Transmission Control Protocol/Internet Protocol - an agreed upon set of rules that tells computers how to exchange information over the Internet

Transport Communications Protocol/Internet Protocol - The communications protocol that the Windows CE uses to communicate to the internet and synchronization

Transmission Control Protocol over Internet Protocol. The TCP/IP protocol defines how data can be transmitted in a secure manner between networks. TCP/IP is the most widely used communications standard and is the basis for the Internet

In the two decades since their invention, the heterogeneity of networks has expanded further with the deployment of Ethernet, Token Ring, Fiber Distributed Data Interface (FDDI), X.25, Frame Relay, Switched Multimegabit Data Service (SMDS), Integrated Services Digital Network (ISDN), and most recently, Asynchronous Transfer Mode (ATM). The Internet protocols are the best proven approach to internetworking this diverse range of LAN and WAN technologies.

The Internet protocol suite includes not only lower-level specifications (such as TCP and IP), but specifications for such common applications as electronic mail, terminal emulation, and file transfer. Figure 1 shows some of the more important Internet protocols and their relationship to the OSI Reference Model.

The Internet protocols are the most widely implemented multivendor protocol suite in use today. Support for at least part of the Internet protocol suite is available from virtually every computer vendor.


TCP/IP Technology
This section describes technical aspects of TCP, IP, related protocols, and the environments in which these protocols operate. Because the primary focus of this document is routing (a layer 3 function), the discussion of TCP (a layer 4 protocol) will be relatively brief.

TCP
TCP is a connection-oriented transport protocol that sends data as an unstructured stream of bytes. By using sequence numbers and acknowledgment messages, TCP can provide a sending node with delivery information about packets transmitted to a destination node. Where data has been lost in transit from source to destination, TCP can retransmit the data until either a timeout condition is reached or until successful delivery has been achieved. TCP can also recognize duplicate messages and will discard them appropriately. If the sending computer is transmitting too fast for the receiving computer, TCP can employ flow control mechanisms to slow data transfer. TCP can also communicate delivery information to the upper-layer protocols and applications it supports.
 

Introduction to TCP/IP

Summary: TCP and IP were developed by a Department of Defense (DOD) research project to connect a number different networks designed by different vendors into a network of networks (the "Internet"). It was initially successful because it delivered a few basic services that everyone needs (file transfer, electronic mail, remote logon) across a very large number of client and server systems. Several computers in a small department can use TCP/IP (along with other protocols) on a single LAN. The IP component provides routing from the department to the enterprise network, then to regional networks, and finally to the global Internet. On the battlefield a communications network will sustain damage, so the DOD designed TCP/IP to be robust and automatically recover from any node or phone line failure. This design allows the construction of very large networks with less central management. However, because of the automatic recovery, network problems can go undiagnosed and uncorrected for long periods of time.

As with all other communications protocol, TCP/IP is composed of layers:

IP- is responsible for moving packet of data from node to node. IP forwards each packet based on a four byte   destination address (the IP number). The Internet authorities assign ranges of numbers to different organizations. The organizations assign groups of their numbers to departments. IP operates on gateway machines that move data from department to organization to region and then around the world.

*TCP - is responsible for verifying the correct delivery of data from client to server. Data can be lost in the intermediate network. TCP adds support to detect errors or lost data and to trigger retransmission until the data is correctly and completely received.

*Sockets - is a name given to the package of subroutines that provide access to TCP/IP on most systems.