The most important application layer protocol as it is the one used mainly for the WWW and viewing webpages. Transaction orientated, client-server protocol. CLIENT sends a request message and the SERVER send back a confirmation message. HTTP defines the format of the message and the first line is the REQUEST LINE. This is then followed by header lines where needed. HTTP uses ASCII coding.
REQUEST:
SUGGESTED TRANSMISSION ALGORITHM SEQUENCE
SMTP is a push protocol which sends message between email servers. POP3 is a pull protocol which is used between servers and clients.
Much of the traditional schematic has been superseded by HTTp with email existing in browser now mainly, though SMTP still used between mail servers.
The application layer protocol responsible for transferring files from one client to another. It is computer and operating system independent. Seperates the control process from the data-transfer process