A keypunch or key punch is a device used for precisely punching holes in specific locations on a stiff card. It was used in conjunction with early punched card computers. The punched card served as the program instruction for the computer. The locations of the punches were determined by the keys being struck by a human operator, much like typing...
A circuit-level gateway is a firewall that provides User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) connection security, and works between an Open Systems Interconnection (OSI) network model’s transport and application layers such as the session layer. Unlike application gateways, circuit-level gateways monitor TCP data packet handshaking and session fulfillment of firewall rules and policies.
A proxy server is a security barrier between internal and external computers, while a circuit-level gateway is a virtual circuit between the proxy server and internal client. For example, when a user Web page access request passes through the circuit gateway, basic internal user information, such as IP address, is exchanged for proper feedback. Then, the proxy server forwards the request to the Web server. Upon receiving the request, the external server sees the proxy server’s IP address but does not receive any internal user information. The Web or real server sends the proxy server a proper response, which is forwarded to the client or end user via the circuit-level gateway.
Read More »
Join 138,000+ IT pros on our weekly newsletter
Home | Advertising Info | Write for Us | About | Contact Us
2010 - 2015
Partner Sites :