Sec Form 4 Filing - Marmurek Eric S @ Ribbon Communications Inc. - 2022-03-15

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 Marmurek Eric S 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) SVP, Finance & CAO (Last) (First) (Middle) C/O RIBBON COMMUNICATIONS, 6500 CHASE OAKS BLVD., SUITE 100 3. Date of Earliest Transaction (MM/DD/YY) 03/15/2022 (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 03/15/2022 M 8,234 A 85,991 D Common Stock 03/15/2022 A 11,301 A 97,292 D Common Stock 03/15/2022 M 11,047 A 108,339 D Common Stock 03/15/2022 F 8,386( 2 ) D $ 2.81( 2 ) 99,953 D Common Stock 03/16/2022 M 15,432 A 115,385 D Common Stock 03/16/2022 F 3,663( 2 ) D $ 2.99( 2 ) 111,772 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 Exercisable Expiration Date Title Amount or Number of Shares Restricted Stock Units (RSU) ( 1 ) 03/15/2022 M 8,234 ( 3 ) ( 3 ) Common Stock 8,234 $ 0 16,466 D Performance-based Restricted Stock Unit (PSUs) ( 6 ) 03/15/2022 M 11,047 ( 6 ) ( 6 ) Common Stock 11,047 $ 0 0 D Restricted Stock Unit (RSU) ( 1 ) 03/16/2022 M 15,432 ( 4 ) ( 4 ) Common Stock 15,432 $ 0 30,864 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Marmurek Eric S C/O RIBBON COMMUNICATIONS 6500 CHASE OAKS BLVD., SUITE 100 PLANO, TX75023 SVP, Finance & CAO Signatures Patrick Macken, Attorney-in-Fact 03/17/2022 Signature of Reporting Person Date

Explanation of Responses:

( 1 )RSUs convert to 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 of RSUs and/or PSUs. ( 3 )The RSU vested as to one third on March 15, 2022 and the remaining two-thirds will vest in four equal semi-annual installments thereafter through March 15, 2024 ( 4 )The RSUs originally vested as to one third on March 16, 2021, and the remaining two-thirds will vest in four equal semi-annual installments thereafter through March 16, 2023. ( 5 )PSUs that convert to Common Stock on a one-for-one basis based on the achievement of financial metrics in each of the 2019, 2020 and 2021 fiscal years establised by the Issuer's Compensation Committee of it's Board of Directors (Compensation Committee) at the time of grant. The PSUs then vested on March 15, 2022. Any unearned shares were forefeited. ( 6 )PSUs that convert to Common Stock on a one-for-one basis based on the achievement of the Issuer's total sharholder return (TSR) for the 3-year period ended December 31, 2021 compared to TSR goals established by the Compensation Committee at the time of grant based on the TSR of a group of peer companies identified by the Compensation Committee. The PSUs then vested on March 15, 2022. Any unearned shares were forefeited.

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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