Update: Zte F670 Firmware
No. ISP push customized firmware with specific VLAN and TR-069 settings. A generic update could break internet connectivity. Always use your ISP’s provided file.
[Feature] Enabling Telnet on ZTE firmware with post ... - GitHub Zte F670 Firmware Update
Firmware for devices like the ZTE F670 is typically delivered via: Zte F670 Firmware Update