Document:

EX-10.12

 Exhibit 10.12 

CASA SYSTEMS, INC. 
 2017 STOCK
INCENTIVE PLAN 
 1.    Purpose 

The purpose of this 2017 Stock Incentive Plan (the “Plan”) of Casa Systems, Inc., a Delaware corporation (the
“Company”), is to advance the interests of the Company’s stockholders by enhancing the Company’s ability to attract, retain and motivate persons who are expected to make important contributions to the Company and by
providing such persons with equity ownership opportunities and performance-based incentives that are intended to better align the interests of such persons with those of the Company’s stockholders. Except where the context otherwise requires,
the term “Company” shall include any of the Company’s present or future parent or subsidiary corporations as defined in Sections 424(e) or (f) of the Internal Revenue Code of 1986, as amended, and any regulations
thereunder (the “Code”) and any other business venture (including, without limitation, joint venture or limited liability company) in which the Company has a controlling interest, as determined by the Board of Directors of
the Company (the “Board”). 
 2.    Eligibility 

All of the Company’s employees, officers and directors, as well as consultants and advisors to the Company (as such terms consultants and
advisors are defined and interpreted for purposes of Form S-8 under the Securities Act of 1933, as amended (the “Securities Act”), or any successor form) are eligible to be granted
Awards under the Plan. Each person who is granted an Award under the Plan is deemed a “Participant.” “Award” means Options (as defined in Section 5), SARs (as defined in Section 6),
Restricted Stock (as defined in Section 7), Restricted Stock Units (as defined in Section 7) and Other Stock-Based Awards (as defined in Section 8). 

3.    Administration and Delegation 

(a)    Administration by Board of Directors. The Plan will be administered by the Board. The Board shall have
authority to grant Awards and to adopt, amend and repeal such administrative rules, guidelines and practices relating to the Plan as it shall deem advisable. The Board may construe and interpret the terms of the Plan and any Award agreements entered
into under the Plan. The Board may correct any defect, supply any omission or reconcile any inconsistency in the Plan or any Award in the manner and to the extent it shall deem expedient and it shall be the sole and final judge of such expediency.
All decisions by the Board shall be made in the Board’s sole discretion and shall be final and binding on all persons having or claiming any interest in the Plan or in any Award. 

(b)    Appointment of Committees. To the extent permitted by applicable law, the Board may delegate any or all of
its powers under the Plan to one or more committees or subcommittees of the Board (a “Committee”). All references in the Plan to the “Board” shall mean the Board or a Committee of the Board or the
officers referred to in Section 3(c) to the extent that the Board’s powers or authority under the Plan have been delegated to such Committee or officers. 

 (c)    Delegation to Officers. Subject to any requirements of
applicable law (including as applicable Sections 152 and 157(c) of the General Corporation Law of the State of Delaware), the Board may delegate to one or more officers of the Company the power to grant Awards (subject to any limitations under the
Plan) to employees or officers of the Company and to exercise such other powers under the Plan as the Board may determine, provided that the Board shall fix the terms of Awards to be granted by such officers, the maximum number of shares subject to
Awards that the officers may grant, and the time period in which such Awards may be granted; and provided further, that no officer shall be authorized to grant Awards to any “executive officer” of the Company (as defined by Rule 3b-7 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”)) or to any “officer” of the Company (as defined by Rule
16a-1(f) under the Exchange Act). 
 4.    Stock Available for Awards 

(a)    Number of Shares; Share Counting. 

(1)    Authorized Number of Shares. Subject to adjustment under Section 9, Awards may be made under the Plan
(any or all of which Awards may be in the form of Incentive Stock Options, as defined in Section 5(b)) for up to such number of shares of common stock, $0.001 par value per share, of the Company (the “Common Stock”) as
is equal to the sum of: 
 (A)    1,432,137 shares of Common Stock; plus 

(B)    such additional number of shares of Common Stock (up to 3,749,209 shares) as is equal to the sum of (x) the
number of shares of Common Stock reserved for issuance under the Company’s 2011 Stock Incentive Plan, as amended (the “Existing Plan”) that remain available for grant under the Existing Plan immediately prior to the
effectiveness of the registration statement for the Company’s initial public offering and (y) the number of shares of Common Stock subject to awards granted under the Existing Plan which awards expire, terminate or are otherwise
surrendered, canceled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right (subject, however, in the case of Incentive Stock Options to any limitations of the Code); plus 

(C)    an annual increase to be added on the first day of each fiscal year, beginning with the fiscal year ending
December 31, 2019 and continuing for each fiscal year until, and including, the fiscal year ending December 31, 2027, equal to the least of (i) 4,000,000 shares of Common Stock, (ii) 4% of the outstanding shares on such date and
(iii) an amount determined by the Board. 
 Shares issued under the Plan may consist in whole or in part of authorized but unissued shares or treasury
shares. 
 (2)    Share Counting. For purposes of counting the number of shares available for the grant of Awards
under the Plan: 

  
 -2- 

 (A)    all shares of Common Stock covered by SARs shall be counted against
the number of shares available for the grant of Awards under the Plan; provided, however, that (i) SARs that may be settled only in cash shall not be so counted and (ii) if the Company grants an SAR in tandem with an Option for the
same number of shares of Common Stock and provides that only one such Award may be exercised (a “Tandem SAR”), only the shares covered by the Option, and not the shares covered by the Tandem SAR, shall be so counted, and the
expiration of one in connection with the other’s exercise will not restore shares to the Plan; 
 (B)    if any
Award (i) expires or is terminated, surrendered or canceled without having been fully exercised or is forfeited in whole or in part (including as the result of shares of Common Stock subject to such Award being repurchased by the Company at the
original issuance price pursuant to a contractual repurchase right) or (ii) results in any Common Stock not being issued (including as a result of an SAR that was settleable either in cash or in stock actually being settled in cash), the unused
Common Stock covered by such Award shall again be available for the grant of Awards; provided, however, that (1) in the case of Incentive Stock Options, the foregoing shall be subject to any limitations under the Code, (2) in the
case of the exercise of an SAR, the number of shares counted against the shares available under the Plan shall be the full number of shares subject to the SAR multiplied by the percentage of the SAR actually exercised, regardless of the number of
shares actually used to settle such SAR upon exercise and (3) the shares covered by a Tandem SAR shall not again become available for grant upon the expiration or termination of such Tandem SAR; and 

