STOCK PURCHASE AGREEMENT

NET2PHONE, INC., a Delaware corporation (the “Company”), proposes to issue and sell to IDT Corporation., a Delaware corporation (“IDT”), 1,250,000 shares (the “Shares”) of the Company’s Common Stock, par value $0.01 per share (the “Common Stock”). The Shares are in addition to 1,250,000 shares (the “Liberty Shares”) of Common Stock to be sold to Liberty N2P III, Inc., a Delaware corporation and a wholly owned subsidiary of Liberty Media Corporation (“Liberty”), 10,500,000 shares (the “Underwritten Shares”) of Common Stock to be sold to certain underwriters engaged by the Company (the “Underwriters”) and up to an additional 1,575,000 shares (the “Option Shares”) of Common Stock that may be sold to the Underwriters upon exercise of an over-allotment option. The Shares, the Liberty Shares, the Underwritten Shares and the Option Shares are herein referred to collectively as the “Offered Shares.”

The Company hereby confirms its agreement with IDT concerning the purchase and sale of the Shares, as follows:

1. Registration Statement. The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Securities Act”), a registration statement (File No. 333-110118) relating to the Offered Shares, which includes two prospectuses: one of which relates to the sale of the Underwritten Shares and the Option Shares and the other of which relates to the sale of the Shares and the Liberty Shares. Such registration statement, as amended at the time it becomes effective, including the information, if any, deemed pursuant to Rule 430A under the Securities Act to be part of the registration statement at the time of its effectiveness (“Rule 430 Information”), is referred to herein as the “Registration Statement”; and as used herein, the term “Preliminary Prospectus” means each prospectus included in such registration statement (and any amendments thereto) before it becomes effective, any prospectus filed with the Commission pursuant to Rule 424(a) under the Securities Act and any prospectus included in the Registration Statement at the time of its effectiveness that omits Rule 430A Information, and the term “Prospectus” means each of (i) the prospectus in the form first used to confirm sales of the Underwritten Shares (the “Underwritten Prospectus”) and (ii) the prospectus (the “L/IDT Prospectus”) in the form delivered to IDT and Liberty on November 19, 2003. If the Company files an abbreviated registration statement pursuant to Rule 462(b) under the Securities Act (“Rule 462 Registration Statement”), then any reference herein to the term “Registration Statement” shall be deemed to include such Rule 462 Registration Statement. Any reference in this Agreement to the Registration Statement, any Preliminary

Prospectus or any Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act, as of the effective date of the Registration Statement or the date of such Preliminary Prospectus or Prospectus, as the case may be, and any reference to “amend”, “amendment” or “supplement” with respect to the Registration Statement, any Preliminary Prospectus or any Prospectus shall be deemed to refer to and include any documents filed after such date under the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Exchange Act”) that are deemed to be incorporated by reference therein. Capitalized terms used but not defined herein shall have the meanings given to such terms in the Registration Statement and the Prospectus.

2. Purchase of the Shares by IDT. (a) The Company agrees to issue and sell the Shares to IDT as provided in this Agreement, and IDT, on the basis of the representations, warranties and agreements set forth herein and subject to the conditions set forth herein, agrees to purchase the Shares from the Company at a price per Share of $4.50 (the “Purchase Price”).

(b) Subject to the satisfaction or waiver, if applicable, by IDT of the conditions set forth in Section 5 hereof, the purchase of the Shares shall take place at the offices of Mayer, Brown, Rowe & Maw LLP, 1675 Broadway, New York, New York 10019 at 10:00 A.M. New York City time on November 24, 2003, or at such other time or place as IDT and the Company shall mutually agree. The time and date of such purchase is referred to herein as the “Closing Date”.

(c) Payment for the Shares shall be made on the Closing Date by wire transfer in immediately available funds to the account specified by the Company to IDT not later than 11:00 A.M., New York City time, on the business day prior to the Closing Date. Payment for the Shares to be purchased on the Closing Date shall be made against delivery to IDT of the Shares to be purchased on such date in definitive form registered in the name of IDT with any transfer taxes payable in connection with the sale of the Shares duly paid by the Company.

