Communication data forwarding procedure: proxy, gateway, tunnel
Agent: There is an application forwarding function, he played a role in the server and the client "middleman", receiving a request sent by the client and forwarded to the server; and also to receive a response returned by the server and forwarded to the client.
Use a proxy server does not change the URI request.
Proxy features:
- The use of caching technology to reduce network bandwidth traffic
- Internal control organization for access to specific websites
Gateway: Forward Servers Other server communication data, their communications gateway is the next target.
Can be converted by the gateway using an http request to other communication protocols, the gateway can service server provided on a communication line non-HTTP protocol. The gateway can use to improve the security of communications.
Tunnel: is a transit between the two far apart the customer end and server applications to communicate and keep both sides of the link.
Tunnels can be required to establish a line of communication with other servers, then using SSL encryption and other means of communication. The purpose of the tunnel is to ensure that the client can communicate securely with the server. Intact tunnel will request sent to the server, when the communication ends both disconnected.
references:
"Graphic HTTP"