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                                                                   Exhibit 10.11

                              EMPLOYMENT AGREEMENT

This is an Employment Agreement ("Agreement") dated September 10, 2001, between
you, James M. Bannantine, a resident of the State of Texas, and Dorsal Networks,
Inc., a Delaware corporation ("Dorsal" or the "Company"). Whereas the Company
desires to employ you and to assure itself of your continued services, and you
desire to be employed by the Company for the period set forth below, we both
agree, in consideration of the following covenants and agreements, to be legally
bound by the terms and conditions of this Agreement.

1.   Employment Term.

The Company agrees to employ you as its Chief Executive Officer. Additionally,
you will be a member of the Board of Directors representing the class of common
shareholders of the Company. You will begin your employment with the Company on
September 10, 2001, which date is referred to as the Commencement Date in this
Agreement. Your employment will end after this initial four-year period, unless
terminated earlier (see Termination, Section 6 below), or unless automatically
renewed for an additional one-year period (As used in this Agreement, "Term"
shall mean the initial four-year period and any renewal periods.) No later than
sixty (60) days before the expiration of the Term, the parties shall negotiate
in good faith relative to the terms and conditions of Section 4 to renew this
Agreement based upon the performance of the Company and you during the Term.

2.   Employee Representations.

You make the following representations and guarantees about your ability to
enter this Agreement and to comply with its terms and conditions: that you enter
this Agreement voluntarily, and that your employment under this Agreement,
except to the extent acknowledged in this Subsection, will not conflict with any
legal duties owed to others, or with any other agreement to which you are a
party or by which you are bound, including but not limited to any
non-competition or non-solicitation clause contained in an earlier employment
agreement. Furthermore, you represent that your outside activities will be
contained and will not interfere with your ability to perform the duties
required in this position. Notwithstanding the foregoing, nothing herein shall
prevent you from serving on charitable boards or committees, so long as such
activities do not significantly interfere with the performance of your
responsibilities hereunder.

3.   Duties and Extent of Services.

As Chief Executive Officer and a member of the Board of Directors, you will
devote substantially all of your business time, attention, and efforts
diligently performing to the best of your ability all of the duties required in
this position, according to the direction and under the supervision of the Board
of Directors, and in compliance with all Company policies. You will also serve
in such other positions or offices of the Company or its subsidiaries as the
Board of Directors shall determine.


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4.   Compensation.

You will receive the following compensation package to take effect on the
Commencement Date:

     a.   A base salary of $350,000 per annum. This salary is effective and
          payable beginning on the Commencement Date, or upon the renewal of
          this Agreement, and will be paid to you in accordance with the
          Company's payroll policy. The Board of Directors will review your base
          salary annually.

     b.   Under the terms and conditions of the Dorsal Networks, Inc. 2000
          Equity Compensation Plan (the "Plan"), and any other terms and
          conditions that the Board may impose under the Plan, such other terms
          and conditions being imposed consistent with Section 13 of the Plan,
          you will be eligible to join the Company's Equity Compensation
          program. Pursuant to the terms of the Plan, you will receive options
          to purchase an amount of shares of the Company's common stock
          representing 5.00% of the Company's outstanding share capital as of
          the close of its Series B financing ("Option Grant"). If the Company
          issues more shares in connection with its Series B financing than is
          indicated on the capitalization table provided to you, you will
          receive additional options so that your equity in the Company equals
          5% at the final closing of the Series B financing. Options are
          immediately exercisable as of the Commencement Date. After exercise,
          the shares purchased by your exercising options will vest as follows:
          Twenty-five percent (25%) of the shares purchasable with the Option
          Grant will vest on your Commencement Date, but will be subject to
          divestiture as set forth below and will be held in escrow by the
          Company until the first anniversary of your Commencement Date ("Vested
          Shares"). Pursuant to the terms of this Agreement and the escrow
          agreement, on the first anniversary of your Commencement Date the
          Company will release the Vested Shares to you. The remainder will vest
          ratably, in an equal amount each month, for the 36-month period
          commencing the month after the first anniversary of your Commencement
          Date. If shares received through these options are unvested when your
          employment with the Company terminates for any reason, the Company has
          the right to buy back the unvested shares at the same exercise price
          you paid for them within thirty (30) days of termination. You are
          responsible for obtaining your own tax and other legal and accounting
          advice in connection with the options.