3. Representations and Warranties of the Company. The Company represents and warrants to IDT that:

(a) Preliminary Prospectus. No order preventing or suspending the use of any Preliminary Prospectus has been issued by the Commission, and each Preliminary Prospectus, at the time of filing thereof, complied in all material respects with the Securities Act and did not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the Company makes no representation and warranty with respect to any statements or omissions made in reliance upon and in conformity with information relating to IDT furnished to the Company by or on behalf of IDT expressly for use in any Preliminary Prospectus.

(b) Registration Statement and Prospectus. The Registration Statement has been declared effective by the Commission. No order suspending the effectiveness of the Registration Statement has been issued by the Commission and no proceeding for that purpose has been initiated or threatened by the Commission; as of the applicable effective date of the Registration

Statement and any amendment thereto, the Registration Statement complied and will comply in all material respects with the Securities Act, and did not and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading; and as of the applicable filing date of each Prospectus and any amendment or supplement thereto and as of the Closing Date such Prospectus will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the Company makes no representation and warranty with respect to any statements or omissions made in reliance upon and in conformity with information relating to IDT furnished to the Company by or on behalf of IDT expressly for use in the Registration Statement and the Prospectus and any amendment or supplement thereto.

(c) Incorporated Documents. The documents incorporated by reference in the Prospectus, when they became effective or were filed with the Commission, as the case may be, conformed in all material respects to the requirements of the Securities Act or the Exchange Act, as applicable, and none of such documents contained any untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; and any further documents so filed and incorporated by reference in the Prospectus, when such documents become effective or are filed with the Commission, as the case may be, will conform in all material respects to the requirements of the Securities Act or the Exchange Act, as applicable, and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(d) Financial Statements. The consolidated financial statements and the related notes thereto of the Company and its consolidated subsidiaries included or incorporated by reference in the Registration Statement, any Preliminary Prospectus and the Prospectus comply in all material respects with the applicable requirements of the Securities Act and the Exchange Act, as applicable, and present fairly the consolidated financial position of the Company and its subsidiaries as of the dates indicated and the results of their operations and the changes in their cash flows for the periods specified; such consolidated financial statements have been prepared in conformity with generally accepted accounting principles applied on a consistent basis throughout the periods covered thereby, and the supporting schedules included or incorporated by reference in the Registration Statement present fairly the information required to be stated therein; the other financial information included or incorporated by reference in the Registration Statement, any Preliminary Prospectus and the Prospectus has been derived from the accounting records of the Company and its subsidiaries and presents fairly the information shown thereby.

(e) No Material Adverse Change. Since the date of the most recent consolidated financial statements of the Company included or incorporated by reference in the Registration Statement and the Prospectus, (i) there has not been any change in the capital stock or long-term debt of the Company or any of its subsidiaries, or any dividend or distribution of any kind declared, set aside for payment, paid or made by the Company on any class of capital stock, or any material adverse change, or any development involving a prospective material adverse change, in or affecting the business, properties, management, financial position, stockholders’

equity, results of operations or prospects of the Company and its subsidiaries taken as a whole, or the right, power or authority of the Company to consummate the transactions contemplated by this Agreement (collectively, a “Material Adverse Effect”); (ii) neither the Company nor any of its subsidiaries has entered into any transaction or agreement that is material to the Company and its subsidiaries taken as a whole or incurred any liability or obligation, direct or contingent, that is material to the Company and its subsidiaries taken as a whole; and (iii) neither the Company nor any of its subsidiaries has sustained any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor disturbance or dispute or any action, order or decree of any court or arbitrator or governmental or regulatory authority, except in each case as otherwise disclosed in the Registration Statement and the L/IDT Prospectus delivered to IDT and Liberty on November 19, 2003.

