Transcript LO1 Understand web architecture and components

Y/601/6623
Level 3 Unit 12
Assessment Criteria
Learning Outcome
Pass
Merit
Distinction
The learner will:
The assessment criteria are the
pass requirements for this unit
The Learner can:
To achieve a merit the
evidence must show that, in
addition to the pass criteria,
the learner is able to:
To achieve a distinction
the evidence must show
that, in addition to the pass
and merit criteria, the
learner is able to:
1 Understand web
architecture and
components
P1 Outline the web architecture
and components which enable
internet and web functionality
2 Understand the
factors that influence
website performance
P2 Explain the user side and
server side factors that
influence the performance of a
website
P3 Explain the security risks and
protection mechanisms
involved in website
performance
M1 Compare and contrast
current interactive
websites for performance
and security
D1 Discuss the impact that
cases of website security
breaches have had on
society
3 Be able to design
websites
P4 Using appropriate design
tools, design an interactive
website to meet a client need
M2 Produce annotated
design documentation for
an interactive website to
meet a client need
4 Be able to create
websites
P5 Create an interactive website
to meet a client need
M3 Implement CSS in an
interactive website to
improve the site to meet a
client’s needs
D2 Carry out acceptance
testing with client on an
interactive website
Understand web architecture and components
 Learners should gain an understanding of what each of
the architecture, components and protocols are as
identified in the teaching content. This can be facilitated
by group discussion, exercises, presentations, or group
research tasks.
 Assessment criterion P1 could be evidenced by the use of
a report or presentation, delivered to a group and
evidenced through the presentation, and supported by a
tutor observation sheet, or recorded evidence. Each of the
listed topics in the web architecture, components and
protocols section of the teaching content should be
covered, by an explanation of what it is and what it does.
LO1 Understand web architecture and
components - Architecture
Internet service providers (e.g. Virgin Media, BT, Sky)
 Internet service providers are there for a reason, companies and individuals need to
either connect through a provider or use their own T-Line like a T1. ISP’s provide a
service that most individuals are not aware of, from minor hosting to providing a
static IP address. The range of ISP’s is broad, each sells a connection package with
phone options and each can be measured in terms of speed of connection,
bandwidth and for most, a small degree of site or file hosting.
 Speed of connection – this is how fast an individual file can go from the website to
your screen, measures in Megabit speed which is 1/8 of a Megabyte per second. The
faster the speed the faster a page opens.
 Bandwidth – this is how large a file can be downloaded at one time and can be
compared to road width, smaller the bandwidth, the more buffering a file has to do
to load.
 Static IP – Used by business to limit down activity such as blocking, easier to block
and restrict a static address than a dynamic address, whereas dynamic addresses are
more difficult to hack or be subject to DDOS attacks.
 Hosting – a lot of small companies host on their ISP and bounce to a registered
domain name from. This is good for small businesses as the storage space for small
sites is already there. Bouncing the web address is not seen by the customers and it
is a secondary site that makes it more difficult to hack.
P1.1 – Task 1 – Describe, with evidence, the purpose and function of ISP’s for a specific
client.
LO1 Understand web architecture and
components - Architecture
Web hosting services (e.g. free hosts; Google Sites, Free-space; paid hosts; JimdoPro,
Fasthosts)
 Web hosting differs from ISP’s because they provide a place to store, locate, display
and manage website functions. Where ISP’s can bounce, hosts store. The difference
is the range of hosts is the service they provide for that fee. These services include:

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Database management through SQL
Auto redirecting of IP addressing
Email exchanging
Virtual Private networking
Dedicated server activity
The difference between pricing strategies depends on the level of service the user
requires, free hosts like Google share the space but not the activity, Bit and tinyurl
provide space and a small degree of activity management whereas fasthosts and others
provide more management facilities such as forums, secure logins and database
management, shopping basket protection, blog and wiki activity etc. None of these
provide filtering, that is something that the user still has to manage like forum
maintenance and management. Ultimately the provision of hosting is the difference
between a look-at-me site and an managed shopping experience.
