Editing Port triggering (section)

=== Disadvantages ===

Port triggering has the disadvantage that it binds the triggered port to a single client at a time. As long as the port is bound to that particular client, port triggering is effectively unavailable to all other clients. In FTP file sharing, for example, this means that no two clients can download files from an FTP server running on "active mode" simultaneously. For IRC, even though the authentication step happens very quickly, the port triggering timeout may still prevent other clients from logging into IRC servers. Port triggering is unsuitable for servers behind a NAT router because it relies on the local computer to make an outgoing connection before it can receive incoming ones. On some routers it is possible to have more than one client use port triggering and port forwarding, but not simultaneously.
{{clarify|date=October 2015}}