BITS 2513 - Assignment 5

Assignment 5

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

web-based email is a email service that can be accessed by using a web browser. There are a variety of web-based email such as gmail, hotmail and yahoo. Web-based email can be accessed by a client anytime anywhere as long as the client remembers the email address and password. Client email program is used to download email from the email server by using a program such as outlook or thunderbird.

Briefly explain all Client Email Program that you know.

Mail

Mail is a client email program found in iOS devices. The Mail apps in iOS devices is designed to work using iCloud and also supports other popular email services such as Gmail, Outlook and Yahoo! Mail. The mail apps will download a preview of any email received by the user from the mail server configured, and the user will be notified. The mail apps will download the email content once the user opens the mail to read it, or replying the email without using a web browser which consumes more resources and processing speed of the user's device, and it can save some bandwidth of your network too. There are also many other client email programs where some are designed to suit most of the email services and some other such as Gmail apps which are only made for gmail service and outlook for microsoft accounts only, but they generally shares the same functionality.

Mozilla Thunderbird

Mozilla Thunderbird is a n open source, cross-platform email client program. It supports all platforms including Microsoft Windows, Mac OS X, Linux, BSD and Unix. It supports many features such as Junk filtering, image blocking, UTF-8, Phishing filtering, Thread or conversation view, PGP and S/MIME which makes it one of the most popularly used client email programs with half a million downloads on the first 3 days of its release until Mozilla decides to drop Thunderbird from their development priority.

Microsoft Outlook

Microsoft Outlook is developed by microsoft used mainly as an email program. It also comes with features such as calendar, task manager, contact manager, note, journal and web browsing. It can be used to share mailboxes, calendars and meeting schedules with people inside your contact.

What is the differences between POP3 and IMAP? Show how to configure these email client.

To set up POP3 or IMAP in Microsoft Outlook,

1. In Microsoft Outlook, from the E-mail Accounts menu, select Tools.
2. On the E-mail Accounts wizard window, select Add a new e-mail account, and then click Next. 
3. Select POP3 or IMAP, and then click Next.
4. Fill in the required fields with the email account details and click More Settings.
5. On the Settings window, go to the Outgoing Server tab.
6. Select My outgoing server (SMTP) requires authentication.
7. If you did not change the SMTP relay section, select "Use same settings as my incoming mail server". If you changed the user name and password in the SMTP relay section of your Manage Email Accounts page, select "Log on using and enter the user name and password" and fill in the required fields.
8. Go to the Advanced tab, and then change the Outgoing server (SMTP) port to 80 or 3535.
9. Click OK and next until the set up finishes.

Task 4: Client-Server Model

Task 4

1. What is a Client-Server?

Unlike master slave relationship with one device acting as a master and another device as a slave, or P2P where each device can act as a client or server at the same time, Client-Server is a relationship between two workstations where the server shares a service or resource with a client over a local area network or wide-area network.

2. How does it work?

The data exchange between client and server follows a request and response manner. To ensure the server and client can communicate, they must have a common language as defined in the protocol of the application that uses the server's resource. For example, when a user access the web server of a website to convert from PDF to word format, the client will send a request to the server. The PDF file will be received by the server and the PDF file received by the server will be converted into word format and send back to the client. The client now receives the desired output by using the resource of the server.

3. Why is a Client-Server Network good?

Centralization

The server administor the access rights and the settings are concentrated at the server for a better management

Management

Files and resources are all stored in a server and any faulty are easy to troubleshoot.

Backup and Recovery

The data can be backed up so that a data recovery is possible in some cases, where there is a great chance to lose data with P2P model and the lost data are not recoverable.

Higher Degree of Flexibility and Scalability

If the server is uncapable of processing the data or resources, an upgrade is always possible and new resources can be added.

Accessibility

The server can be accessed in different platforms anytime anywhere.

4. What are the drawbacks to the Client-Server Model?

Network Congestion

In P2P model, multiple devices can act as a server. This is why there are almost no congestion of network in P2P model. The client server model have no other devices to help the server to share its resource. Too many incoming request from clients can cause overloading in server and the congestion of the network bandwidth.

