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Protocols, Hardware, and Remote Access
Protocols
create the standards for communication, and hardware connects
all the pieces together.
Protocols
In order for two
computers to "talk", they must speak the same language.
For instance, if you went to a restaurant in Russia and
ordered a hamburger in English, the chances of the waiter or
waitress understanding you are slim. If you had an
English-To-Russian translator, you could convey your request
properly, as both you and your server would be speaking the
same language. It is the same for computers. All
computers on the network must speak the same language in order
to communicate. These languages are called
protocols.
Protocols set out the
standards for how computers communicate. They each work
within the OSI model (Remember a few lessons ago) to provide
services to allow this communication. You don't need as
much to know how protocols work as you need to know what they
do and what layer they work at.
There are hundreds of
protocols.
For your reference, here are a baker's dozen that make up what
you could possibly see;
| Protocol |
Definition |
Description |
| SLIP |
Serial Line Internet Protocol |
Used to
manage modem connections that do not have dynamic IP
hosting services. (Physical/Datalink
Layers) |
| PPP |
Point-To-Point Protocol |
Used to
manage modem connections that use Dynamic Host Control
Protocol (DHCP) to dynamically assign IP addresses.
(Physical/Datalink Layers) |
| PPTP |
Point-To-Point Tunneling Protocol |
Used to
manager modem connections that use DHCP and use
tunneling technology to create Virtual Private Networks
(VPN) (Physical/ Datalink Layers) |
| TCP/IP |
Transmission Control Protocol/Internet
Protocol |
The most
common communication protocol in use today, mainly
because it controls most communication over the
Internet. It uses IP addressing and Domain Name
Servers to allow for large-scale networks.
(Network/Transport Layers) |
| NetBEUI |
NetBIOS Extended User Interface |
Used for
small Microsoft networks that do not require external
connections. NetBEUI is not routable.
(Network/Transport Layers) |
| IPX/SPX |
Internetwork Packet Exchange/Sequenced Packet
Exchange |
The standard
Novell Networks protocol, although newer versions of
Novell are transferring to TCP/IP.
(Network/Transport Layers) |
| HTTP |
HyperText Transfer Protocol |
The format
used to transmit information from a web page to a
computer. This protocol servers to allow HTML,
JavaScript, Flash, and other types of Internet documents
to be viewed. (Session/Presentation
Layers) |
| WAP |
Wireless Application Protocol |
Similar to
HTTP in that it allows viewing of Internet documents,
but is designed for wireless equipment. It is
smaller and less complex than HTTP, but allows for
Internet connections over wireless connections.
(Session/Presentation Layers) |
| FTP |
File Transfer Protocol |
Allows for
direct file transfer between computers. Where HTTP
allows you to view documents, FTP actually sends the
file to the remote computer. (Session/Presentation
Layers) |
| SMTP |
Simple Mail Transfer Protocol |
Used to send
e-mail messages across a network (Session/Presentation
Layers) |
| POP |
Post Office Protocol |
Used to
receive e-mail messages across a network.
(Session/Presentation Layers) |
| Telnet |
- |
A Unix
emulator that allows you to transfer files and
administer computers remotely. (Session/Presentation
Layers) |
| NFS |
Network File Services |
Allows
computers across a network to see a networked drive as
if it were local. (Session/Presentation
Layers) |
Hardware
In order to make
these protocols work, there must be additional hardware
present. Although it is possible to connect a Network
Interface Card to another Network Interface Card and
communicate, it rarely happens that way. You must use
equipment that manages and maintains connections in order to
create larger, more productive networks. Some of this
equipment is listed below;
| Equipment |
Function |
| Repeater |
A Repeater
takes the incoming signal and amplifies it so that it
may go longer distances. There are two types of
repeaters. Amplifiers simply take the
signal and boost it up. They are good in clean
networks, but in noisy networks will amplify the noise
as well. Signal Regenerators examine the
signal and retransmit it the way it was originally sent,
avoiding the noise problem but slowing down
communication slightly. |
| Hub |
A hub is a
center point in a network. Much like an airline
hub, a network hub is the center point where all network
traffic passes through on an Ethernet network. If
you think about a star network topology, a hub is always
in the middle of the star, and all data transmitted on
the network passes through that hub. |
| Bridge |
A bridge is a
method of segmenting networks into two or more
sections. Data transmitted on one segment only
passes through to the other segment if the receiving
computer is on that other segment. This can speed
up networks were the bandwidth is almost complete used
by splitting network traffic into useable
chunks. |
| Router |
A router
examines the source and destination addresses of network
traffic and decided where it should go. Rather
than have the signal transmitted to every node, the
router decides which route is best by use of a Router
Table. When several routers are connected
together, they can allow communication over
internetworks (large networks made up of smaller
networks) without the bandwidth problems of having one
giant network.
A Brouter is a
router and a bridge combined. It is used for both
network segmentation and routing purposes. Most
routers are inherently brouters now, as the two tasks
are quite similar. |
| Gateway |
A gateways is
a translation tool. The best way to explain it is
with our restaurant example. Let's say you want to
order a hamburger, but they don't understand the word
hamburger in Russia. A gateway would tell the
waiter or waitress that you want a piece of cooked
ground beef on bread.
In networking, a gateway
translates messages between computers using different
topologies. In order to connect your FDDI backbone
to your Ethernet network, you must have a gateway
installed in order to allow the two to understand each
other. |
Remote
Access
In order to allow
communications between computers separated by large distances,
you need to have a method of accessing those computers.
This is called Remote Access. Most likely if you're
reading this web page, you're using remote access, as it is
the primary means of connecting to an Internet Service
Provider over telephone lines. Remote access allows you
to log on to a remote network and see it as if it was local to
your computer. You know Remote Access better as Dial-Up
Networking.
Remember that remote
access uses PPP or SLIP to set up connections to remote
networks, and uses TCP/IP, NetBEUI, and IPX/SPX to transfer
data over the remote
connections.
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