Assignment 5

1 What the differences between Web-based Email and Client Email Program?

	Web-based Email	Client Email Program
Accessibility	Can access from any internet-connected device. Can be only read when online	Can only use an email client on the specific device that the client software is installed. Provides offline access
Storage Space	Size of inbox is limited	Can save the email to own storage
Interface	Web mail interface looks same no matter what browser you access it from.	User of Client-based email can choose the program that suits their needs.
Security	Eliminates many physical security risks a mail client user might encounter.	User can control where their mail is physically stored. Offer advanced security features like encryption.

 2. Briefly explain all Client Email Program that you know.

a.       Mozilla Thunderbird

A fully featured, secure and very functional email client and RSS feed reader. User can handle email efficiently and with style and Mozilla Thunderbird can filters away junk mail too.

b.      Opera

Opera email client is a slick and flexible interface that will satisfy almost all your email needs and opera integrates RSS feeds in this experience as well.

c.       Windows Live Mail

Window Live Mail is a comfortable email program that lets you access IMAP, POP and window live hotmail accounts with verve and ambition to connect with Window Live Messenger, Window Live Calendar and some RSS new feeds too. Windows Live Mail offers solid spam filters, fast search folders, but it could do better helping you organize and manage mail.

d.      Pegasus Mail

Pegasus mail is one of the most powerful, secure and generally best email programs available for Windows, but the interface could need some polishing to make its features more accessible.

e.      IncrediMail

IncrediMail is a fun and easy to use email client that adds spice to the messages you send while protecting you from spam, phishing and fraud attempts in a convenient manner. But incredimail lacks some productivity features if you have to deal with a large amount of mail.

f.        Mulberry

Mulberry is a powerful and incredibly versatile email client available for all the popular platforms.

g.       Foxmail

Foxmail is a nice email clients with a lot of great features that make email easy and fun. It includes a way to send large attachments, but does not unify inboxes across accounts.

h.      DreamMail

DreamMail manage email and RSS feeds handily and handsomely with stationery, labels and related message search. But international languages support is limited, spam filter seems ineffective and IMAP accounts are not supported.

i.         Alpine

Alpine is powerful console email program that makes you use email productively with automation aplenty and nary a distraction.

j.        Sylpheed

Sylpheed is a surprisingly versatile email client.

k.       i.Scribe

i.Scribe is small, fast, efficient and very usable. But they lack secure messaging and the IMAP support in scribe is not perfect.

3. What the differences between POP3 and IMAP? Show how to configure these email clients.

POP3 – Post Office Protocol	IMAP – Internet Messaging Access Protocol
Can use only one computer to check email ( no other devices)	Can use multiple computers and devices to check email
Mails are stored on the computer that you use.	Mails are stored in the server
Sent mail is stored locally on PC, not a mail server.	Sent mail stays on the server so you can see it from any devices.

POP3 Configuration

You can read your Gmail messages from a client or device that supports POP, like Microsoft Outlook. Here's how to enable POP in Gmail:

1.       Sign in to Gmail.

2.       Click the gear in the top right 

3.       Select Settings.

4.       Click Forwarding and POP/IMAP.

5.       Select Enable POP for all mail or Enable POP for mail that arrives from now on.

6.       Choose what to do with your messages after your POP client or device receives them.

7.       Click Save Changes.

Although the radio button next to your selected option may not stay selected, Gmail displays the status next to 'POP Status:.' When you enable POP, your settings display 'POP Status: POP is enabled.'

If your POP settings are turned off, the status will indicate that POP is disabled.

Once you've enabled POP in your Gmail settings, you need to configure your client. Select a client below to see specific configuration instructions.

·         Outlook

·         Thunderbird

·         Windows Mail

·         Other

IMAP Configuration

1.       Sign in to Gmail.

2.       Click the gear in the top right

3.       Select Settings.

4.       Click Forwarding and POP/IMAP.

5.       Select Enable IMAP.

6.       Click Save Changes.

Note: This setting is not available while using the basic HTML view of Gmail. To enable IMAP, use the standard view instead. Find out more about standard view and basic HTML view.

Once you've enabled IMAP in your Gmail settings, you need to configure your client. Select a client below to see specific configuration instructions.

·         Android

·         iPhone, iPad, or iPod touch

·         Outlook / Windows Mail

·         Apple Mail

·         Thunderbird

·         Other

Assignment 4 - Client - Server

1.    What is a Client-Server?
-  Client-server is an architecture used for networking.
-  A common form of system which software is split between server task and client task
-  Usually at least a manager(server) and an agent(client) had set up in the network


2.     How does it work?
-   All client-server protocols operate in application layer.
-   Server are the processes dedicated to managing the server and the clients are the workstation which run the applications.
-   Client will report an event to the server and the server will do something either to response to the client or nor.

3.     Why is a Client-Server Network good?
-   Client-Server Network is centralization,Server help in administering the network.Access right is done by servers.
-   Comes with proper management. The file easy to find out because all files are stored at the same place.
-   Back-up and recovery possible
-   Accessibility, server can be accessed remotely.
-   Security, rules defining security and access right can be defined at the time of set-up server
server can play different roles for different clients

4.   What are the drawbacks to the Client-Server Model?
-   Congestion in network. too mnay request from the clients may lead to congestion
-   Client-server architecture is not as robust as peer-to-peer
-   Expensive to install and manage

5.     What correlation the thin and thick client to this topic?
Thin Clients
- Easy to deploy as they require no extra or specialized software installation
- Needs to validate with the server after data capture
- If the server goes down, data collection is halted as the client needs constant communication with the server
- Cannot be interfaced with other equipment (in plants or factory settings for example)
- Clients run only and exactly as specified by the server
- More downtime
-Portability in that all applications are on the server so any workstation can access
- Opportunity to use older, outdated PCs as clients
- Reduced security threat

Thick Clients
- More expensive to deploy and more work for IT to deploy
- Data verified by client not server (immediate validation)
- Robust technology provides better uptime
- Only needs intermittent communication with server
- More expensive to deploy and more work for IT to deploy
- Require more resources but less servers
- Can store local files and applications
- Reduced server demands
- Increased security issues

Task 3: TCP vs. UDP

TCP and UDP are two different protocols which both can handle data communications between terminal through an Internet. In OSI model, both protocols are classified as Transport Layer Protocols.