          For your benefit, if you choose to exercise your options to purchase
          Vested Shares, we will set aside those shares in an escrow account,
          for which the Company will be the escrow agent. The terms of the
          escrow agreement, a copy of which has been provided to you ("Escrow
          Agreement") will provide relevant in part, that (i) if you are
          terminated Without Cause as defined in Section 6(d) within the first
          year of employment, the escrow agent will release the shares to you;
          (ii) if you are terminated for Cause as defined in Section 6(c) within
          the first year of employment, you forfeit any rights you may have to
          those shares so long as the Company pays you an amount equal to the
          exercise price you paid for those Shares within thirty (30) days of
          your termination; and (iii) if you terminate your

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          employment for Good Cause as defined in Section 6(e) within the first
          year of employment, one-half of the shares that are set aside in the
          escrow account will be released to you by the escrow agent and the
          Company may repurchase the remaining shares held in escrow at a price
          equal to the exercise price paid by you for those shares within thirty
          (30) days of the effective date of your termination. If you terminate
          your employment with the Company within the first year of employment
          for any reason other than Good Cause as defined in Section 6(e), you
          forfeit any rights you have to those shares so long as the Company
          pays you an amount equal to the exercise price you paid for those
          Shares within thirty (30) days of your termination. If the Company
          does not offer to repurchase the Shares within thirty (30) days of
          termination, the Company's repurchase right shall terminate. Upon the
          occurrence of (i), (ii) or (iii), the escrow agent will not release
          the shares absent the Company and you executing a definitive
          separation agreement which includes a mutual release.

          i.   Change of Control. Notwithstanding the provisions of this
               Subsection, you shall have the following rights with respect to
               this option in the event of a Change of Control
               (as that term is defined in the Plan). First, if the surviving
               company does not assume the Plan, all unvested shares held by you
               shall automatically vest. Second, if, upon a Change of Control,
               the Plan is assumed by the surviving corporation, and within
               twelve (12) months of such Change of Control you are terminated
               Without Cause as defined in Subsection 6(d) below, then all
               unvested shares held by you under this option shall automatically
               vest on the day of termination. Finally, in the event a Change of
               Control occurs, the Plan is assumed by the surviving corporation,
               and within twelve (12) months of a Change in Control you resign
               for Good Reason as defined in Subsection 6(f) below, fifty
               percent (50%) of any remaining unvested shares held by you under
               this option shall automatically vest on the day of your
               resignation. Under no other circumstances shall you be eligible
               to receive automatic vesting in the event of a Change of Control.

          ii.  Termination of Employment: The release of the Vested Shares in
               the event of Termination shall take place pursuant to the terms
               of the Escrow Agreement between you and the Company.

          iii. Loan. To assist you in exercising the Option Grant, the Company
               will provide you with an interest-bearing loan to acquire the
               shares that you may purchase therewith. Under the terms of the
               loan you will be required to repay any outstanding amount due the
               Company (a) within 30 days of the date of termination of your
               employment with the Company for any reason, or (b) within 180
               days of (i) the Initial Public Offering of the Company's stock,
               or (ii) a Change of Control, whichever occurs earlier. You may
               repay the loan and any interest due thereon at any time prior to
               these events without any penalty.

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5.   Other Employee Benefits.

     a.   General. You will be entitled to participate in any employee benefits
          programs and arrangements generally made available to executive
          officers by the Company or the Company's affiliates, such as pension
          plans, contributory and noncontributory welfare and benefit plans,
          disability plans, medical insurance, and death benefit and life
          insurance plans. Alternatively, the Company shall reimburse you for
          the cost of your current permanent Enron COBRA health and life
          insurance plans, provided that the cost to the Company of reimbursing
          you for your participation in those plans does not exceed the cost of
          providing you with coverage under the Company's health and life
          insurance plans. While you are an employee, the Company will provide,
          at the Company's expense, directors and officers liability insurance,
          in accordance with industry practice in the United States, and allow
          you three (3) weeks of annual leave per year in accordance with the
          Company's leave policies.

