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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Pqs+pPuQdEmM10ly/dHxdI8MDnfqTDwLARm7+HXkmedN+/iP1k4tiNbjPyoDnolE
 57q6U7SnH2KZqK70fF0epw==

<SEC-DOCUMENT>0001209191-03-033439.txt : 20031203
<SEC-HEADER>0001209191-03-033439.hdr.sgml : 20031203
<ACCEPTANCE-DATETIME>20031203162609
ACCESSION NUMBER:		0001209191-03-033439
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031202
FILED AS OF DATE:		20031203

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NETSCOUT SYSTEMS INC
		CENTRAL INDEX KEY:			0001078075
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMPUTER INTEGRATED SYSTEMS DESIGN [7373]
		IRS NUMBER:				042837575
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		4 TECHNOLOGY PARK DR
		CITY:			WESTFORD
		STATE:			MA
		ZIP:			01886
		BUSINESS PHONE:		9786144000

	MAIL ADDRESS:	
		STREET 1:		4 TECHNOLOGY PARK DRIVE
		CITY:			WESTFORD
		STATE:			MA
		ZIP:			01886

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ADVENT ATLANTIC & PACIFIC III LP
		CENTRAL INDEX KEY:			0001235810
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26251
		FILM NUMBER:		031035560

	BUSINESS ADDRESS:	
		STREET 1:		125 HIGH STREET
		STREET 2:		SUITE 2500
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110
		BUSINESS PHONE:		6175746781

	MAIL ADDRESS:	
		STREET 1:		125 HIGH STREET
		STREET 2:		SUITE 2500
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>b48711lp.xml
<DESCRIPTION>MAIN DOCUMENT DESCRIPTION
<TEXT>
<XML>
<?xml version="1.0"?><ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-12-02</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0001078075</issuerCik><issuerName>NETSCOUT SYSTEMS INC</issuerName>        <issuerTradingSymbol>NTCT</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001235810</rptOwnerCik><rptOwnerName>ADVENT ATLANTIC &amp; PACIFIC III LP</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>125 HIGH STREET</rptOwnerStreet1><rptOwnerStreet2>SUITE 2500</rptOwnerStreet2><rptOwnerCity>BOSTON</rptOwnerCity><rptOwnerState>MA</rptOwnerState><rptOwnerZipCode>02110</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>0</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>1</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDeriva
tiveTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-12-02</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>19875</value></transactionShares><transactionPricePerShare><value>8.30</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>914062</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><ownerSignature><signatureName>Advent Atlantic and Pacific III L.P.</signatureName><signatureDate>2003-12-03</signatureDate></ownerSignature><ownerSignature><signatureName>By: TA Ass
ociates AAP III Partners., its General Partner</signatureName><signatureDate>2003-12-03</signatureDate></ownerSignature><ownerSignature><signatureName>By: TA Associates, Inc., its General Partner</signatureName><signatureDate>2003-12-03</signatureDate></ownerSignature><ownerSignature><signatureName>By: Thomas P. Alber, Chief Financial Officer</signatureName><signatureDate>2003-12-03</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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