Packet-switched network having alternate virtual paths

Patent 5239537 Issued on August 24, 1993. Estimated Expiration Date:

October 17, 2011. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Packet-switched communications network with parallel virtual circuits for re-routing message packets
Patent #: 4884263
Issued on: 11/28/1989
Inventor: Suzuki

Multiple path routing mechanism for packet communications network
Patent #: 4905233
Issued on: 02/27/1990
Inventor: Cain, et al.

Dynamic shared facility system for private networks
Patent #: 4993014
Issued on: 02/12/1991
Inventor: Gordon

Automatic fault recovery in a packet network Patent #: 5016243
Issued on: 05/14/1991
Inventor: Fite, Jr.

Inventor

Sakauchi, Hideki

Assignee

NEC Corporation

Application

No. 776431 filed on 10/17/1991

US Classes:

370/218, Packet switching system or element340/2.23, Alternate routing370/395.61, Adapting constant bit rate (CBR) data (e.g., voice, or narrow band ISDN over ATM, or using AAL1)379/221.03, Failure (e.g., disaster, overload, blockage)379/221.04, Restoration (e.g., backup, recovery)714/4, Of network714/43Bus, I/O channel, or network path component fault

Examiners

Primary: Olms, Douglas W.
Assistant: Blum, Russell W.

Attorney, Agent or Firm

Foley & Lardner

International Class

H04J 003/14

Foreign Application Priority Data

1990-10-17 JP

Abstract

In a broadband ISDN system where each switching node is connected to each adjacent node by a transmission line having communication links and a service link, the switching node comprises a self-routing network for routing a cell from an input to an output of the network according to a virtual path identifier it contains. Static connections are established between communication links and the routing network by a digital cross-connect system. A virtual path memory stores data indicating link-to-link connections associated with normal virtual paths and link-to-link connections associated with alternate virtual paths. A fault detector is coupled to the communication links to detect a link failure. If a link failure occurs, a fault message is transmitted to adjacent switching nodes through service links, and data corresponding to the faulty link is retrieved from the memory in response to a fault message that is received from the fault detector or from an adjacent node. The cross-connect system is controlled in accordance with the retrieved data so that the route of the cells is switched from a normal virtual path to an alternate virtual path.