TABLE OF CONTENTS

		Page
ARTICLE I DEFINITIONS			2
SECTION 1.1. Certain Definitions			2
ARTICLE II THE MERGER			14
SECTION 2.1. The Merger			14
SECTION 2.2. Effective Time			14
SECTION 2.3. Effects of the Merger			15
SECTION 2.4. Certificate of Incorporation and Bylaws			15
SECTION 2.5. Board of Directors			15
SECTION 2.6. Officers			15
SECTION 2.7. Conversion of Securities			15
SECTION 2.8. Payment of Merger Consideration; Other Payments			16
SECTION 2.9. Appraisal Rights			21
SECTION 2.10. Withholding Rights			21
SECTION 2.11. Lost Certificates			21
SECTION 2.12. Closing; Purchase Price Adjustments			22
SECTION 2.13. Post-Closing Purchase Price Adjustments			23
SECTION 2.14. Further Assurances			25
ARTICLE III REPRESENTATIONS AND WARRANTIES OF THE COMPANY			25
SECTION 3.1. Organization			25
SECTION 3.2. Subsidiaries			25
SECTION 3.3. Authorization			25
SECTION 3.4. Capitalization			26
SECTION 3.5. Noncontravention			27
SECTION 3.6. Government Consents and Approvals			27
SECTION 3.7. Financial Statements			27
SECTION 3.8. Absence of Certain Changes			29
SECTION 3.9. Litigation			31
SECTION 3.10. Material Contracts			31
SECTION 3.11. Real Property			32
SECTION 3.12. Personal Property			33
SECTION 3.13. Compliance with Laws; Permits			33
SECTION 3.14. Taxes			34
SECTION 3.15. Intellectual Property			36
SECTION 3.16. Compliance With Environmental Laws			40
SECTION 3.17. Employees; Labor Matters			41
SECTION 3.18. ERISA			43
SECTION 3.19. Insurance			44
SECTION 3.20. Government Contracts			44
SECTION 3.21. Bank Accounts			45

SECTION 3.22. Company Transaction Expenses			45
SECTION 3.23. Ethical Practices			45
SECTION 3.24. Affiliate Transactions			45
SECTION 3.25. Customers			46
SECTION 3.26. Accounts Receivable and Payable			46
SECTION 3.27. Books and Records			46
SECTION 3.28. Telecom Service Providers			46
SECTION 3.29. Brokers			47
ARTICLE IV REPRESENTATIONS AND WARRANTIES OF PARENT AND MERGER SUB			47
SECTION 4.1. Organization			47
SECTION 4.2. Authorization			47
SECTION 4.3. Noncontravention			47
SECTION 4.4. Government Consents and Approvals			48
SECTION 4.5. No Prior Activities			48
SECTION 4.6. Financial Ability			48
SECTION 4.7. Brokers			48
ARTICLE V COVENANTS			48
SECTION 5.1. Conduct of Business of the Company			48
SECTION 5.2. Approval of Stockholders			51
SECTION 5.3. Access to Information			51
SECTION 5.4. Exclusivity			51
SECTION 5.5. Cooperation			52
SECTION 5.6. Public Announcements			53
SECTION 5.7. Notification of Certain Matters			53
SECTION 5.8. Company Transaction Expenses			53
SECTION 5.9. Termination of Certain Agreements			53
SECTION 5.10. Payoff Letters			53
SECTION 5.11. Employee Matters			54
SECTION 5.12. Indemnification of Officers and Directors			54
SECTION 5.13. Taxes			55
SECTION 5.14. Cancellation of Options			58
ARTICLE VI CONDITIONS TO CONSUMMATION OF THE MERGER			58
SECTION 6.1. Conditions to Each Partys Obligations to Effect the Merger			58
SECTION 6.2. Conditions to the Obligations of Parent and Merger Sub			58
SECTION 6.3. Conditions to the Obligations of the Company			59
ARTICLE VII TERMINATION, AMENDMENT AND WAIVER			60
SECTION 7.1. Termination			60
SECTION 7.2. Effect of Termination			61
SECTION 7.3. Amendment			61
SECTION 7.4. Extension; Waiver			61

ARTICLE VIII INDEMNIFICATION			61
SECTION 8.1. Survival of Representations and Covenants			61
SECTION 8.2. Indemnification			62
SECTION 8.3. Manner of Indemnification			64
SECTION 8.4. Notice of Claims			64
SECTION 8.5. Third-Party Claims			65
SECTION 8.6. Mitigation; Exclusivity of Remedy			66
SECTION 8.7. Holder Representative			66
SECTION 8.8. Tax Treatment			68
ARTICLE IX MISCELLANEOUS			68
SECTION 9.1. Entire Agreement			68
SECTION 9.2. Assignment			69
SECTION 9.3. Severability			69
SECTION 9.4. Expenses			69
SECTION 9.5. Governing Law			69
SECTION 9.6. Jurisdiction; Forum			69
SECTION 9.7. Waiver of Jury Trial			69
SECTION 9.8. Specific Performance			70
SECTION 9.9. Notices			70
SECTION 9.10. Parties in Interest			71
SECTION 9.11. Counterparts; Facsimiles			71

