X0306 4 2020-03-06 0001708055 Ribbon Communications Inc. RBBN 0001424201 McClelland Bruce William C/O RIBBON COMMUNICATIONS INC. 4 TECHNOLOGY PARK DRIVE WESTFORD MA 01886 1 1 0 0 President & CEO Common Stock 2020-03-06 4 P 0 24161 3.0584 A 24161 D Common Stock 2020-03-09 4 P 0 11414 2.8807 A 35575 D The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $3.0399 to $3.09, inclusive. The reporting person undertakes to provide to Ribbon Communications Inc. ("Ribbon"), any security holder of Ribbon, or the staff of the Securities and Exchange Commission (the "Staff"), 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 $2.85 to $2.96, inclusive. The reporting person undertakes to provide to Ribbon, any security holder of Ribbon, or the Staff, upon request, full information regarding the number of shares sold at each separate price with the ranges set forth in this footnote. Bruce W. McClelland 2020-03-10