Please follow the upgrade procedure:

1. Please check HW version of your device first.

2. Select a correct firmware version and upgrade method.
- If your device is HW Ver. A3 or B2, you can directly upgrade to v3.11 common firmware.
- If your device is HW Ver. A2 or B1, please upgrade to intermediate firmware v.3.11 first, then upgrade to v3.11 common firmware.

Examples:
- DSR-250N HW A2 v2.11-> DSR-250N_A2_FW3.11_WW-> DSR-250N_A2_A3_FW3.11_WW
- DSR-250N HW A3 v2.11-> DSR-250N_A2_A3_FW3.11_WW
