NETWORK ARCHITECTURE – A BEGINNER’S GUIDE

 NETWORK ARCHITECTURE – A BEGINNER’S GUIDE

WHAT IS NETWORK ARCHITECTURE?

Network Architecture is the design of a computer network. It depicts how computers are connected to each other on a network. Think of it like a blueprint of a building or a project. The Architecture is where you plan what the requirements from the network are and decide the hardware that is required for setting the network up.

It is crucial to make such that the network gets proper security and that we also set up a strong password to avoid strangers from being able to connection to the network and attempt something fishy.

TYPES OF NETWORKS

The two types of networks that are used are:

·        Peer-To-Peer Network: Also known as the P2P network. In a P2P network, the “peers” are computer systems which are connected to each other via the Internet. Files can be shared directly between systems on the network without the need of a central server. In other words, each computer on a P2P network becomes a file server as well as a client.

·        Client/Server Network: A computer network in which one centralized, powerful computer (called the server) is a hub to which many less powerful personal computers or workstations (called clients) are connected. The clients run programs and access data that are stored on the server.

Let’s learn about these networks in detail in the following slides.

 

PEER-TO-PEER NETWORK

Peer-To-Peer network, also know as P2P network, is a network in which all the computers are linked together with equal privilege and responsibilities for processing the data. Peer-To-Peer network is useful for small environments, usually up to 10 computers. Peer-To-Peer network has no dedicated server.

Special permissions are assigned to each computer for sharing the resources, but this can lead to problem if the computer with the resource is down.

The Peer-To-Peer Network is quite like the communication and connections that takes place between you and your friends during a group project. Everyone has (or is supposed to have) equal privilege and responsibilities.

All communication happens directly between any two people, without having to go through a mediator. Everyone has specific roles for said projects, and if any one says, falls sick, it would affect the overall project.

HOW CAN ONE HACK THIS NETWORK?

A P2P network treats every user as a peer. In file sharing protocols, each peer uploads files to other peers while also downloading. This opens a channel for files stored in the user machine to be uploaded to other foreign peers.

Some security risks include:

·        TCP port issues:

Usually, P2P applications need the firewall to open a number of ports in order to function properly. Each open port in the firewall is a potential avenue that an attacker can use to exploit the network.

·        Propagation of malicious code such as viruses:

As P2P networks facilitate file transfer and sharing, malicious code can exploit this channel to propagate to other peers. Through this, sensitive and personal information stored in the infected computer could be copied to other machines on the P2P network.

·        Risk of downloaded content:

When a file is downloaded using the P2P software, it is not possible to know who created the file or what peers are connected at any time and whether the files or peers are trustworthy. Malicious code, Viruses, etc. can be downloaded onto the target machine through these untrusted sources.

·        Vulnerability in P2P software:

Like any software, P2P software is vulnerable to bugs. It constantly receives requests from other peers, and if the server component of the P2P software is buggy, it could introduce certain vulnerabilities to user’s machine, which can be exploited to launch security threads like DDoS (Distributed Denial of Service) attacks and so on.

 

CLIENT/SERVER NETWORK

Client/Server network is designed for end users called clients, to access resources such as videos, songs, etc. from a central computer known as Server. The central controller is known as a server while all other computer in the network is called as client.

 The server performs all the major operations such as security and network management and manages the resources. All clients communicate with each other through a server. All requests go to the server for permission, and are initiated only after the server responds.

HOW TO HACK INTO THIS NETWORK?

Having a central server does not necessarily make the client/server network safe. Some vulnerabilities of this network are:

·        These are publicly available utilities and hardware you can use to eavesdrop on a network, or “sniff” the network to read packets of information. These packets can contain useful information, like passwords, company details, etc., or reveal weaknesses in the system that can be used to break the system.

·        Encryption of this data can solve this problem. However, some network operating systems don’t start encryption until the user has been authenticate (i.e., the password is sent unencrypted).

·        Most systems employ re-usable passwords for authenticating users which allows the attacker to monitor the network, extract the login information and access the system posing as that user.

THE OSI MODEL (A QUICK LOOK)

The OSI Model is a conceptual or logical model created by ISO (International Organization for Standardization) which enables different communication systems communicate with each other. One can say that it acts as a universal language for computer networking.

The model is split into seven abstract layers stacks one on top of the other-

1.      Application Layer- Human-computer interaction layer, where applications can access the network services.

2.      Presentation Layer- Ensures that data is in a usable format and is where data encryption occurs.

3.      Session Layers- Maintains connections and is responsible for controlling ports and sessions.

4.      Transport Layer- Transmits data using transmission protocols including TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).

5.      Network Layer- Decides which physical path the data will take and the size of data that would be sent.

6.      Datalink Layer- Defines the format of data on the network.

7.      Physical Layer- Transmits raw bit stream over the physical medium.

 

1.      In which layer of the OSI model is the format of the data defined?

a.      Network layer

b.      Data-link layer

c.      Presentation Layer

d.      Session Layer

Ans- b. Data-link Layer.

2.      Which of the following contains high risk when downloading content?

a.      Peer-to-Peer

b.      Client-server

Ans- a. Peer-to-Peer

3.      Which one of the following is designed for accessing resources like videos or song?

a.      Client-server

b.      Peer-to-Peer

Ans- a. Client-Server

 

KEY TAKEAWAYS!

Let’s look at a few key pointers from the previous lesson

·        A computer network in which one centralized, powerful computer (called the server) is a hub to which many less powerful personal computers or workstations (called clients) are connected

·        In a P2P network, the “peers” are computer systems which are connected systems which are connected to each other via the Internet. Files can be shared directly between systems on the network without the need of a central server.

·        The Open Systems Interconnection model (OSI model) is a conceptual model that characteristic and standardizes the communication functions of a telecommunication or computing system without regard to its underlying internal structure and technology.