Introduction to Networking Part -3

India’s first longest 1km mall has all elegance of beauty, design, fashion, entertainment and food. It is the hottest place of people of Gurgaon, Delhi and other visitors. It consists of 250 stores of consisting retail outlets, garments, electronics, food court and entertainment. We also go there and checked the flare of mall. It was so amused by graceful lighting and modern culinary items that we don’t want to come back to home and feel like London in INDIA.

The best part is the management of stores and hundreds of people under one roof. Once thing that is spectacular is every store was equipped with air conditioned, computers, cctv’s and fancy lights to attract customer. Reliance digital where all digital equipments are displayed and operational is again a difficult task to maintain.

If everything is placed in random then, in later stages network management will be difficult and entire setup will disturbed. So Networking of computers or data has also follow some rules and structure which we will be going to discuss in today’s section.

Operations of data networks can be classified as:

1.       Networks Devices & Components

2.       Interpreting Data Networks

3.       OSI Reference Model

4.       TCP/IP Reference Model

5.       Web, VOIP and Network Applications.

6.       Understanding Network Flows.

Network Devices & Components are the elements of networks which are used in a hierarchical design to accomplish desired task. Those devices are classified into following categories :

·         Endpoints

·         Interconnections

·         Switches

·         Routers

 The devices over which network application is running are called as Network Endpoints. PC’s, laptop, Servers, IP Phones, Printers, Smart phones are came under the category of Endpoint device, where we can install the application and able to control data network as per our requirement. With the help of PC or Laptops we can raise the bill after the sale, took display of CCTV’s, manage websites, do emails to customer about new offers, etc.

Interconnections are the network devices which are used to connect different endpoints to interpret the desired output. Interconnections are broadly classified as Network Interface Cards NIC’s, Media like Cables (Category 5 UTP cable, Category 3 Cable etc), and connectors (RJ45, RJ49, etc).

 A network switch (sometimes known as a switching hub) is a computer networking device that is used to connect many devices together on a computer network. A switch is considered more advanced than a hub because a switch will only send a message to the device that needs or requests it, rather than broadcasting the same message out of each of its ports. A network Switch connects endpoints to a LAN.

Interpreting Data Networks means how data flows in the network; this can be further illustrated as the hierarchical distribution of data as per devices installed in the network.

Cisco has provided a distribution of data in three different layers :

1.       Core Layer

2.       Distribution Layer

3.       Access Layer

The core network provides high-speed, highly-redundant forwarding services to move packets between distribution-layer devices in different regions of the network. Core switches and routers are usually the most powerful, in terms of raw forwarding power, in the enterprise; core network devices manage the highest-speed connections, such as 10 Gigabit Ethernet.
For Example: Cisco Catalyst 4800x  series Switches

The distribution layer is the "smart" layer in the three-layer model. Routing, filtering, and QoS policies are managed at the distribution layer. Distribution layer devices also often manage individual branch-office WAN connections.For Example: Cisco 6800 series switches

End-stations and servers connect to the enterprise at the access layer. Access layer devices are usually commodity switching platforms, and may or may not provide layer 3 switching services. The traditional focus at the access layer is minimizing "cost-per-port": the amount of investment the enterprise must make for each provisioned Ethernet port.For example: Cisco Catalyst 4500 E series Switches

                                    

                                      

The above model can be understood as, the hierarchy model in company, or anywhere , where management is required. Let us consider a in a telecom company, if some customer wanted to log a complaint , he would go to helpdesk or dial toll free number, where customer relationship executives takes his complaint .In access layers switches do the same thing they interact with end points and do the segmentation of the data.

Once complaint has been logged, it went to the higher order technical team, which filtered the complaint on the basis of fault analysis, area zone, etc. In the same way distribution switches provide segmentation, filtration of data services.

One the data has been filtered it went to the concerned team and overall fast action and trouble solution has been provided by the same. In this way Core Layer switches work, the fastest action has been provided by those switches and make fastest data access to the concerned team.

Technically access layers switches provide ports to connect customer to enterprise port, distribution layer switches do action over the data and core layer switches has highest capacity which provide fastest switching.

A router is a device used to connect multiple LAN together and decide the shortest path for a packet to travel over a LAN to reach its destination.

On the basis of network topologies routers are classified as:

1. Branch Routers: Routers present at lower end of SOHO network or remote office connections.Example a DSL router, 3900 series routers
2. WAN/ Enterprise Edge Network: It means some business network, like a retail store where router needs to connected to other computers and other end is connected to Internet Service provider.Example Catalyst 6500 series router
3. Service Provider: These routers are high end for large scale Internet routing. Cisco 7600, cisco 12000 series.

Network Diagrams are used to understand the flow of network, basically how in a network data flows with the help of switches and routers.

Network diagrams are typically classified as Physical network diagram and logical Network diagrams.

Physical Network Diagrams are used to identify how devices are physically connected together in a network, above all Physical network diagram used to identify:

1. Physical Port Assignments
2. Physical Device Connections.
3. Useful for troubleshooting of Layer 1 and Layer2 issues.

While Logical Network Diagrams gives you a high level overview that how a data moves over the network, from point A to point B.

1.       Ethernet VLAN information.

2.       Layer 2 WAN addressing.

3.       Help in finding Layer3 IP addressing.

4.       We find routing protocol information and troubleshooting layer 3 or above issues.

Cisco has provided network topology icons to create logical diagrams with the help of these icons we can easily create and understand network topological scenarios in a network.