Computer system and method of communication between modules within computer system

• US 7,844,730 B2
• Filed: 02/04/2002
• Issued: 11/30/2010
• Est. Priority Date: 02/05/2001
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Kawaguchi, Shinichi
• Primary Examiner(s): Lee; Philip C
• Application Number:
  US10/061,242
• Publication Number:
  US 20020107980A1
• Time in Patent Office: 3,221 Days
• Field of Search: 709/238, 709/239, 714/4, 714/776
• US Class Current: 709/238
• CPC Class Codes: G06F 11/0751 Error or fault detection not based on redundancy power supply failures G06F1/30; network fault management H04L41/06
• CPC Class Codes: G06F 11/2007 using redundant communication media
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 45/24 Multipath

Abstract

A computer system comprising a plurality of modules that transfer data in packets mutually, whose major feature is that each of the modules comprises an output controlling part for sending out a packet to transmit to the destination via each of a plurality of communication paths, and an input controlling part for receiving packets transmitted from a plurality of communication paths, identifying the identical packets transmitted from different communication paths, and capturing transmit data properly, wherein the input controlling part stores information for use for identifying the captured packets, identifies whether the packet received has already been captured or not, and newly captures a packet if the packet received is yet to be captured, and discards a packet if the packet received has already been captured.

Claims

1. A computer system that transfers data in packets mutually between a plurality of modules, comprising:

a first module and a second module which are connected by at least two communication paths, said first and second modules transmitting and receiving packets via the communication paths,

wherein the first module duplicates a packet to be transmitted into a plurality of duplicate packets and transmits each of said plurality of duplicate packets of the packet to be transmitted to the second module by a different one of the communication paths,

wherein the second module comprises a packet loss detection circuit and error detection circuit, which respectively check each of said plurality of duplicate packets received at the second module by the different one of the communication paths for packet loss and error,

wherein the second module further comprises a packet selector circuit that determines which of the plurality of duplicate packets arrives first in time at the second module and selects a first received packet among the plurality of duplicate packets, the first received packet being determined as the duplicate packet arriving first in time from the first module, said packet selector circuit discarding the duplicate packets not arriving first in time after the packet loss detection circuit and error detection circuit check each of the plurality of duplicate packets for packet loss and error,

wherein the packet loss detection circuit and error detection circuit of the second module disconnect one of the communication paths if packet loss or transmission error are detected in the plurality of duplicate packets received via the one of the communication paths and checked by the packet loss detection circuit and error detection circuit prior to being discarded by the packet selector circuit such that the disconnected one of the communication paths is not used to transmit the packets from the first module to the second module.

2. The computer system as set forth in claim 1,

wherein each of the first and second modules comprises

an output controlling part for duplicating the packet to be transmitted and outputting said plurality of duplicate packets on the at least two communication paths, and

an input controlling part for identifying said plurality of duplicate packets that have been received from the at least two communication paths and selecting the first received packet only.

3. The computer system as set forth in claim 1, wherein said first and second modules comprises

a CPU module and an I/O module that transfer data in packets mutually.

4. The computer system as set forth in claim 2, wherein said output controlling part comprises

a means for assigning identification information to the packet to be transmitted for identifying said packet to be transmitted uniquely, and a means for duplicating said packet with said identification information and outputting said plurality of duplicate packets, and

said input controlling part comprising

a selecting means for identifying said identification information of the plurality of duplicate packets which are received, selecting the first received packet among said plurality of duplicate packets to which a same identification information has been, assigned, and discarding any packet of said plurality of duplicate packets which is not first received.

5. The computer system as set forth in claim 1,

wherein a switching module is provided between said first and second modules for performing switching of the at least two communication paths.

6. The computer system as set forth in claim 1 , wherein

said first and second modules are connected with one another via a communication network.

7. The computer system as set forth in claim 1, wherein at least the first and second modules are connected directly via the communication paths on a one-to-one basis.

8. A communication method that transfers data in packets mutually between a plurality of modules within a computer system, comprising the steps of:

duplicating, at a transmitting module, a packet to be transmitted into a plurality of duplicate packets and transmitting each of said plurality of duplicate packets of the packet to be transmitted to a receiving module by a different communication path,

checking, at the receiving module, each of said plurality of duplicate packets received at the receiving module by the different communication paths for packet loss and error,

determining, at the receiving module, which of the plurality of duplicate packets arrives first in time at the receiving module,

selecting, at the receiving module, a first received packet among the plurality of duplicate packets, the first received packet being determined as the duplicate packet arriving first in time from the transmitting module,

discarding the duplicate packets not arriving first in time after each of the plurality of duplicate packets have been checked for packet loss and error, and

disconnecting one of the different communication paths if packet loss or transmission error are detected in checking the plurality of duplicate packets received via the one of the different communication paths for packet loss and error prior to being discarded such that the disconnected one of the different communication paths is not used to transmit the packets from the transmitting module to the receiving module.

9. The communication method as set forth in claim 8, wherein

said selecting comprises

identifying said plurality of duplicate packets which are received and selecting the first received packet only.

10. The communication method as set forth in claim 8, wherein

said duplicating and transmitting comprises

assigning identification information to the packet to be transmitted for identifying said packet to be transmitted uniquely,

duplicating said packet to be transmitted with said identification information and outputting said plurality of duplicate packets on at least two communication paths, and

said selecting comprises identifying said identification information of the plurality of duplicate packets which are received, selecting the first received packet among said plurality of duplicate packets to which a same identification information has been assigned, and discarding any packet of said plurality of duplicate packets which is not first received.

11. A receiving module that receives data transmitted in packets via a plurality of communication paths, comprising:

an input controlling part that receives a plurality of duplicate packets, which were duplicated by a transmitting module and each of said duplicate packets transmitted by a different one of the communication paths connecting the transmitting module to the input controlling part of the receiving module,

a packet loss detection circuit and error detection circuit, which respectively check each of said plurality of duplicate packets received at the input controlling part of the receiving module by the one of the different communication paths for packet loss and error, and

a packet selector circuit that determines which of the plurality of duplicate packets arrives first in time at the receiving module and selects a first received packet among the plurality of duplicate packets, the first received packet being determined as the duplicate packet arriving first in time from the transmitting module, said packet selector circuit discarding the duplicate packets not arriving first in time after the packet loss detection circuit and error detection circuit check each of the plurality of duplicate packets for packet loss and error,

wherein the packet loss detection circuit and error detection circuit disconnect one of the communication paths if packet loss or transmission error are detected in the plurality of duplicate packets received via the one of the communication paths and

checked by the packet loss detection circuit and error detection circuit prior to being discarded by the packet selector circuit such that the disconnected one of the communication paths is not used to transmit the packets from the transmitting module to the receiving module.