Cost

It cost a huge sum to build a server and a server room to place it. Managing these server also requires a IT professional to keep the server running and monitoring it.

5. What correlation the thin and thick client to this topic?

A thin client is highly dependent on the resource of a server. It process a limited amount of resources by itself or in some cases it is just a device with an input that displays the output of the processed data from the server, and a good example is a web browser. A thick client is highly independent of the server. It will perform most of the process without using resource from servers. In contrast, a fat client will process most of the processes that are possible to be processed by it while a thin client process the possibly least amount of process. In both cases, both the thin and thick client runs an application or a program by their own in order to exchange data with the server.

Task 3: Explain the Difference Between TCP and UDP

 Reliability

TCP is more reliable than UDP since it manages acknowledgement and any packet loss will be resent while UDP does not check the readiness of receiver for the packet and any packet loss will not be sent. Acknowledgement, time out and retransmission are not present in UDP.

Difference Between TCP and UDP

TCP delivers a stream of data in a reliable order while UDP is not dedicated to end-to-end connection, and does not check for the readiness of the receiver.

Task 2: Briefly Describe the Process of Sending Packets from Host A to Host D.

Process of packets sent from host A to host D:

The IP address of host D is requested by host A to send a packet from host A to the destination which is host D. Host A will send an ARP request to the network with the destination IP address. If the destination IP is a local IP, the destination host will reply to host A with its MAC address or if the IP belongs to a global network, the gateway router will reply with its own MAC address.

With the MAC address replied, the packet can be transferred until the hub. The hub will determine the port and the MAC address of the destination. If it cant determine it, the packet will be flooded to every single port, guaranteeing the arrival of the packet.

Task 1

Task 1: List all the dial up modem speed (connection vs bitrate).

The figure below shows the connection and birate speed of dial up modem.

The speeds of dial up modem can be affected by the physical condition of the modem and the surrounding

Assignment 1

 How many visitors who have visited my website?

420 visitors

With reference to Chapter 2, answer the following questions

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

1. Layer 1: the physical layer is consists of network equipment such as USB, Bluetooth and 802.11 Wi-Fi connection. Raw data are transmitted and received in the form of bits through communication mediums such as copper cable, signal waves or light. The content of the raw data are not concerned at this layer.
2. Layer 2: the data link layer is concerned with delivery of frames between two devices in a network. It can also detect and recover collisions where a medium is used simultaneously by a device and prevent it from happening again. some examples of data link layer is PPP and Ethernet MAC
3. Layer 3: the network layer is responsible for packet forwarding by routing it to its destination through the routers. The packets are data that contains the IP address. It has a few functions including connection model, host addressing, and message forwarding. Examples are routers.

Specify 7 criteria to consider when selecting a NOS.

• Reliability - stable performance in any condition
• Performance - serves client seamlessly
• Adaptability- adapt to all different platforms
• Affordability - the cost are affordable
• Security - ability to eliminate and repel threads
• Scalability - can continue to function with the expansion of its size
• Ease - ease of use and installation

 Explain the differences between Logical address and Physical address.

The physical address is a unique 48-bit MAC address encoded in NICs by manufacturers. It is unchangeable but can be spoofed. It is associated with the data link layer. The logical address is a 32-bit IP address assigned to NICs for routing purposes between networks. The logical address operates at the network layer in the OSI model.

Explain the differences between OS and NOS.

OS or simply operating system is a system installed in a computer mainly to manage applications, hardware and connection to networks by enabling the computer on a LAN to share resources. The resources are shared using p2p model or client/server model. NOS or network operating system are system installed on a server with the basic functions of OS but it can also be used to manage network resources including user accounts, printer and file sharing across the network.

In your opinion why IPv6 is still not fully implemented.

The IPv6 address have 128bits for the entire address. One of the reasons it is still unimplemented is that there are still plenty of devices that are designed only to hold 32-bit IP address. For example, IPv6 are only introduced after windows 7 while there are still plenty of users using older devices that cannot support the length of IPv6 address. This means with the full implementation of IPv6, older devices are unable to work. Therefore the full implementation of IPv6 will take years.