuer under the Loan Agreement with the
intention that the Bondholder enjoy the rights of the Issuer thereunder except
to the extent of certain rights reserved with respect to certain rights to
notice and "Additional Payments," as defined in the Financing Agreement; and

         WHEREAS, as further evidence of its obligations to the Bondholder
arising under the Loan Agreement, the Borrower executed that certain First
Amended and Restated Note (as amended from time to time, the "Note") dated April
25, 1997 payable to the order of the Bondholder in the maximum principal amount
of Fifty Million and No/100 Dollars ($50,000,000.00); and

         WHEREAS, one condition to the Bondholder's agreement to purchase the
Bond was that the Bondholder shall have a first priority lien upon certain
deposit accounts maintained with the Bondholder to secure the Note and
obligations under the Loan Agreement, with such deposits to be derived from
sources other than the proceeds of the Bond; and

         WHEREAS, the Borrower, the Bondholder and AmSouth Bank of Alabama
("AmSouth") entered into that certain Investment Agreement (the "Original
Investment Agreement") dated as of April 25, 1997, pursuant to the terms and
conditions of which the Borrower granted to Bondholder a lien and security
interest upon certain Deposit Accounts (as defined therein) established with
Bondholder and AmSouth; and

         WHEREAS, concurrently with the execution hereof, the Bondholder and
AmSouth are entering into an Assignment and Assumption Agreement, pursuant to
the terms and conditions of which AmSouth is irrevocably

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selling and assigning to the Bondholder, and the Bondholder is irrevocably
purchasing and assuming, AmSouth's participation and interest in the Bond, the
Note, the Loan Agreement and the collateral security thereof; and

         WHEREAS, in connection with such sale and assignment from AmSouth to
the Bondholder, the Borrower and Bondholder desire to amend and restate the
Original Investment Agreement in its entirety, pursuant to the terms and
conditions hereinafter set forth.
         NOW, THEREFORE, as an inducement to cause the Bondholder to purchase
the Bond, and for other valuable consideration, the receipt and sufficiency of
which are acknowledged, it is agreed as follows:

         1.      Establishment and Maintenance of Certificate of Deposit.
                 Prior to the execution of this Agreement, the Borrower
                 established a commercial money market deposit account with
                 the Bondholder bearing the account number 2000010106277 in
                 the amount of Thirty Million and No/100 Dollars
                 ($30,000,000.00) (the "Deposit Account"). Prior or
                 concurrently with the execution of this Agreement, Borrower
                 shall apply the amounts on the deposit in the Deposit
                 Account, together with an additional Twenty Million and
                 No/100 Dollars ($20,000,000.00) for a total of Fifty
                 Million and No/100 Dollars ($50,000,000.00), toward the
                 purchase of a 5-year certificate of deposit with the
                 Bondholder (the "Certificate of Deposit"). The Certificate
                 of Deposit shall be established in the name of the Borrower
                 and is and shall be subject to the restriction that the
                 Borrower shall have no access to funds on deposit or
                 applied thereto absent the consent of the Bondholder. The
                 interest rate on the Certificate of Deposit shall be a
                 fixed rate throughout the term of the Certificate of
                 Deposit, pursuant to the Loan Agreement.
         2.      Source of Deposited Funds. Funds applied by the Borrower
                 toward the Certificate of Deposit shall not be funds that
                 are proceeds of the Bond.
         3.      Definition of Secured Indebtedness. As used herein, "Secured
                 Indebtedness" shall mean all present and future debts and
                 other obligations of the Borrower evidenced by the Bond, the
                 Note and the Loan Agreement, as they may hereafter from time
                 to time be amended, modified, extended, renewed or restated,
                 and all obligations arising hereunder.
         4.      Security Interest; Assignment. To secure the payment of the
                 Secured Indebtedness, the Borrower hereby assigns, pledges and
                 grants a continuing security interest in and lien on the
                 Certificate of Deposit to the Bondholder, together with all
                 replacement certificates of deposit, however denominated, and
                 all proceeds thereof (collectively, the "Account").
         5.      Representations and Warranties. The Borrower warrants and
                 represents to the Bondholder the following:

