X0306 4 2023-01-08 0 0001333835 Casa Systems Inc CASA 0001723967 Xie Lucy C/O CASA SYSTEMS, INC. 100 OLD RIVER ROAD ANDOVER MA 01810 1 0 0 0 Common Stock 2023-01-08 4 M 0 31570 A 2200949 D Common Stock 2023-01-08 4 M 0 106606 A 2307555 D Common Stock 2023-01-08 4 M 0 143802 A 2451357 D Common Stock 2023-01-08 4 M 0 321875 A 2773232 D Common Stock 2023-01-08 4 M 0 128750 A 2901982 D Common Stock 2023-01-08 4 F 0 272545 3.265 D 2629437 D Restricted Stock Units 2023-01-08 4 M 0 31570 0.00 D Common Stock 31570 0 D Restricted Stock Units 2023-01-08 4 M 0 106606 0.00 D Common Stock 106606 0 D Restricted Stock Units 2023-01-08 4 M 0 143802 0.00 D Common Stock 143802 0 D Restricted Stock Units 2023-01-08 4 M 0 321875 0.00 D Common Stock 321875 0 D Restricted Stock Units 2023-01-08 4 M 0 128750 0.00 D Common Stock 128750 0 D Restricted stock units ("RSUs") converted into common stock, $0.001 par value per share (the "Common Stock"), of Casa Systems, Inc. (the "Company") on a one-for-one basis upon vesting of the RSUs. Shares withheld by the Company to satisfy tax withholding requirements on vesting of RSUs. Each RSU represents the right to receive one share of Common Stock upon vesting, subject to the reporting person's continued service relationship with the Company and the other terms and conditions set forth in the applicable RSU agreement. In the sole discretion of the Company's board of directors, the Company may, with respect to any applicable vesting date, deliver to the reporting person Common Stock or cash having a fair market value equal to the number of shares of Common Stock underlying the portion of the RSU that vested on such date, payable within 30 days of the vesting date, less applicable taxes. Pursuant to the Separation Agreement entered into by the Company and the reporting person on November 29, 2022 (the "Separation Agreement"), the vesting of the RSUs granted to the reporting person on February 5, 2019 was fully accelerated and all of the shares underlying the award became vested as of January 8, 2023. The RSUs have no expiration date. Pursuant to the Separation Agreement, the vesting of the RSUs granted to the reporting person on February 25, 2020 was fully accelerated and all of the shares underlying the award became vested as of January 8, 2023. The RSUs have no expiration date. Pursuant to the Separation Agreement, the vesting of the RSUs granted to the reporting person on February 23, 2021 was fully accelerated and all of the shares underlying the award became vested as of January 8, 2023. The RSUs have no expiration date. Pursuant to the Separation Agreement, the vesting of the RSUs granted to the reporting person on May 9, 2022 was fully accelerated and all of the shares underlying the award became vested as of January 8, 2023. The RSUs have no expiration date. Pursuant to the Separation Agreement, the vesting of the RSUs granted to the reporting person on May 9, 2022 was fully accelerated and all of the shares underlying the award became vested as of January 8, 2023. The RSUs have no expiration date. /s/ Timothy C. Rodenberger, as Attorney-in-Fact 2023-01-10