tailieunhanh - Applications Using IP

Applications Using IP No discussion of TCP/IP would be complete without a look at the applications that use IP. | Applications Using IP No discussion of TCP IP would be complete without a look at the applications that use IP. Unlike services which frequently perform functions that are then used by IP the applications that use IP are relatively independent of IP and typically interface with the users and are rarely used by other IP processes. Common Applications Using IP The most common applications that use IP tend to revolve around access to Internetbased resources such as web servers and mail servers. In addition file and print services are the most common application that is implemented in most corporate networks. Web browsers and web servers allow users to access graphical content using HTTP which uses TCP port 80. In addition if secure web browsing is required the data can be secured using Secure Sockets Layer SSL commonly known as HTTPS which uses TCP port 443. Electronic mail is delivered via two primary mechanisms SMTP and POP3. SMTP uses TCP port 25 and serves to primarily transmit e-mail messages to the mail server or between mail servers because it has a limited ability to queue email messages on the client side. This is where POP3 which uses TCP port 110 comes in. It does a much better job of queuing e-mail messages and therefore is typically used by the client to receive e-mail messages from the mail server. File and printer sharing typically but not always occurs over TCP ports to provide for a reliable and connection-oriented delivery mechanism. A notable exception to this is Network File System NFS which is typically used by UNIXbased hosts and typically uses UDP port 2049. Microsoft file and print services typically use TCP port 139 or TCP port 445. Less-Common Applications Using IP Some less-common but still frequently used applications that are based on IP include the following Telnet Telnet is used to provide remote console connections over TCP port 23. Telnet is an insecure protocol which means that the data being transmitted is not encrypted rather it is