                 a.       Title. The Borrower is the sole legal and equitable
                          owner of the Account.
                 b.       No Encumbrances. The Account is not subject to any
                          assignment, lien or other encumbrance other than
                          rights in favor of the Bondholder pursuant to this
                          Agreement.
                 c.       Valid Lien. This Agreement provides the Bondholder
                          with a valid first priority assignment of and lien
                          interest in the Certificate of Deposit.
                 d.       Representations and Warranties in the Financing
                          Agreement and Loan Agreement. All of the
                          representations and warranties set
                          forth in Article 2 of the Financing Agreement and
                          set forth in Section 2.2 of the Loan Agreement are
                          true and correct as of the date hereof.

         6.      Covenants. The Borrower covenants with the Bondholder as
                             follows:

                 a.       No Transfer. The Borrower shall not sell or assign
                          the Account in whole or in part and will not grant or
                          allow any other lien or encumbrance to attach thereto.
                 b.       No Withdrawal. The Borrower shall not withdraw any
                          funds from or otherwise applied to the Account or
                          convert the Account to any other savings instruments
                          or account in whole

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                          or in part, without the prior specific written
                          approval of the Bondholder; provided, however, (i) in
                          the absence of the Event of Default hereunder the
                          Borrower shall be entitled to receive interest
                          accrued on the Account as such interest would
                          normally become payable under the terms and
                          conditions of the respective account contracts, and
                          (ii) the Borrower may at any time use funds from the
                          Account to prepay the Secured Indebtedness, in whole
                          or in part.

         7.      Perfection. The Borrower acknowledges and agrees that the
                 Certificate of Deposit is a bank deposit and that the
                 Bondholder's security interest therein is duly protected
                 against lien creditors of the Borrower, bona fide purchasers
                 from the Borrower and the rights of the Borrower or a Trustee
                 for Borrower under any filing under the Bankruptcy Code by the
                 absolute control of the Bondholder as to the right of
                 withdrawal from the Certificate of Deposit. Should the
                 Bondholder in the future determine that the filing of a
                 financing statement or other action is necessary or desirable
                 as further evidence of the perfection of the interest of the
                 Bondholder in the Account, the Borrower shall bear all costs of
                 the preparation and filing of such financing statements or the
                 taking of such other action, including the reasonable fees and
                 expenses of the Bondholder's attorneys.
         8.      The Bondholder's Right of Set-off. As a further inducement to
                 the Bondholder to purchase the Bond, the Borrower hereby
                 grants to the Bondholder (and acknowledges the existence of)
                 the right of set-off against the Account and grants to the
                 Bondholder (and acknowledges the existence of) a banker's lien
                 against the Account, both of which rights serve as additional
                 security for the Secured Obligations.
         9.      The Borrower's Right of Set-off Against the Bondholder. The
                 Bondholder hereby grants to the Borrower and acknowledges the
                 existence of the Borrower's right to set-off the balance of
                 the Account against and to the reduction of all or part of the
                 balance of the Secured Indebtedness in the event that the
                 Bondholder should fail to pay to the Borrower the funds in the
                 Account upon the tender of full payment of Secured
                 Indebtedness or upon the tender of partial payment thereof, to
                 the extent such partial payment is then allocated to the
                 Bondholder's interest in the Bond.
         10.     Warranty of the Bondholder. The Bondholder represents and
                 warrants that this Agreement constitutes a legal, valid, and
                 binding obligation of the Bondholder and is enforceable
                 against the Bondholder in accordance with its terms, except as
                 enforcement hereof may be limited by (i) bankruptcy,
                 insolvency, or other similar laws affecting the enforcement of
                 creditors' rights and (ii) general principles of equity,
                 including the exercise of judicial discretion in appropriate
                 cases.
         11.     Event of Default Defined. The occurrence of any one or more
                 of the following events shall constitute an Event of Default
                 under this Agreement:

