As filed with the Securities and Exchange Commission on May 17, 2022.

Registration No. 333-          

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

CASA SYSTEMS, INC.

(Exact name of registrant as specified in its charter)

100 Old River Road

Andover, Massachusetts 01810

(978) 688-6706

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Jerry Guo

President, Chief Executive Officer and Chairman

Casa Systems, Inc.

100 Old River Road

Andover, Massachusetts 01810

(978) 688-6706

(Name, address, including zip code, and telephone number, including area code, of agent for service)

With copies to:

John M. Mutkoski, Esq.

Goodwin Procter LLP

100 Northern Avenue

Boston, Massachusetts 02210

(617) 570-1000

Approximate date of commencement of proposed sale to the public: From time to time after this Registration Statement becomes effective.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box.  ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, as amended, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box:  ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.  ☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF THE SECURITIES ACT OF 1933, AS AMENDED, OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME EFFECTIVE ON SUCH DATE AS THE SECURITIES AND EXCHANGE COMMISSION ACTING PURSUANT TO SAID SECTION 8(a) MAY DETERMINE.

The information in this prospectus is not complete and may be changed. The selling stockholder may not sell these securities pursuant to this prospectus until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and is not soliciting offers to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED MAY 17, 2022

PROSPECTUS

9,323,000 Shares

Common Stock

This prospectus relates to the possible resale, from time to time, by the selling stockholder identified in this prospectus of up to 9,323,000 shares of our common stock, par value $0.001 per share (the “Common Stock”), initially issued in a private placement (the “Private Placement”), pursuant to a securities purchase agreement, dated as of April 18, 2022, by and between us and the selling stockholder (the “Securities Purchase Agreement”).

The selling stockholder may offer the shares from time to time in amounts, at prices and on terms as the selling stockholder may determine through public or private transactions or through other means described in the section entitled “Plan of Distribution” or a supplement to this prospectus. If agents, underwriters or dealers are used to sell the securities, we will name them and describe their compensation in a prospectus supplement. The selling stockholder may also sell shares under Rule 144 under the Securities Act of 1933, as amended, if available, rather than under this prospectus.

The registration of these shares does not necessarily mean that any holders will sell any of their shares. We are not offering for sale any shares of our Common Stock pursuant to this prospectus. We will not receive any proceeds from the sale of these shares.

We are paying the cost of registering the shares of Common Stock covered by this prospectus as well as various related expenses of any offering of such shares by the selling stockholder. The selling stockholder is responsible for all applicable underwriting discounts, selling commissions, transfer taxes and similar charges related to the offer and sale of their shares of our Common Stock.

Our Common Stock is listed on the Nasdaq Global Select Market under the symbol “CASA.” On May 13, 2022, the closing price for our Common Stock, as reported on the Nasdaq Global Select Market, was $4.07 per share.

We may amend or supplement this prospectus from time to time by filing amendments or supplements as required. You should read the entire prospectus and any amendments or supplements carefully before you make your investment decision.

We are an “emerging growth company” as defined under the federal securities laws and, as such, are eligible for reduced public company reporting requirements. See “Prospectus Summary- Implications of being an emerging growth company”.

Investing in our Common Stock involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” contained in this prospectus beginning on page 1 and any applicable prospectus supplement, and under similar headings in the other documents that are incorporated by reference into this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is                , 2022.

TABLE OF CONTENTS

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ABOUT THIS PROSPECTUS

We have not, and the selling stockholder has not, authorized anyone to give you any information other than the information contained in this prospectus, the information incorporated by reference herein, any applicable prospectus supplement or any free writing prospectus filed with the Securities and Exchange Commission (the “SEC”). We and the selling stockholder take no responsibility for, and can provide no assurances as to the reliability of, any other information that others may give you. Neither we nor the selling stockholder have authorized anyone to provide you with additional information or information different from that contained in this prospectus filed with the SEC. This prospectus does not constitute an offer to sell, or a solicitation of an offer to purchase shares of our Common Stock in any jurisdiction in which it is unlawful to make such offer or solicitation. You should assume that the information appearing in this prospectus, the applicable prospectus supplement and any related free writing prospectus is accurate only as of the respective dates of those documents. Our business, financial condition, results of operations and prospects may have changed since those dates.

We use various trademarks and trade names in our business, including without limitation our corporate name, product names and logo. All other trademarks or trade names referred to in this prospectus are the property of their respective owners. Solely for convenience, the trademarks and trade names in this prospectus may be referred to without the ^® and ^™ symbols, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto.

For Non-U.S. investors

Neither we nor the selling stockholder have done anything that would permit this offering or possession or distribution of this prospectus, any prospectus supplement or free writing prospectus filed with the SEC, in any jurisdiction where action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus, any prospectus supplement or free writing prospectus must inform themselves about, and observe any restrictions relating to, the offering of the shares of Common Stock and the distribution of this prospectus, any prospectus supplement or free writing prospectus outside the United States.

As used in this prospectus, unless the context otherwise requires, references to the “Company,” “we,” “us,” “our” and “Casa Systems” refer to Casa Systems, Inc., and, where appropriate, our subsidiaries.

