ELECTRONIC MAIL
EMAIL ADDRESS FORMAT
All email addresses contain the @ symbol between the user name and the domain.
alice@wonderland.com
All email addresses contain the @ symbol between the user name and the domain.
alice@wonderland.com
TCP/IP PROTOCOL
TCP/IP allows computers with various operating systems and capabilities to communicate. It is the most widely used networking protocol suite in the world, and is the language of communication on the Internet.
For one computer to communicate with another over this network, it must know the other computer's Internet address.
TCP/IP allows computers with various operating systems and capabilities to communicate. It is the most widely used networking protocol suite in the world, and is the language of communication on the Internet.
For one computer to communicate with another over this network, it must know the other computer's Internet address.
INTERNET PROTOCOL (IP) ADDRESS
The IP address uniquely identifies and distinguishes one computer from another, and to ensure each user on the Internet has a unique IP address, a central authority (Internet Corporation of Assigned Names and Numbers - (ICANN) issues all the addresses. www.icann.org
The IP address uniquely identifies and distinguishes one computer from another, and to ensure each user on the Internet has a unique IP address, a central authority (Internet Corporation of Assigned Names and Numbers - (ICANN) issues all the addresses. www.icann.org
A CHECKSUM
A checksum is a mathematical calculation that allows the receiving computer to verify whether the packet is valid.
When a sending host transmits a packet, it calculates a CRC, then adds this information to the TRAILER. When the receiving host reads the packet, it runs its own CRC, then compares it with the one stored in the trailer. If the two match, the packet is not damaged and the receiving host processes the packet. If the CRCs do not match, the receiving host discards the entire packet.
When sending an email message or transfer a file from one computer to another, the message or file undergoes a transformation from a complete file into smaller pieces of information called packets. Beginning with the APPLICATION layer of the OSI/RM, the file continues to be divided until the initial message becomes smaller and more manageable pieces of information sent at the PHYSICAL layer.
As the message travels through the layers, each layer adds its own information, called a HEADER to the packet. This information enables each layer to communicate with the others, and also allows the receiving computer to process the message.
When receiving the message, the host processes the packet and reverses the packet creationu process and removes each header, beginning a Layer 1 and ending at Layer 7. All that is then left at the end of this process is the original, unaltered data, which the host can then process.
A checksum is a mathematical calculation that allows the receiving computer to verify whether the packet is valid.
When a sending host transmits a packet, it calculates a CRC, then adds this information to the TRAILER. When the receiving host reads the packet, it runs its own CRC, then compares it with the one stored in the trailer. If the two match, the packet is not damaged and the receiving host processes the packet. If the CRCs do not match, the receiving host discards the entire packet.
When sending an email message or transfer a file from one computer to another, the message or file undergoes a transformation from a complete file into smaller pieces of information called packets. Beginning with the APPLICATION layer of the OSI/RM, the file continues to be divided until the initial message becomes smaller and more manageable pieces of information sent at the PHYSICAL layer.
As the message travels through the layers, each layer adds its own information, called a HEADER to the packet. This information enables each layer to communicate with the others, and also allows the receiving computer to process the message.
When receiving the message, the host processes the packet and reverses the packet creationu process and removes each header, beginning a Layer 1 and ending at Layer 7. All that is then left at the end of this process is the original, unaltered data, which the host can then process.