(C)    shares of Common Stock delivered (by actual delivery, attestation, or net exercise) to the Company by a
Participant to (i) purchase shares of Common Stock upon the exercise of an Award or (ii) satisfy tax withholding obligations with respect to Awards (including shares retained from the Award creating the tax obligation) shall be added back
to the number of shares available for the future grant of Awards. 
 (b)    Substitute Awards. In connection with
a merger or consolidation of an entity with the Company or the acquisition by the Company of property or stock of an entity, the Board may grant Awards in substitution for any options or other stock or stock-based awards granted by such entity or an
affiliate thereof. Substitute Awards may be granted on such terms as the Board deems appropriate in the circumstances, notwithstanding any limitations on Awards contained in the Plan. Substitute Awards shall not count against the overall share limit
set forth in Section 4(a)(1), except as may be required by reason of Section 422 and related provisions of the Code. 

5.    Stock Options 

(a)    General. The Board may grant options to purchase Common Stock (each, an “Option”)
and determine the number of shares of Common Stock to be covered by each Option, the exercise price of each Option and the conditions and limitations applicable to the exercise of each Option, including conditions relating to applicable federal or
state securities laws, as it considers necessary or advisable. 
 (b)    Incentive Stock Options. An Option that
the Board intends to be an “incentive stock option” as defined in Section 422 of the Code (an “Incentive Stock Option”) shall only be 

  
 -3- 

 
granted to employees of Casa Systems, Inc., any of Casa Systems, Inc.’s present or future parent or subsidiary corporations as defined in Sections 424(e) or (f) of the Code, and any
other entities the employees of which are eligible to receive Incentive Stock Options under the Code, and shall be subject to and shall be construed consistently with the requirements of Section 422 of the Code. An Option that is not intended
to be an Incentive Stock Option shall be designated a “Nonstatutory Stock Option.” The Company shall have no liability to a Participant, or any other party, if an Option (or any part thereof) that is intended to be an
Incentive Stock Option is not an Incentive Stock Option or if the Company converts an Incentive Stock Option to a Nonstatutory Stock Option. 

(c)    Exercise Price. The Board shall establish the exercise price of each Option or the formula by which such
exercise price will be determined. The exercise price shall be specified in the applicable Option agreement. The exercise price shall be not less than 100% of the Grant Date Fair Market Value (as defined below) of the Common Stock on the date the
Option is granted; provided that if the Board approves the grant of an Option with an exercise price to be determined on a future date, the exercise price shall be not less than 100% of the Grant Date Fair Market Value on such future date.
“Grant Date Fair Market Value” of a share of Common Stock for purposes of the Plan will be determined as follows: 

(1)    if the Common Stock trades on a national securities exchange, the closing sale price (for the primary trading
session) on the date of grant; or 
 (2)    if the Common Stock does not trade on any such exchange, the average of the
closing bid and asked prices on the date of grant as reported by an over-the-counter marketplace designated by the Board; or 

(3)    if the Common Stock is not publicly traded, the Board will determine the Grant Date Fair Market Value for purposes
of the Plan using any measure of value it determines to be appropriate (including, as it considers appropriate, relying on appraisals) in a manner consistent with the valuation principles under Code Section 409A, except as the Board may
expressly determine otherwise. 
 For any date that is not a trading day, the Grant Date Fair Market Value of a share of Common Stock for such date will be
determined by using the closing sale price or average of the bid and asked prices, as appropriate, for the immediately preceding trading day and with the timing in the formulas above adjusted accordingly. The Board can substitute a particular time
of day or other measure of “closing sale price” or “bid and asked prices” if appropriate because of exchange or market procedures or can, in its sole discretion, use weighted averages either on a daily basis or such longer period
as complies with Code Section 409A. 
 The Board has sole discretion to determine the Grant Date Fair Market Value for purposes of the Plan, and all
Awards are conditioned on the Participants’ agreement that the Administrator’s determination is conclusive and binding even though others might make a different determination. 

  
 -4- 

 (d)    Duration of Options. Each Option shall be exercisable at such
times and subject to such terms and conditions as the Board may specify in the applicable option agreement; provided, however, that no Option will be granted with a term in excess of 10 years. 

(e)    Exercise of Options. Options may be exercised by delivery to the Company of a notice of exercise in a form
(which may be electronic) approved by the Company, together with payment in full (in the manner specified in Section 5(f)) of the exercise price for the number of shares for which the Option is exercised. Shares of Common Stock subject to the
Option will be delivered by the Company as soon as practicable following exercise. 
 (f)    Payment Upon
Exercise. Common Stock purchased upon the exercise of an Option granted under the Plan shall be paid for as follows: 

(1)    in cash or by check, payable to the order of the Company; 

(2)    except as may otherwise be provided in the applicable Option agreement or approved by the Board, by
(i) delivery of an irrevocable and unconditional undertaking by a creditworthy broker to deliver promptly to the Company sufficient funds to pay the exercise price and any required tax withholding or (ii) delivery by the Participant to the
Company of a copy of irrevocable and unconditional instructions to a creditworthy broker to deliver promptly to the Company cash or a check sufficient to pay the exercise price and any required tax withholding; 

(3)    to the extent provided for in the applicable Option agreement or approved by the Board, by delivery (either by
actual delivery or attestation) of shares of Common Stock owned by the Participant valued at their fair market value (valued in the manner determined by (or in a manner approved by) the Board), provided (i) such method of payment is then
permitted under applicable law, (ii) such Common Stock, if acquired directly from the Company, was owned by the Participant for such minimum period of time, if any, as may be established by the Board and (iii) such Common Stock is not
subject to any repurchase, forfeiture, unfulfilled vesting or other similar requirements; 
 (4)    to the extent
provided for in the applicable Nonstatutory Stock Option agreement or approved by the Board in its sole discretion, by delivery of a notice of “net exercise” to the Company, as a result of which the Participant would receive (i) the
number of shares underlying the portion of the Option being exercised, less (ii) such number of shares as is equal to (A) the aggregate exercise price for the portion of the Option being exercised divided by (B) the fair market value
of the Common Stock (valued in the manner determined by (or in a manner approved by) the Board) on the date of exercise; 

(5)    to the extent permitted by applicable law and provided for in the applicable Option agreement or approved by the
Board by payment of such other lawful consideration as the Board may determine; or 
 (6)    by any combination of the
above permitted forms of payment. 