(f) Organization and Good Standing. The Company and each of its Significant Subsidiaries (as defined below) have been duly organized and are validly existing and in good standing under the laws of their respective jurisdictions of organization, are duly qualified to do business and are in good standing in each jurisdiction in which their respective ownership or lease of property or the conduct of their respective businesses requires such qualification, and have all power and authority necessary to own or hold their respective properties and to conduct the businesses in which they are engaged, except where the failure to be so qualified or have such power or authority would not, individually or in the aggregate, have a Material Adverse Effect. The subsidiaries of the Company listed in Schedule 1 of this Agreement (the “Significant Subsidiaries”) are the only subsidiaries of the Company that are significant subsidiaries of the Company within the meaning of Regulation S-K promulgated under the Securities Act of 1933, as amended.

(g) Capitalization. The Company has an authorized capitalization as set forth in the Prospectus under the heading “Capitalization”; all the outstanding shares of capital stock of the Company have been duly and validly authorized and issued and are fully paid and non-assessable and are not subject to any pre-emptive or similar rights; except as described in or expressly contemplated by the Prospectus, there are no outstanding rights (including, without limitation, pre-emptive rights), warrants or options to acquire, or instruments convertible into or exchangeable for, any shares of capital stock or other equity interest in the Company or any of its subsidiaries, or any contract, commitment, agreement, understanding or arrangement of any kind relating to the issuance of any capital stock of the Company or any such subsidiary, any such convertible or exchangeable securities or any such rights, warrants or options; the capital stock of the Company conforms in all material respects to the description thereof contained in the Registration Statement and the Prospectus; and all the outstanding shares of capital stock or other equity interests of each subsidiary of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and are owned directly or indirectly by the Company, free and clear of any lien, charge, encumbrance, security interest, restriction on voting or transfer or any other claim of any third party, except where the failure to be so authorized, issued, fully paid, non-assessable or free and clear would not be likely to have a Material Adverse Effect.

(h) Due Authorization. The Company has full right, power and authority to execute and deliver this Agreement and to perform its obligations hereunder; and all action required to be taken for the due and proper authorization, execution and delivery of this Agreement and the

consummation of the transactions contemplated hereby by the Company has been duly and validly taken.

(i) The Shares. The Shares to be issued and sold by the Company hereunder have been duly authorized by the Company and, when issued and delivered to IDT and paid for as provided herein, will be duly and validly issued and will be fully paid and nonassessable and will conform to the description thereof in the L/IDT Prospectus; and the issuance of the Shares will not be subject to any preemptive or similar rights. The Shares will be sold to IDT in a transaction that is registered under Section 5 of the Securities Act.

(j) Stock Purchase Agreement. This Agreement has been duly authorized, executed and delivered by the Company and constitutes a valid and legally binding agreement of the Company enforceable against the Company in accordance with its terms, except as enforceability may be limited by applicable bankruptcy, insolvency or similar laws affecting creditors’ rights generally or by equitable principles relating to enforceability.

(k) No Violation or Default. Neither the Company nor any of its Significant Subsidiaries is (i) in violation of its charter or by-laws or similar organizational documents; (ii) in default, and no event has occurred that, with notice or lapse of time or both, would constitute such a default, in the due performance or observance of any term, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or any of its Significant Subsidiaries is a party or by which the Company or any of its Significant Subsidiaries is bound or to which any of the property or assets of the Company or any of its Significant Subsidiaries is subject; or (iii) in violation of any law or statute or any judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority, except for any such default or violation that is described in the Registration Statement, any Preliminary Prospectus and the Prospectus or that would not, individually or in the aggregate, have a Material Adverse Effect.

(l) No Conflicts. The execution, delivery and performance by the Company of this Agreement and the agreements pursuant to which the Company will issue and sell the Liberty Shares, the Underwritten Shares and the Option Shares (collectively, the “Other Sale Agreements”), the issuance and sale of the Offered Shares and the consummation of the transactions contemplated by this Agreement and the Other Sale Agreements will not (i) conflict with or result in a material breach or violation of any of the terms or provisions of, or constitute a default under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company or any of its Significant Subsidiaries pursuant to, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or any of its Significant Subsidiaries is a party or by which the Company or any of its Significant Subsidiaries is bound or to which any of the property or assets of the Company or any of its Significant Subsidiaries is subject, (ii) result in any violation of the provisions of the charter or by-laws or similar organizational documents of the Company or any of its Significant Subsidiaries or (iii) result in the violation of any law or statute or any judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority.

