Newer software releases often fix bugs related to "No Dial Tone" or intermittent voice mail failures.
Keeping your system updated is about more than just new features; it is often a matter of security. nec sl1000 firmware upgrade
Older firmware versions contain "Critical" vulnerabilities (such as CVE-2019-20025) that can be exploited if the system is exposed to the internet. Newer software releases often fix bugs related to