What is Difference between Public Network and Private Network

Public vs. Private Networks - A Complete Guide

A public network, like the public telephone system and the Internet, is a large collection of unrelated peers who exchange information almost freely with each other.

The people who access the public network do not need to have any commonality and generally communicate with only a small fraction of potential users.

A private network is composed of computers owned by a single corporation that shares information specifically and solely with each other.

The owners are assured that those are the only computers using the network, and others will only see that information that is among the using group members. The typical corporate local area network (LAN) or wide area network (WAN) are examples of private networks.

The line between private and public is usually thought to be a gateway router, where a company will construct a firewall to sway intruders from the public network out of their private network or keep internal users from perusing the public network.

Firewalls are computer hardware, software, or both used to restrict and monitor the usage of a computer or network. A gateway router is a unique type of device or computer that attaches to two or more networks and directs packets from one network to the other.

The function of gateways is to route or direct packets to other gateways for faster delivery to their final destination directly across one physical network. The packet is the smallest unit of data transmitted over a network or the Internet.

Packets are numbered by the sender and routed independently through the Internet to the recipient. The route of each packet is determined by the load and availability of any given segment of the net.

Work, thereby relieving traffic overloads on busy networks. The packets are then reassembled in order by the receiving computer. Each pack contains from 40 to 32,000 bytes of information.

Mobility

Mobility of personnel has changed the way that companies have organized their LANS. From separate, isolated branch offices, with their own email, naming schemes, and favorite network protocols (generally incompatible with other office setups), companies found that it was profitable to interconnect.

Traditionally, this was done with 800- numbers and leased lines. Both are billed flat rate plus mileage and represent significant costs. The cost is prohibitive when a company has multiple offices across the country or overseas.

Private networks typically have difficulty supporting traveling executives, salespeople, and other personnel. Distributed and remote computing is now a well-established practice.

Traveling employees and telecommuters access their corporate network by dialing into remote access servers to download e-mail, share files with other employees, and use the network resources (printer, fax, and file servers) as if they were directly on the LAN.

Remote computing technology has existed for some time and has proven reliable from most locations. Again, the problem is rising telecommunications costs.

Virtual Private Network Technology

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Virtual private network technology represents a crossover from public to private networks. VPNs allow the creation of a secure, private network over a public network such as the Internet. This is done through IPSec, encryption, packet tunneling, and firewalls.

VPN dramatically reduces annual telecommunications expenses by advantageous use of the real timely low-cost Internet connectivity. The leased-line costs are skirted by using the Internet as a WAN. VPN technology appears to be cost-effective for both large and small companies.

The government is employing VPN technology in many DoD sites throughout the country.

A VPN is a way to simulate a private network over a public network (Internet). A VPN connection is said to be virtual because it depends mostly on the use of virtual connections, I. e, temporary connections that have zero physical presence.

But comprises packets routed over numerous machines on the Internet. A temporary basis Secure virtual connections are created between two machines, a machine, and a network, or two networks.

Tunneling is one example of a VPN. A tunnel is established between the user’s machine and a server at the corporate site.

Tunnels have the additional advantage over a LAN connection of easier filtering since it is done at a single point and the boxes actually route the packets such that each packet takes the optimal route to the intended LAN.

6 Advantages of using VPN

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Besides lower costs, VPN technology offers other clear advantages

Home office employees can securely connect to the home network by dialing in to a local ISP/national network such as AOL or CompuServe.
Employees seconded at customer sites may connect to their corporate network via the customer’s Internet connections and tunnel through the customer’s private network to the Internet and into their corporate LAN.
Customers and channel partners can be granted extranet access to certain restricted areas of the company's private network. The extranet is an extension of the private network bounds. It is accomplished by equipping the partner or customer with VPN client software and creating the appropriate account in the database. This works with the de facto standard of TCP/IP traffic, and the partner is able to build a secure link into a selected area of the company’s network, with user-specific privileges.
Intranet access to sensitive corporate data can be accorded to restricted employees or departments by establishing a subnetwork area in the company LAN.
VPN savings grow with the network. More offices lead to efficient and effective service delivery, that is to say, the intranet brings a degree of flexibility just by adding more access. There is an ease of management because it is no longer necessary to manage PVC lines between offices. Global expansion is ideal for international connectivity.
VPNs are platform-independent. The Internet Protocol can run over any communications infrastructure.