(m) No Consents Required. No consent, approval, authorization, order, registration or qualification of or with any court or arbitrator or governmental or regulatory authority is required

for the execution, delivery and performance by the Company of this Agreement or any of the Other Sale Agreements, the issuance and sale of the Offered Shares and the consummation of the transactions contemplated by this Agreement and the Other Sale Agreements, except for such as have been obtained or will be obtained by the Closing Date.

(n) Independent Accountants. Ernst & Young LLP, who have certified the financial statements of the Company and its subsidiaries which are included in the Registration Statement and the Prospectus, are independent public accountants with respect to the Company and its subsidiaries as required by the Securities Act.

(o) Investment Company Act. The Company is not and, after giving effect to the offering and sale of the Offered Shares and the application of the proceeds thereof as described in the Prospectus, will not be required to register as an “investment company” within the meaning of the Investment Company Act of 1940, as amended, and the rules and regulations of the Commission thereunder (collectively, “Investment Company Act”).

(p) Public Utility Holding Company Act. Neither the Company nor any of its Significant Subsidiaries is a “holding company” or a “subsidiary company” of a holding company or an “affiliate” thereof within the meaning of the Public Utility Holding Company Act of 1935, as amended.

(q) Taxes. The Company and its Significant Subsidiaries have paid all material federal, state, local and foreign taxes and filed all tax returns required to be paid or filed through the date hereof; and except as otherwise disclosed in the Prospectus, there is no material tax deficiency that has been, or could reasonably be expected to be, asserted against the Company or any of its Significant Subsidiaries or any of their respective properties or assets.

(r) No Restrictions on Significant Subsidiaries. No Significant Subsidiary of the Company is currently prohibited, directly or indirectly, under any agreement or other instrument to which it is a party or is subject, from paying any dividends to the Company, from making any other distribution on such Significant Subsidiary’s capital stock, from repaying to the Company any loans or advances to such Significant Subsidiary from the Company or from transferring any of such Significant Subsidiary’s properties or assets to the Company or any other subsidiary of the Company.

(s) Legal Proceedings. Except as described in the Prospectus and the Registration Statement, there are no legal, governmental or regulatory investigations, actions, suits or proceedings pending to which the Company or any of its subsidiaries is or may be a party or to which any property of the Company or any of its subsidiaries is or may be the subject that, individually or in the aggregate, if determined adversely to the Company or any of its subsidiaries, could reasonably be expected to have a Material Adverse Effect or materially and adversely affect the ability of the Company to perform its obligations under this Agreement or the Other Sale Agreements; no such investigations, actions, suits or proceedings are threatened or, to the best knowledge of the Company, contemplated by any governmental or regulatory authority or threatened by others; and (i) there are no current or pending legal, governmental or regulatory actions, suits or proceedings that are required under the Securities Act to be described in the Prospectus that are not so described and (ii) there are no statutes, regulations or contracts

or other documents that are required under the Securities Act to be filed as exhibits to the Registration Statement or described in the Registration Statement or the Prospectus that are not so filed or described.

(t) Title to Real and Personal Property. Other than as set forth in the Prospectus and the Registration Statement, the Company and its subsidiaries have good and marketable title in fee simple to, or have valid rights to lease or otherwise use, all items of real and personal property that are material to the respective businesses of the Company and its subsidiaries, in each case free and clear of all liens, encumbrances, claims and defects and imperfections of title except those that (i) do not materially interfere with the use made and proposed to be made of such property by the Company and its subsidiaries or (ii) could not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect.