P1.1 – Task 2 - Describe, with evidence, the purpose and functions of Web Hosting for
a specific client.
LO1 Understand web architecture and
components – Architecture - Domains
 Part 1 - Transfer Protocol
 http:// – Hypertext Transfer Protocol
 https:// – Hypertext Transfer Protocol, Secure
 ftp:// - File Transfer Protocol for FTP site. Allows upload/download of files.
 Part 2 – www (which part of internet is being addressed)
 Part 3 – domain name – name of organisation that controls the
site that the page is stored on
 Part 4 – indicates the type of organisation (.co/.sch/.gov/.edu/.org
etc)
 Part 5 – the country in which the site is located
 Part 6 – sub domain or webpage currently viewing
 http://www.purelygadgets.co.uk/aboutus.php
Part 1
Part 2
Part 3
Part 4
Part 5
Part 6
LO1 Understand web architecture and
components – Architecture - Domains
 Web addresses as seen in the previous slide are broken down for a reason. First there was IP
addresses, then the web grew to the point when remembering all those numbers was impossible.
When the system of DNS came into place, the translation of IP addresses to wording allowed
businesses, government offices, companies and individuals to generate their own unique address
that was more memorable for the customer.
 How difficult would Easyjet.com find business if the customer has to remember 12 numbers, or
Thetrainline, Google, Amazon, all branded names based on their DNS name rather than their IP.
 Internet Service Provider (ISP)
 has unique IP (Internet Protocol) address
 four numbers separated by full stops
 Domain Name System (DNS)
 translates IP address numbers into domain name
 Without the DNS you would have to remember numbers instead of names.
 For example – typing http://193.164.107.139 would lead to the same page as
http://www.brookweston.org
 URL (Uniform Resource Locator)
 standard address used to find a page
P1.1 – Task 3 - Describe, with evidence, what DNS and URL are and what it does in terms of securing
business, naming and address management.
LO1 Understand web architecture and
components – Design Creation
 In the early days of web design all code had to be created using HTML, now HTML is hidden
behind the GUI of websites, still there running the system and still accessible but not as
obvious. Programmers still use HTML but programs have surpassed this. The inclusion of
JavaScript, CSS, MySql, embedded flash, dHTML, sHTML etc. means that more lines of code
are added than ever before.
 Look at the examples from here to see the difference even major companies have gone through
to revamp their image through effective web design.
 Programs that generate this additional code include Dreamweaver, Moodle, Web Plus and
Coffeecup. There are two kinds for this, offline and online. Offline programs create the whole
site with additional language add ins like JavaScript and allow the user more control over the
finishes result rather than template altering. Additions in terms of behaviours add
functionality to the site. Coffeecup and WebPlus are similar, basing designs on templates and
adding in code.
 Online site creators like moonfruit, wix and godaddy all give the user options to customise the
layout and content. This will contain dynamic code and everything tricky that can be created
with a higher level of technicality within Dreamweaver but reduce the control the user has
and reduces the skillset gained from web creation.
P1.1 – Task 4 - Describe, with evidence, the different levels of Design Creation software available
and the advantages and disadvantages of online vs. offline creation.
LO1 Understand web architecture and
components – Web Servers
 The term web server can refer to either the hardware (the computer) or the software
(the computer application) that helps to deliver web content that can be accessed
through the Internet. The most common use of web servers is to host websites, but
there are other uses such as gaming and data storage The primary function of a web
server is to cater web page to the request of clients using HTTP. This means delivery
of HTML documents and any additional content that may be included by a
document, such as images, style sheets and scripts.
 A user agent, such as a web browser or web crawler, initiates communication by
making a request for a specific piece of information using HTTP and the server
responds with the content of that resource or an error message if it is unable to do
so.
 For companies that prefer to manage their own hosting they will need specific
hardware to store, serve, process and manage user accounts and internet activity.
This is called a Web Server, sets an open traffic line between server and outside
hosting and allows the user to manage their own business.
