As specified earlier, nobody truly owns the Internet, although it is maintained through a group of volunteers interested in supporting this mode of information interchange. Central of this control is the Internet service provider (ISP) that is significant component in the Internet system. Each ISP is a network of routers & communication links. The distinct ISPs provide a variety of distinct types of network access to the end systems, by including fifty six Kbps dial-up modem access, residential broadband access like DSL or cable modem, high-speed LAN access, and wireless access. ISPs also give Internet access to the content providers, connecting Web sites to the Internet directly. To let communication among Internet users and to let users to access worldwide Internet content, these all lower-tier ISPs are interconnected through national & international upper-tier ISPs, as Sprint. An upper-tier ISP contains high- speed routers interconnected along with high-speed fiber-optic links. Every ISP network, whether upper-tier or lower-tier, is managed independently, runs IP protocol and conforms to certain naming and address conventions.