Sec Form 4 Filing - Redington Dan @ Ribbon Communications Inc. - 2024-04-17

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Redington Dan 2. Issuer Name and Ticker or Trading Symbol Ribbon Communications Inc. [ RBBN] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) EVP, Global Sales (Last) (First) (Middle) 6500 CHASE OAKS BOULEVARD, SUITE 100 3. Date of Earliest Transaction (MM/DD/YY) 04/17/2024 (Street) PLANO, TX75023 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 04/17/2024 M 36,143 A 102,982 D Common Stock 04/17/2024 M 24,465 A 127,447 D Common Stock 04/17/2024 F 21,793 D 105,654 D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisab le Expiration Date Title Amount or Number of Shares Restricted Stock Units (RSUs) ( 1 ) 04/17/2024 M 36,143 ( 3 ) ( 3 ) Common Stock 36,143 $ 0 72,283 D Performance Share Units (PSUs) ( 1 ) 04/17/2024 M 24,465 ( 4 ) ( 4 ) Common Stock 24,465 $ 0 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Redington Dan 6500 CHASE OAKS BOULEVARD SUITE 100 PLANO, TX75023 EVP, Global Sales Signatures Patrick Macken, By POA from Dan Redington, EVP of Global Sales 04/19/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Each Restricted Stock Unit (RSU) and Performance Share Unit (PSU) converts into common stock on a one-for-one basis. ( 2 )Reflects shares of Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting. ( 3 )The RSUs were granted on April 17, 2023 and vested as to one-third on April 17, 2024; the remaining two-thirds of the RSUs will vest in four equal semi-annual installments thereafter through April 17, 2026. ( 4 )The PSUs were issued on April 17, 2023. The number of PSUs earned and vested was based on achievement of a revenue goal set (prior to grant) by the Compensation Committee of the Issuer's Board of Directors for the fiscal year ended December 31, 2023. The remaining PSUs were forfeited.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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