X0206 3 2017-12-14 0 0001333835 Casa Systems Inc CASA 0001239366 CHUNG PETER Y C/O SUMMIT PARTNERS 222 BERKELEY STREET 18TH FLOOR BOSTON MA 02116 0 0 1 0 0001018067 MANNION MARTIN J C/O SUMMIT PARTNERS 222 BERKELEY STREET 18TH FLOOR BOSTON MA 02116 0 0 1 0 Series C Convertible Prefered Stock Common Stock 38592000 I See Footnotes. 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 without payment of consideration 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. 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. 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. 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. Each of the Summit entities and persons mentioned in this footnote disclaims beneficial ownership of the shares, except for those shares held of record by such entity, and except to the extent of their pecuniary interest therein. Exhibit 24.1 Powers of Attorney /s/ Robin W. Devereux, Power of Attorney for Peter Y. Chung 2017-12-14 /s/ Robin W. Devereux, Power of Attorney for Martin J. Mannion 2017-12-14