 Managing the website internally allows the users to change anything without the
need to upload, making the changes automatic and live each time. Longer term this
is more beneficially for a company for the sheer reason of being able to manage your
own content and expand through software rather than proxy.
LO1 Understand web architecture and
components – Web Servers
 The two main types of server for this is IIS and Apache. Internet
Information Services (IIS) is a server designed to work with a Microsoft
environment, and manages web activity in terms of modules, Security,
Content, Compression, Caching, Logging and Diagnostics which all add up
to a website management bundle for all activity on the site. Ruby on Rails,
ASP (.net and classic) and Python are all languages that work out of the
box on IIS whereas they have it be added to Apache as modules to be
managed. More importantly it comes free with Microsoft Windows and
functions well within with similar coding parameters.
 Apache server is often referred to as simply Apache, a public-domain
open source Web server developed by a loosely-knit group of
programmers. Core development of the Apache Web server is performed
by a group of about 20 programmers, called the Apache Group. However,
because the source code is freely available, anyone can adapt the server for
specific needs, and there is a large public library of Apache add-ons. It is
the most accepted web server because it offers all the functionality of the
IIS and is more adaptable. Being free is it’s biggest selling point though it
does everything IIS can do with add –ins.
 P1.2 – Task 5 - Describe, what web servers do and how they work and
outline the benefits and disadvantages of IIS and Apache.
LO1 Understand web architecture and
components – Components - Email
E-mail is a great way to give your employees the means to collaborate and share
information with co-workers, vendors, manufacturers, customers, and students.
A mail server is a server that handles the network’s e-mail needs. It is configured with email server software, such as Microsoft Exchange Server. Exchange Server is designed to
work with Microsoft Outlook, the e-mail client software that comes with Microsoft Office.
Most mail servers actually do much more than just send and receive electronic mail.
 Hardware wise this usually is a dedicated server that handles the client (software)
processes the tens of thousands of emails that come in every day and manages these
emails to the client. With the server software, emails are processed before rerouting. A
server application like Exchange Server will:
 Spam and virus filter through the emails
 Block DOS attacks
 Filter for swearwords
 Flag up erroneous or dangerous emails
 Process attachments, groups, reminders, and account information.
 Manage the email folder limits.
LO1 Understand web architecture and
components – Components - Email
 Email servers can be internal or external similar to Web Servers but the need for
email management is more urgent than web filtering and proxy management.
Emails server work on two levels, Pop3 and SMTP, or incoming and outgoing
connections. Once an email is sent to a registered company and the server receives
it through ISP distribution, the email server will then process the email through a
content filter and pass it on to the relevant internal email address.
 All sorts of actions happen between the receiving and arriving, such as address
redirection, filtering, content management, email box size management, priority
management, delivery and distribution management, backup storage and data
logging. This is taken care of by the email server.
 Similarly an online server like Icewarp manages some of these tasks, for a fee. The
service they provide depends on the user needs and the annual subscription. This is
one step away from Cloud Computing which is more interactive but in the 10 years
of development the professionalism and customisation of the online email
providers has put them on a par with offline providers, except for the
individualisation.
P1.2 – Task 6 - Describe, what email servers do and how they work and outline the
benefits and disadvantages of internal vs. external server provision.
LO1 Understand web architecture and
components – Components - Proxy
 A proxy server (or Application Gateway) is a server that sits between a client computer and a real
server. The proxy server intercepts packets that are intended for the real server and processes
them. The proxy server can examine the packet and decide to pass it on to the real server, or it
can reject the packet. Or the proxy server may be able to respond to the packet itself, without
involving the real server at all.
 For example, Web proxies often store copies of commonly used Web pages in a local cache.
When a user requests a Web page from a remote Web server, the proxy server intercepts the
request and checks to see whether it already has a copy of the page in its cache. If so, the Web
proxy returns the page directly to the user. If not, the proxy passes the request on to the real
server.
