144 0001967463 XXXXXXXX LIVE 0001708055 RIBBON COMMUNICATIONS INC. 001-38267 6500 Chase Oaks Blvd., Suite 100, Plano TX 75023 (978) 614-8100 DANIEL REDINGTON Officer Common Morgan Stanley Smith Barney LLC Executive Financial Services

1 New York Plaza 8th Floor New York NY 10004

155434 626352.39 177081847 09/05/2025 NASDAQ Common 06/15/2024 Restricted Stock Issuer N 13052 06/15/2024 Not Applicable Common 12/15/2024 Restricted Stock Issuer N 12636 12/15/2024 Not Applicable Common 06/15/2025 Restricted Stock Issuer N 12636 06/15/2025 Not Applicable Common 04/17/2025 Restricted Stock Issuer N 10961 04/17/2025 Not Applicable Common 10/17/2024 Restricted Stock Issuer N 10961 10/17/2024 Not Applicable Common 12/15/2023 Restricted Stock Issuer N 46839 12/15/2023 Not Applicable Common 04/17/2024 Restricted Stock Issuer N 22758 04/17/2024 Not Applicable Common 05/16/2025 Restricted Stock Issuer N 25591 05/16/2025 Not Applicable N DANIEL REDINGTON

6500 Chase Oaks Blvd., Suite 100, Plano TX 75023

Common 09/04/2025 20000 83252.00 09/05/2025 /s/ Daniel Thomas Redington