     b.   Reimbursement of Expenses. While you are an employee, the Company will
          reimburse you for travel, entertainment, and other out-of-pocket
          expenses, provided the following requirements are met: (i) you incur
          the expense on the Company's behalf; (ii) the expenses result from the
          performance of your duties; (iii) the type and amount of expenses are
          like those customarily incurred by others in similar positions; (iv)
          you adequately account for the expenses, as required by the Internal
          Revenue Code; and (v) you timely provide copies of receipts for all
          expenses greater than twenty-five dollars ($25.00).

     c.   Relocation. You will receive a comprehensive relocation package
          pursuant to the Company's relocation policy, a copy of which has been
          provided to you. The Company shall pay reasonable commuting costs
          between Baltimore and Houston and temporary housing (but not
          transportation) in the Baltimore-Washington area through June 30,
          2002.

6.   Termination.

This Agreement and your employment with the Company may be terminated in any one
of the following ways:

     a.   Death. If you die during the term of this Agreement, this Agreement
          will automatically terminate and the Company will have no further
          obligations except those detailed in the Separation Pay subsection
          (Subsection 6(g) below);

     b.   Disability.

          i.   If you become permanently disabled (as defined in subparagraph
               (ii) below) during your employment, the Company has the right to
               terminate you with written notice, and such termination may be
               effective immediately or on such other future date as specified
               in the notice. Afterwards the Company will have no further
               obligations to you under this Agreement, except those detailed in
               this subsection 6(b) and in the

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               Separation Pay subsection (Subsection 6(g) below). For one year
               following the date of termination for permanent disability, the
               Board of Directors, in its discretion, may allow you to continue
               to participate in all benefit plans and programs, including
               pension and insurance, offered by the Company to its executive
               officers. After that year ends, your ability to continue
               participation in such plans, or to receive other coverage, will
               be determined by those plans and programs.

          ii.  For purposes of this Agreement, "permanent disability" is defined
               in one of two ways. If the Company maintains a disability
               insurance policy that defines the term, and you are insured by
               that policy, that definition will apply to this Agreement. If the
               Company does not maintain such a policy, or the policy does not
               contain a definition of "permanent disability," then the term
               will be defined as any physical or mental disability or
               incapacity that renders you incapable of performing the essential
               functions of your job and its duties, as described in the Duties
               and Extent of Services section (Section 3 above), for a period of
               three (3) consecutive months or an aggregate of four (4) months
               during any one-year term of employment.

     c.   Cause.

          i.   The Company may terminate you for Cause (as defined below) with
               written notice to you, effective immediately (unless a future
               effective date is specified in the Company's notice). After
               termination for Cause, the Company will have no further
               obligations to you under this Agreement. In addition, except as
               otherwise required by applicable law, the Board of Directors will
               determine if you will retain the right to participate in any
               benefit programs or plans. After you receive written notice of
               termination for Cause, you will have the opportunity to discuss
               the allegations with the Board within five (5) days prior to the
               Board making a final determination of the existence of Cause.

               The term "Cause" shall mean that the Board of Directors has found
               that that you have: (i) breached this Agreement; (ii) engaged in
               (a) criminal or quasi-criminal acts of disloyalty to the Company,
               including without limitation, fraud, embezzlement, theft,
               commission of a felony or (b) proven job-related dishonesty;
               (iii) disclosed trade secrets or confidential information of the
               Company to persons not entitled to receive such information; (iv)
               breached any non-competition or non-solicitation agreement
               between you and the Company; (v) willfully and continuously
               failed to substantially perform your duties under this Agreement
               (other than as a result of physical or mental illness or injury),
               after the Board of the Company delivers to you a written demand
               for substantial performance that specifically identifies the
               manner in which the Board believes that you have not
               substantially performed your duties; or (vi) allowed your outside
               activities to preclude you from performing your job functions as
               described herein and you have been unable to cure such deficiency
               within the ten

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               (10) day period immediately following the date on which the Board
               provides you with written notice of such deficiency.