TCP (Transmission Control Protocol)

>> Connection-oriented protocol

>> Suitable for applications that require high reliability, and transmission time is relatively less critical

>> Function as a message makes its way across the internet from one host to another host

>> Use by other protocols such as HTTP,HTTPs,FTP,SMTP,Telnet

>> Rearranges data packet in order specified

>> Speed slower than UDP

>> Reliability

>> Header size : 20bytes

>> TCP does error checking

>> Acknowledge segments

UDP (Universal Datagram Protocol)

>> Connectionless protocol

>> Used in message transport transfer

>> Suitable for application that need fast, efficient transmission

>> Use by other protocols such as DNS.DHCP,SNMP and etc

>> Has no inherent order as all packet are independent of each others

>> Speed UDP is fast because there no error-checking for packets

>> No reliability

>> UDP header size: 8 bytes

>> Do not need acknowledgement

Task 2: Briefly describe the process of sending packets from Host A to Host D

The transmission would go like this:

Host A wants to send a packet to Host D. Host A must knows Host D's IP address. However, if it does not know, then it will send something called an ARP request (Address Resolution Protocol) to the network, with the destination IP. 

 A few things will happen here:

1. If the IP is local. The host with that IP will reply back to the sender with its MAC address.
2. If the IP is non-local. The gateway router will detect this and send its MAC address.
3. If the IP is non-local and Host A's default gateway and subnet mask are set. Using this information Host A can determine the non-locality of the IP address and send it to the router's MAC address (ARPing if not known yet).

If Host A found this out earlier, it will be in the ARP cache and Host A will just use that. Now that the MAC address is sent, the packet can be transferred. The next stop will be the hub. The hub knows which outbound port the MAC address listed as the destination is on, because it tracks every MAC address it's seen a packet come from and which port it came on, If it does not know, then it will flood it out every single port, guaranteeing it'll arrive.

As such, the packet arrives at the router. The IP model is that it divides every single IP address in the network/world into a hierarchy which is subnet. The packet is then sent out that port.

Task 1 : List all the dial-up modem speed ( Connection VS Bitrate )

Figure below shows the list of dial-up speed and the bitrate

The values given are maximum values and actual values may be slower under certain conditions such as noisy phone lines.

Figure above shows that the connection with its modulation, bitrate and year released.

BITS 2513 Assignment 1

QUESTION

1.       How many visitors who have visited my website?

        Due to the number of visitor keep increasing time by time, the number of visitor on 10.35pm ( 28/9/2015) is 415.

2.       With reference to Chapter 2, answer the following questions

i.         Briefly describe the function of the equipment at layers 1, 2 and 3.

        Layer 1 (Physical Layer): consists of network equipment such as usb, bluetooth and 802.11 wifi connection. Data are transmitted and received in the form of bits through communication medium such as copper cable.

        Layer 2 (Data Link Layer): concerned with delivery of frames between two devices in a network, it also can detect and recover collisions where a medium is used simultaneously by a device and prevent it from happening again.

       Layer 3(Network Layer): responsible for packet forwarding by routing it to its destination through the routers with using IP address.

ii.       Specify 7 criteria to consider when selecting a NOS.

       a. Performance : serves client seamlessly

       b. Reliability : stable performance in any condition

       c. Adaptability : adapt to all different platform

       d. Affordability : the cost are affordable

       e. Security : ability to eliminate and repel threads

       f. Scalability : can continue to function with expansion of its size

       g. Ease : ease of use and installation

iii.      Explain the differences between Logical address and Physical address.

        

       Logical address is a address which generated by a CPU while physical address is a address which seen by a memory unit and it allows the data bus to access the particular memory cell in main memory. Logical address space is the set of logical addresses generated by a program and logical addresses need to be mapped to physical address using a hardware device called Memory Management Unit (MMU) before they are used. Physical and logical address are same when using compile time and load time address binding but they differ when using execution time address binding. Furthermore, the physical address is a unique MAC address which contains 48 bit while logical address is contain 32 bit. 

iv.     Explain the differences between OS and NOS.

       OS also known as Server Operating System while NOS known as Network Operating System. A server operating system is a software that especially developed to serve as a platform for running multi-user computer programs or application such as Window Server Versions or Linux server. However, network operating system is a software which implements a operating system which oriented to computer networking. The network operating system is typically designed to allow shared file among multiple computer in a network such as LAN (Local Area Network). Network operating system can embedded a router or a firewall which operates in OSI layer 3 (Network Layer). Example of NOS is CISCO IOS or RouterOS.

3.       In your opinion why IPv6 is still not fully implemented.

         IPv6 is designed to solve many of the problems of IPv4, including mobility, auto-configuration, and overall extensibility. IPv6 expands the address space on the Internet and supports a nearly unlimited number of devices that can be directly connected to the Internet.But IPv6 is still not fully implemented because nowsadays not much device can support IPv6. For example, IPv6 only can implemented in device which using Window 7 or above while who still using the older version device could not be implemented.