Dial-in virtual private networks using layer 3 tunneling

Corporate networks are making increasing use of the Internet to connect geographically diverse site networks rather than developing their own "leased line" WAN networks. Similarly, they are outsourcing their dial-in capability by replacing their banks of modems with a single connection to a service provider with geographically diverse Points Of Presence (POPs). In this way, users in a corporate network can dial local (or toll free) numbers which will be routed to the nearest POP; then, be connected to their corporate network using some form of tunneling. There are two common forms of tunneling in use in the Internet today: Layer 2 (using L2TP, for example) and Layer 3 (using Mobile IP, for example). The paper presents a design for a Layer 3 Dial-in Virtual Private Network Service (DVS), based on Mobile IP. This design has been implemented by Bay Networks.