                 a.       Financing Agreements. The occurrence of an Event of
                          Default under the Financing Agreement, the Loan
                          Agreement of the Note.
                 b.       Monetary Default. The Borrower's failure to pay any
                          amount due to the Bondholder under this Agreement
                          within five (5) days of demand.
                 c.       Breach of Covenant. The Borrower's failure to perform
                          or observe any obligation or covenant made herein with
                          respect to the Secured Indebtedness.
                 d.       Breach of Representation or Warranty. The Borrower's
                          making of any representation or warranty in connection
                          with this Agreement or the Secured Indebtedness that
                          is materially false.

         12.     Remedies Upon Event of Default. Upon the occurrence of an
                 Event of Default hereunder, the Bondholder may pursue any or
                 all of the following remedies without any notice to the
                 Borrower except as required below:

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                 a.       Withdrawal from Account. The Bondholder may withdraw
                          some or all of the funds in the Account and apply the
                          proceeds thereof to the Secured Indebtedness. The
                          Borrower hereby appoints the Bondholder as the
                          Borrower's attorney-in-fact for the purpose of
                          withdrawing funds from the Account in such event.
                 b.       Exercise of Set-off. The Bondholder may exercise its
                          right to set-off and lien against the Account.
                 c.       Other Remedies. The Bondholder may pursue any other
                          remedy that may be available to it under any other
                          document pertaining to the Secured Indebtedness or
                          that may otherwise be available to the Bondholder
                          at law or equity.
                 d.       Application of Proceeds. All amounts received by the
                          Bondholder for the Borrower's account by exercise of
                          its remedies hereunder shall be applied as follows:
                          First, to the payment of all expenses incurred by the
                          Bondholder in exercising its rights hereunder,
                          including attorney's fees, and any other expenses due
                          the Bondholder from the Borrower; Second, to the
                          payment of all interest included in the Secured
                          Indebtedness, in such order as the Bondholder may
                          elect; Third, to the payment of all principal
                          included in the Secured Indebtedness, in such order
                          as the Bondholder may elect; and Fourth, surplus to
                          the Borrower or other party entitled thereto.

         13.     Expenses. Upon demand, the Borrower will advance to the
                 Bondholder or, at the Bondholder's option, reimburse the
                 Bondholder for, the following expenses:

                 a.       Taxes. All taxes that the Bondholder may be required
                          to pay because of the Secured Indebtedness (excluding
                          taxes based upon the net income of the Bondholder) or
                          because of the Bondholder's interest in any property
                          securing the payment of the Secured Indebtedness;
                 b.       Administration. All expenses that the Bondholder may
                          incur in connection with the preparation, execution,
                          administration or enforcement of this Agreement or of
                          any other document pertaining to the Secured
                          Indebtedness;
                 c.       Protection of Collateral. All costs of preserving
                          or disposing of any collateral securing the Secured
                          Indebtedness.
                 d.       Costs of Collection. All court costs and other costs
                          of collecting any debt, overdraft or other obligation
                          included in the Secured Indebtedness, including
                          compensation for time spent by employees of the
                          Bondholder;
                 e.       Litigation. All costs arising from any litigation,
                          investigation, or administrative proceeding (whether
                          or not the Bondholder is a party thereto) that the
                          Bondholder may incur as a result of the Secured
                          Indebtedness or as a result of the Bondholder's
                          association with the Borrower, including, but not
                          limited to, expenses incurred by the Bondholder in
                          connection with a cause or proceeding involving the
                          Borrower under any chapter of the Bankruptcy Code
                          or any successor statute thereto;
                 f.       Attorneys' Fees. Reasonable attorneys' fees and costs
                          incurred in connection with any of the foregoing.