  
 -5- 

 (g)    Limitation on Repricing. Unless such action is approved by the
Company’s stockholders, the Company may not (except as provided for under Section 9): (1) amend any outstanding Option granted under the Plan to provide an exercise price per share that is lower than the then-current exercise price per
share of such outstanding Option, (2) cancel any outstanding option (whether or not granted under the Plan) and grant in substitution therefor new Awards under the Plan (other than Awards granted pursuant to Section 4(b)) covering the same
or a different number of shares of Common Stock and having an exercise price per share lower than the then-current exercise price per share of the cancelled option, (3) cancel in exchange for a cash payment any outstanding Option with an
exercise price per share above the then-current fair market value of the Common Stock (valued in the manner determined by (or in the manner approved by) the Board) or (4) take any other action under the Plan that constitutes a
“repricing” within the meaning of the rules of the NASDAQ Stock Market (“NASDAQ”). 
 6.    Stock
Appreciation Rights 
 (a)    General. The Board may grant Awards consisting of stock appreciation rights
(“SARs”) entitling the holder, upon exercise, to receive an amount of Common Stock or cash or a combination thereof (such form to be determined by the Board) determined by reference to appreciation, from and after the date of
grant, in the fair market value of a share of Common Stock (valued in the manner determined by (or in the manner approved by) the Board) over the measurement price established pursuant to Section 6(b). The date as of which such appreciation is
determined shall be the exercise date. 
 (b)    Measurement Price. The Board shall establish the measurement
price of each SAR and specify it in the applicable SAR agreement. The measurement price shall not be less than 100% of the Grant Date Fair Market Value of the Common Stock on the date the SAR is granted; provided that if the Board approves
the grant of an SAR effective as of a future date, the measurement price shall be not less than 100% of the Grant Date Fair Market Value on such future date. 

(c)    Duration of SARs. Each SAR shall be exercisable at such times and subject to such terms and conditions as
the Board may specify in the applicable SAR agreement; provided, however, that no SAR will be granted with a term in excess of 10 years. 

(d)    Exercise of SARs. SARs may be exercised by delivery to the Company of a notice of exercise in a form (which
may be electronic) approved by the Company, together with any other documents required by the Board. 

(e)    Limitation on Repricing. Unless such action is approved by the Company’s stockholders, the Company may
not (except as provided for under Section 9): (1) amend any outstanding SAR granted under the Plan to provide a measurement price per share that is lower than the then-current measurement price per share of such outstanding SAR, (2) cancel
any outstanding SAR (whether or not granted under the Plan) and grant in substitution therefor new Awards under the Plan (other than Awards granted pursuant to Section 4(b)) covering the same or a different number of shares of Common Stock and
having an exercise or measurement price per share lower than the then-current measurement price per share of the cancelled SAR, (3) cancel in exchange for a cash payment any outstanding SAR with a measurement price per share

  
 -6- 

 
above the then-current fair market value of the Common Stock (valued in the manner determined by (or in a manner approved by) the Board) or (4) take any other action under the Plan that
constitutes a “repricing” within the meaning of the rules of NASDAQ. 
 7.    Restricted Stock; Restricted Stock Units

 (a)    General. The Board may grant Awards entitling recipients to acquire shares of Common Stock
(“Restricted Stock”), subject to the right of the Company to repurchase all or part of such shares at their issue price or other stated or formula price (or to require forfeiture of such shares if issued at no cost) from the
recipient in the event that conditions specified by the Board in the applicable Award are not satisfied prior to the end of the applicable restriction period or periods established by the Board for such Award. The Board may also grant Awards
entitling the recipient to receive shares of Common Stock or cash to be delivered at the time such Award vests or is settled (“Restricted Stock Units”) (Restricted Stock and Restricted Stock Units are each referred to herein
as a “Restricted Stock Award”). 
 (b)    Terms and Conditions for All Restricted Stock
Awards. The Board shall determine the terms and conditions of a Restricted Stock Award, including the conditions for vesting and repurchase (or forfeiture) and the issue price, if any. 

(c)    Additional Provisions Relating to Restricted Stock. 

(1)    Dividends. Unless otherwise provided in the applicable Award agreement, any dividends (whether paid in cash,
stock or property) declared and paid by the Company with respect to shares of Restricted Stock (“Accrued Dividends”) shall be paid to the Participant only if and when such shares become free from the restrictions on
transferability and forfeitability that apply to such shares. Each payment of Accrued Dividends will be made no later than the end of the calendar year in which the dividends are paid to stockholders of that class of stock or, if later, the 15th day
of the third month following the lapsing of the restrictions on transferability and the forfeitability provisions applicable to the underlying shares of Restricted Stock. 