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RISK FACTORS

Investing in our securities involves a high degree of risk. You should carefully consider the risks described in the documents incorporated by reference in this prospectus and any prospectus supplement, as well as other information we include or incorporate by reference into this prospectus and any applicable prospectus supplement, before making an investment decision. Our business, financial condition or results of operations could be materially adversely affected by the materialization of any of these risks. The trading price of our securities could decline due to the materialization of any of these risks, and you may lose all or part of your investment. This prospectus and the documents incorporated herein by reference also contain forward-looking statements that involve risks and uncertainties. Actual results could differ materially from those anticipated in these forward-looking statements as a result of certain factors, including the risks described in the documents incorporated herein by reference, including (i) our annual report on Form 10-K for the fiscal year ended December 31, 2021, filed with the SEC on February 25, 2022 and incorporated herein by reference, and (ii) our most recent quarterly reports on Form 10-Q, our current reports on Form 8-K and other documents we file with the SEC that are deemed incorporated by reference into this prospectus.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, including the documents that we incorporate by reference, contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. All statements other than statements of historical fact contained in this prospectus, including statements regarding our future results of operations and financial position, business strategy and plans and objectives of management for future operations, are forward-looking statements. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements.

In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expects,” “intends,” “plans,” “anticipates,” “could,” “intends,” “target,” “projects,” “seeks,” “contemplates,” “believes,” “estimates,” “endeavor,” “predicts,” “potential” or “continue” or the negative of these terms or other similar expressions. The forward-looking statements in this prospectus are only predictions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. Accordingly, these statements involve estimates, assumptions, risks and uncertainties which could cause actual results to differ materially from those expressed in them. These forward-looking statements speak only as of the date of this prospectus and are subject to a number of risks, uncertainties and assumptions described in the “Risk Factors” section and elsewhere in this prospectus and such forward-looking statements are qualified in their entirety by reference to the factors discussed throughout this prospectus, and in particular those factors referenced in the section “Risk Factors.” Because forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified, you should not rely on these forward-looking statements as predictions of future events. The events and circumstances reflected in our forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements.

This prospectus contains forward-looking statements that are based on our management’s belief and assumptions and on information currently available to our management. These statements relate to future events or our future financial performance, and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Forward-looking statements include, but are not limited to, statements about:

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This prospectus and the documents incorporated by reference also contain estimates, projections and other information concerning our industry, our business and the markets for our solutions. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances reflected in this information. Unless otherwise expressly stated, we obtained this industry, business, market and other data from reports, research surveys, studies and similar data prepared by market research firms and other third parties, industry and general publications, government data and similar sources.

You should read this prospectus and the documents that we incorporate by reference in this prospectus completely and with the understanding that our actual future results may be materially different from what we expect. The forward-looking statements in this prospectus and the documents we incorporate by reference herein represent our views as of their respective dates. We anticipate that subsequent events and developments will cause our views to change. However, while we may elect to update these forward-looking statements at some point in the future, we have no current intention of doing so except to the extent required by applicable law. You should, therefore, not rely on these forward-looking statements as representing our views as of any date subsequent to the date of this prospectus.

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PROSPECTUS SUMMARY

This summary highlights certain information about us, this offering and selected information contained elsewhere in this prospectus. This summary is not complete and does not contain all of the information that you should consider before deciding whether to invest in the securities covered by this prospectus. For a more complete understanding of the Company and this offering, we encourage you to read and consider carefully the more detailed information in this prospectus, any related prospectus supplement and any related free writing prospectus, including the information set forth in the section titled “Risk Factors” in this prospectus, any related prospectus supplement and any related free writing prospectus in their entirety before making an investment decision.

About the Company

With our physical, virtual and cloud-native 5G infrastructure and customer premise networking equipment solutions, we help our CSP customers transform and expand their public and private high-speed data and multi-service communications networks so they can meet the growing demand for bandwidth and new services. Our core and edge convergence technology enables CSPs and enterprises to cost-effectively and dynamically increase network speed, add bandwidth capacity and new services, reduce network complexity, and reduce operating and capital expenditures regardless of access technology.

Our solutions are commercially deployed in over 70 countries by more than 475 customers, including regional service providers as well as some of the world’s largest Tier 1 CSPs, serving millions of subscribers. Our principal customers include Charter Communications, Rogers, Videotron, T-Mobile, Verizon, AT&T, Bell Canada, Cable One, Mediacom Windstream and Lumen in North America; Televisa/IZZI Mexico, Megacable Mexico, Cablevision Argentina, Claro Brazil, America Móvil and Claro Colombia in Latin America; Liberty Global, Vodafone and DNA Oyj in Europe; and NBN, Jupiter Communications, Beijing Gehua CATV Networks, Softbank, Kbro, Guangdong Cable, TRUE and CNS in Asia-Pacific.

We believe that our products are well suited to address these trends and accordingly present us with a significant market opportunity across all access technologies. Historically, we have generated the significant majority of our revenue from the cable market with our converged cable access platform, or CCAP. However, since 2019 we have become more diversified as a result of our acquisition of NetComm and the introduction of solutions for wireless and fixed-line broadband networks, as well as the introduction of our cloud-native software solutions. We believe that this has expanded our total addressable market from approximately $1.2 billion in 2019 to $49.4 billion in 2023.

We expect to continue to generate revenue in the future from growth in the cable market and increased revenue from sales of both wireless and fixed-line broadband solutions to new and existing customers. We believe there is an opportunity for us to take new market share as fixed and wireless networks continue to converge and as we continue to grow our cloud-native software business.

NetComm Acquisition

On July 1, 2019, we acquired NetComm for cash consideration of approximately $162.0 million Australian dollars, or AUD ($112.7 million United States dollars, or USD), based on an exchange rate of USD $0.700 per AUD $1.00 on July 1, 2019). This acquisition has enabled us to expand our customer base, enhance our global footprint, extend our product portfolio to the customer premise networking technology and further diversify our revenue sources.

Private Placement

On April 18, 2022, we entered into the Securities Purchase Agreement with the selling stockholder named in this prospectus, pursuant to which we sold and issued an aggregate of 9,323,000 shares of our Common Stock at a purchase price of $4.24 per share, for an aggregate purchase price of approximately $39,529,520.

