Mobile networking method and apparatus

• US 5,572,528 A
• Filed: 03/20/1995
• Issued: 11/05/1996
• Est. Priority Date: 03/20/1995
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Novell Incorporated (Open Text Corporation)
• Inventors: Shuen, Pauline
• Primary Examiner(s): HSU, ALPUS
• Application Number:
  US08/408,230
• Time in Patent Office: 596 Days
• Field of Search: 370/54, 370/58.1, 370/58.2, 370/58.3, 370/60, 370/60.1, 370/61, 370/79, 370/85.6, 370/85.13, 370/85.14, 370/94.1, 370/94.2, 370/94.3, 370/95.1, 395/200, 395/325, 395/500, 395/725, 395/800, 340/825.5, 340/825.51
• US Class Current: 370/402
• CPC Class Codes: H04L 12/4604 LAN interconnection over a backbone network, e.g. Internet, Frame Relay

Abstract

An internetwork including a plurality of local area networks may include wireless and hard-wired local area networks. The internetwork may also include wide area network links between routers. The system includes routers between networks, which may be bridged networks. Certain routers are configured as home routers. Home routers bind two addresses for each mobile node on a given network when that node logs-in with a home router. Mobile nodes log-in with a home router that assigns a virtual address that does not change throughout a session. Each time, a mobile node roams to another network across a router boundary, the virtual address remains the same and all packets directed to the mobile node are received by the home router which advertises that it can reach the mobile node. As the mobile node roams, it reports back to the home router a local address to which the home router forwards all packets directed originally by correspondent nodes to the virtual address. Mobile nodes may log-in to a router many hops removed from a local area network of the situs. Mobile nodes may also roam across wide area links. The system is transparent to a user.

Claims

1. For interconnecting devices in an internetwork comprising multiple networks, a system comprising:

a router for receiving, transmitting, and directing data over a plurality of networks, and for providing a first signal uniquely corresponding to a network of the plurality of networks;

a plurality of nodes associated with the network and positioned to communicate data with the router;

a carrier structure operably positioned between the router and the plurality of nodes for transmitting and receiving data between the router and the plurality of nodes;

a network card operably associated with a node of the plurality of nodes for transmitting and receiving data between the node and the carrier structure, and for providing to the node a second signal unique to the network card;

the node operably connected to the router to automatically receive the first signal and the second signal and to form, in accordance with the first and second signals, a local address corresponding to the node;

a home router programmed to automatically maintain session level connectivity between the node and the home router after the node is disconnected and reconnected to the carrier structure.

2. The system of claim 1 wherein the node further comprises a processor for providing the local address and wherein the local address comprises data corresponding to the first and second signals.

3. The system of claim 1 wherein the home router is operably connected to the internetwork to provide a third signal corresponding to a virtual network.

4. The system of claim 3 wherein the home router further comprises a home processor for providing a virtual address corresponding to the node.

5. The system of claim 4 wherein the home processor is programmed to automatically provide to the router the virtual address.

6. The home router of claim 4 wherein the home processor is programmed to create the virtual address to comprise the third signal and the second signal.

7. The system of claim 1 wherein the node further comprises a node processor programmed to provide the local address comprising the first and second signals.

8. The system of claim 1 wherein the home router comprises a memory device for automatically storing the local address and a virtual address.

9. The system of claim 8 further comprising a correspondent node operably connected to the internetwork, and wherein the home router is programmable to unbind the virtual address from incoming data received from the correspondent node addressed to the virtual address, to bind to the incoming data the local address, and to forward the incoming data to the node.

10. The system of claim 8 wherein the home router is further provided with a memory device for binding the local address to the virtual address.

11. The system of claim 1 wherein the home router including a first memory location for storing the virtual network address and a second memory location for storing the local network address simultaneously.

12. The system of claim 1 wherein the node comprises a computer connectable to the network card and wherein the network card further comprises a network connector for selectively connecting the network card to communicate with the network, and for removing the network card from communication with the network.

13. The system of claim 12 further comprising a network server operably connected to the internetwork to communicate with the node the connection status corresponding to whether the computer is connected to the network, and wherein the home router is programmed to provide a virtual response to the network server when the computer is not connected to the network, the virtual response being indistinguishable by the network server from a real response provided by the computer when the computer is connected to the network.