 Application gateways are aware of the details of how various types of TCP/IP servers handle
sequences of TCP/IP packets, so they can make more intelligent decisions about whether an
incoming packet is legitimate or is part of an attack. As a result, application gateways are more
secure than simple packet-filtering firewalls, which can deal with only one packet at a time. A
good proxy server will:
 Learn from attacks and add them to a barred list
 Download updates from an online security system like Janet
 Filter the network as an added level of protection.
 Act as a barrier, together with the firewall and SSL against DOS attacks.
P1.2 – Task 7 - Describe, what proxy servers do and how they work and outline the benefits in terms of
security to a company.
LO1 Understand web architecture and
components – Components - Routers
 A router is like a bridge, but with a key difference. Bridges are Data Link layer devices, that can’t peek into the message itself
to see what type of information is being sent. In contrast, a router is a Network layer device, so it can work with the
network packets at a higher level. In particular, a router can examine the IP address of the packets that pass through it. And
because IP addresses have both a network and a host address, a router can determine what network a message is coming
from and going to. Bridges cannot.
 Unlike a bridge, a router is itself a node on the network, with its own MAC and IP addresses. This means that messages can
be directed to a router, which can then examine the contents of the message to determine how it should handle the
message.
 You can configure a network with several routers that can work cooperatively together. For example, some routers are able
to monitor the network to determine the most efficient path for sending a message to its ultimate destination. If a part of
the network is extremely busy, a router can automatically route messages along a less-busy route, for example, the router
knows that the Rockingham Road is gridlocked all the way through to the A6003, so it sends the message for cars to go on
A45 instead.
 Routers aren’t cheap. For big networks, though, they’re worth it. The functional distinctions between bridges and routers
get blurrier all the time. As bridges, hubs, and switches become more sophisticated, they’re able to take on some of the
chores that used to require a router, thus putting many routers out of work.
 Some routers are nothing more than computers with several network interface cards and special software to perform the
router functions. Routers can also connect networks that are geographically distant from each
other via a phone line (using modems) or ISDN. You can also use a router to join your LAN to
the Internet.
P1.2 – Task 8 - Describe, what a router does and how they work and outline the benefits
in terms of network traffic flow to a company.
LO1 Understand web architecture and
components – Components - Browsers
Browsers (e.g. Internet Explorer, Mozilla Firefox, Google Chrome, Opera,
Safari)
 Browsers exist merely to display results and translate the HTML code from
the external and internal sites onto a GUI for the user to read and use. The
choice of Browser is dependant on the users preferences rather than needs.
They all do the same thing, display results. Browsers come with a small
range of additional options to benefit the user and claim loyalty, for
example:
• Embedded Email in IE
• Proxy and Java blocking in Opera
• Compatibility with OS like Safari
• Ease of Use like Chrome
• Adding favourites or stash like Opera.
• Speed of display like Firefox
• From within all Browsers is the options for connectivity
which allows the easier access to networking. Also the
access to history, RSS feeds, setting privacy levels,
security settings etc. are all available on any web
browser.
LO1 Understand web architecture and
components – Components - Browsers
 At the end of the day all browsers are free,
some come preinstalled with the OS like IE
in windows, Safari on IOS, Firefox in Linux
and there is nothing to stop a user from
installing other browsers for their own
particular reasons. For comparison details
click here.
 Heavy web users need an internet browser
that is both fast and secure, and though all
browsers enable internet access, not all are
created equal. Different browsers can render
webpages differently, and there can be a large
disparity in performance between the top
competitors. The three main things to
consider when choosing an internet browser
are simplicity, speed and security.
P1.2 – Task 9 - Describe what a web browser does and how they
work and outline the range of different choices are available for a
company.
LO1 Understand web architecture and
components – Components – TCP/IP
 You need TCP/IP to connect to the Internet. Realize that there is a difference
between installing TCP/IP on your network and installing it for dial-up networking
use; these are two separate installations and uses for the protocol.
