Router for establishing connection among a plurality of LANs

• US 5,519,705 A
• Filed: 01/20/1995
• Issued: 05/21/1996
• Est. Priority Date: 01/26/1994
• Status: Expired due to Fees

• Current Assignee: Furukawa Electric Company Limited
• Original Assignee: Furukawa Electric Company Limited
• Inventors: Fukutomi, Shoji
• Primary Examiner(s): Kizou, Hassan
• Application Number:
  US08/375,640
• Time in Patent Office: 487 Days
• Field of Search: 370/60, 370/60.1, 370/85.13, 370/85.14, 370/94.1, 370/94.2, 370/94.3, 370/97, 379/220
• US Class Current: 370/402
• CPC Class Codes: H04L 12/4604 LAN interconnection over a backbone network, e.g. Internet, Frame Relay

Abstract

To transmit a data frame between different LANs, a connection is established, through a switching network, between routers respectively connected to the LAN'"'"'s. The data frame is then forwarded from a source router to a destination router through the established connection. When a data frame is received from a LAN-side transmitter-receiver section in the source router, a network layer section samples from a routing table, according to the destination address included in the data frame, an address of the destination router, and samples a telephone number index corresponding to this gateway from a destination number table. A communication network line control section samples a telephone number corresponding to this index from a telephone number table, places a call in accordance with this telephone number, thereby connecting lines of the communication network, and automatically relays the frame from a LAN-side transmitter-receiver section to a destination LAN through the lines.

Claims

1. A router for establishing connection among a plurality of LANs (Local Area Networks) via a data communication network to relay network layer data, each of said plurality of LANs including at least one said router, each said router comprising:

first storage means including a routing table for storing gateway addresses corresponding to destination LAN addresses, and a destination number table for storing indexes corresponding to the gateway addresses;

second storage means for storing numbers corresponding to the indexes;

sampling means for, upon receiving network layer data to be relayed to a destination LAN, fetching from the routing table a gateway address corresponding to a destination LAN address included in the received network layer data, and for fetching from the destination number table an index corresponding to the fetched gateway address; and

line control means for fetching from said second storage means a number corresponding to the index fetched by said sampling means, and for establishing, in accordance with the fetched number, a connection to a router of the destination LAN via the communication network.

2. The router according to claim 1, wherein each of the numbers stored in said second storage means comprises a telephone number.