Old firmware suffers from broken SIP ALG. Newer "better" firmware lets you turn it off.
Go to Administration or System Management > Firmware Upgrade . zte f602w firmware better better
This article will help you navigate everything you need to know about Go to product viewer dialog for this item. Old firmware suffers from broken SIP ALG
Go to the official ZTE Support Portal . Enter your exact model number to locate official, stable firmware releases. zte f602w firmware better better
Fiber providers modify their back-end Optical Line Terminal (OLT) configurations. If your device runs obsolete firmware, it can experience synchronization drops with the provider's central network. Firmware upgrades preserve seamless handshake operations with modern ISP protocols. Comparing Old vs. Updated ZTE Firmware Performance Feature / Metric Outdated Firmware Updated Stable Firmware