Overview of TCP/IP
In This Chapter
- The Benefits of Using TCP/IP
- TCP/IP Layers and Protocols
- File Transfer Protocol (FTP)
- Trivial File Transfer Protocol (TFTP)
- Simple Mail Transfer Protocol (SMTP)
- Network File System (NFS)
- How TCP/IP Fits into Your System
- The Intranet Concept
TCP/IP is everywhere. It's not something physical that can only be in one place at a time. It's a set of protocols that allows anyone with a computer, modem, and an Internet service provider to access and share information over the Internet. In fact, users of AOL's Instant Messenger service and ICQ (also owned by AOL) account for over 750 million messages per day. This is an incredible amount of traffic, and most of it is transmitted over the Internet.
It is TCP/IP that allows these millions of transactions per day to occur (it's actually well into the billions because many more things are going on than email and instant messaging), mostly without a hitch. And it shows no signs of letting up anytime soon. TCP/IP is a stable, well-established, complete set of protocols, and this chapter takes a close look at exactly what makes it tick.
Both TCP and IP, two separate protocols that work hand-in-hand, perform chores that manage and guide the general mobility of data packets over the Internet. They both use special headers that define each packet's contents and, if there is more than one, how many others should be expected. TCP concerns itself with making the connections to remote hosts. IP, on the other hand, deals with addressing so that messages are directed to where they are intended. The following section takes a look at the benefits of TCP/IP.
The Benefits of Using TCP/IP
TCP/IP enables cross-platform, or heterogeneous, networking. For example, a Windows NT/2000 network could contain Unix and Macintosh workstations or even networks mixed in it. TCP/IP also has the following characteristics:
Good failure recovery
The ability to add networks without interrupting existing services
High error-rate handling
Low data overhead
Because TCP/IP was originally designed for Department of Defenserelated purposes, what we now call features or characteristics were actually design requirements. The idea behind "Good Failure Recovery" was that if a portion of the network were disabled during an incursion or attack, its remaining pieces would still be able to function fully. Likewise is the capability of adding entire networks without any disruption to the services already in place. The ability to handle high error rates was built in so that if a packet of information got lost using one route, there would be a mechanism in place to ensure that it would reach its destination using another route. Platform independence means that the networks and clients can be Windows, Unix, Macintosh, or any other platform or combination thereof. The reason TCP/IP is so efficient lies in its low overhead. Performance is key for any network. TCP/IP is unmatched in its speed and simplicity.