If "Disallow use of extension outside the LAN" is enabled, what happens to remote 3CX Clients?

When the option "Disallow use of extension outside the LAN" is enabled, it specifically restricts the registration of that extension to clients who are connected to the Local Area Network (LAN). As a result, remote 3CX Clients attempting to register using that extension will not be able to do so, as they are outside the designated network. This setting is often implemented to enhance security by limiting access to internal users only, thereby preventing unauthorized access from external locations.

Remote clients that are not physically on the network cannot register or use that extension, ensuring that calls and communications can only be handled by users within the local network infrastructure. This measure protects against potential vulnerabilities associated with remote access, making it a crucial security feature for organizations that want to maintain strict control over their telephony system.