X0306 4 2022-05-02 0001708055 Ribbon Communications Inc. RBBN 0001824854 Bucci Sam C/O RIBBON COMMUNICATIONS 6500 CHASE OAKS DR., SUITE 100 PLANO TX 75023 0 1 0 0 EVP & GM IP Optical Networks Common Stock 2022-05-02 4 S 0 15000 3.49 D 151394 D Common Stock 2022-05-03 4 S 0 25000 3.46 D 126394 D Planned open market sale for income tax purposes. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.47 to $3.51, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, 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. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.43 to $3.51, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, 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. Patrick Macken, Attorney-in-Fact 2022-05-04