(2)    Stock Certificates. The Company may require that any stock certificates issued in respect of shares of
Restricted Stock, as well as dividends or distributions paid on such Restricted Stock, shall be deposited in escrow by the Participant, together with a stock power endorsed in blank, with the Company (or its designee). At the expiration of the
applicable restriction periods, the Company (or such designee) shall deliver the certificates no longer subject to such restrictions to the Participant or if the Participant has died, to his or her Designated Beneficiary. “Designated
Beneficiary” means (i) the beneficiary designated, in a manner determined by the Board, by a Participant to receive amounts due or exercise rights of the Participant in the event of the Participant’s death or (ii) in the
absence of an effective designation by a Participant, the Participant’s estate. 
 (d)    Additional Provisions
Relating to Restricted Stock Units. 
 (1)    Settlement. Upon the vesting of and/or lapsing of any other
restrictions (i.e., settlement) with respect to each Restricted Stock Unit, the Participant shall be entitled to 

  
 -7- 

 
receive from the Company such number of shares of Common Stock or (if so provided in the applicable Award agreement) an amount of cash equal to the fair market value (valued in the manner
determined by (or in a manner approved by) the Board) of such number of shares of Common Stock as are set forth in the applicable Restricted Stock Unit agreement. The Board may provide that settlement of Restricted Stock Units shall be deferred, on
a mandatory basis or at the election of the Participant in a manner that complies with Section 409A of the Code. 

(2)    Voting Rights. A Participant shall have no voting rights with respect to any Restricted Stock Units. 

(3)    Dividend Equivalents. The Award agreement for Restricted Stock Units may provide Participants with the right
to receive an amount equal to any dividends or other distributions declared and paid on an equal number of outstanding shares of Common Stock (“Dividend Equivalents”). Dividend Equivalents may be settled in cash and/or shares
of Common Stock and shall be subject to the same restrictions on transfer and forfeitability as the Restricted Stock Units with respect to which paid, in each case to the extent provided in the Award agreement. 

8.    Other Stock-Based Awards 

(a)    General. The Board may grant other Awards of shares of Common Stock, and other Awards that are valued in
whole or in part by reference to, or are otherwise based on, shares of Common Stock or other property (“Other Stock-Based Awards”). Such Other Stock-Based Awards shall also be available as a form of payment in the settlement
of other Awards granted under the Plan or as payment in lieu of compensation to which a Participant is otherwise entitled. Other Stock-Based Awards may be paid in shares of Common Stock or cash, as the Board shall determine. 

(b)    Terms and Conditions. Subject to the provisions of the Plan, the Board shall determine the terms and
conditions of each Other Stock-Based Award, including any purchase price applicable thereto. 
 9.    Adjustments for Changes in
Common Stock and Certain Other Events 
 (a)    Changes in Capitalization. In the event of any stock split,
reverse stock split, stock dividend, recapitalization, combination of shares, reclassification of shares, spin-off or other similar change in capitalization or event, or any dividend or distribution to holders
of Common Stock other than an ordinary cash dividend, (i) the number and class of securities available under the Plan, (ii) the share counting rules set forth in Section 4(a), (iii) the number and class of securities and exercise
price per share of each outstanding Option, (iv) the share and per-share provisions and the measurement price of each outstanding SAR, (v) the number of shares subject to and the repurchase price per
share subject to each outstanding Restricted Stock Award and (vi) the share and per-share-related provisions and the purchase price, if any, of each outstanding Other Stock-Based Award, shall be equitably
adjusted by the Company (or substituted Awards may be made, if applicable) in the manner determined by the Board. Without limiting the generality of the foregoing, in the event the Company effects a split of the Common Stock by means of a stock
dividend and the exercise price of and the number of shares 

  
 -8- 

 
subject to an outstanding Option are adjusted as of the date of the distribution of the dividend (rather than as of the record date for such dividend), then an optionee who exercises an Option
between the record date and the distribution date for such stock dividend shall be entitled to receive, on the distribution date, the stock dividend with respect to the shares of Common Stock acquired upon such Option exercise, notwithstanding the
fact that such shares were not outstanding as of the close of business on the record date for such stock dividend. 

(b)    Reorganization Events. 

(1)    Definition. A “Reorganization Event” shall mean: (a) any merger or
consolidation of the Company with or into another entity as a result of which all of the Common Stock of the Company is converted into or exchanged for the right to receive cash, securities or other property or is cancelled, (b) any transfer or
disposition of all of the Common Stock of the Company for cash, securities or other property pursuant to a share exchange or other transaction or (c) any liquidation or dissolution of the Company. 

(2)    Consequences of a Reorganization Event on Awards Other than Restricted Stock. 

(A)    In connection with a Reorganization Event, the Board may take any one or more of the following actions as to all
or any (or any portion of) outstanding Awards other than Restricted Stock on such terms as the Board determines (except to the extent specifically provided otherwise in an applicable Award agreement or another agreement between the Company and the
Participant): (i) provide that such Awards shall be assumed, or substantially equivalent Awards shall be substituted, by the acquiring or succeeding corporation (or an affiliate thereof), (ii) upon written notice to a Participant, provide
that all of the Participant’s unvested Awards will be forfeited immediately prior to the consummation of such Reorganization Event and/or unexercised Awards will terminate immediately prior to the consummation of such Reorganization Event
unless exercised by the Participant (to the extent then exercisable) within a specified period following the date of such notice, (iii) provide that outstanding Awards shall become exercisable, realizable or deliverable, or restrictions
applicable to an Award shall lapse, in whole or in part prior to or upon such Reorganization Event, (iv) in the event of a Reorganization Event under the terms of which holders of Common Stock will receive upon consummation thereof a cash
payment for each share surrendered in the Reorganization Event (the “Acquisition Price”), make or provide for a cash payment to Participants with respect to each Award held by a Participant equal to (A) the number of
shares of Common Stock subject to the vested portion of the Award (after giving effect to any acceleration of vesting that occurs upon or immediately prior to such Reorganization Event) multiplied by (B) the excess, if any, of (I) the
Acquisition Price over (II) the exercise, measurement or purchase price of such Award and any applicable tax withholdings, in exchange for the termination of such Award, (v) provide that, in connection with a liquidation or dissolution of
the Company, Awards shall convert into the right to receive liquidation proceeds (if applicable, net of the exercise, measurement or purchase price thereof and any applicable tax withholdings) and (vi) any combination of the foregoing. In
taking any of the actions permitted under this Section 9(b)(2), the Board shall not be obligated by the Plan to treat all Awards, all Awards held by a Participant, or all Awards of the same type, identically. 