EXHIBITS

Exhibits:

Exhibit A: Individuals Party to the Employment Agreements
Exhibit B: Form of Employment Letter
Exhibit C: Form of Escrow Agreement
Exhibit D: Knowledge Group
Exhibit E: Net Working Capital Methodology

AGREEMENT AND PLAN OF MERGER

     THIS AGREEMENT AND PLAN OF MERGER, dated as of April 19, 2006 (this Agreement), is by and among UltraDNS Corporation, a Delaware corporation (the Company), NeuStar, Inc., a Delaware corporation (Parent), UDNS Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Parent (Merger Sub), and Ron Lachman, solely in his capacity as the Holder Representative hereunder.

R E C I T A L S

          WHEREAS, Parent has formed Merger Sub for the purpose of merging it with and into the Company in order to acquire the Company as a wholly owned subsidiary;

          WHEREAS, the respective Boards of Directors of Parent, Merger Sub and the Company have approved and declared advisable the merger of Merger Sub with and into the Company upon the terms and subject to the conditions of this Agreement, and the respective Boards of Directors of Merger Sub and the Company have approved and adopted this Agreement;

          WHEREAS, the respective Boards of Directors of Merger Sub and the Company have determined that the Merger is in the best interest of their respective stockholders;

          WHEREAS, certain stockholders of the Company have entered into a voting agreement with Parent, dated the date hereof (the Voting Agreement), agreeing, among other things, to support the transactions contemplated by this Agreement;

          WHEREAS, the individuals listed on Exhibit A hereto have received employment letters from Parent in the form attached hereto as Exhibit B that will become effective as of the Effective Time;

          WHEREAS, Parent, Merger Sub and the Company desire to make certain representations, warranties, covenants and agreements in connection with the Merger and also to prescribe various conditions to the Merger; and

          WHEREAS, for certain limited purposes, and subject to the terms set forth herein, the Holder Representative shall serve as a representative of the holders of the outstanding shares of the Companys capital stock as of the Effective Time.

A G R E E M E N T

          NOW THEREFORE, in consideration of the respective covenants and promises contained herein and for other good and valuable consideration, the receipt and adequacy of which is hereby acknowledged, the parties hereto agree as follows:

ARTICLE I

DEFINITIONS

          SECTION 1.1. Certain Definitions. As used herein, the terms below shall have the following meanings. Any of such terms, unless the context otherwise requires, may be used in the singular or plural, depending upon the reference.

          Affiliate means, as applied to any Person, (a) any other Person directly or indirectly controlling, controlled by or under common control with, that Person, (b) any other Person that owns or controls 10% or more of any class of equity securities (including any equity securities issuable upon the exercise of any option or convertible security) of that Person or any of its Affiliates, or (c) any director, partner, officer, manager, agent, employee or relative of such Person. For the purposes of this definition, control (including with correlative meanings, the terms controlling, controlled by, and under common control with) as applied to any Person, means the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of that Person, whether through ownership of voting securities or by contract or otherwise.

          Aggregate Series A Preference Amount means the product of (x) the Series A Preference Amount and (y) the number of shares of Series A Preferred Stock outstanding immediately prior to the Effective Time.

          Aggregate Series B Preference Amount means the product of (x) the Series B Preference Amount and (y) the number of shares of Series B Preferred Stock outstanding immediately prior to the Effective Time.

          Agreement has the meaning specified in the preamble of this Agreement.

          Annual Financial Statements has the meaning specified in Section 3.7(a).

          Applicable Law means, with respect to any Person, any federal, state or local statute, law, ordinance, policy, guidance, rule, administrative interpretation, regulation, order, writ, injunction, directive, judgment, award, decree or other requirement, of any Governmental Entity (including any Environmental Law) applicable to such Person or its respective properties or assets.

          Arbitrator has the meaning specified in Section 2.13(c).

          Audited Financial Statements has the meaning specified in Section 3.7(a).

          Business Day means any day that is not a Saturday, a Sunday or other day on which banks are required or authorized by Applicable Law to be closed in New York, New York.

          Cap has the meaning specified in Section 8.2(d).

          Cash means an amount equal to the total amount of cash and cash equivalents of the Company, determined in accordance with GAAP.

          CERCLA means the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended (42 U.S.C. 9601 et seq.).

          Certificate of Merger has the meaning specified in Section 2.2.

          Certificates has the meaning specified in Section 2.8(b).

          Claim Notice has the meaning specified in Section 8.4(a).

          Closing has the meaning specified in Section 2.12(a).

          Closing Date has the meaning specified in Section 2.12(a).

          Closing Date Balance Sheet has the meaning specified in Section 2.13(b).