(u) Title to Intellectual Property. Other than as set forth in the Prospectus and the Registration Statement, the Company and its subsidiaries own or possess adequate rights to use all patents, patent applications, trademarks, service marks, trade names, trademark registrations, service mark registrations, copyrights, licenses and know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures) necessary for the conduct of their respective businesses; and the conduct of their respective businesses will not conflict in any respect with any such rights of others, except, in each case, as would not reasonably be expected to have a Material Adverse Effect, and the Company and its subsidiaries have not received any notice of any claim of infringement or conflict with any such rights of others.

(v) Licenses and Permits. Other than as set forth in the Prospectus and the Registration Statement, the Company and its subsidiaries possess all licenses, certificates, permits and other authorizations issued by, and have made all declarations and filings with, the appropriate federal, state, local or foreign governmental or regulatory authorities that are necessary for the ownership or lease of their respective properties or the conduct of their respective businesses as described in the Registration Statement and the Prospectus, except where the failure to possess or make the same would not, individually or in the aggregate, have a Material Adverse Effect; and except as described in the Prospectus, neither the Company nor any of its subsidiaries has received notice of any material revocation or material adverse modification of any such license, certificate, permit or authorization or has any reason to believe that any such license, certificate, permit or authorization will not be renewed in the ordinary course.

(w) No Labor Disputes. No labor disturbance by or dispute with employees of the Company or any of its subsidiaries exists or, to the best knowledge of the Company, is contemplated or threatened.

(x) Compliance With Environmental Laws. The Company and its subsidiaries (i) are in compliance with any and all applicable federal, state, local and foreign laws, rules, regulations, decisions and orders relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants (collectively, “Environmental Laws”); (ii) have received and are in compliance with all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct their respective businesses; and (iii) have not received notice of any actual or potential liability for the

investigation or remediation of any disposal or release of hazardous or toxic substances or wastes, pollutants or contaminants, except, in the case of clauses (i), (ii) or (iii), for any such failure to comply, or failure to receive required permits, licenses or approvals, or liability as would not, individually or in the aggregate, have a Material Adverse Effect.

(y) Compliance With ERISA. Each employee benefit plan, within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), that is maintained, administered or contributed to by the Company or any of its affiliates for employees or former employees of the Company and its affiliates has been maintained in material compliance with its terms and the requirements of any applicable statutes, orders, rules and regulations, including but not limited to ERISA and the Internal Revenue Code of 1986, as amended (the “Code”); except as would not have a Material Adverse Effect, no prohibited transaction, within the meaning of Section 406 of ERISA or Section 4975 of the Code, has occurred with respect to any such plan excluding transactions effected pursuant to a statutory or administrative exemption; and for each such plan that is subject to the funding rules of Section 412 of the Code or Section 302 of ERISA, no “accumulated funding deficiency” as defined in Section 412 of the Code has been incurred, whether or not waived, and the fair market value of the assets of each such plan (excluding for these purposes accrued but unpaid contributions) exceeds the present value of all benefits accrued under such plan determined using reasonable actuarial assumptions.

(z) Compliance With Telecommunications Laws. Other than as set forth in the Prospectus and the Registration Statement, the Company and its subsidiaries (i) are in compliance with all federal, state and foreign laws, rules and regulations governing telecommunications matters (collectively “Telecommunications Laws”), and (ii) have obtained all licenses, permits, authorizations and approvals (collectively “Telecommunications Permits”) from and made all filings with the Federal Communications Commission (the “FCC”) and all other federal, state and international regulatory agencies having regulatory jurisdiction over telecommunications matters necessary for the Company and its subsidiaries to conduct their business as described in the Prospectus, except, in each case, as would not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect.

(aa) Accounting Controls. The Company and its significant subsidiaries maintain systems of internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

(bb) Insurance. The Company and its subsidiaries have insurance covering their respective properties, operations, personnel and businesses, including business interruption insurance, which insurance is in amounts and insures against such losses and risks as are reasonably adequate to protect the Company and its subsidiaries and their respective businesses; and neither the Company nor any of its significant subsidiaries has (i) received notice from any insurer or agent of such insurer that capital improvements or other expenditures are required or

necessary to be made in order to continue such insurance or (ii) any reason to believe that it will not be able to renew its existing insurance coverage as and when such coverage expires or to obtain similar coverage at reasonable cost from similar insurers as may be necessary to continue its business.

