UNITED STATES

WASHINGTON, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(AMENDMENT NO. _12__)*

Netscout Systems, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

64115t104

(Cusip Number)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and for
any subsequent amendment containing information which would alter disclosures
provided in a prior cover page.

The information required on the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the
Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13G

CUSIP No.

64115t104

Page 2 of 6 Pages

1. NAMES OF REPORTING PERSONS S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

Brown Capital Management, Inc.

2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

(a)[ ]
(b)[ ]

3. SEC USE ONLY

4. CITIZENSHIP OR PLACE OF ORGANIZATION

Maryland

REPORTING NUMBER OF SHARES
BENEFICIALLY OWNED BY EACH
PERSON WITH

5.
6
7.
8.

SOLE VOTING POWER
SHARED VOTING POWER
SOLE DISPOSITIVE POWER
SHARED DISPOSITIVE POWER

1,454,094
None
3,107,637
None

9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

3,107,637

10. CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

7.64%

12. TYPE OF REPORTING PERSON*

IA CO

CUSIP No.

64115t104

Page 3 of 6 Pages

Item 1

(a)

Name of Issuer:

Netscout Systems, Inc.

(b)

Address of Issuer's Principal Executive Offices

Westford, MA 01886

Item 2

(a)

Name of Person Filing:

Brown Capital Management, Inc.

(b)

Address of Principal Business Office or, if none, Residence:

1201 N. Calvert Street
Baltimore, Maryland 21202

(c)

Citizenship:

Maryland

(d)

Title of Class of Securities:

Common Stock

(e)

CUSIP Number:

64115t104

Item 3:

Capacity in Which Person is Filing:

[x]

Investment Adviser registered under Section 203 of the Investment Advisers Act of 1940

CUSIP No.

64115t104

Page 4 of 6 Pages

Item 4:

Ownership As of December 31 2009:

(a)

Amount Beneficially Owned:

3,107,637

(b)

Percent of class:

7.64%

(c)

Number of shares to which such person has:

(i)
(ii)
(iii)
(iv)

Sole power to vote or to direct the vote:
Shared power to vote or to direct the vote:
Sole power to dispose or to direct the disposition of:
Shared power to dispose or to direct the disposition of :

1,454,094
None
3,107,637
None

Item 5:

Ownership of Five Percent or Less of Class:

Not applicable

CUSIP No.

64115t104

Page 5 of 6 Pages

Item 6:

Ownership of More than Five Percent on Behalf of Another Person

All of the shares of Common Stock set forth in Item 4 are owned by various
investment advisory clients of Brown Capital Management, Inc., which is deemed
to be a beneficial owner of those shares pursuant to Rue 13d-3 under the Securities
Exchange Act of 1934, due to it discretionary power to make investment decisions
over such shares for its clients and its ability to vote such shares. In all cases,
persons other than Brown Capital Management, Inc. has the right to receive, or
the power to direct the receipt of, dividends from, or the proceeds from the sale
of the shares. No individual client holds more than five percent of the class.

CUSIP No.

64115t104

Page 5 of 6 Pages

Item 7:

Identification and Classification of the Subsidiary
Which Acquired the Security Being Reported on
By the Parent Holding Company:

Not applicable

Item 8:

Identification and Classification of members of the Group:

Not applicable

Item 9:

Notice of Dissolution of Group:

Not applicable

CUSIP No.

64115t104

Page 6 of 6 Pages

Item 10:

Certification:

By signing below I certify that, to the best of my knowledge and belief, the securities
referred to above were acquired in the ordinary course of business and were not acquired
for the purpose of and do not have the effect of changing or influencing the control of the
issuer of such securities and were not acquired in connection with or as a participant in any
transaction having such purposes or effect

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief,
I certify that the information set forth in this statement is true, complete and correct.

By: /s/ Eddie C. Brown

President

Date:

December 31, 2009