International Journal of Scientific Research Engineering &Technology (IJSRET)
Today whole world is connected via internet for worldwide communication. Public networks are used to give network connectivity and different ISP (Internet Service Provider) companies are working at this network. It is not possible to send all data over public networks; some confidential data required Private Network, Encryption, User Authentication, Quality of Service and more security for protection. To make a private network for long distance is not possible for every company because it is very costly and difficult. All companies use public network, which is provided by ISP companies.VPN, is the best solution to protect the authors' confidential data and make a private network through public networks on reduced cost, so they can replace leased-line or Frame Relay services by VPN.