14. The system of claim 13 wherein the computer further comprises a node processor for running an application thereon, wherein, while the application is running, the computer is selectively, physically removable from communication with the network by a process selected from moving out of range of a wireless carrier structure, de-activation of the node processor by the application, and physical disconnection of the computer from the network, and wherein the node processor is programmed to provide an instruction to prevent crashing of the application whenever the application requires a connection of the computer to the network and the computer is removed from communication with the network.

15. The system of claim 12 wherein the computer further comprises a node processor for running an application thereon, wherein the computer is selectively removable from the network while the application is running, and wherein the node processor is programmed to provide an instruction to prevent crashing of the application whenever the application requires a connection of the computer to the network and the computer is unconnected to the network.

16. The system of claim 15 wherein the node processor is programmed to provide a suspend instruction effective to suspend operation of the application whenever the application requires a connection of the computer to the network, and the network card is not connected to the computer.

17. The system of claim 12 wherein the computer further comprises a node processor for running an application thereon, the network card is removable from the computer while the application is running, and the node processor is programmed to provide an instruction to prevent crashing of the application whenever the application requires a connection of the computer to the network and the network card is absent from the computer.

18. The system of claim 17 further comprising a second network card selectively connectable between the computer and the network, and wherein the node processor is programmed to forward a resume instruction to the application to resume operation whenever the application requires connection of the computer to the network, the second network card has replaced the network card in the computer, and the computer is connected to the network.

19. The system of claim 17 further comprising a second network card selectively connectable and removable between the computer and a second network of the multiple networks comprising the internetwork, and wherein the node processor is programmed to provide a resume instruction to effect a resumption of operation by the application when the second network card has replaced the network card in the computer, and the second network card is connected to the second network.

20. An apparatus for providing automatic addressing and roaming across an internetwork, the apparatus comprising:

a first primary network;

a router connectable to the first primary network;

at least one second primary network operably connectable at a first location to the router to extend away from the first primary network;

at least one second router connectable to a second location on the second primary network, the second location being spaced away from the first location and spaced away from the first primary network;

a third primary network operably connected to a second router of the at least one second router to be extendible away from the second router and from a second network of the at least one second primary network;

a mobile node connectable to the first primary network to transmit and receive data, and to automatically provide a local address uniquely associated with the mobile node and the first primary network; and

a home router operably connected to the internetwork to provide a virtual network address uniquely corresponding to the mobile node to forward to the mobile node at the local address incoming data directed to the virtual address, and to provide continuous session level connectivity of the mobile node to the internetwork during roaming of the mobile node.

21. An apparatus for connecting a node to an internetwork, the apparatus comprising:

a network connected to an internetwork;

a node comprising a processor effective to create a local address identifying the node in the network, and for communicating the address to the internetwork;

a home router connected to the internetwork to communicate with the node, to provide a virtual address associated with the node, the node remaining continuously addressable at the virtual address during roaming by the node between the local address and a new local address, for maintaining session level connectivity of the node.

22. The apparatus of claim 21 wherein the home router comprises a processor for providing the virtual address, and wherein the virtual address corresponds to a virtual network and a virtual node number, the processor forwarding to the local address packets directed to the virtual address.

23. A method for addressing a node connected to an internetwork comprising:

connecting a node to a network in the internetwork in a session;

acquiring a network number associated with the network;

acquiring a number associated with the node;

creating a local address uniquely associated with the node in the network;

logging the node in to a home router connected to the internetwork;

providing to the home router the local address;

providing from the home router to the node a virtual address;

binding the local address to the virtual address in a memory device of the home router;

providing to another node connected to the internetwork the virtual address corresponding to the node;

forwarding to the local address packets directed to the virtual address during the session;

disconnecting the node from the network, and connecting the node to a new network in the internetwork, while maintaining session level connectivity of the node.

24. The method of claim 23 wherein connecting the node to the new network further comprises:

acquiring a new network number associated with the new network;

acquiring a new node number associated with the node;

providing to the home router the new local address;

forwarding to the new local address packets directed to the virtual address.