  
 -9- 

 (B)    Notwithstanding the terms of Section 9(b)(2)(A), in the case of
outstanding Restricted Stock Units that are subject to Section 409A of the Code: (i) if the applicable Restricted Stock Unit agreement provides that the Restricted Stock Units shall be settled upon a “change in control event”
within the meaning of Treasury Regulation Section 1.409A-3(i)(5)(i), and the Reorganization Event constitutes such a “change in control event”, then no assumption or substitution shall be
permitted pursuant to Section 9(b)(2)(A)(i) and the Restricted Stock Units shall instead be settled in accordance with the terms of the applicable Restricted Stock Unit agreement; and (ii) the Board may only undertake the actions set forth
in clauses (iii), (iv) or (v) of Section 9(b)(2)(A) if the Reorganization Event constitutes a “change in control event” as defined under Treasury Regulation Section 1.409A-3(i)(5)(i)
and such action is permitted or required by Section 409A of the Code; if the Reorganization Event is not a “change in control event” as so defined or such action is not permitted or required by Section 409A of the Code, and the
acquiring or succeeding corporation does not assume or substitute the Restricted Stock Units pursuant to clause (i) of Section 9(b)(2)(A), then the unvested Restricted Stock Units shall terminate immediately prior to the consummation of
the Reorganization Event without any payment in exchange therefor. 
 (C)    For purposes of
Section 9(b)(2)(A)(i), an Award (other than Restricted Stock) shall be considered assumed if, following consummation of the Reorganization Event, such Award confers the right to purchase or receive pursuant to the terms of such Award, for each
share of Common Stock subject to the Award immediately prior to the consummation of the Reorganization Event, the consideration (whether cash, securities or other property) received as a result of the Reorganization Event by holders of Common Stock
for each share of Common Stock held immediately prior to the consummation of the Reorganization Event (and if holders were offered a choice of consideration, the type of consideration chosen by the holders of a majority of the outstanding shares of
Common Stock); provided, however, that if the consideration received as a result of the Reorganization Event is not solely common stock of the acquiring or succeeding corporation (or an affiliate thereof), the Company may, with the consent of
the acquiring or succeeding corporation, provide for the consideration to be received upon the exercise or settlement of the Award to consist solely of such number of shares of common stock of the acquiring or succeeding corporation (or an affiliate
thereof) that the Board determines to be equivalent in value (as of the date of such determination or another date specified by the Board) to the per share consideration received by holders of outstanding shares of Common Stock as a result of the
Reorganization Event. 
 (3)    Consequences of a Reorganization Event on Restricted Stock. Upon the occurrence
of a Reorganization Event other than a liquidation or dissolution of the Company, the repurchase and other rights of the Company with respect to outstanding Restricted Stock shall inure to the benefit of the Company’s successor and shall,
unless the Board determines otherwise, apply to the cash, securities or other property which the Common Stock was converted into or exchanged for pursuant to such Reorganization Event in the same manner and to the same extent as they applied to such
Restricted Stock; provided, however, that the Board may provide for termination or deemed satisfaction of such repurchase or other rights under the instrument evidencing any Restricted Stock or any other agreement between a Participant
and the Company, either initially or by amendment. Upon the occurrence of a Reorganization Event involving the liquidation or dissolution of the Company, except to the extent specifically provided to the contrary in the instrument evidencing any
Restricted Stock or any other agreement between a Participant and the Company, all restrictions and conditions on all Restricted Stock then outstanding shall automatically be deemed terminated or satisfied. 

  
 -10- 

 10.    General Provisions Applicable to Awards 

(a)    Transferability of Awards. Awards shall not be sold, assigned, transferred, pledged or otherwise encumbered
by the Participant, either voluntarily or by operation of law, except by will or the laws of descent and distribution or, other than in the case of an Incentive Stock Option, pursuant to a qualified domestic relations order, and, during the life of
the Participant, shall be exercisable only by the Participant; provided, however, that, except with respect to Awards subject to Section 409A of the Code, the Board may permit or provide in an Award for the gratuitous transfer of the
Award by the Participant to or for the benefit of any immediate family member, family trust or other entity established for the benefit of the Participant and/or an immediate family member thereof if the Company would be eligible to use a Form S-8 under the Securities Act for the registration of the sale of the Common Stock subject to such Award to such proposed transferee; provided further, that the Company shall not be required to recognize any
such permitted transfer until such time as such permitted transferee shall, as a condition to such transfer, deliver to the Company a written instrument in form and substance satisfactory to the Company confirming that such transferee shall be bound
by all of the terms and conditions of the Award. References to a Participant, to the extent relevant in the context, shall include references to authorized transferees. For the avoidance of doubt, nothing contained in this Section 10(a) shall
be deemed to restrict a transfer to the Company. 
 (b)    Documentation. Each Award shall be evidenced in such
form (written, electronic or otherwise) as the Board shall determine. Each Award may contain terms and conditions in addition to those set forth in the Plan. 

(c)    Board Discretion. Except as otherwise provided by the Plan, each Award may be made alone or in addition or
in relation to any other Award. The terms of each Award need not be identical, and the Board need not treat Participants uniformly. 

(d)    Termination of Status. The Board shall determine the effect on an Award of the disability, death,
termination or other cessation of employment, authorized leave of absence or other change in the employment or other status of a Participant and the extent to which, and the period during which, the Participant, or the Participant’s legal
representative, conservator, guardian or Designated Beneficiary, may exercise rights under the Award. 

