WebPro Series

1
WebPro Series

• Networking
• Practical Application of skills

2
Introduction

• You have just completed an intensive course on
  networking. In this lesson we will underscore
  the skills from that course that are important to
  you as a webmaster. After this lesson, you will
  complete a hands-on exercise using these skills.
  

3
Lesson Objectives

• Identify hardware components of a network
• Explain how TCP/IP is used to transmit data over
  the Internet
• Write a proposal to construct a local Ethernet
  network

4
Network Topology

• There are two typical types of network topology
• linear bus
• star

5
Linear Bus Topology

• Computers are arranged in a straight series, and
  are typically connected with coaxial cable (RG
  58)
• main advantage is its simple layout, no hub is
  required
• disadvantage is that if there is any break in the
  line, the network fails

6
Star Topology

• Computers are arranged in a star pattern using
  Twisted-Pair Category 3 (10 Mbs/sec) or Category
  5 (10/100 Mbs/sec) cable. A hub in the center
  connects the machines.

• this arrangement is more costly, but generally
  more reliable than Linear Bus
• not every machine has to be connected in order
  for the network to function

7
Cabling

• In this lesson were going to discuss the most
  popular type of cabling, Category 5 or cat-5 as
  it is commonly known. This is the best solution
  for most office applications and the one we will
  focus on for our project.
• Cat-5 cable consists of eight strands of wire
  twisted into pairs.
• These wires fit into a connector called an RJ-45
  plug on one end and a patch panel in the wiring
  closet.

8
Cabling

• The RJ-45 plug looks like a standard telephone
  plug, except it carries eight wires instead of
  four.
• Cabling a local network with Cat-5 is similar in
  many ways to telephone wiring. Each room has a
  receptacle with one or more connectors. The
  cables for each receptacle are run to a central
  location in the office (commonly called the
  wiring closet).

9
The Wiring Closet

• Typically consists of the following hardware
• 19 metal rack to mount hardware on
• patch panel to wire cabling into bridge or hub
• The wiring closet may also have the following
• surge protection unit
• system diagnostic hardware

10
What is TCP/IP

• TCP/IP is the network protocol that computers on
  the Internet use to communicate with one another.
• The name TCP/IP is a combination of two of the
  four protocols that make up the suite of
  protocols that the Internet uses. The four
  protocols are
• IP
• TCP
• UDP
• ICMP

11
TCP and UDP

• The two protocols that we are most concerned with
  are TCP and UDP.
• TCP (Transport Control Protocol) -- a
  connection-based protocol that guarantees data
  transmission.
• UDP (User Datagram Protocol) -- connectionless
  protocol that does not guarantee data transmission

12
TCP

• TCP provides a point-to-point channel for
  applications that require reliable
  communications. The Hypertext Transfer Protocol
  (HTTP), File Transfer Protocol (FTP), and Telnet
  are all examples of applications that require a
  reliable communication channel. The order in
  which the data is sent and received over the
  network is critical to the success of these
  applications. When HTTP is used to read from a
  URL, the data must be received in the order in
  which it was sent. Otherwise, you end up with a
  jumbled HTML file, a corrupt zip file, or some
  other invalid information.

13
UDP

• The UDP protocol provides for communication that
  is not guaranteed between two applications on the
  network. UDP is not connection-based like TCP.
  Rather, it sends independent packets of data,
  called datagrams, from one application to
  another.

14
How does a network work?

• Diagram of two networks connected to the Internet

15
How does a network work?

• In the diagram, there are two networks --
  anyguy.com and stooge.com -- that are connected
  to each other, and the Internet, by a router.
  The routers job is to pass information
  (datagrams) to computers in different subnets.
• For example, if moe.stooge.com and
  larry.stooge.com want to speak to each other the
  datagrams never pass through the router. If moe
  wanted to speak to tom.anyguy.com, however, the
  router would have to route that information to
  the proper network, using information stored in
  its routing table.

16
The TCP Frame

• Most Internet applications, including the web,
  ftp and email, require a certain degree of data
  integrity and a 100 transmission rate.
• To achieve 100 data integrity, TCP can be used.
  Basically, TCP requires that the destination
  computer acknowledge every DATAGRAM that the
  source computer sends.
• This is much more reliable, but requires a lot
  more bandwidth to achieve.

17
What about the names?

• Names for machines, (www.somecompany.com) dont
  mean anything in terms of networking.
• The machines only use the IP numbers (i.e.,
  192.168.1.1). It is much more difficult for
  humans to remember 207.25.71.25 than www.cnn.com
  so the domain name schema was invented.

18
How does it work?

• Basically, whenever you use a computer name, that
  name is sent to a DNS (domain name service) and
  translated into the corresponding IP address.
  This is called resolving an IP address.
• The IP address of the DNS is specified in your
  computers network settings.
• There are many DNSs, and they work in a
  hierarchy. In other words, not every DNS has
  every computer on the Internet listed.

19
Choosing a Server

• When it comes to a server, there are many points
  to consider
• What tasks will this machine perform?
• How long will we need to use this server?
• How many people will access this server?

20
Some Tasks

• Your server typically performs the following
  tasks
• Web Server
• Email Server
• Database Server
• Application Server
• Office Backups

21
Typical Choices

• The type of server you buy will depend mostly on
  personal choices. Things to keep in mind
• What operating system are you familiar with?
• What OS does the office staff use?
• What programs does your office want to use, what
  OSs will they run on?
• You can mix systems, but only UNIX mixes cross
  platform very well

22
Typical Choices

• No matter what system you choose, there are three
  main considerations
• Get the fastest processor with the most RAM your
  budget will allow.
• Size the Hard Drive to the tasks that the server
  will perform.
• Make sure you have a way to back up the server
  (tape backup, RAID controller, etc.)

23
Practical Application why is this important to
me?

• It is important to know how the webpages you
  design are delivered.
• It is also possible that you may be asked to do
  some simple networking in your office. The
  following example will require you to do just
  that create a network in your office using the
  skills youve learned in the networking course.

24
The Task

• Your boss wants to develop a web presence. You
  are given a 8,000 budget to buy a server, and
  upgrade the existing cabling and equipment for a
  100 Mbps network.
• You need to assess what equipment you need to
  buy, obtain price quotes and compose a one-page
  proposal outlining what needs to be purchased.

25
What you already have

• 2000 ft of Cat-3 Cable
• 10 Desktops running Win98
• 7 with 10/100 Ethernet cards, 3 with 10Mb cards
• 1 10 port, 10 Mb hub
• 48 port, Cat-5 capable patch panel
• A router

26
Equipment You Need

• Server
• Cat-5 Cabling
• 100Mb bridge
• Power Backup
• Enough 100 Mb Ethernet cards

27
Keep in mind

• You should take into account the existing
  equipment and build off of that.
• Dont forget about future expandability. You may
  only need a 10 port hub for your 10 existing
  computers, but if you add one more computer you
  will have outgrown your hub.

28
Resources

• Feel free to get quotes from any source you like.
  Youll need to include a copy of the quotes with
  your proposal.
• If youre unsure of where to get started, here is
  an alphabetical list of online stores
• Apple (www.apple.com)
• Compaq (www.compaq.com)
• Dell Computer (www.dell.com)
• Gateway 2000 (www.gateway.com)
• IBM (commerce.www.ibm.com)
• microWarehouse (www.warehouse.com)

29
Final Thoughts

• It doesnt matter what equipment you choose, as
  long as you defend your choices in your proposal.
  Brand reputation, past experience and peer
  recommendations are all good justifications.