     d.   Without Cause. The Company may terminate you Without Cause and for any
          reason whatsoever upon thirty (30) days prior written notice. If,
          within your first twelve (12) months of employment, you are terminated
          Without Cause, subject to the terms and conditions of the Company's
          benefit plans and programs then in effect, the Company shall permit
          you to continue to participate in all benefit plans and programs
          offered to the Company's officers for a period equal to six (6) months
          or the remainder of the then-current term of this Agreement, whichever
          period is shorter. Any termination by the Company, other than
          termination for Cause, disability, or death, shall be considered
          termination Without Cause.

     e.   By Executive.

          i.   You may also terminate your employment with the Company for any
               reason whatsoever, but in all cases upon thirty (30) days written
               notice to the Company. If you terminate your employment for Good
               Cause (as defined below), subject to the terms and conditions of
               the Company's benefit plans and programs then in effect, the
               Company shall permit you to continue to participate in all
               benefit plans and programs offered to the Company's officers for
               a period equal to three (3) months or the remainder of the
               then-current term of this Agreement, whichever period is shorter.
               If you terminate for a reason other than Good Cause, the Company
               will have no further obligations under this Agreement, and you
               will not be eligible to receive any severance compensation.

          ii.  Under this Agreement, Good Cause means that you have terminated
               this Agreement thirty (30) days after the occurrence of any one
               of the following events, and the Company has failed to cure such
               event within the time period set forth in this Section 6(e)(ii):
               (a) any reduction in your base salary as set forth in this
               Agreement or thereafter increased as established by Section 4(a)
               above, unless such reduction is (1) pursuant to a change in the
               Company's compensation policies generally and (2) effects all of
               the executives with titles of Senior Vice President and higher,
               or (b) a material reduction in your job duties. In either of the
               above instances, however, you must promptly notify the Company in
               writing and in reasonable detail the basis for your resignation
               for Good Cause, and allow the Company twenty (20) business days
               in which to correct the circumstances prompting the resignation.
               The definition of Good Cause under this Section 6(e) shall not
               apply to a termination for Good Reason within the Window Period
               as defined in Section 6(f), below.

          f.   Change of Control, Good Reason; Window Period. You may terminate
               your employment for Good Reason during the Window Period. For
               purposes of this Agreement, the "Window Period" shall mean the 12
               months immediately following the event constituting a Change of
               Control. For example, if the Change

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               of Control were September 3, 2002, the Window Period would close
               on September 2, 2003. For purposes of this section, "Good Reason"
               shall mean:

          i.   The assignment to you of any duties materially inconsistent with
               the duties or responsibilities as contemplated under Section 1 or
               any other action by the Company that results in a material
               diminution in such position, authority, duties, or
               responsibilities, excluding for this purpose a change in title or
               an isolated, insubstantial, and inadvertent action not taken in
               bad faith and which is remedied by the Company promptly after
               receipt of notice thereof given by you;

          ii.  Any failure by the Company to comply with any of the applicable
               provisions of Section 4, other than an isolated, insubstantial,
               and inadvertent failure not occurring in bad faith and which is
               remedied by the Company promptly after receipt of notice thereof
               given by you; or

          iii. The Company requires you to be based at any office or location
               other than Columbia, Maryland for a period of in excess of sixty
               (60) consecutive days.

In any of the above instances, however, you must promptly notify the Company in
writing and in reasonable detail the basis for your resignation for Good Reason
and allow the Company twenty (20) business days in which to correct the
circumstances prompting the resignation.

     g.   Effect of Termination. Unless otherwise provided by this Agreement or
          the Plan, the Company will have no further obligations to you once
          your employment is terminated. You will continue to be bound by the
          Confidentiality, Return of Company Property (Section 7) and Unfair
          Competition (Section 8) sections of this Agreement after termination.

