United States securities and exchange commission logo January 11, 2022 Bruce McClelland President and Chief Executive Officer Ribbon Communications Inc. 6500 Chase Oaks Boulevard Suite 100 Plano, Texas 75023 Re: Ribbon Communications Inc. Form 10-K for the Fiscal Year Ended December 31, 2020 Filed February 26, 2021 File No. 001-38267 Dear Mr. McClelland: We have completed our review of your filing. We remind you that the company and its management are responsible for the accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or absence of action by the staff. Sincerely, Division of Corporation Finance Office of Technology