 You install TCP/IP to use with the dial-up networking feature. This installation
enables you to connect to the Internet by means of a modem. The TCP/IP
communicates with Web servers on the Internet. If you install TCP/IP on your
network, you use it to connect to the other computers on your LAN. One
installation has nothing to do with the other. For more information,
 Using TCP/IP to connect to the Internet provides you with all the Internet features
and advantages, including e-mail, Web browsers, and file transfer. Also, TCP/IP
includes various programs (which are also protocols) that you can use to access
information on the Internet. If you have special needs for FTP or Telnet, for
example, TCP/IP provides those programs for you to use. If you plan to expand your
network to the Internet someday, your knowledge and use of TCP/IP will help you
tremendously. Knowing how to configure TCP/IP will make it easier for you to
transfer your Web sites and pages to the Web and to configure clients and servers
for the Internet. Having TCP/IP in place means less configuring when you move to
the Internet.
 P1.2 - Task 10 – Define TCP/IP and in terms of web components define the benefits
of TCP/IP in constructing and Intranet and Internet presence.
LO1 Understand web architecture and
components – Components - Email
 There are two types of Email components used in private and
business, Browser based such as Outlook express and Site based
such as GMail, Hotmail, Yahoo Mail etc. Both of these types have
their own purposes and often users will use several online and an
offline mail program to access their accounts. With modern
Smartphones, synchronising accounts is standard practice but users
will still maintain a separation between accounts, usually for
professional and personal reasons.
 The difference between the two systems is minimal, once activated
they provide the same systems of storage and access, mail,
calendars, reminders, CC, BCC, folders structures, tracking RSS
accounts, out of office reminders, collaborative calendar sharing,
meeting invites and reminders.
 The difference between offline and online is ease of access, online
email programs save the emails as drafts to be re-accessed, offline
email programs resend when reconnected. It is the ease of use that
defines the multiple accounts, online can be accessed remotely,
allows multiple accounts but is also less secure.
Program and Browser based email
 Microsoft Outlook and Outlook Express are e-mail programs
that allow the user to send and receive mail, manage and sort
messages, check and remind the user of their feeds, attach
files, and more. The User can read their messages while still
attached to the Internet, or they can read and answer them
offline if you use a telephone line and ADSL to connect to the
Internet. If the User uses a permanent connection, such as a
cable modem, their computer is always online. With a
permanent connection, they can choose to
 Have Outlook Express check your mail every 10 minutes, or every
30 minutes, and so on.
 Create folders to organize your messages, and keep an address
book that makes addressing your messages quick and easy.
P1.2 - Task 11 – Define the purpose and function of Browser based
email programs and define the advantages and drawbacks against
internal mailing systems.
Task List
P1.1 – Task 1 – Describe, with evidence, the purpose and function of ISP’s for a specific client.
P1.1 – Task 2 - Describe, with evidence, the purpose and functions of Web Hosting for a specific
client.
P1.1 – Task 3 - Describe, with evidence, what DNS and URL are and what it does in terms of
securing business, naming and address management.
P1.1 – Task 4 - Describe, with evidence, the different levels of Design Creation software available
and the advantages and disadvantages of online vs. offline creation.
P1.2 – Task 5 - Describe, what web servers do and how they work and outline the benefits and
disadvantages of IIS and Apache.
P1.2 – Task 6 - Describe, what email servers do and how they work and outline the benefits and
disadvantages of internal vs. external server provision.
P1.2 – Task 7 - Describe, what proxy servers do and how they work and outline the benefits in
terms of security to a company.
P1.2 – Task 8 - Describe, what a router does and how they work and outline the benefits in terms
of network traffic flow to a company.
P1.2 – Task 9 - Describe what a web browser does and how they work and outline the range of
different choices are available for a company.
P1.2 - Task 10 – Define TCP/IP and in terms of web components define the benefits of TCP/IP in constructing
and Intranet and Internet presence.
P1.2 - Task 11 – Define the purpose and function of Browser based email programs and define the advantages
and drawbacks against internal mailing systems.