It also includes NetScaler application firewall and SSL encryption capabilities. These techniques are analyzed considering security mechanisms like firewall network address translation. A GUI (GUI for Uncomplicated Firewall) is available to configure it. No opened ports on the client firewall. Developed as a stateful packet inspection (SPI) firewall. Most modern operating systems include a software firewall, which is enabled by default. It generally consists of gateways and filters which vary from one firewall to another. The first reported type of network firewall is called a packet filter. The Tor anonymity network was and is subject to partial blocking by China's Great Firewall. No special settings on the firewall or NAT are necessary. Cloudflare allows customers on paid plans to utilize a web application firewall service. "TechRadar" recommended NordVPN for bypassing state-level Internet censorship, including the Great Firewall in China. A screened host is a dual-homed host that is dedicated to running the firewall. Whisper Systems also produced a firewall and tools for encrypting other forms of data. Technology that secures communications outside a corporate firewall is relatively new.