Protocol Overview

Communication Protocols:

All communications between devices require that the devices agree on the format of the data.

The set of rules defining a format is called a protocol.

At the very least, a communications protocol must define the following:

-rate of transmission (in baud or bps)

-whether transmission is to be synchronous or asynchronous

-whether data is to be transmitted in half-duplex or full-duplex mode

In addition, protocols can include sophisticated techniques for detecting and recovering from

transmission errors and for encoding and decoding data.

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tcp/ip - transmission control protocol/internet protocol

-Tcp is responsible for veryfying the correct delivery of data from client to server.

-Ip is responsible for moving packets of data from node to node.

Sockets: name given to the package of subroutines that provide access to tcp/ip on most systems

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DNS - Domain Name System

The Domain Name System (DNS) as a whole consists of a network of servers that map Internet domain

names like www.livinginternet.com to a local IP addresses. The DNS enables domain names to stay

constant while the underlying network topology and IP addresses change. This provides stability

at the application level while enabling network applications to find and communicate with each

other using the Internet protocol no matter how the underlying physical network changes.

Domain Names:

Internet domain names come in four main types -- top-level domains, second-level domains,

third-level domains, and country domains.Internet domain names are the alphanumeric identifiers

we use to refer to hosts on the Internet

fyi: bind - Berkeley Internet Name Domain

The application that runs almost every DNS server on the Internet is called BIND,

for Berkeley Internet Name Domain, first developed as a graduate student project

at the University of California at Berkeley, and maintained through version 4.8.3

by the university's Computer Systems Research Group (CSRG). The initial BIND devel-

opment team consisted of Mark Painter, David Riggle, Douglas Terry, and Songnian Zhou.

Later work was done by Ralph Campbell and Kevin Dunlap, and others that contributed

include Jim Bloom, Smoot Carl-Mitchell, Doug Kingston, Mike Muuss, Craig Partridge,

and Mike Schwartz. Application maintenance was done by Mike Karels and O. Kure.

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Email Protocols:

smtp - simple mail transfer protocol

pop3 - post office protocol 3

Simple Mail Transfer Protocol (SMTP) is one of the most venerable of the Internet protocols.

Designed in the early 1980s, its function is purely and simply to transfer electronic mail

across