     h.   Separation Pay. Upon any termination of this Agreement, you (or your
          estate or personal representative, as applicable) shall be entitled to
          receive all compensation earned (including all benefits and
          reimbursements accrued and due) through the effective date of
          termination, and all other amounts payable to you under this
          Agreement. Your right to receive any special separation pay is as
          follows: (i) if you are terminated for Cause, subject to the
          provisions of this Subsection (h), you will receive compensation for
          one (1) month, for a sum total equal to eight and three-tenths percent
          (8.3%) of your base salary as set forth in this Agreement or
          thereafter increased; (ii) if you are terminated Without Cause,
          subject to the provisions of this Subsection, you will receive
          compensation for twelve (12) months, paid monthly, for a sum total
          equal to your base salary as set forth in this Agreement or thereafter
          increased; and (iii) if your employment is terminated for Good Cause,
          you will receive compensation for six (6) months, paid monthly, for a
          sum total equal to fifty percent (50%) of your base salary as set
          forth in this Agreement or thereafter increased. The Company may
          require as a condition of receiving any separation pay that you sign a
          mutual release with the Company, a draft copy of which has been
          provided to you.


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7.   Confidentiality, Return of Company Property.

     a.   Confidentiality. You acknowledge that, as an employee, you will have
          access to a wide range of confidential information of the Company.
          This includes information and knowledge pertaining to products,
          inventions, discoveries, improvements, innovations, designs, ideas,
          trade secrets, proprietary information, manufacturing, packaging,
          advertising, marketing, distribution and sales methods, sales and
          profit figures, personnel records and practices, customer and client
          lists, and relationships between the Company and dealers,
          distributors, sales representatives, wholesalers, customers, clients,
          suppliers and others who have business dealings with them. You further
          acknowledge that such confidential information is a valuable and
          unique asset to the Company. Therefore, you agree that both during and
          after your employment with the Company, you will not disclose any
          confidential information of the Company to any person or entity,
          except as your job duties may require, without prior written
          authorization from the Board of Directors. This obligation does not
          apply to confidential information that becomes public knowledge,
          unless it becomes public through your breach of this Agreement, a
          violation of an existing confidentiality agreement with the Company by
          someone else, or a required disclosure by court order or applicable
          law.

     b.   Company Property. All records, designs, business plans, financial
          statements, customer lists, manuals, memoranda, lists, research and
          development plans, Intellectual Property (as that term is defined in
          the accompanying Proprietary Information and Inventions Agreement),
          and other property delivered to or compiled by you or at your
          direction by or on behalf of the Company or its vendors or customers
          that pertain to the business of the Company shall be and remain the
          property of the Company and be subject at all times to the Company's
          discretion and control. Likewise, upon termination of your employment,
          all correspondence, reports, records, charts, advertising materials
          and other similar data pertaining to the business, activities,
          research and development, Intellectual Property, or future plans of
          the Company that you collect or obtain access to shall be delivered
          promptly to the Company without request.

8.   Unfair Competition.

     a.   Non-Compete Covenant. You agree that during the term of this
          Agreement, and for a period equal to: one (1) year from the
          termination of your employment you shall not, directly or indirectly,
          for yourself or on behalf of or in conjunction with any other person,
          company, partnership, business, group, venturer, or other entity
          (each, a "Person"), without the prior written consent of the Company:

          i.   engage, directly or indirectly, as an officer, director,
               shareholder, owner, partner, joint venturer, or in any managerial
               capacity, whether as an employee, independent contractor,
               consultant or advisor (paid or unpaid), or as a sales
               representative, in any business selling, marketing, or in
               providing any products or services, or in research and
               development for the

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               purposes of providing any products or services in competition
               with any aspect of any business of the Company over which you
               have had management responsibility within the United States (the
               "Territory") during your employment;

          ii.  directly or indirectly, solicit, recruit, call upon or hire any
               Person who is, at that time, or who was at any time within the
               prior two (2) years, an employee of the company in a managerial
               capacity for the purpose or with the intent of enticing such
               employee away from or out of the employ of the Company, although
               you may call upon and hire any member of your immediate family;

          iii. directly or indirectly, solicit, entice, induce or otherwise call
               upon any Person who is, at that time, or who has been, within the
               prior two (2) years, a customer of the Company within the United
               States, or in any other country in which the Company conducts a
               material amount of business, for the purpose of soliciting or
               selling products or services in competition with the Company; or

          iv.  directly or indirectly, solicit, entice, induce or otherwise call
               upon any prospective acquisition candidate, on your own behalf or
               on behalf of any competitor of the Company, which candidate was
               either called upon by the Company or for which the Company made
               an acquisition analysis, for the purpose of acquiring such
               entity.