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Under the terms of the Securities Purchase Agreement, we agreed to prepare and file, within 45 days after the closing of the Private Placement, which took place on April 18, 2022, one or more registration statements with the SEC to register for resale the shares of our Common Stock issued under the Securities Purchase Agreement, and to use commercially reasonable efforts to cause the applicable registration statement(s) declared effective within 30 days of filing the registration statement if there is no review by the SEC, or within 120 days following April 18, 2022 in the event of such review.

Company information

Casa Systems was incorporated under the laws of the State of Delaware on February 28, 2003. Our principal executive offices are located at 100 Old River Road, Andover, Massachusetts 01810, and our telephone number at that address is (978) 688-6706. Our website address is www.casa-systems.com. We do not incorporate the information on or accessible through our website into this prospectus, and you should not consider any information on, or that can be accessed through, our website as part of this prospectus. You should not rely on any such information in making your decision whether to purchase our Common Stock. Our Common Stock trades on The Nasdaq Global Select Market under the symbol “CASA”.

Implications of being an emerging growth company

We qualify as an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, as amended. As an emerging growth company, we may take advantage of specified reduced disclosure and other requirements that are otherwise applicable generally to public companies. These provisions include:

We may take advantage of these exemptions until the last day of our fiscal year following the fifth anniversary of our initial public offering or such earlier time that we are no longer an emerging growth company. We would cease to be an emerging growth company on the date that is the earliest of (i) the last day of the fiscal year in which we have total annual gross revenues of $1.07 billion or more; (ii) the last day of our fiscal year following the fifth anniversary of the date of the completion of our initial public offering; (iii) the date on which we have issued more than $1.0 billion in nonconvertible debt during the previous three years; or (iv) the date on which we are deemed to be a large accelerated filer under the rules of the SEC. We may choose to take advantage of some but not all of these exemptions. We have taken advantage of reduced reporting requirements in this prospectus supplement. Accordingly, the information contained herein may be different from the information you receive from other public companies in which you hold stock.

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THE OFFERING

All information in this prospectus related to the number of shares of our Common Stock to be outstanding immediately after this offering is based on 94,180,160 shares of our Common Stock outstanding as of April 29, 2022, which excludes as of that date, unless otherwise indicated:

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USE OF PROCEEDS

We will not receive any of the proceeds from the sale of the shares offered by this prospectus. The selling stockholder will receive all of the proceeds from this offering, if and when the selling stockholder elects to sell all or any of such shares. The selling stockholder will bear any underwriting discounts, selling commissions, transfer taxes and similar charges attributable to its sale of our Common Stock, and we will bear the remaining expenses.

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DETERMINATION OF OFFERING PRICE

The selling stockholder may offer the shares of Common Stock offered by this prospectus at varying prices that will be determined at the time of the offering. The offering price of our Common Stock does not necessarily bear any relationship to our book value, assets, past operating results, financial condition or any other established criteria of value. Our Common Stock might not trade at market prices in excess of the offering price as prices for our Common Stock in any public market will be determined in the marketplace and may be influenced by many factors, including the depth and liquidity of the market for shares of our Common Stock. See “Plan of Distribution” for more information.

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DESCRIPTION OF CAPITAL STOCK

The following description of our common stock and preferred stock, together with the additional information we include in any applicable prospectus supplements, summarizes the material terms and provisions of the common stock and preferred stock that we may offer under this prospectus. The following description of our capital stock does not purport to be complete and is subject to, and qualified in its entirety by, our amended and restated certificate of incorporation, or our Charter, and amended and restated by-laws, or our By-laws, which are exhibits to the registration statement of which this prospectus forms a part, and by applicable law. The terms of our Common Stock and preferred stock may also be affected by Delaware law.

Authorized Capital Stock

Our authorized capital stock consists of 500,000,000 shares of Common Stock and 5,000,000 shares of preferred stock, par value $0.001 per share (the “Preferred Stock”). Our Common Stock is registered under Section 12(b) of the Securities Exchange Act of 1934 (the “Exchange Act”). As of April 29, 2022, 94,180,160 shares of our Common Stock were outstanding and held by 15 stockholders of record.

Common Stock

Voting Rights. Holders of our Common Stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders and do not have cumulative voting rights. Any matter other than the election of directors to be voted upon by the stockholders at any meeting at which a quorum is present shall be decided by the vote of the holders of shares of stock having a majority in voting power of the votes cast by the holders of all of the shares of stock present or represented at the meeting and voting affirmatively or negatively on the matter, except when a different vote is required by law, our Charter or our By-laws. An election of directors by our stockholders shall be determined by a plurality of the votes cast by the stockholders entitled to vote on the election.

Dividends. Holders of Common Stock are entitled to receive proportionately any dividends as may be declared by our board of directors, subject to any preferential dividend rights of any series of Preferred Stock that we may designate and issue in the future.

Liquidation, Dissolution and Winding Up. In the event of our liquidation or dissolution, the holders of Common Stock are entitled to receive proportionately our net assets available for distribution to stockholders after the payment of all debts and other liabilities and subject to the prior rights of any outstanding Preferred Stock.

Other Rights. Holders of Common Stock have no preemptive, subscription, redemption or conversion rights and there are no sinking fund provisions applicable to our Common Stock. The rights, preferences and privileges of holders of Common Stock are subject to and may be adversely affected by the rights of the holders of shares of any series of Preferred Stock that we may designate and issue in the future.

All outstanding shares are fully paid and non-assessable. When we issue shares of Common Stock under this prospectus, the shares will fully be paid and non-assessable and will not have, or be subject to, any preemptive or similar rights.

