X0508 4 2024-03-15 0001708055 Ribbon Communications Inc. RBBN 0001600024 LOPEZ MIGUEL A C/O RIBBON COMMUNICATIONS INC. 6500 CHASE OAKS BOULEVARD, SUITE 100 PLANO TX 75023 0 1 0 0 EVP, CFO 0 Common Stock 2024-03-15 4 P 0 2000 2.8992 A 280875 D Common Stock 2024-03-15 4 M 0 8960 A 289835 D Common Stock 2024-03-15 4 M 0 3441 A 293276 D Common Stock 2024-03-15 4 F 0 4155 2.83 D 289121 D Restricted Stock Units (RSUs) 2024-03-15 4 M 0 8960 0 D Common Stock 8960 0 D Performance Share Units (PSUs) 2024-03-15 4 M 0 3441 0 D Common Stock 3441 0 D The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $2.8991 to $2.8992, inclusive. The reporting person undertakes to provide to Ribbon Communications, any security holder of Ribbon Communications, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price with the ranges set forth in this footnote. Each Restricted Stock Unit (RSU) and Performance Share Unit (PSU) converts into common stock on a one-for-one basis. The number of PSUs earned and issued upon vesting was determined based on goals (set by the Compensation Committee of the Issuer's Board of Directors (the "Compensation Committee") on an annual basis) for each of the three fiscal years ended December 31, 2023. Based on the Compensation Committee's determination of achievement of these pre-established financial goals, 32% of the shares subject to the 2023 financial period were earned and vested on March 15, 2024, and no shares were earned for the 2021 and 2022 performance periods and were forfeited. Reflects shares of Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting of the RSUs and PSUs. The RSUs were granted on March 15, 2021 and vested as to one-third on March 15, 2022; the remaining two-thirds of the RSUs vested in four equal semi-annual installments thereafter through March 15, 2024. Patrick Macken, By POA from Miguel Lopez 2024-03-18