(cc) No Unlawful Payments. Neither the Company nor any of its subsidiaries nor, to the best knowledge of the Company, any director, officer, agent, employee or other person associated with or acting on behalf of the Company or any of its subsidiaries has (i) used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expense relating to political activity; (ii) made any direct or indirect unlawful payment to any foreign or domestic government official or employee from corporate funds; (iii) violated or is in violation of any provision of the Foreign Corrupt Practices Act of 1977; or (iv) made any bribe, rebate, payoff, influence payment, kickback or other unlawful payment.

(dd) Business With Cuba. The Company has complied with all provisions of Section 517.075, Florida Statutes (Chapter 92-198, Laws of Florida) relating to doing business with the Government of Cuba or with any person or affiliate located in Cuba.

(ee) Statistical and Market Data. Nothing has come to the attention of the Company that has caused the Company to believe that the statistical and market-related data included in the Registration Statement and the Prospectus is not based on or derived from sources that are reliable and accurate in all material respects.

(ff) No Broker’s Fees. Neither the Company nor any of its Significant Subsidiaries is a party to any contract, agreement or understanding with any person that would give rise to a valid claim against the Company or any of its subsidiaries or any underwriter for a brokerage commission, finder’s fee or like payment in connection with the offering and sale of the Shares.

(gg) No Registration Rights. No person has the right to require the Company or any of its subsidiaries to register any securities for sale under the Securities Act by reason of the filing of the Registration Statement with the Commission or the issuance and sale of the Offered Shares.

(hh) Margin Rules. Neither the issuance, sale and delivery of the Offered Shares nor the application of the proceeds thereof by the Company as described in the Registration Statement and the Prospectus will violate Regulation T, U or X of the Board of Governors of the Federal Reserve System or any other regulation of such Board of Governors.

(ii) Forward-Looking Statements. No forward-looking statement (within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act) contained in the Registration Statement and the Prospectus has been made or reaffirmed without a reasonable basis or has been disclosed other than in good faith.

(jj) Sarbanes-Oxley Act. The Company and, to its knowledge, its officers and directors are in present compliance with the provisions of the Sarbanes-Oxley Act of 2002 and the rules and regulations promulgated in connection therewith, including but not limited to Section 402 related to loans and Sections 302 and 906 related to certifications, to the extent the same are applicable to the Company and its officers and directors.

(kk) No Undisclosed Relationships. No relationship, direct or indirect, exists between or among the Company, IDT, Liberty Media Corporation or any of the Company’s subsidiaries, on the one hand, and the directors, officers, stockholders, customers or suppliers of the Company or any of its subsidiaries, on the other, that is required by the Securities Act to be described in the Registration Statement and the Prospectus and that is not so described.

4. Further Agreements of the Company. The Company covenants and agrees with IDT that:

(a) Rule 144. The Company will file timely all reports and any definitive proxy or information statements required to be filed by the Company with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date hereof.

(b) Delivery of Copies. The Company will deliver, without charge, to IDT, three signed copies of the Registration Statement as originally filed and each amendment thereto, in each case including all exhibits and consents filed therewith and documents incorporated by reference therein.

(c) Amendments or Supplements. Before filing any amendment (whether pre- or post-effective) or supplement to the Registration Statement or the L/IDT Prospectus, before the Closing Date, the Company will furnish to IDT and its counsel a copy of the proposed amendment or supplement for review.

(d) Use of Proceeds. The Company will apply the net proceeds from the sale of the Offered Shares as described in the Prospectus under the heading “Use of Proceeds”.

5. Conditions of IDT’s Obligations. The obligation of IDT to purchase the Shares on the Closing Date as provided herein is subject to the performance by the Company of its covenants and other obligations hereunder and to the following additional conditions:

(a) Registration Compliance; No Stop Order. The Registration Statement (or if a post-effective amendment thereto is required to be filed under the Securities Act, such post-effective amendment) shall be effective; no order suspending the effectiveness of the Registration Statement shall be in effect, and no proceeding for such purpose shall be pending before or threatened by the Commission; and the Prospectus shall have been timely filed with the Commission under the Securities Act.