Preferred Stock

Our board of directors is authorized, without further action by the stockholders, to designate and issue up to an aggregate of 5,000,000 shares of Preferred Stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number

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of shares constituting, or the designation of, such series, any or all of which may be greater than the rights of Common Stock. Our board of directors may authorize the issuance of Preferred Stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of Common Stock and the likelihood that such holders will receive dividend payments and payments upon our liquidation.

The purpose of authorizing our board of directors to issue Preferred Stock in one or more series and determine the number of shares in the series and its rights, preferences, privileges and restrictions is to eliminate delays associated with a stockholder vote on specific issuances. The issuance of Preferred Stock, while providing flexibility in connection with possible future financings and acquisitions and other corporate purposes, could, under certain circumstances, have the effect of delaying, deferring or preventing a change in control of our company, as further discussed below under “Provisions of Our Certificate of Incorporation and By-laws and the Delaware General Corporation Law That May Have Anti-Takeover Effects.”

When we issue shares of Preferred Stock under this prospectus, the shares will be fully paid and non-assessable and will not be subject to any preemptive or similar rights.

Registration Rights

Pursuant to the terms of our registration rights agreement, dated as of April 26, 2010, certain of our stockholders are entitled to rights with respect to the registration of their shares under the Securities Act until the earliest of the seventh (7th) anniversary of our initial public offering, or until no registrable securities could remain outstanding. We refer to these shares collectively as registrable securities.

Demand Registration Rights

Four holders of an aggregate of 34,124,480 shares of our Common Stock are entitled to demand registration rights. Under the terms of the registration rights agreement, we will be required, upon the written request of any holder to register at least 20% of the securities eligible for registration then outstanding and held by such holder, or such lesser percentage that would result in an aggregate offering price of at least $5.0 million, to file a registration statement and use commercially reasonable efforts to effect the registration of all or a portion of these shares for public resale. We are required to effect only two registrations for each holder pursuant to this provision of the registration rights agreement.

Short-Form Registration Rights

Pursuant to the registration rights agreement, if we are eligible to file a registration statement on Form S-3, upon the written request of one or more holders to sell registrable securities at an aggregate price of at least $5.0 million, we will be required to use our best efforts to effect a registration of such shares. We are not required to effect more than two registrations in any twelve-month period pursuant to this provision of the registration rights agreement. The right to have such shares registered on Form S-3 is further subject to other specified conditions and limitations.

Piggyback Registration Rights

Pursuant to the registration rights agreement, if we register any of our securities either for our own account or for the account of other security holders, the holders of 34,124,480 shares of our Common Stock are entitled to include their shares in the registration. Subject to certain exceptions contained in the registration rights agreement, we and the underwriters may limit the number of shares included in the underwritten offering to the number of shares which the managing underwriters determine advise us will not jeopardize the success of the offering.

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Indemnification

Our registration rights agreement contains customary cross-indemnification provisions, under which we are obligated to indemnify holders of registrable securities in the event of material misstatements or omissions in the registration statement attributable to us, and they are obligated to indemnify us for material misstatements or omissions attributable to them.

Expiration of Registration Rights

The demand registration rights and short form registration rights granted under the investors’ rights agreement will terminate on the seventh anniversary of the completion of our initial public offering or at such time after such offering when no registrable securities remain outstanding.

Provisions of Our Certificate of Incorporation and By-laws and the Delaware General Corporation Law That May Have Anti-Takeover Effects

Delaware Law. We are subject to Section 203 of the DGCL. Subject to certain exceptions, Section 203 prevents a publicly held Delaware corporation from engaging in a “business combination” with any “interested stockholder” for three years following the date that the person became an interested stockholder, unless the interested stockholder attained such status with the approval of our board of directors or unless the business combination is approved in a prescribed manner. A “business combination” includes, among other things, a merger or consolidation involving us and the “interested stockholder” and the sale of more than 10% of our assets. In general, an “interested stockholder” is any entity or person beneficially owning 15% or more of our outstanding voting stock and any entity or person affiliated with or controlling or controlled by such entity or person.

Preferred Stock. Under the terms of our Charter, our board of directors is authorized to direct us to issue shares of Preferred Stock in one or more series without stockholder approval. Our board of directors has the discretion to determine the rights, preferences, privileges and restrictions, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences, of each series of Preferred Stock. The purpose of authorizing our board of directors to issue Preferred Stock and determine its rights and preferences is to eliminate delays associated with a stockholder vote on specific issuances. The issuance of Preferred Stock, while providing flexibility in connection with possible acquisitions, future financings and other corporate purposes, could have the effect of making it more difficult for a third party to acquire, or could discourage a third party from seeking to acquire, a majority of our outstanding voting stock.

Staggered Board; Removal of Directors. Our Charter and our By-laws divide our board of directors into three classes with staggered three-year terms. In addition, a director may be removed only for cause and only by the affirmative vote of the holders of at least 75% of the votes that all our stockholders would be entitled to cast in an election of directors. Any vacancy on our board of directors, including a vacancy resulting from an enlargement of our board of directors, may be filled only by vote of a majority of our directors then in office. The classification of our board of directors and the limitations on the removal of directors and filling of vacancies could make it more difficult for a third party to acquire, or discourage a third party from seeking to acquire, control of our company.

Supermajority Voting. The DGCL provides generally that the affirmative vote of a majority of the shares entitled to vote on any matter is required to amend a corporation’s certificate of incorporation or bylaws, unless a corporation’s certificate of incorporation or bylaws, as the case may be, requires a greater percentage. Our By-laws may be amended or repealed by a majority vote of our board of directors or the affirmative vote of the holders of at least 75% of the votes that all our stockholders would be entitled to cast in an election of directors. In addition, the affirmative vote of the holders of at least 75% of the votes which all our stockholders would be entitled to cast in an election of directors is required to amend, repeal, or adopt any provisions inconsistent with, any of the provisions of the Certificate of Incorporation described above.

