NETSCOUT SYSTEMS, INC.
1999 EMPLOYEE STOCK PURCHASE PLAN, AS AMENDED
This 1999 Employee Stock Purchase Plan (the "Plan") is intended to encourage stock ownership by all eligible
employees of NetScout Systems, Inc. (the "Company"), a Delaware corporation, and its participating subsidiaries
(as defined in Article 17) so that they may share in the growth of the Company by acquiring or increasing their
proprietary interest in the Company. The Plan is designed to encourage eligible employees to remain in the
employ of the Company and its participating subsidiaries. The Plan is intended to constitute an "employee stock
purchase plan" within the meaning of Section 423(b) of the Internal Revenue Code of 1986, as amended (the
ARTICLE 2--ADMINISTRATION OF THE PLAN.
The Plan may be administered by a committee appointed by the Board of Directors of the Company (the
"Committee"). The Committee shall consist of not less than two members of the Company's Board of Directors.
The Board of Directors may from time to time remove members from, or add members to, the Committee.
Vacancies on the Committee, however caused, shall be filled by the Board of Directors. The Committee may
select one of its members as Chairman, and shall hold meetings at such times and places as it may determine.
Acts by a majority of the Committee, or acts reduced to or approved in writing by a majority of the members of
the Committee, shall be the valid acts of the Committee.
The interpretation and construction by the Committee of any provisions of the Plan or of any option granted
under it shall be final, unless otherwise determined by the Board of Directors. The Committee may from time to
time adopt such rules and regulations for carrying out the Plan as it may deem best, provided that any such rules
and regulations shall be applied on a uniform basis to all employees under the Plan. No member of the Board of
Directors or the Committee shall be liable for any action or determination m