(b) No Legal Impediment to Issuance. No action shall have been taken and no statute, rule, regulation or order shall have been enacted, adopted or issued by any federal, state or foreign governmental or regulatory authority that would, as of the Closing Date, prevent the issuance or sale of any of the Offered Shares; and no injunction or order of any federal, state or foreign court shall have been issued that would, as of the Closing Date, prevent the issuance or sale of any of the Offered Shares.

(c) Bring Down. The representations and warranties of the Company contained herein shall be true and correct on the date hereof and on and as of the Closing Date, and IDT shall have received an officer’s certificate to the foregoing effect dated the Closing Date and signed by the Company’s chief financial officer.

(d) Listing of Shares. The Shares to be delivered on the Closing Date shall have been approved for listing on the Nasdaq National Market, subject to official notice of issuance.

(e) Underwritten Shares. The Stock Purchase Agreement, dated as of the date hereof, among the Company, J.P. Morgan Securities, Inc. and Jefferies & Company, Inc., as representatives of the several underwriters (the “Underwriters Agreement”) with respect to the purchase of the Underwritten Shares and the Option Shares shall have been consummated or shall be consummated concurrently herewith. The Underwriters Agreement conforms in all material respects to the description thereof contained in the Registration Statement and the Underwritten Prospectus.

(f) Liberty Shares. The Stock Purchase Agreement, dated as of the date hereof, with Liberty (the “Liberty Agreement”) with respect to the purchase of the Liberty Shares shall have been consummated or shall be consummated concurrently herewith at a purchase price per Liberty Share that is no more favorable to the Company than the Purchase Price. The Liberty Agreement conforms in all material respects to the description thereof contained in the Registration Statement and the L/IDT Prospectus.

(a) Indemnification of IDT. The Company agrees to indemnify and hold harmless IDT and its affiliates (including, without limitation, NTOP Holdings, L.L.C.) from and against any and all losses, claims, damages and liabilities (including, without limitation, legal fees and other expenses incurred in connection with any suit, action or proceeding or any claim asserted, whether involving a third party action or a direct action to enforce this Agreement, as such fees and expenses are incurred), joint or several, that arise out of, or are based upon, any misrepresentation or breach by the Company of any of its representations, warranties or covenants contained herein.

(b) Notice and Procedures. If any suit, action, proceeding (including any governmental or regulatory investigation), claim or demand shall be brought or asserted against IDT or any other person in respect of which indemnification may be sought pursuant to paragraph (a) above, such person (the “Indemnified Person”) shall promptly notify the Company (the “Indemnifying Person”) in writing; provided that the failure to notify the Indemnifying Person shall not relieve it from any liability that it may have under this Section 6 except to the extent that it has been materially prejudiced (through the forfeiture of substantive rights or defenses) by such failure; and provided, further, that the failure to notify the Indemnifying Person shall not relieve it from any liability that it may have to an Indemnified Person otherwise than under this Section 6. If any such proceeding shall be brought or asserted against an Indemnified Person and it shall have notified the Indemnifying Person thereof, the Indemnifying Person shall retain counsel reasonably satisfactory to the Indemnified Person to represent the Indemnified Person and any others entitled to indemnification pursuant to this Section 6 that the Indemnifying Person may designate in such proceeding and shall pay the fees and expenses of such counsel related to such proceeding, as incurred. In any such proceeding, any Indemnified Person shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such Indemnified Person unless (i) the Indemnifying Person and the Indemnified Person shall have mutually agreed to the contrary; (ii) the Indemnifying Person has failed within a reasonable time