If the Bondholder pays any of the foregoing expenses, they shall become a part
of the Secured Indebtedness and shall bear interest at the highest rate
applicable to the Secured Indebtedness from time to time. This paragraph shall
remain in full effect regardless of the full payment of the Secured
Indebtedness, the purported termination of this Agreement, the delivery of the
executed original of this Agreement to the Borrower, or the content or accuracy
of any representation made by the Borrower to the Bondholder; provided, however,
the Bondholder may terminate this paragraph by executing and delivering to the
Borrower a written instrument of termination specifically referring to this
paragraph.

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         14.      Consent to Jurisdiction and Service of Process. The Borrower
                  hereby irrevocably consents to the jurisdiction of the federal
                  and state courts of the State of New Jersey, for the purpose
                  of any litigation to which the Bondholder may be a party and
                  which concerns this Agreement or the Secured Indebtedness. It
                  is further agreed that venue for any such action shall lie
                  exclusively with courts sitting in the State of New Jersey,
                  unless the Bondholder agrees to the contrary in writing. The
                  Borrower hereby further irrevocably consents to service of
                  process being served in any suit, action or proceeding
                  concerning this Agreement or the Secured Indebtedness by
                  mailing a copy thereof by registered mail or certified mail,
                  postage prepaid, return receipt requested, or by overnight
                  courier service, to it at its address set forth herein or in
                  the Loan Agreement.
         15.      Not Partners:  No Third Party Beneficiaries. Nothing
                  contained herein or in any related document shall be deemed to
                  render the Bondholder a partner of the Borrower for any
                  purpose. This Agreement has been executed for the sole
                  benefit of the Bondholder and no third party is authorized to
                  rely upon the Bondholder's rights hereunder or to rely upon an
                  assumption that the Bondholder has or will exercise its
                  rights under this Agreement or under any document referred to
                  herein.
         16.      No Marshaling of Assets. The Bondholder may proceed against
                  collateral securing the Secured Indebtedness and against
                  parties liable therefore in such order as it may elect, and
                  neither the Borrower nor any creditor of the Borrower shall be
                  entitled to require the Bondholder to marshal assets. The
                  benefit of any rule of law or equity to the contrary is hereby
                  expressly waived.
         17.      Notices. Any communications concerning this Agreement or the
                  credit described herein shall be addressed as provided in the
                  Financing Agreement.
         18.      No Reliance on the Bondholder's Analysis. The Borrower
                  acknowledges and represents that, in connection with the
                  Secured Indebtedness, the Borrower has not relied upon any
                  financial projection, budget, assessment or other analysis by
                  the Bondholder or upon any representation by the Bondholder as
                  to the risks, benefits or prospects of the Borrower's business
                  activities or present or future capital needs incidental
                  thereto, all such considerations having been examined fully
                  and independently by the Borrower.
         19.      Legal and Binding Agreement. The Borrower warrants that the
                  execution and performance of this Agreement will not violate
                  any judicial or administrative order or government law or
                  regulation, and that this Agreement is valid, binding and
                  enforceable in every respect according to its terms, subject
                  to principles of equity and laws applicable to the rights of
                  creditors generally, including bankruptcy laws.
         20.      No Consent Required. The Borrower warrants that the Borrower's
                  execution, delivery and performance of this Agreement do not
                  require the consent of or the giving of notice to any third
                  party including, but not limited to, any other lender,
                  governmental body or regulatory authority, except for the
                  Issuer, to who such notice has been given.
         21.      Indulgence Not Waiver. The Bondholder's indulgence in the
                  existence of an Event of Default hereunder or any other
                  departure from the terms of this Agreement shall not prejudice
                  the Bondholder's rights to declare an Event of Default or
                  otherwise strict compliance with this Agreement
         22.      Cumulative Remedies. The remedies provided the Bondholder in
                  this Agreement are not exclusive of any other remedies that
                  may be available to the Bondholder under any other document or
                  at law or equity.
         23.      Amendment and Waiver in Writing. No provision of this
                  Agreement can be amended or waived, except by a statement
                  in writing signed by the party against which enforcement of
                  the amendment or waiver is sought.
         24.      Assignment. This Agreement shall be binding upon and inure to
                  the benefit of the respective heirs, successors and assigns of
                  the parties except that the Borrower shall not assign any
                  rights or delegate any obligations arising hereunder without
                  the prior written consent of the Bondholder.