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Stockholder Action; Special Meeting of Stockholders; Advance Notice Requirements for Stockholder Proposals and Director Nominations. Our Charter provides that any action required or permitted to be taken by our stockholders must be effected at a duly called annual or special meeting of such stockholders and may not be effected by any consent in writing by such stockholders. Our Charter and our By-laws also provide that, except as otherwise required by law, special meetings of our stockholders can only be called by our board of directors. In addition, our By-laws establish an advance notice procedure for stockholder proposals to be brought before an annual meeting of stockholders, including proposed nominations of candidates for election to our board of directors. Stockholders at an annual meeting may only consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of our board of directors, or by a stockholder of record on the record date for the meeting, who is entitled to vote at the meeting and who has delivered timely written notice in proper form to our secretary of the stockholder’s intention to bring such business before the meeting. These provisions could have the effect of delaying until the next stockholder meeting stockholder actions that are favored by the holders of a majority of our outstanding voting securities. These provisions also could discourage a third party from making a tender offer for our Common Stock, because even if such third party acquired a majority of our outstanding voting stock, it would be able to take action as a stockholder, such as electing new directors or approving a merger, only at a duly called stockholders meeting and not by written consent.

Exclusive Forum Selection. Our Charter provides that unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware shall, to the fullest extent permitted by law, be the sole and exclusive forum for (1) any derivative action or proceeding brought on behalf of our company, (2) any action asserting a claim of breach of fiduciary duty owed by any director, officer or other employee or stockholder of our company to us or our stockholders, (3) any action asserting a claim arising pursuant to any provision of the DGCL or as to which the DGCL confers jurisdiction on the Court of Chancery or (4) any action asserting a claim governed by the internal affairs doctrine. This choice of forum provision will not apply to actions arising under the Exchange Act. Our Charter further provides that, unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States of America shall, to the fullest extent permitted by law, be the sole and exclusive forum for the resolution of any complaint asserting a cause of action arising under the Securities Act. Although our Charter contains the forum selection provision described above, there is uncertainty as to whether a court would enforce this provision or conclude that such provision applies to a particular claim or action.

Nasdaq Global Select Market Listing

Our Common Stock is listed on The Nasdaq Global Select Market under the symbol “CASA.”

Transfer Agent and Registrar

The transfer agent and registrar for our Common Stock is American Stock Transfer & Trust Company, LLC. The transfer agent and registrar’s address is 6201 15^th Avenue, Brooklyn, New York, 11219, and its telephone number is (781) 921-8300.

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SELLING STOCKHOLDER

This prospectus relates to the registration and possible sale by Verizon Ventures LLC (“Verizon LLC”) of up to 9,323,000 shares of our Common Stock that were acquired in the Private Placement. See “Prospectus Summary” above. The selling stockholder may offer and sell some, all or none of the shares of our Common Stock. The total number of shares of Common Stock sold under this prospectus may be adjusted to reflect adjustments due to stock dividends, stock distributions, splits, combinations or recapitalizations with regard to the Common Stock. Unless otherwise stated below in the footnotes, to our knowledge, neither the selling stockholder, nor any affiliate of such stockholder: (i) has held any position or office with us during the three years prior to the date of this prospectus; or (ii) is a broker-dealer, or an affiliate of a broker-dealer.

Set forth below is the name of the selling stockholder and the amount and percentage of Common Stock owned by such selling stockholder (including shares which such stockholder has the right to acquire within 60 days) prior to the offering, including the shares to be registered for resale under this prospectus. The footnotes provide information about persons who have voting and dispositive power with respect to shares held by the selling stockholder.

The following table is based on information provided to us by the selling stockholder and is as of April 29, 2022. The selling stockholder may sell all or some of the shares of Common Stock, and may sell shares of our Common Stock otherwise than pursuant to this prospectus, including in transactions exempt from the registration requirements of the Securities Act. We are unable to determine the exact number of shares that will actually be sold or when or if these sales will occur. There is no assurance that the selling stockholder will resell all or any of the shares of our Common Stock. For purposes of this table, we have assumed that the selling stockholder will have sold all of its shares of Common Stock subject to resale pursuant to this prospectus.

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PLAN OF DISTRIBUTION

The selling stockholder, which as used herein includes donees, pledgees, transferees or other successors-in-interest selling shares of Common Stock or interests in shares of Common Stock received after the date of this prospectus from a selling stockholder as a gift, pledge, partnership distribution or other transfer, may, from time to time, sell, transfer or otherwise dispose of any or all of their shares of Common Stock or interests in shares of Common Stock on any stock exchange, market or trading facility on which the shares are traded or in private transactions. These dispositions may be at fixed prices, which may be changed from time to time, at prevailing market prices at the time of sale, at prices related to the prevailing market price, at varying prices determined at the time of sale, or at negotiated prices.

The selling stockholder may use any one or more of the following methods when disposing of shares or interests therein:

To the extent required, the shares of our Common Stock to be sold, the name of the selling stockholder, the respective purchase prices and public offering prices, the names of any agents, dealer or underwriter, any applicable commissions or discounts and any other terms with respect to a particular offer will be set forth in an accompanying prospectus supplement or, if appropriate, a post-effective amendment to this registration statement that includes this prospectus.