     b.   Investments. Irrespective of Subsection 8(a) above, you may make and
          hold certain investments in the Company's competitors and not violate
          these competition restrictions. These investments must be held as
          shares that are actively traded on a national exchange or NASDAQ NMS,
          an over-the-counter market in the United States, or any recognized
          foreign exchange. Your investment may not exceed five percent (5%) of
          the competitor's outstanding securities, and such investment shall not
          relieve you of any of your obligations under this Agreement.

     c.   Reasonableness. You agree that the foregoing covenants in this Section
          8 impose a reasonable restraint on you in light of the activities and
          business of the Company on the date of the execution of this Agreement
          and the current plans of the Company. You acknowledge that the
          covenants in this Section shall not prevent you from earning a
          livelihood upon the termination of your employment hereunder, but
          merely prevents unfair competition with the Company for a limited
          period of time. Notwithstanding the foregoing, it is your intent and
          the Company's intent that such covenants be construed and enforced in
          accordance with the changing activities, business, and locations of
          the Company throughout the term of these covenants.

     d.   Severability of this Section. Each part and restriction of this
          Section 8 can stand alone and be enforced separately. If any part of
          this Section is unenforceable, the



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          other parts will not be affected. If a court found any of the
          restrictions to be unenforceable, the remainder will be enforced to
          the extent the court finds reasonable. This Agreement will then
          conform to the court's decision.

     e.   Company's Enforcement is not Limited. All of the covenants in this
          Section 8 shall be construed as an agreement independent of any other
          provision in this Agreement, and the existence of any claim or cause
          of action you may assert against the Company, whether predicated on
          this Agreement or otherwise, shall not constitute a defense to the
          enforcement by the Company of such covenants.

9.   Specific Performance.

You acknowledge that your services are of a special, unique, and extraordinary
character, and in connection with such services, you will have access to
confidential information vital to the Company's business. By reason of this, you
consent and agree that if you violate any of the provisions of Section 7 or 8 of
this Agreement relating to confidential information and unfair competition, the
Company would sustain irreparable injury and that monetary damages would not
provide adequate remedy to the Company. You hereby agree that the Company shall
be entitled to have Sections 7 or 8 of this Agreement specifically enforced
(including, without limitation, by injunctions and restraining orders) by any
court having equity jurisdiction. Nothing in this Section, however, shall be
construed as prohibiting the Company from pursuing any other remedies available
to it for such breach or threatened breach, including the recovery of damages
from you.

10.  Complete Agreement.

This Agreement and its related documents (i.e., the Proprietary Information and
Inventions Agreement and your offer letter of employment) contain all provisions
and conditions relating to your employment. Any prior agreements, arrangements,
or understandings you had are no longer valid or applicable. Any change to this
Agreement must be made in writing and signed by both parties.

11.  Waiver.

Either party may waive a breach of this Agreement committed by the other. If
this occurs, that waiver will not serve as a waiver of a later breach.

12.  Indemnity.

The Company shall provide you with indemnity and shall hold you harmless against
judgments, fines, amounts paid in settlement, and reasonable expenses incurred
by you in connection with the defense of any action or proceeding in which you
are a party by reason of your position as Chief Executive Officer and a member
of the Board of Directors of the Company, or for any acts or omissions made by
you in good faith in the performance of any of your duties hereunder, including
duties undertaken as an officer or director of any affiliated company or entity;
provided, however, that such indemnity shall be consistent with Delaware law and
with the provisions contained within the Company's By-laws and charter, or the
affiliated company or

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entity's By-laws or charter, addressing the indemnification of its directors,
officers and authorized representatives for actions of the nature described
herein.

13.  Governing Law.

The laws of the State of Maryland govern the interpretation and enforcement of
this Agreement. In determining the governing law, no reference shall be made to
Maryland's choice of law provisions.

14.  Assignability.

You may not assign or transfer all or any portion of this Agreement without the
Company's prior written permission. Any attempt you make to do so is null and
void. The Company may transfer and assign this Agreement to any of the Company's
successors, if necessary. The successors must assume all rights and obligations
of this Agreement and will be bound by them.