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                  Any attempted assignment or delegation by the Borrower without
                  such required prior consent shall be void.
         25.      Entire Agreement; Termination of Existing Investing Agreement.
                  This Agreement and the other written agreements among the
                  parties represent the entire agreement among the parties
                  concerning the subject matter hereof, and all oral discussions
                  and prior agreements are merged herein. This Agreement is
                  intended to replace and supercede that certain Investment
                  Agreement dated as of April 25, 1997 among Borrower,
                  Bondholder (successor-in-interest to First Union National Bank
                  of Tennessee) and AmSouth Bank of Alabama.
         26.      Severability. Should any provision of this Agreement be
                  invalid or unenforceable for any reason, the remaining
                  provisions hereof shall remain in full effect.
         27.      Time of Essence. Time is of the essence of this Agreement,
                  and all dates and time periods specified herein shall be
                  strictly observed, except that the Bondholder may permit
                  specific deviations therefrom by its written consent.
         28.      Applicable Law. The validity, construction and enforcement of
                  this Agreement shall be determined according to the laws of
                  the State of New Jersey applicable to contracts executed and
                  performed entirely within the state. In this regard, it is
                  acknowledged that the Note, Loan Agreement and Financing
                  Agreement are governed by the substantive laws of the State of
                  Alabama, and the parties wish for New Jersey law to apply
                  hereto because the Bondholder has its places of business and
                  all payments on the Secured Indebtedness are due in the State
                  of New Jersey.
         29.      Gender and Number. Words used herein indicating gender or
                  number shall be read as context may apply.
         30.      Captions Not Controlling. Captions and headings have been
                  included in this Agreement for the convenience of the parties,
                  and shall not be construed as affecting the content of the
                  respective paragraphs.
         31.      Waivers Regarding Damages and Trial by Jury. The Borrower
                  agrees with the Bondholder, and the Bondholder agrees with the
                  Borrower, that they shall not have a remedy of punitive or
                  exemplary damages against the other in any dispute arising out
                  of this Agreement, and hereby waive any right or claim to
                  punitive or exemplary damages as they have not or which may
                  arise in the future in connection with any dispute arising out
                  of this Agreement. EACH PARTY HERETO HEREBY IRREVOCABLY WAIVES
                  ITS RIGHT TO A TRAIL BY JURY IN ANY ACTION ARISING HEREUNDER.
         32.      Other Concurrent Deliveries to Bondholder. Concurrently with
                  the execution hereof, the Borrower shall have delivered to the
                  Bondholder a good standing certificate issued by the
                  Borrower's state of incorporation within the last thirty (30)
                  days and such Uniform Commercial Code lien, tax lien, judgment
                  and pending litigation search results (which results shall be
                  in form and substance satisfactory to the Bondholder) as may
                  be requested by the Bondholder.
         33.      Counterparts. This Agreement may be executed in any number of
                  counterparts, all of which taken together shall constitute
                  one and the same document.

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             Duly executed and delivered as of the date first written above.

ATTEST:                                               ADTRAN, Inc.
/s/ Pat Gill                                          By: /s/ James E. Matthews
- ------------                                          -------------------------
Pat Gill                                              James E. Matthews
Executive Assistant                                   Senior Vice President/CFO

                                                      FIRST UNION NATIONAL BANK
                                                      By: /s/ Robyn G. Beh
                                                      --------------------
                                                      Robyn G. Beh
                                                      Vice President

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