Protocols
A protocol is the language, so to speak, that your computer uses to communicate
with other computers on a network. Now, the days of configuring
individual network protocols are long past, having died out with
the Windows 95/98 generation. As long as your stuff speaks TCP/IP,
it??™ll work, provided you don??™t mind occasionally typing in numeric IP
addresses.
TCP/IP
TCP/IP is a protocol, or more accurately, a collection of protocols, used
in all Internet communications and by most modern LANs. For those of
you excited by acronyms, the TCP/IP specification includes TCP
(Transmission Control Protocol), IP (Internet Protocol), UDP (User
Datagram Protocol), and ICMP (Internet Control Message Protocol).
The amazing thing about TCP/IP, and the reason that it serves as the
foundation of every connection to the Internet, is that data is broken up
into packets before it??™s sent on its way. The packets then travel to their
destinations independently, possibly arriving in a different order than
they were originally sent. The receiving computer then reassembles the
packets (in the correct order) back into data.
TCP Ports
TCP/IP data moves in and out of your PC through ports, virtual doors
opened by the software that uses your network connection. For example,
your email program uses port 25 to send email (using the SMTP
protocol) and port 110 to retrieve email (using the POP3 protocol),
while your web browser downloads pages through port 80 (using the
HTTP protocol).
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