15.  Severability of the Provisions of the Agreement.

If a court determines any part of this Agreement to be void or unenforceable,
the remainder of the Agreement will still have its full effect.

16.  Delivery of Notices.

All notices permitted or required by the agreement must be in writing and
delivered by one of these means, in each case with confirmation of receipt:

          o    In person;

          o    By telecopier;

          o    By courier service providing for next-day delivery; or

          o    By registered or certified mail, return receipt requested, to the
               following addresses:

                            If to the Company:

                            9212 Berger Road
                            Columbia, Maryland  21046

                            If to you:

                            5847 San Felipe, Suite 1700
                            Houston, Texas  77057

Either party may change their address with written notice.

Notice is deemed given depending on the manner it is sent:

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          o    Personally - upon receipt;

          o    By telecopier - when telecopied;

          o    By courier service - the next business day after deposit with the
               service; or

          o    By certified or registered mail - three days after mailing with
               postage paid.

17.  Counterparts of the Agreement.

If this Agreement is executed in one or multiple counterparts, we both deem each
to be an original. Together these counterparts will constitute one instrument.

As witnessed, both parties execute this employment agreement as of September __,
2001.

                                         DORSAL NETWORKS, INC.


                                         By: /s/ John Spirtos
                                            ------------------------------------
                                            John Spirtos

                                         Acting President

                                         /s/ James M. Bannantine
                                         ---------------------------------------
                                         James M. Bannantine


                                       12

<PAGE>



                               AMENDMENT AGREEMENT

     This AMENDMENT AGREEMENT, dated as of January ___, 2002, is made and
entered into by and among Dorsal Networks, Inc., a Delaware corporation
("Dorsal") and James M. Bannantine ("Bannantine").

     WHEREAS, reference is made to the Agreement and Plan of Merger dated as of
January __, 2002 (the "Merger Agreement"), among Corvis Corporation, a Delaware
corporation ("Corvis"), Corvis Acquisition Company, Inc., a Delaware corporation
and a wholly-owned subsidiary of Corvis ("Corvis Sub"), and Dorsal, providing
for, among other things, the merger (the "Merger") of Corvis Sub with and into
Dorsal, with Dorsal surviving the Merger as a wholly-owned subsidiary of Corvis
and the Principal Stockholders, along with other stockholders of Dorsal,
receiving shares of common stock of Corvis, $.01 par value per share ("Corvis
Common Stock"), in exchange for shares of capital stock of Dorsal, in the manner
provided in the Merger Agreement (capitalized terms used herein and not
otherwise defined shall have the meaning ascribed to such terms in the Merger
Agreement);

     WHEREAS, Bannantine and Dorsal are parties to that certain Employment
Agreement, dated September 10, 2001 (the "Employment Agreement");

     WHEREAS, in connection with the transactions contemplated by the Merger
Agreement, Bannantine and Dorsal have agreed to make certain provisions with
respect to the amendment of certain terms of the Employment Agreement; and

     WHEREAS, the amendment of the Employment Agreement is a material term of
the Merger.

     NOW, THEREFORE, in consideration of the premises and the representations
and warranties and agreements contained herein, the parties hereto agree as
follows:

     1.   Amendments and Acknowledgments Regarding Employment Agreement.

          (a)  Reference to Company. Effective as of the Effective Time (as
defined in the Merger Agreement), the term "Company", as used in the Employment
Agreement, shall mean the Surviving Corporation (as defined in the Merger
Agreement).

          (b)  Options. The first three (3) sentences of Section 4(b) of the
Employment Agreement shall be deleted in their entirety and the following shall
be inserted in lieu thereof:

     "Effective as of the Effective Time, and pursuant to the terms of Section
1.8 of the Merger Agreement, Corvis shall grant Corvis Options (as defined in
the Merger Agreement) to Bannantine to purchase the number of shares of Corvis
Common Stock set forth opposite Bannantine's name on Schedule II to the Merger
Agreement which Corvis Options shall be subject to the terms of the 2000 Corvis
Long Term Incentive Plan."

