Tcp Tutorial-8

There are certain new fields in the TCP header which you may not know off. Let's see what these new fields signify. The Windows field specifies the octets of new data which is ready to be processed. You see not all computers connected to the Internet run at the same speed and to ensure that a faster system does not send datagrams to a slow system at a rate which is faster than it can handle, we use the Window field. As the computer receives data , the space in the Window field gets decreased indicating that the receiver has received the data. When it reaches zero the sender stops sending further packets. Once the receiver finishes processing the received data, it increases the Window field, which in turn indicates that the receiver has processed the earlier sent data and is ready to receive more chunks of data.

The Urgent Field tells the remote computer to stop processing the last octet and instead receive the new octet. This is normally not commonly used.

The TCP protocol is a reliable protocol, which means that we have a guarantee that the data will arrive at the destination properly and without any errors. It ensures that the data being received by the receiving end is arranged in the same correct order in which it was sent.