X0306 4 2020-08-25 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 Common Stock 2020-08-25 4 P 0 10000 4.21 A 10000 D The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $4.205 to $4.223, inclusive. The reporting person undertakes to provide to Ribbon, any security holder of Ribbon, 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 2020-08-27