<PAGE>

          (c)  Change of Control. The parties hereby acknowledge and agree that
the transactions contemplated by the Merger constitute a Change in Control for
all purposes referenced in the Employment Agreement. However, Bannantine hereby
acknowledges and agrees that notwithstanding the terms and conditions of Section
4(b)(i) of the Employment Agreement, for purposes of such Section 4(b)(i) only,
the Merger will not, in and of itself, trigger any accelerated vesting of the
Option Grant and accordingly Bannantine agrees to waive any accelerated vesting
under Section 4(b)(i) solely as a result of the Merger. In addition,
notwithstanding the fact that Corvis is not assuming the Plan (as defined in the
Employment Agreement), for purposes of the third and fourth sentences of Section
4(b)(i), the condition of assumption of the Plan shall be deemed to have been
satisfied.

          (d)  Loans. Pursuant to the terms of Section 4(b)(iii) of the
Employment Agreement, Dorsal agreed to provide you with an interest bearing loan
to be used in connection with the exercise of the Option Grant granted to you
under Section 4 of the Employment Agreement. In connection therewith, the second
sentence of Section 4(b)(iii) shall be deleted in its entirety and the following
shall be inserted in lieu thereof:

          "Under the terms of the loan you will be required to repay any
outstanding amount due the Company (i) within thirty (30) days of the
termination of your employment with the Company for any reason, or (ii) within
one (1) year following the Effective Time, whichever occurs earlier."

          (e)  Good Reason. The parties acknowledge that Dorsal will become a
wholly-owned subsidiary of Corvis as a result of the Merger and Bannantine will
therefore report to different persons and his responsibilities will be
commensurate with his role as the CEO of a wholly-owned subsidiary of a public
company rather then as the CEO of a privately held company (a "Change in
Circumstances"). In connection therewith, Bannantine hereby acknowledges and
agrees that notwithstanding the terms and conditions of Section 6(f)(i) of the
Employment Agreement, the Change in Circumstances in connection with the Merger,
shall not be deemed to be inconsistent with or in violation of Section 6(f)(i)
of the Employment Agreement, and Bannantine hereby acknowledges and agrees that
such Change in Circumstances in connection with the Merger shall not be reason
for a Good Reason termination as set described in Section 6(f) of the Employment
Agreement.

     2.   Miscellaneous.

     (a)  Good Faith. Following the execution hereof and prior to the Effective
Time, the parties agree to negotiate in good faith to reach agreement on the
terms of an employment agreement between Bannantine and Corvis to replace the
Employment Agreement as amended hereby.

     (b)  Counterparts. This Agreement may be executed in any number of
counterparts, and each such counterpart hereof shall be deemed to be an original
instrument, but all such counterparts together shall constitute but one
agreement.

                                       2

<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Amendment Agreement
to be executed and delivered on the date first above written.


                                       DORSAL NETWORKS, INC.


                                       By: /s/ Sanford C. Reback
                                          ___________________________
                                       Name:  Sanford C. Reback
                                       Title: Secretary and General Counsel

                                       /s/ James M. Bannantine
                                       ______________________________
                                       James M. Bannantine

                                       3

<PAGE>

November 18, 2002

James Bannantine
Corvis Corporation
7015 Albert Einstein Drive
Columbia, MD  21046

         Re:   Salary Reduction

Dear Jim:

         In response to recent market conditions, our Board of Directors has
determined that it is necessary for Corvis to make a change in its compensation
policies. This policy change will result in the reduction of your salary by ten
(10%) percent from its current level.

         This letter will have the effect of amending your employment agreement
to provide for this reduced salary; however, except as expressly set forth
herein, it does not modify any other terms of your employment agreement. By
signing in the space provided below, and in consideration of your continued
employment and this year's annual option grant, you will have agreed to this
amendment to your employment agreement, and to accept this salary reduction and
waive any and all potential claims against the company, its officers, directors
and employees, arising therefrom.

         Should you have any additional questions regarding the foregoing,
please feel free to contact me.

Sincerely,

/s/ David Huber
David Huber
Chairman and CEO

                  Agreed and Accepted:

                   /s/ James Bannantine
                  ----------------------------
                  James Bannantine