This acronym means "Generic Service Passer". See also Special Service. GSPs are used to provide application-level proxy for protocols not handled by the standard proxies. A single GSP can be used to manage a single TCP or UDP port for either transparent or non-transparent, inbound or outbound access. Examples of protocols that should be managed using a GSP include POP-3, Notes, and IRC. Like the standard proxies on the firewall, GSPs are controlled using authorization rules. They also perform address hiding and traffic logging. The major difference between the standard proxies and the GSP is that the GSP has no knowledge of the underlying application level protocol, and hence, cannot perform any protocol-specific security monitoring. Another related limitation is that authentication cannot be applied to any rule that governs a GSP, as there is no means to guarantee that the application can respond. Hence, applying a rule to a GSP will cause it to fail.