Network and Operating System

In this blog, we will cover the content on COMNET,  WAN, LAN, Router, Token Ring, Processing Server, Computer Group, Message Source, Message Response Source, WAN Cloud Model, Access Link, Virtual Circuit, and much more.

COMNET

COMNET is a communication network that is entirely driven by a Graphical User Interface (GUI). 

It allows the users to interact with the simulation model during the execution. 

This communication network is very much simple to use and understand. 

It also encompasses the verification option for making the model error-free. 

Similarly, it enables a lot of features like running the simulation, creating the reports, browsing and analyzing those created reports, and so on. 

Moreover, it contains the GUI components like toolbar, palette, canvas, menu bar, etc. 

The palette contains a lot of tools like Diagonal arc, Router, Computer Group, Processing Node, Access Point, Subnet, Cloud, WAN Link or VC, Point-to-point link, Token-passing link, Message Source, Response Source, Session Source, etc. that are most important for designing the model. 

Basically, the main purpose of using COMNET is for network model simulation in an effective, simple, and systematic way.

WAN

WAN stands for Wide Area Network. 

As the name signifies that WANs cover wide geographical areas or distances. 

The interconnection of multiple LANs is considered WAN. These networks are manipulated by large-scale companies. 

Comparatively, this model is quite costly but acquires high speed and security. 

Internet i.e. the global interconnection of computer networks is an example of WAN. 

Some other examples of WAN technologies and protocols are Frame Relay, Automated Teller Machine (ATM), Digital Subscriber Line (DSL), and so on.

LAN

A Local Area Network (LAN) is a computer network that connects the computers within limited areas or sectors like houses, schools, colleges, or offices. 

LANs are confined to a small region. 

The technology called Ethernet allows us to connect multiple devices to form a LAN. 

The data in LANs are more secure from being copied or destroyed. 

Home Router, Computer, Television (TV), Mobile Phone connected to a single network through Wi-Fi/Cables/Hotspot/Bluetooth, etc. is the best example of a LAN device. 

Generally, there are mainly two types of LAN that include: peer-to-peer and client/server LANs.

Router

Basically, the router is a network device that passes information through packets (a container that carries data over a TCP/IP network and internetworks) within a network or to another network. 

It assists in connecting multiple networks and forwarding respective packets to their respective destinations. 

In COMNET, it can be designed either from the toolbar or by selecting the Network Device option from the Create menu.

Token Ring

In a LAN (Local Area Network), a token-passing ring is considered as a channel access technique where a signal known as a token is proceeded between the nodes to authorize that node to communicate. 

In a token ring network, only a host that holds a token can send the data after confirmation. 

This helps in preventing the data packets from colliding on a network. 

Token Ring topology uses token passing. 

In COMNET, it can be designed either from the toolbar or by choosing the Token-passing link option from the Create menu.

Processing Server

A processing node can be used to represent any sort of node in a network, varying from sole workstation or PC to mainframes, telephone switches, and so on. 

In COMNET, a processing node can be designed either from the toolbar or by selecting the Processing node option from the Palette menu.

Computer Group

Basically, a computer group is a node that is especially used to represent a group of similar processing nodes. 

Parameters of computer group are totally carbon-copy of the processing node but in computer group there exhibits one extra parameter i.e. “number in-group”, which determines the amount of processing node nodes that we are literally modeling. 

Computer group nodes can be designed either from the toolbar or by picking the Computer Group option from the Create menu in COMNET.

Message Source

A message source is a message producer that is eligible for transferring messages to one or different destinations. 

It is applicable in transferring data including emails and file transfers in a model. 

It may be designed either by selecting the Message source option from the Create menu or by using the toolbar.

Message Response Source

Response Source in COMNET is a message generator that is used to send the message response (replies) after receiving the message. 

These sources are applicable to represent the client-server association, where a workstation sends a request to the server and the server sends back a response to the same workstation. 

In COMNET, it can be designed either from the toolbar or by selecting the Response source option from the Create menu.

WAN Cloud Model

WAN cloud provides a conceptual (theoretical) method of modeling WAN using router and ATM switch nodes and point-to-point links. 

The internal structure of the WAN cloud is defined using the Access Links and Virtual Circuits. 

In COMNET, it can be designed either from the toolbar or by selecting the Cloud option from the Create menu. 

The operation of the WAN cloud and subnetwork are similar.

Point-to-point (Access) Link

Access Link in COMNET is identified as having blue color as their underlying icon color. 

The major use of links is to complete the topology i.e. representing how the nodes are linked together. 

In COMNET, access links can be designed within the WAN cloud either from the toolbar or by choosing the Point-to-point link option from the Create menu. 

Each and every access link of the WAN cloud must be connected to an access point.

Virtual Circuit (VC)

Virtual circuits can be created only within the WAN cloud and the main purpose of VC is to connect the two access links within the WAN cloud. 

Single VC provides the one-way data flow direction. 

So for a two-way flow of data, two VCs should be joined in the opposite directions in a model. 

They are designed in COMNET either by picking the WAN Link or VC option from Create menu or by using the toolbar.