• TCP makes the Internet work better for all users.World Wide Web image by Sirena Designs from Fotolia.com
  
  Transfer Control Protocol, or TCP, was designed to be a reliable and robust method of transmitting data between computers regardless of differences between the sending and receiving servers. Originally developed by the Department of Defense, TCP became an important protocol for the development of the Internet and has continued to evolve with new technology. There are three main characteristics of the TCP protocol.
  
  

Ability to Recover from Transmission Failure

• The sending server expects an acknowledgment from the receiving server. Should transmission fail due to a line being dropped along the route, TCP will resend the data until an acknowledgment is received. The failure may be due to a physical interruption in the connection or a point that has become too congested to forward the data.
  
  

Breaks Data into Packets and Transmits

• TCP takes the data and breaks it into bytes, assigning each a sequential number. The header will contain information on the beginning byte number and how many bytes of data are being transmitted. The destination address is also included in the header. The receiving server acknowledges which byte numbers have been received and, if there are any missing, TCP will resend just those pieces.
  
  

Connectivity Independence

• TCP was formatted to allow communication between the receiving and sending servers that does not rely on the program used, the method of accessing the Internet or the brand of equipment used. This means that it does not matter if one end of the transmission is on a LAN (local area network) that utilizes Ethernet and the other is on a WAN (wide area ntework) using ATM (Asynchronous Transfer Mode). Nor does it matter if one party is using a dial-up connection and the other a high-speed connection.