to retain counsel reasonably satisfactory to the Indemnified Person; (iii) the Indemnified Person shall have reasonably concluded that there may be legal defenses available to it that are different from or in addition to those available to the Indemnifying Person; or (iv) the named parties in any such proceeding (including any impleaded parties) include both the Indemnifying Person and the Indemnified Person and representation of both parties by the same counsel would be inappropriate due to actual or potential differing interests between them. It is understood and agreed that the Indemnifying Person shall not, in connection with any proceeding or related proceeding in the same jurisdiction, be liable for the fees and expenses of more than one separate firm (in addition to any local counsel) for all Indemnified Persons, and that all such fees and expenses shall be paid or reimbursed as they are incurred. Any such separate firm shall be designated in writing by the Indemnified Person(s). The Indemnifying Person shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the Indemnifying Person agrees to indemnify each Indemnified Person from and against any loss or liability by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an Indemnified Person shall have requested that an Indemnifying Person reimburse the Indemnified Person for fees and expenses of counsel as contemplated by this paragraph, the Indemnifying Person shall be liable for any settlement of any proceeding effected without its written consent if (i) such settlement is entered into more than 45 days after receipt by the Indemnifying Person of such request and (ii) the Indemnifying Person shall not have reimbursed the Indemnified Person in accordance with such request prior to the date of such settlement. No Indemnifying Person shall, without the written consent of the Indemnified Person, effect any settlement of any pending or threatened proceeding in respect of which any Indemnified Person is or could have been a party and indemnification could have been sought hereunder by such Indemnified Person, unless such settlement (x) includes an unconditional release of such Indemnified Person, in form and substance reasonably satisfactory to such Indemnified Person, from all liability or claims that are the subject matter of such proceeding and (y) does not include any statement as to or any admission of fault, culpability or a failure to act by or on behalf of any Indemnified Person.

(c) Non-Exclusive Remedies. The remedies provided for in this Section 6 are not exclusive and shall not limit any rights or remedies which may otherwise be available to any Indemnified Person at law or in equity.

7. Persons Entitled to Benefit of Agreement. This Agreement shall inure to the benefit of and be binding upon the parties hereto and their respective successors and the affiliates of IDT referred to in Section 6 hereof. Nothing in this Agreement is intended or shall be construed to give any other person any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision contained herein. No purchaser of Shares from IDT shall be deemed to be a successor merely by reason of such purchase.

8. Survival. The indemnities, representations, warranties and agreements of the Company and the agreements of IDT contained in this Agreement or made by or on behalf of the Company or IDT pursuant to this Agreement or any certificate delivered pursuant hereto shall survive the delivery of and payment for the Shares and shall remain in full force and effect, regardless of any termination of this Agreement.

9. Certain Defined Terms. For purposes of this Agreement, (a) except where otherwise expressly provided, the term “affiliate” has the meaning set forth in Rule 405 under the Securities Act; (b) the term “business day” means any day other than a day on which banks are permitted or required to be closed in New York City; and (c) the term “subsidiary” has the meaning set forth in Rule 405 under the Securities Act.

(a) Notices. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted and confirmed by any standard form of telecommunication. Notices to IDT shall be given to it at 520 Broad Street, Newark, New Jersey 07102 (fax: 973-438-3111); Attention: James A. Courter.

(b) Governing Law. This Agreement shall be governed by and construed in accordance with the laws of the State of New York.

(c) Counterparts. This Agreement may be signed in counterparts (which may include counterparts delivered by any standard form of telecommunication), each of which shall be an original and all of which together shall constitute one and the same instrument.

(d) Amendments or Waivers. No amendment or waiver of any provision of this Agreement, nor any consent or approval to any departure therefrom, shall in any event be effective unless the same shall be in writing and signed by the parties hereto.

(e) Headings. The headings herein are included for convenience of reference only and are not intended to be part of, or to affect the meaning or interpretation of, this Agreement.

If the foregoing is in accordance with your understanding, please indicate your acceptance of this Agreement by signing in the space provided below.

Very truly yours, NET2PHONE, INC.

By:		/s/ Stephen Greenberg
		Name: Stephen Greenberg
		Title: Chief Executive Officer

Accepted: November 19, 2003 IDT CORPORATION

By:		/s/ Joyce Mason
		Name: Joyce Mason
		Title: Senior Vice President