The selling stockholder may, from time to time, pledge or grant a security interest in some or all of the shares of Common Stock owned by them and, if they default in the performance of their secured obligations, the pledgees or secured parties may offer and sell the shares of Common Stock, from time to time, under this prospectus, or under an amendment to this prospectus under Rule 424(b)(3) or other applicable provision of the Securities Act amending the list of selling stockholders to include the pledgee, transferee or other successors in interest as selling stockholders under this prospectus. The selling stockholder also may transfer the shares of Common Stock in other circumstances, in which case the transferees, pledgees or other successors in interest will be the selling beneficial owners for purposes of this prospectus.

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In connection with the sale of our Common Stock or interests therein, the selling stockholder may enter into hedging transactions with broker-dealers or other financial institutions, which may in turn engage in short sales of the Common Stock in the course of hedging the positions they assume. The selling stockholder may also sell shares of our Common Stock short and deliver these securities to close out their short positions, or loan or pledge the Common Stock to broker-dealers that in turn may sell these securities. The selling stockholder may also enter into options or other transactions with broker-dealers or other financial institutions or the creation of one or more derivative securities which require the delivery to such broker-dealer or other financial institution of shares offered by this prospectus, which shares such broker-dealer or other financial institution may resell pursuant to this prospectus (as supplemented or amended to reflect such transaction).

The aggregate proceeds to the selling stockholder from the sale of the Common Stock offered by them will be the purchase price of the Common Stock less discounts or commissions, if any. The selling stockholder reserves the right to accept and, together with their agents from time to time, to reject, in whole or in part, any proposed purchase of Common Stock to be made directly or through agents. We will not receive any of the proceeds from this offering. Registration of shares of our Common Stock covered by this prospectus does not mean that those securities necessarily will be offered or sold.

The selling stockholder may offer our Common Stock to the public through underwriting syndicates represented by managing underwriters or through underwriters without an underwriting syndicate. If underwriters are used for the sale of our Common Stock, the securities will be acquired by the underwriters for their own account. The underwriters may resell the Common Stock in one or more transactions, including in negotiated transactions at a fixed public offering price or at varying prices determined at the time of sale. In connection with any such underwritten sale of Common Stock, underwriters may receive compensation from the selling stockholder, for whom they may act as agents, in the form of discounts, concessions or commissions. Underwriters may sell Common Stock to or through dealers, and the dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters and/or commissions from the purchasers for whom they may act as agents. Such compensation may be in excess of customary discounts, concessions or commissions.

If the selling stockholder uses an underwriter or underwriters to effectuate the sale of Common Stock, we and/or they will execute an underwriting agreement with those underwriters at the time of sale of those securities. To the extent required by law, the names of the underwriters will be set forth in the prospectus supplement used by the underwriters to sell those securities. Unless otherwise indicated in the prospectus supplement relating to a particular offering of Common Stock, the obligations of the underwriters to purchase the securities will be subject to customary conditions precedent and the underwriters will be obligated to purchase all of the securities offered if any of the securities are purchased.

In effecting sales, brokers or dealers engaged by the selling stockholder may arrange for other brokers or dealers to participate. Broker-dealers may receive discounts, concessions or commissions from the selling stockholder (or, if any broker-dealer acts as agent for the purchaser of shares, from the purchaser) in amounts to be negotiated. Such compensation may be in excess of customary discounts, concessions or commissions. If dealers are utilized in the sale of securities, the names of the dealers and the terms of the transaction will be set forth in a prospectus supplement, if required.

The selling stockholder may also sell shares of our Common Stock from time to time through agents. We will name any agent involved in the offer or sale of such shares and will list commissions payable to these agents in a prospectus supplement, if required. These agents will be acting on a best efforts basis to solicit purchases for the period of their appointment, unless we state otherwise in any required prospectus supplement.

The selling stockholder may sell shares of our Common Stock directly to purchasers. In this case, it may not engage underwriters or agents in the offer and sale of such shares.

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The selling stockholder and any underwriters, broker-dealers or agents that are involved in selling the Common Stock or interests therein may be deemed to be “underwriters” within the meaning of Section 2(a)(11) of the Securities Act. In such event, any commissions received by such broker-dealers or agents and any profit on the resale of the shares purchased by them may be deemed to be underwriting commissions or discounts under the Securities Act. If the selling stockholder is deemed to be an “underwriter” within the meaning of the Securities Act, it will be subject to the prospectus delivery requirements of the Securities Act.

Certain of the underwriters, broker-dealers or agents who may become involved in the sale of the shares of our Common Stock may engage in transactions with and perform other services for us in the ordinary course of their business for which they will receive ordinary compensation.

We are not aware of any plans, arrangements or understandings between the selling stockholder and any underwriter, broker-dealer or agent regarding the sale of the shares of our Common Stock by the selling stockholder. We cannot assure you that the selling stockholder will sell any or all of the shares of our Common Stock offered by them pursuant to this prospectus. In addition, we cannot assure you that the selling stockholders will not transfer, devise or gift the shares of our Common Stock by other means not described in this prospectus. Moreover, shares of Common Stock covered by this prospectus that qualify for sale pursuant to Rule 144 under the Securities Act may be sold under Rule 144 rather than pursuant to this prospectus.

In order to comply with the securities laws of some states, if applicable, the Common Stock may be sold in these jurisdictions only through registered or licensed brokers or dealers. In addition, in some states the Common Stock may not be sold unless it has been registered or qualified for sale or an exemption from registration or qualification requirements is available and is complied with.

We have advised the selling stockholder that the anti-manipulation rules of Regulation M under the Exchange Act may apply to sales of shares in the market and to the activities of the selling stockholder and their affiliates. In addition, we will make copies of this prospectus (as it may be supplemented or amended from time to time) available to the selling stockholder for the purpose of satisfying the prospectus delivery requirements of the Securities Act.