(e)    Withholding. The Participant must satisfy all applicable federal, state, and local or other income and
employment tax withholding obligations before the Company will deliver stock certificates or otherwise recognize ownership of Common Stock under an Award. The Company may elect to satisfy the withholding obligations through additional withholding on
salary or wages. If the Company elects not to or cannot withhold from other compensation, the Participant must pay the Company the full amount, if any, required for withholding or have a broker tender to the Company cash equal to the withholding
obligations. Payment of withholding obligations is due before the Company will issue any shares on exercise, vesting or release from forfeiture of an Award or at the same time as payment of the exercise or purchase price, unless the Company
determines otherwise. If provided for in an Award or approved by the 

  
 -11- 

 
Committee, a Participant may satisfy the tax obligations in whole or in part by delivery (either by actual delivery or attestation) of shares of Common Stock, including shares retained from the
Award creating the tax obligation, valued at their fair market value (valued in the manner determined by (or in a manner approved by) the Company); provided, however, except as otherwise provided by the Committee, that the total tax
withholding where stock is being used to satisfy such tax obligations cannot exceed the Company’s minimum statutory withholding obligations (based on minimum statutory withholding rates for federal and state tax purposes, including payroll
taxes, that are applicable to such supplemental taxable income), except that, to the extent that the Company is able to retain shares of Common Stock having a fair market value (determined by, or in a manner approved by, the Company) that exceeds
the statutory minimum applicable withholding tax without financial accounting implications or the Company is withholding in a jurisdiction that does not have a statutory minimum withholding tax, the Company may retain such number of shares of Common
Stock (up to the number of shares having a fair market value equal to the maximum individual statutory rate of tax (determined by, or in a manner approved by, the Company)) as the Company shall determine in its sole discretion to satisfy the tax
liability associated with any Award. Shares used to satisfy tax withholding requirements cannot be subject to any repurchase, forfeiture, unfulfilled vesting or other similar requirements. 

(f)    Amendment of Award. Except as otherwise provided in Sections 5(g) and 6(e) with respect to repricings and
Section 11(d) with respect to actions requiring stockholder approval, the Board may amend, modify or terminate any outstanding Award, including but not limited to, substituting therefor another Award of the same or a different type, changing
the date of exercise or realization, and converting an Incentive Stock Option to a Nonstatutory Stock Option. The Participant’s consent to such action shall be required unless (i) the Board determines that the action, taking into account
any related action, does not materially and adversely affect the Participant’s rights under the Plan or (ii) the change is permitted under Section 9. 

(g)    Conditions on Delivery of Stock. The Company will not be obligated to deliver any shares of Common Stock
pursuant to the Plan or to remove restrictions from shares previously issued or delivered under the Plan until (i) all conditions of the Award have been met or removed to the satisfaction of the Company, (ii) in the opinion of the
Company’s counsel, all other legal matters in connection with the issuance and delivery of such shares have been satisfied, including any applicable securities laws and regulations and any applicable stock exchange or stock market rules and
regulations and (iii) the Participant has executed and delivered to the Company such representations or agreements as the Company may consider appropriate to satisfy the requirements of any applicable laws, rules or regulations. 

(h)    Acceleration. The Board may at any time provide that any Award shall become immediately exercisable in whole
or in part, free from some or all restrictions or conditions, or otherwise realizable in whole or in part, as the case may be. 

11.    Miscellaneous 

(a)    No Right To Employment or Other Status. No person shall have any claim or right to be granted an Award by
virtue of the adoption of the Plan, and the grant of an Award 

  
 -12- 

 
shall not be construed as giving a Participant the right to continued employment or any other relationship with the Company. The Company expressly reserves the right at any time to dismiss or
otherwise terminate its relationship with a Participant free from any liability or claim under the Plan, except as expressly provided in the applicable Award. 

(b)    No Rights As Stockholder; Clawback Policy. Subject to the provisions of the applicable Award, no Participant
or Designated Beneficiary shall have any rights as a stockholder with respect to any shares of Common Stock to be issued with respect to an Award until becoming the record holder of such shares. In accepting an Award under the Plan, a Participant
agrees to be bound by any clawback policy the Company has in effect or may adopt in the future. 
 (c)    Effective
Date and Term of Plan. The Plan shall become effective immediately prior to the effectiveness of the Company’s registration statement for its initial public offering (the “Effective Date”). No Awards shall be granted
under the Plan after the expiration of 10 years from the Effective Date, but Awards previously granted may extend beyond that date. 

(d)    Amendment of Plan. The Board may amend, suspend or terminate the Plan or any portion thereof at any time
provided that no amendment that would require stockholder approval under the rules of NASDAQ may be made effective unless and until the Company’s stockholders approve such amendment. In addition, if at any time the approval of the
Company’s stockholders is required as to any other modification or amendment under Section 422 of the Code or any successor provision with respect to Incentive Stock Options, the Board may not effect such modification or amendment without
such approval. Unless otherwise specified in the amendment, any amendment to the Plan adopted in accordance with this Section 11(d) shall apply to, and be binding on the holders of, all Awards outstanding under the Plan at the time the
amendment is adopted, provided the Board determines that such amendment, taking into account any related action, does not materially and adversely affect the rights of Participants under the Plan. No Award shall be made that is conditioned upon
stockholder approval of any amendment to the Plan unless the Award provides that (i) it will terminate or be forfeited if stockholder approval of such amendment is not obtained within no more than 12 months from the date of grant and
(2) it may not be exercised or settled (or otherwise result in the issuance of Common Stock) prior to such stockholder approval. 

(e)    Authorization of Sub-Plans (including for Grants to non-U.S. Employees). The Board may from time to time establish one or more sub-plans under the Plan for purposes of satisfying applicable securities, tax or other laws of
various jurisdictions. The Board shall establish such sub-plans by adopting supplements to the Plan containing (i) such limitations on the Board’s discretion under the Plan as the Board deems
necessary or desirable or (ii) such additional terms and conditions not otherwise inconsistent with the Plan as the Board shall deem necessary or desirable. All supplements adopted by the Board shall be deemed to be part of the Plan, but each
supplement shall apply only to Participants within the affected jurisdiction and the Company shall not be required to provide copies of any supplement to Participants in any jurisdiction which is not the subject of such supplement. 

