You can imagine that the sheer size and resource cost of sending large amounts of information through a single channel will grow exponentially. This checksum uses a false header and encapsulates the data of the original TCP header, such as source/destination entries, header length and byte count. The check sum is used to validate each packet being sent to ensure error free transmission. The receiver can use this to determine if it has already seen the packet and discard if necessary. The sequence number and byte count identifies each packet sent from the source, and accounts for all of the text within the segment. The source and destination entries, along with the IP address, uniquely identify every host on the network so that the gateway can accurately forward packets. Vince and Bob called this the internetwork header prefixed to the packet by the source host. Since the gateway must understand the addresses of each host on the network, it is necessary to have a standard format in every packet that arrives. The gateway plays an essential role in the development of any network and bares the responsibility of routing data properly between these two networks. In the Figure 1 we have two networks connected by a single gateway. When Vinton and Bob first conceptualized TCP/IP, they set up a basic network topology and a device that can interface between two other hosts. Thanks to two DARPA scientists, Vinton Cerf and Bob Kahn who developed TCP/IP in 1970, we have a specific set of rules that define how we communicate over a network. When sending your emails or just browsing the web you are relying on TCP to send and receive your packets in a reliable fashion.

Transmission Control is an essential aspect of network activity and governs the behavior of many services we take for granted.

.pcap wireshark