We have agreed to indemnify the selling stockholder against liabilities, including liabilities under the Securities Act and state securities laws, relating to the registration of the shares offered by this prospectus. We and the selling stockholder may enter agreements under which underwriters, dealers and agents who participate in the distribution of our Common Stock may be entitled to indemnification by us and/or the selling stockholder against various liabilities, including liabilities under the Securities Act, and to contribution with respect to payments which the underwriters, dealers or agents may be required to make.

If underwriters or dealers are used in the sale of shares of our common stock, until the distribution of the shares is completed, rules of the SEC may limit the ability of any underwriters to bid for and purchase our Common Stock. As an exception to these rules, representatives of any underwriters are permitted to engage in transactions that stabilize the price of our Common Stock. These transactions may consist of bids or purchases for the purpose of pegging, fixing or maintaining the price of our Common Stock. If the underwriters create a short position in shares of our Common Stock in connection with an offering (that is, if they sell more shares than are set forth on the cover page of the applicable prospectus supplement) the representatives of the underwriters may reduce that short position by purchasing shares in the open market.

We make no representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of our Common Stock. In addition, we make no representation that the representatives of any underwriters will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice.

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LEGAL MATTERS

The validity of the shares of our Common Stock being offered by this prospectus will be passed upon for us by Goodwin Procter LLP, Boston, Massachusetts. Certain legal matters with respect to the Common Stock may be passed upon by counsel for any underwriters, dealers or agents, each of whom will be named in the related prospectus supplement.

EXPERTS

The consolidated financial statements of Casa Systems, Inc. at December 31, 2021 and 2020, and for the years then ended, appearing in Casa Systems Inc.’s Annual Report (Form 10-K) for the year ended December 31, 2021, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their report thereon included therein, and incorporated herein by reference. Such financial statements are, and audited financial statements to be included in subsequently filed documents will be, incorporated herein in reliance upon the report of Ernst & Young LLP pertaining to such financial statements (to the extent covered by consents filed with the Securities and Exchange Commission) given on the authority of such firm as experts in accounting and auditing.

The consolidated financial statements of Casa Systems, Inc. for the year ended December 31, 2019 incorporated in this Form S-3 by reference to the Annual Report on Form 10-K for the year ended December 31, 2021 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the information requirements of the Exchange Act and, in accordance therewith, file annual, quarterly and special reports, proxy statements and other information with the SEC. These documents may be accessed through the SEC’s electronic data gathering, analysis and retrieval system, or EDGAR, via electronic means, including the SEC’s home page on the Internet (www.sec.gov). Copies of certain information filed by us with the SEC are also available on our website at http://www.casa-systems.com. The information contained on our website is not incorporated by reference into this prospectus and, therefore, is not part of this prospectus or any accompanying prospectus supplement.

This prospectus is part of a registration statement that we have filed with the SEC. Certain information in the registration statement has been omitted from this prospectus in accordance with SEC rules and regulations. For more detail about us and any securities that may be offered by this prospectus, you may examine the registration statement on Form S-3 and the exhibits filed with it at the locations listed in the previous paragraph. Please be aware that statements in this prospectus referring to a contract or other document are summaries and you should refer to the exhibits that are part of the registration statement for a copy of the contract or document.

INCORPORATION BY REFERENCE

The SEC allows us to incorporate by reference the information and reports we file with it, which means that we can disclose important information to you by referring you to these documents. The information incorporated by reference is considered to be a part of this prospectus, and the information that we file later with the SEC will automatically update and, where applicable, supersede the information already incorporated by reference. We incorporate by reference the documents listed below that we filed with the SEC:

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Upon request, either orally or in writing, we will provide, without charge, to each person, including any beneficial owner, to whom a copy of this prospectus is delivered, a copy of the documents incorporated by reference into this prospectus but not delivered with the prospectus. You may request a copy of these filings, and any exhibits we have specifically incorporated by reference as an exhibit in this prospectus, at no cost by writing us at the following address: Casa Systems, Inc., 100 Old River Road, Andover, Massachusetts 01810, Attention: Corporate Secretary.

You should rely only on the information incorporated by reference or provided in this prospectus or any prospectus supplement. We have not, and the selling stockholder has not, authorized anyone to provide you with different information. We are not, and the selling stockholder is not, making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus or in the documents incorporated by reference is accurate as of any date other than the date on the front of this prospectus or those documents.

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9,323,000 Shares

Common Stock

PROSPECTUS

            , 2022

We have not, and the selling stockholder has not, authorized any dealer, salesperson or other person to give any information or represent anything not contained in this prospectus. You must not rely on any unauthorized information. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus does not offer to sell any securities in any jurisdiction where it is unlawful. Neither the delivery of this prospectus, nor any sale made hereunder, shall create any implication that the information in this prospectus is correct after the date hereof.

PART II-INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution

The expenses payable by Casa Systems, Inc. (the “registrant” or “we”) in connection with the issuance and distribution of the securities being registered (other than underwriting discounts and commissions, if any) are set forth below. Each item listed is estimated, except for the Securities and Exchange Commission (the “SEC”) registration fee.

Item 15. Indemnification of Directors and Officers

Section 145 of the Delaware General Corporation Law (the “DGCL”) authorizes a corporation to indemnify its directors and officers against liabilities arising out of actions, suits and proceedings to which they are made or threatened to be made a party by reason of the fact that they have served or are currently serving as a director or officer to a corporation. The indemnity may cover expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by the director or officer in connection with any such action, suit or proceeding. Section 145 permits corporations to pay expenses (including attorneys’ fees) incurred by directors and officers in advance of the final disposition of such action, suit or proceeding. In addition, Section 145 provides that a corporation has the power to purchase and maintain insurance on behalf of its directors and officers against any liability asserted against them and incurred by them in their capacity as a director or officer, or arising out of their status as such, whether or not the corporation would have the power to indemnify the director or officer against such liability under Section 145.

