X0306 4 2020-07-15 0001708055 Ribbon Communications Inc. RBBN 0001600024 LOPEZ MIGUEL A C/O RIBBON COMMUNICATIONS INC. 4 TECHNOLOGY PARK DRIVE WESTFORD MA 01886 0 1 0 0 EVP and CFO Restricted Stock Units (RSUs) 2020-07-15 4 A 0 53730 0 A Common Stock 53730 53730 D RSUs 2020-07-15 4 A 0 99558 0 A Common Stock 99558 99558 D Performance-Based Restricted Stock Units (PSUs) 2020-07-15 4 A 0 39823 0 A 2022-12-31 Common Stock 39823 39823 D Each RSU represents a contingent right to receive one share of the Issuer's common stock. The RSUs shall vest in full on July 15, 2021. The RSUs vest over a three-year period as follows: one-third of the restricted stock units shall vest on July 15, 2021, and the remaining two-thirds of the RSUs shall vest in four equal, semi-annual installments thereafter through July 15, 2023. Each PSU represents a contingent right to receive one share of the Issuer's Common Stock, based on the Issuer's total shareholder return (TSR) compared to pre-established relative TSR goals, based on the TSR of the Russell 2500 Telecommunications Sub Sector Index, that were set by the Compensation Committee (the "Compensation Committee") of the Issuer's Board of Directors. The aggregate number of shares issued may range from zero (0) shares to 200% of the target number of shares reported in columns 5, 7 and 9 of Table II. The number of PSUs reported in columns 5, 7 and 9 of Table II reflects achievement at the target level of performance. Between zero (0) and 200% of the PSUs will vest, if at all, as determined by the Compensation Committee after the TSR performance period, commencing on January 1, 2020 and ending on December 31, 2022. Patrick Macken, Attorney-in-Fact 2020-07-17