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6.
Sixth Concept: Ethernet cable
There are two main types of ethernet cable used to connect networks of this type. Actually, it would be
more accurate to say that there is one cable type and two different pin orders commonly used. The type
of cable is called Category 5 —
or Cat 5 for short. The connectors on the end of the cable look like
large telephone jacks (and are called RJ-45 connectors).
The difference is in the order of the pins —
specifically, which wires go to which pins. The two types
are referred to as straight and crossover , with the straight cable being the same wires pin-for-pin
on both ends —
or straight through. The crossover cable has a few wires that are connected to
different pins on either end - thus the wires are crossed over on each end.
Crossover cable is used when two computers are networked/connected directly together, without a
hub or a router in between.
The computer senses when the wires are crossed over, and will allow
direct connection between clients.
Straight cable is used when the computer is first connected to a hub or a router before going on to
connect to other computers on the network.
With a straight cable, the computer looks to a hub or a
router for packet routing information.
NOTE: Some newer computers can auto-sense when straight or crossover cables are connected to them.
If you are not absolutely sure that your computer operates this way, or if you are experiencing
communication problems, follow the above guidelines: crossover cables between two machines with
no device in between (like a hub or a router), and straight cable between a machine and a router or hub.
7.
Seventh Concept: FTP
FTP stands for File transfer protocol , and it is a simple language that was created to aid in the
transfer of files back and forth on a network —
with very few commands or user interface needed. In
fact, all FTP commands can be given from a text terminal, if you are so inclined.
Both Windows and Macintosh platforms have both third-party applications and other solutions for
using FTP —
Windows users who know the commands can simply use a DOS terminal to communicate
with the SX-1 over FTP.
Macintosh owners using OS9 and earlier often turn to an application called Fetch for FTP. Users who
know the command-line prompts (text commands), and who are using OSX, can now use the Terminal
application within the Mac OS to utilize FTP.
FTP uses a system of usernames and passwords to protect data on the network. If you do not have the
correct username and password, you will not be able to access the server you are trying to reach.
As a last comment, FTP uses two commands most often: PUT and GET . If you want to download
a file from the SX-1 to your computer, your computer will issue a GET command to the SX-1. If you
want to send a file from your computer to the SX-1, your computer will be issuing a PUT command.
As an easy way to remember which command is which, remember that both commands stem from
conversational language:
Put
this file on your hard drive , and I need to
Get
this file from you .