We have adopted provisions in our amended and restated certificate of incorporation and amended and restated by-laws that limit or eliminate the personal liability of our directors to the fullest extent permitted by the DGCL, as it now exists or may in the future be amended. Consequently, a director will not be personally liable to us or our stockholders for monetary damages or breach of fiduciary duty as a director, except for liability for:

These limitations of liability do not alter director liability under the federal securities laws and do not affect the availability of equitable remedies such as an injunction or rescission.

In addition, our amended and restated by-laws provide that:

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We have entered into indemnification agreements with each of our directors and with certain of our executive officers. These agreements provide that we will indemnify each of our directors, certain of our executive officers and, at times, their affiliates to the fullest extent permitted by Delaware law. We will advance expenses, including attorneys’ fees (but excluding judgments, fines and settlement amounts), to each indemnified director, executive officer or affiliate in connection with any proceeding in which indemnification is available and we will indemnify our directors and officers for any action or proceeding arising out of that person’s services as a director or officer brought on behalf of us and/or in furtherance of our rights. Additionally, each of our directors may have certain rights to indemnification, advancement of expenses and/or insurance provided by their affiliates, which indemnification relates to and might apply to the same proceedings arising out of such director’s services as a director referenced herein. Nonetheless, we have agreed in the indemnification agreements that our obligations to those same directors are primary and any obligation of the affiliates of those directors to advance expenses or to provide indemnification for the expenses or liabilities incurred by those directors are secondary.

We also maintain general liability insurance which covers certain liabilities of our directors and officers arising out of claims based on acts or omissions in their capacities as directors or officers, including liabilities under the Securities Act of 1933, as amended.

Item 16. Exhibits

A list of all exhibits filed with this registration statement on Form S-3 is set forth on the Exhibit Index and is incorporated herein by reference.

Item 17. Undertakings

The undersigned registrant hereby undertakes:

provided, however, that paragraphs (l)(i), (l)(ii) and (l)(iii) of this section do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Securities and Exchange Commission by the registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement;

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EXHIBIT INDEX

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the city of Andover, State of Massachusetts, on this 17th day of May, 2022.

KNOW ALL BY THESE PRESENTS, that each person whose signature appears below hereby severally constitutes and appoints each of Jerry Guo, Edward Durkin and Matthew Slepian, and each of them singly, as such person’s true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution, for such person and in such person’s name, place and stead, in any and all capacities, to sign any or all amendments (including, without limitation, post-effective amendments) to this registration statement (or any registration statement for the same offering that is to be effective upon filing pursuant to Rule 462(b) under the Securities Act of 1933), and to file the same, with all exhibits thereto, and all documents in connection therewith, with the Securities and Exchange Commission, granting unto each said attorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as such person might or could do in person, hereby ratifying and confirming all that any said attorney-in-fact and agent, or any substitute or substitutes of any of them, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the dates indicated.

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Exhibit 5.1

				Goodwin Procter LLP 100 Northern Avenue
				Boston, MA 02210   goodwinlaw.com
				+1 617 570 1000

May 17, 2022

Casa Systems, Inc.

100 Old River Road

Andover, MA 01810

We have acted as counsel to you in connection with your filing of a Registration Statement on Form S-3 (as amended or supplemented, the “Registration Statement”) filed on May 17, 2022 with the Securities and Exchange Commission (the “Commission”) pursuant to the Securities Act of 1933, as amended (the “Securities Act”), relating to the registration of 9,323,000 shares (the “Shares”) of common stock, par value $0.001 per share (the “Common Stock”), of Casa Systems, Inc., a Delaware corporation (the “Company”), to be sold from time to time by the selling stockholder listed in the Registration Statement under “Selling Stockholder.”

We have reviewed such documents and made such examination of law as we have deemed appropriate to give the opinions set forth below. We have relied, without independent verification, on certificates of public officials and, as to matters of fact material to the opinions set forth below, on certificates of officers of the Company.

The opinion set forth below is limited to the Delaware General Corporation Law.

Based on the foregoing, we are of the opinion that the Shares have been duly authorized and validly issued and are fully paid and nonassessable.

We hereby consent to the inclusion of this opinion as Exhibit 5.1 to the Registration Statement and to the references to our firm under the caption “Legal Matters” in the Registration Statement. In giving our consent, we do not admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations thereunder.

Very truly yours,

/s/ Goodwin Procter LLP

GOODWIN PROCTER LLP

Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the reference to our firm under the caption “Experts” in the Registration Statement (Form S-3) and related Prospectus of Casa Systems, Inc. for the registration of 9,323,000 shares of its common stock and to the incorporation by reference therein of our report dated February 25, 2022, with respect to the consolidated financial statements of Casa Systems, Inc. included in its Annual Report (Form 10-K) for the year ended December 31, 2021, filed with the Securities and Exchange Commission.

/s/ Ernst & Young LLP

Boston, Massachusetts

May 17, 2022

Exhibit 23.2

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement on Form S-3 of Casa Systems, Inc. of our report dated February 27, 2020, except for the presentation of disaggregated revenue discussed in Note 15, as to which the date is February 25, 2021 relating to the financial statements, which appears in Casa Systems, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2021. We also consent to the reference to us under the heading “Experts” in such Registration Statement.

/s/ PricewaterhouseCoopers LLP

Boston, Massachusetts

May 17, 2022

Exhibit 107

Calculation of Filing Fee Tables

Form S-3

(Form Type)

Casa Systems, Inc.

(Exact Name of Registrant as Specified in its Charter)

Table 1: Newly Registered and Carry Forward Securities