US 6,606,323 B1 · Mobile MAC protocol for LAN-coupled devices interconnected by an ATM wide area network

Abstract

Enhanced performance of a WAN is achieved by allowing devices to move from LAN to LAN and have the move be transparent to end user applications. This is accomplished by allowing devices to move, with no action being taken in response to a move. Instead, notice is taken of the LANE Emulation Client (LEC) address at which a device can be reached when the device that moved chooses to communicate with some other device. In such a device initiates communication, a table is updated in a LAN Emulation Server (LES), which is an entity maintained by the WAN that interconnects a number of LECs. A similar table is maintained in each LEC, and the table of each LEC is updated whenever a connection is made between one of its devices and some other device. At times, of course, a LEC would have an incorrect address of a sought destination device. In such a case, the LEC sends a query to the LES, and the LES provides what the LES believes to be the correct LEC address. When the LES cannot resolve an address, a message is broadcast to the LES entities of other “emulated LANs,” or ELANs, which contains their own LES entities, and those LES entities have an opportunity to provide the correct address.

Claims24

Dependent claims

A Wide Area Network (WAN) arrangement including a connection fabric and terminal points for accessing said connection fabric, where said terminal points are adapted for connecting LAN Emulation Clients (LECs), where a LEC of said LECs is coupled to an associated LAN that allows at least one device coupled to said LAN to communicate with to other devices coupled to said LAN or to communicate via said connection fabric to a device coupled to a LAN associated with another LEC, said WAN further comprising:

a LAN Emulation Server (LES) with
memory that maintains binding information about devices coupled to LANs of LECs, where the binding information about a device associates a unique address that identifies said device with an address of the LEC that is associated with the LAN to which said device is coupled, and
a controller for updating said binding information of said device in response to a signal sent by a LEC whenever the LEC recognizes that said device coupled to its LAN is not known to the LEC to be coupled to its LAN.

In a Wide Area Network (WAN) arrangement including a connection fabric with terminal points for accessing said connection fabric, and LAN Emulation Clients (LECs) connected to said terminal points, where a LEC includes a LAN that allows at least one device coupled to said LAN to communicate with to other devices coupled to said LAN or to communicate via said connection fabric to a device coupled to a LAN of another LEC, a method comprising:

a first step of a first device connected to a first LAN of a first LEC, sending a message to said first LEC, seeking the establishment of communication with a second device;
a second step, of said first LEC searching a local memory for information about said first device;
a third step, when a record is not found in the course of said searching of said local memory that reflects the fact that said first device is coupled to said first LAN, of said first LEC sending a first message to a LES, informing said LES of a binding between said first device and said first LEC;
a fourth step, of said first LEC searching a local memory for information about said second device;
a fifth step, when said second device is found to be coupled to said first LAN in the course of said searching of said local memory, of said first LEC sending a second message to said first device, informing said first device that intra-LAN communication is to be established with said second device;
a sixth step, when said second device is not found to be coupled to said first LAN in the course of said searching of said local memory but is found to be coupled to a LAN of a second LEC, of sending a third message to said second LEC requesting said second LEC to inform said second device that inter-LAN, intra-WAN, communication is to be established with said second device;
and
a seventh step, when said second device is not found in the course of said searching of said local memory, of sending a fourth message to said LES, requesting said LES to inform said first LEC of a LEC address of said second LEC that has said second device connected to a LAN that is associated with said second LEC.

5 more elements

Dependencies are inferred from the claim text.

Mobile MAC protocol for LAN-coupled devices interconnected by an ATM wide area network

Life of this patent

Mobile MAC protocol for LAN-coupled devices interconnected by an ATM wide area network

Life of this patent

Abstract

Claims24