(f)    Compliance with Section 409A of the Code. If and to the extent (i) any portion of
any payment, compensation or other benefit provided to a Participant pursuant to the Plan in 

  
 -13- 

 
connection with his or her employment termination constitutes “nonqualified deferred compensation” within the meaning of Section 409A of the Code and (ii) the Participant is a
specified employee as defined in Section 409A(a)(2)(B)(i) of the Code, in each case as determined by the Company in accordance with its procedures, by which determinations the Participant (through accepting the Award) agrees that he or
she is bound, such portion of the payment, compensation or other benefit shall not be paid before the day that is six months plus one day after the date of “separation from service” (as determined under Section 409A of the Code) (the
“New Payment Date”), except as Section 409A of the Code may then permit. The aggregate of any payments that otherwise would have been paid to the Participant during the period between the date of separation from service
and the New Payment Date shall be paid to the Participant in a lump sum on such New Payment Date, and any remaining payments will be paid on their original schedule. 

The Company makes no representations or warranty and shall have no liability to the Participant or any other person if any provisions of or payments,
compensation or other benefits under the Plan are determined to constitute nonqualified deferred compensation subject to Section 409A of the Code but do not to satisfy the conditions of that section. 

(g)    Limitations on Liability. Notwithstanding any other provisions of the Plan, no individual
acting as a director, officer, employee or agent of the Company will be liable to any Participant, former Participant, spouse, beneficiary, or any other person for any claim, loss, liability, or expense incurred in connection with the Plan, nor
will such individual be personally liable with respect to the Plan because of any contract or other instrument he or she executes in his or her capacity as a director, officer, employee or agent of the Company. The Company will indemnify and hold
harmless each director, officer, employee or agent of the Company to whom any duty or power relating to the administration or interpretation of the Plan has been or will be delegated, against any cost or expense (including attorneys’ fees) or
liability (including any sum paid in settlement of a claim with the Board’s approval) arising out of any act or omission to act concerning the Plan unless arising out of such person’s own fraud or bad faith. 

(h)    Governing Law. The provisions of the Plan and all Awards made hereunder shall be governed by and interpreted
in accordance with the laws of the State of Delaware, excluding choice-of-law principles of the law of such state that would require the application of the laws of a
jurisdiction other than the State of Delaware. 

  
 -14-EX-10.13

 Exhibit 10.13 

CASA SYSTEMS, INC. 
 STOCK
OPTION AGREEMENT 
 Casa Systems, Inc. (the “Company”) hereby grants the following stock option pursuant to its 2017
Stock Incentive Plan. The terms and conditions attached hereto are also a part hereof. 
 Notice of Grant 

 

			
	 Name of optionee (the “Participant”):
	 	
		
	 Date of grant (the “Grant Date”):
	 	
		
	 Number of shares of the Company’s Common

Stock subject to this option (“Shares”):
	 	
		
	 Option exercise price per Share:1
	 	
		
	 Number, if any, of Shares that vest

immediately on the grant date:
	 	
		
	 Shares that are subject to vesting schedule:
	 	
		
	 Vesting Start Date:
	 	
		
	 Final Exercise Date: 2
	 	
		
	 Type of Option (Incentive Stock Option or

Nonstatutory Stock Option):
	 	

 Vesting Schedule: 

This option satisfies in full all commitments that the Company has to the Participant with respect to the issuance of stock, stock options or
other equity securities. 
  

									
		 		 	 CASA SYSTEMS, INC.

	 	 		 	
	 Signature of Participant
	 		 	
	 	 		 	 By:
	 	 
	Street Address	 		 		 	Name of Officer
	 	 		 		 	Title:
	City/State/Zip Code	 		 		 	

  
  

1    This must be at least 100% of the fair market value of the Common Stock on the
date of grant (or 110% in the case of a Participant that owns more than 10% of the total combined voting power of all classes of stock of the Company or its parent or subsidiary (a “10% Shareholder”)) for the option to qualify as an
incentive stock option (an “ISO”) under Section 422 of the Code. 

2    The Final Exercise Date must be no more than 10 years (5 years in the case of a
10% Shareholder) from the date of grant for the option to qualify as an ISO. The correct approach to calculate the final exercise date is to use the day immediately prior to the date ten years out from the date of the stock option award grant (5
years in the case of a 10% stockholder). For example, an award granted to someone on February 1, 2017 would expire on January 31, 2027 (not on February 1, 2027). 

 CASA SYSTEMS, INC. 

Stock Option Agreement 

Incorporated Terms and Conditions 

1.    Grant of Option. 

This agreement evidences the grant by the Company, on the Grant Date set forth in the Notice of Grant that forms part of this agreement
(the “Notice of Grant”), to the Participant of an option to purchase, in whole or in part, on the terms provided herein and in the Company’s 2017 Stock Incentive Plan (the “Plan”), the number of Shares set
forth in the Notice of Grant of common stock, $0.001 par value per share, of the Company (“Common Stock”), at the exercise price per Share set forth in the Notice of Grant. Unless earlier terminated, this option shall
expire at 5:00 p.m., Eastern time, on the Final Exercise Date set forth in the Notice of Grant (the “Final Exercise Date”). 

It is intended that the option evidenced by this agreement shall be an incentive stock option as defined in Section 422 of the Internal
Revenue Code of 1986, as amended, and any regulations promulgated thereunder (the “Code”) to the extent set forth in the Notice of Grant. If the option is intended to be an incentive stock option, the option is intended to so
qualify to the maximum extent permitted by law. Except as otherwise indicated by the context, the term “Participant”, as used in this option, shall be deemed to include any person who acquires the right to exercise this option
validly under its terms. 
 2.    Vesting Schedule. 

This option will become exercisable (“vest”) in accordance with the vesting schedule set forth in the Notice of Grant. 

The right of exercise shall be cumulative so that to the extent the option is not exercised in any period to the maximum extent permissible it
shall continue to be exercisable, in whole or in part, with respect to all Shares for which it is vested until the earlier of the Final Exercise Date or the termination of this option under Section 3 hereof or the Plan. 

