History of the Internet
By the late 1970s and early 80, many new networks started to form. Some of the new networks were CSNET(Computer Science Research Network), BITnet (Because its time network), SPAN (Space Physics Analysis Network), CDnet (Canadian Network) and one of the largest: the NSFnet or National Science Foundation Network. By the late 1070s most people were using the new TCP/IP protocol but it wasnt until January the 1st 1983 that ARPAnet changed over to the new Protocol, this day became the official birth date of the Internet.
By 1989 the Internet was becoming more and more commercialized and less for the research community, the newer and much more faster NSFnet had far more computers than the ARPAnet. Unable to keep up with new technologies and funding for the ARPAnet, DARPA finally decided that it was time to pull the plug on the 22 year old network. The man who slowly disconnected the ARPAnet computers and connected them to the NSFnet back bone was Mark Pullen. No one really wanted to turn off the ARPAnet but it was bound to happen. Danny Cohen said in a speech:
"In the beginning ARPA created the ARPAnet.
"And the ARPAnet was without form and void.
"And darkness was upon the deep.
"And the spirit of ARPA moved upon the face of the network and ARPA said, Let there be a protocol, and there was a protocol. And ARPA saw that it was good.
"And ARPA said, Let there be more protocols, and it was so. And ARPA saw that it was good.
"And ARPA said, Let there be more networks, and it was so."
Internet Addressing using IP Numbers:
Addresses on the Internet works very similar to that of the postal address which has different levels of information. The Internet uses four 8 bit values that can go from 0.0.0.0 to 255.255.255.255. Unlike the postal address, that has the most specific information at the beginning, the Internets is located at the end. The broader information at the beginning of the address is to simplify things for the computers who are interpreting the packets. If the important information was at the end, each computer at a hop, would have to go through an entire data base to find the correct location to send the packet.
A Domain Name Server is a special computer that translates the domain name, analogous as "orangepeel.com" or "johnabbott.qc.ca," into a IP number for addressing the packets. DNS have a long list of IP addresses that it cross links the number with host and network names (Domain Names.)
The Simple Mail Transfer Protocol works similar to the Transmission Control Protocol (TCP) except it is designed to carry Electronic Messages throughout the Internet. To send a message over the Internet using the SMTP you only need the IP address of the recipient which can be a domain name for the reason that SMTP supports Domain Name Servers. SMPT severs have a built in feature that will send a message back to the sender if their message did not reach the recipient.