SEC FORM 3

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person^*

EVANS BRUCE R

(Last)

(First)

(Middle)

C/O SUMMIT PARTNERS 222 BERKELEY STREET

18TH FLOOR

(Street)

BOSTON

02116

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
12/14/2017

3. Issuer Name and Ticker or Trading Symbol
Casa Systems Inc [ CASA ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
	Officer (give title below)	Other (specify below)

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
Series C Convertible Preferred Stock	⁽¹⁾	⁽¹⁾	Common Stock	38,592,000⁽²⁾	⁽¹⁾	I	See Footnotes.⁽³⁾⁽⁴⁾

Explanation of Responses:

1. The Series C Convertible Preferred Stock is convertible into common stock of Casa Systems, Inc. (the "Issuer") on a ten-for-one basis at any time and will automatically convert into common stock upon the closing of the Issuer's initial public offering. The Series C Convertible Preferred Stock has no expiration date.

2. Consists of 24,052,910 shares of common stock issuable upon the conversion of Series C Convertible Preferred Stock held by Summit Partners Private Equity Fund VII-A, L.P., 14,446,570 shares of common stock issuable upon the conversion of Series C Convertible Preferred Stock held by Summit Partners Private Equity Fund VII-B, L.P., 82,110 shares of common stock issuable upon the conversion of Series C Convertible Preferred Stock held by Summit Investors I, LLC and 10,410 shares of common stock issuable upon the conversion of Series C Convertible Preferred Stock held by Summit Investors I (UK), L.P.

3. Summit Partners, L.P. is the managing member of Summit Partners PE VII, LLC, which is the general partner of Summit Partners PE VII, L.P., which is the general partner of each of Summit Partners Private Equity Fund VII-A, L.P. and Summit Partners Private Equity Fund VII-B, L.P. Summit Master Company, LLC is the managing member of Summit Investors Management, LLC, which is the manager of Summit Investors I, LLC, and the general partner of Summit Investors I (UK), L.P. Summit Master Company, LLC, as the managing member of Summit Investors Management, LLC, has delegated investment decisions, including voting and dispositive power, to Summit Partners, L.P. and its investment committee responsible for voting and investment decisions with respect to the Issuer.

4. Summit Partners, L.P., through a three-person investment committee responsible for voting and investment decisions with respect to the Issuer, currently comprised of Peter Y. Chung, Bruce R. Evans and Martin J. Mannion, has voting and dispositive power over the shares held by each of these entities and therefore may be deemed to beneficially own such shares. Mr. Evans is a member of Summit Master Company, LLC. Mr. Evans may be deemed to share beneficial ownership of the shares of the Issuer held of record by the Summit entities and has an indirect pecuniary interest in such shares through his membership in Summit Master Company, LLC. Mr. Evans expressly disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein.

Remarks:

Exhibit 24.1 Powers of Attorney

	/s/ Robin W. Devereux, Power of Attorney for Bruce R. Evans	12/14/2017
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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