3.    Exercise of Option. 

(a)    Form of Exercise. Each election to exercise this option shall be in writing, in the form of the Stock Option
Exercise Notice attached as Annex A, signed by the Participant, and received by the Company at its principal office, accompanied by this agreement, or in such other form (which may be electronic) as is approved by the Company, together with
payment in full in the manner provided in the Plan. The Participant may purchase less than the number of shares covered hereby, provided that no partial exercise of this option may be for any fractional share. 

(b)    Continuous Relationship with the Company Required. Except as otherwise provided in this Section 3, this
option may not be exercised unless the Participant, at the time he or she exercises this option, is, and has been at all times since the Grant Date, an employee, director or officer of, or consultant or advisor to, the Company or any other entity
the employees, officers, directors, consultants, or advisors of which are eligible to receive option grants under the Plan (an “Eligible Participant”). 
  

  
 - 2 - 

 (c)    Termination of Relationship with the Company. If the
Participant ceases to be an Eligible Participant for any reason, then, except as provided in paragraphs (d) and (e) below, the right to exercise this option shall terminate three months after such cessation (but in no event after
the Final Exercise Date), provided that this option shall be exercisable only to the extent that the Participant was entitled to exercise this option on the date of such cessation. Notwithstanding the foregoing, if the Participant,
prior to the Final Exercise Date, violates the non-competition, non-solicitation, or confidentiality provisions of any employment contract, confidentiality and
nondisclosure agreement or any other agreement between the Participant and the Company, the right to exercise this option shall terminate immediately upon such violation. 

(d)    Exercise Period Upon Death or Disability. If the Participant dies or becomes disabled (within the meaning of
Section 22(e)(3) of the Code) prior to the Final Exercise Date while he or she is an Eligible Participant and the Company has not terminated such relationship for “cause” as specified in paragraph (e) below, this option shall be
exercisable, within the period of one year following the date of death or disability of the Participant, by the Participant (or in the case of death by an authorized transferee), provided that this option shall be exercisable only to
the extent that this option was exercisable by the Participant on the date of his or her death or disability, and further provided that this option shall not be exercisable after the Final Exercise Date. 

(e)    Termination for Cause. If, prior to the Final Exercise Date, the Participant’s employment is terminated
by the Company for Cause (as defined below), the right to exercise this option shall terminate immediately upon the effective date of such termination of employment. If, prior to the Final Exercise Date, the Participant is given notice by the
Company of the termination of his or her employment by the Company for Cause, and the effective date of such employment termination is subsequent to the date of delivery of such notice, the right to exercise this option shall be suspended from the
time of the delivery of such notice until the earlier of (i) such time as it is determined or otherwise agreed that the Participant’s employment shall not be terminated for Cause as provided in such notice or (ii) the effective date
of such termination of employment (in which case the right to exercise this option shall, pursuant to the preceding sentence, terminate upon the effective date of such termination of employment). If the Participant is subject to an individual
employment or severance agreement with the Company or eligible to participate in a Company severance plan or arrangement, in any case which agreement, plan or arrangement contains a definition of “cause” for termination of employment,
“Cause” shall have the meaning ascribed to such term in such agreement, plan or arrangement. Otherwise, “Cause” shall mean willful misconduct by the Participant or willful failure by the Participant to perform his or her
responsibilities to the Company (including, without limitation, breach by the Participant of any provision of any employment, consulting, advisory, nondisclosure, non-competition or other similar agreement
between the Participant and the Company), as determined by the Company, which determination shall be conclusive. The Participant’s employment shall be considered to have been terminated for Cause if the Company determines, within 30 days after
the Participant’s resignation, that termination for Cause was warranted. 

  
 - 3 - 

 4.    Tax Matters. 

(a)    Withholding. No Shares will be issued pursuant to the exercise of this option unless and until the
Participant pays to the Company, or makes provision satisfactory to the Company for payment of, any federal, state or local withholding taxes required by law to be withheld in respect of this option. 

(b)    Disqualifying Disposition. If the Participant disposes of Shares acquired upon exercise of this option
within two years from the Grant Date or one year after such Shares were acquired pursuant to exercise of this option, the Participant shall notify the Company in writing of such disposition. 

5.    Transfer Restrictions; Clawback. 

(a)    This option may not be sold, assigned, transferred, pledged or otherwise encumbered by the Participant, either
voluntarily or by operation of law, except by will or the laws of descent and distribution, and, during the lifetime of the Participant, this option shall be exercisable only by the Participant. 

(b)    In accepting this option, the Participant agrees to be bound by any clawback policy that the Company may adopt in
the future. 
 6.    Provisions of the Plan. 

This option is subject to the provisions of the Plan (including the provisions relating to amendments to the Plan), a copy of which is furnished to the
Participant with this option. 

  
 - 4 - 

 ANNEX A 

CASA SYSTEMS, INC. 
 Stock
Option Exercise Notice 
 Casa Systems, Inc. 
 100 Old
River Road, Unit 100 
 Andover, MA 01810 
 Dear Sir or Madam:

 I,
                         (the “Participant”), hereby irrevocably exercise the right to purchase
                     shares of the Common Stock, $0.001 par value per share (the “Shares”), of Casa Systems, Inc. (the
“Company”) at $                 per share pursuant to the Company’s 2017 Stock Incentive Plan and a stock option agreement with the Company
dated                 (the “Option Agreement”). Enclosed herewith is a payment of $        , the
aggregate purchase price for the Shares. The certificate for the Shares should be registered in my name as it appears below or, if so indicated below, jointly in my name and the name of the person designated below, with right of survivorship. 

 

			
		
	Dated:	 	 
	
	 
	Signature
	Print Name:
	
	Address:
	 
	
	 

			
	
	Name and address of persons in whose name the Shares are to be jointly registered (if applicable):

			
	
	 

  
 - 5 -

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00277-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00277-of-00352.parquet"}]]