DESC:FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

Title: A NOVEL METHOD AND APPARATUS FOR FAULT TOLERANT REDUNDANT NETWORK

APPLICANT DETAILS:
(a) NAME: BHARAT ELECTRONICS LIMITED
(b) NATIONALITY: Indian
(c) ADDRESS: Outer Ring Road, Nagavara, Bangalore 560045, Karnataka, India

PREAMBLE TO THE DESCRIPTION:
The following specification (particularly) describes the nature of the invention (and the manner in which it is to be performed):

A NOVEL METHOD AND APPARATUS FOR FAULT TOLERANT REDUNDANT NETWORK

FIELD OF INVENTION:
The present invention relates a method and an apparatus for a fault tolerant redundant network.

BACKGROUND OF THE INVENTION:
The following background discussion includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication expressly or implicitly referenced is prior art.
Traditional IP based packet data networks work on MAC address-based forwarding of packets. To support the End-to-end requirements of data delivery various types of MAC addresses such as Unicast, Multicast and Broadcast are used.
A network switch (also called switching hub, bridging hub, officially MAC bridge) is a computer networking device that connects devices on a computer network by using packet switching to receive, process, and forward data to the destination device. Some switches can also process data at the network layer (layer 3) by additionally incorporating routing functionality. Such switches are commonly known as layer-3 switches or multilayer switches.
A switching loop occurs in computer networks when there is more than one Layer 2 (OSI model) path between two endpoints (e.g. multiple connections between two network switches or two ports on the same switch connected to each other). The loop creates broadcast storms as broadcasts and multicasts are forwarded by switches out every port, the switch or switches will repeatedly rebroadcast the broadcast messages flooding the network.
The Spanning Tree Protocol (STP) is a network protocol that builds a loop-free logical topology for Ethernet networks. The basic function of STP is to prevent traffic loops storm that results from them. Spanning tree also allows a network design to include backup links to provide fault tolerance if an active link fails by reconverging the network. During reconvergence packet drop happens.
The Parallel Redundancy Protocol (PRP) is a network protocol that provided high availability fault tolerant networks using packet duplication/ De-duplication and replicating the packets on two similar disjointed networks connected only at End Points/ Redundancy Boxes.
US 9,515,845 titled “Utility Communication Method And System” describes an exemplary method and system of the present disclosure use the Parallel Redundancy Protocol PRP (IEC 62439-3) for traffic duplication and redundant transport of the duplicated traffic in a single packet-switched wide-area communication network including a plurality of nodes interconnected via inter-node links in a meshed topology. The method involves identifying, between a send and receive node, two distinct communication paths with no link or node in common except for the send and receive node, and configuring the send and receive nodes to operate according to the Parallel Redundancy Protocol PRP. At any time during regular operation, and for any critical message to be trans mitted from the send to the receive node, two redundant packets can be generated, and each of the redundant packets is sent via one of the two communication paths, resulting in an increased availability of the communication network without incurring the cost of full network duplication.
US 8184527 title “Method For Conducting Redundancy Checks In A Chain Network” relates to a method for conducting redundancy checks in a chain network, wherein the two ends of the chain network are equipped with a first Switch and a second Switch respectively, and a port of the first or second Switch used for communicating with an external network is set to be blocked, so that when an link failure happens to any switch of the chain network, the two switches close to the link failure port sends control packets to the first and second switches respectively to forward the port that is originally blocking, thus making the network to return to normal state quickly.
EP 289631B1 titled “Data Redundancy in a Data Layered Architecture Network” relates to providing data redundancy in a Data Layered Architecture network.

US 2006/0080469 relates to a system and method for providing high availability for telecommunications and data communications by implementing a network bus architecture at a card level. The network bus architecture, which may be a combination of hardware, software, and APIs, replaces the conventional midplane/backplane as the system bus for PCI purposes. The system provides physical redundancy to the system by connecting ports of the various system cards using dual/ redundant ethernet switches.
Therefore, is there felt for a need for an invention which can provide a method and an apparatus for Fault Tolerant Redundant Network.

OBJECTIVES OF THE INVENTION:
The primary object of the present invention is to overcome the problem stated in the prior art.
Another object of the present invention is to provide a method and an apparatus for a fault tolerant redundant network.

SUMMARY OF THE INVENTION:
The present invention provides an apparatus for a fault tolerant redundant network comprising:
a) an element core switches, where the element core switches perform high speed low latency packet forwarding based on a user defined forwarding rules;
b) an access switch, where the access switch receives the packet form the element core switch is configured to provide duplication and de duplication of the packet; and
c) a trunk port (TP), where the trunk port is controlled by the access switch, where an access port (AP) is connected to the access switch and the trunk port (TP) is connected to the core switches to receive the packet;

wherein any packet received at the access port (AP) will be forwarded to the trunk port (TP) and any packet received at the trunk port (TP) will be forwarded to the access ports (AP), where trunk port (TP) to Trunk port (TP) packet transmission is barred.
In an embodiment, the element core switches, and the access switch connected forms a two-tier architecture with a core and an access layer, where the core layer has triple network redundancy with a full mesh architecture and the access layer has dual redundancy with a network element.
In an embodiment, the core switch comprises a summarization table and is updated periodically by the access switch, where if a packet is received at the trunk port (TP) and a destination is available on the summarization table the packet is forwarded to a specific access port (AP) else packet is dropped.
In an embodiment, the packet is received the at trunk port (TP) forwards the packet to all the available listening the access port (AP) based on the summarization table.
In an embodiment, the access switch has a data and the trunk port, the data port (DP) is connected to an end point and the trunk port (TP) is connected to the core switch.
In an embodiment, the access switch is updating the end points details in form of a summarization table to core switches periodically.
In an embodiment, the packet received at Data port (DP) is duplicated and forwarded on all the trunk port (TP) and the packet received at trunk ports (TP) is re-duplicated and forwarded on corresponding Data port (DP).
The present invention provides a method for a fault tolerant redundant network comprising steps of:
a) forwarding low latency packet based on a user defined forwarding rules by an element core switch;
b) performing duplication and de-duplication of the packet by an access switch it received from the element core switch; and
c) receiving the packet by a trunk port (TP) where trunk port (TP) is connected to the core switches to receive the packet;
wherein any packet received at the access port (AP) will be forwarded to the trunk port (TP) and any packet received at the trunk port (TP) will be forwarded to the access ports (AP), where trunk port (TP) to Trunk port (TP) packet transmission is barred.

DETAILED DESCRIPTION OF DRAWINGS:
To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of their scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings in which:
Fig. 1: illustrates a flowchart that depicts the Packet Processing Procedure in Core Layer.
Fig. 2: illustrates a flowchart that depicts the Packet Processing Procedure in Access Layer.

DETAILED DESCRIPTION:
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.
The terms “comprises”, “comprising”, “includes”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or method.
The present invention discloses a method which uses networking elements Core Switch, Access Switch, Client redundancy Adapter, End Points to provide redundancy and fault tolerance.
In an embodiment, the present invention provides an apparatus for a fault tolerant redundant network comprising:
a) an element core switches, where the element core switches perform high speed low latency packet forwarding based on a user defined forwarding rules;
b) an access switch, where the access switch receives the packet form the element core switch is configured to provide duplication and de duplication of the packet; and
c) a trunk port (TP), where the trunk port is controlled by the access switch, where an access port (AP) is connected to the access switch and the trunk port (TP) is connected to the core switches to receive the packet;
wherein any packet received at the access port (AP) will be forwarded to the trunk port (TP) and any packet received at the trunk port (TP) will be forwarded to the access ports (AP), where trunk port (TP) to Trunk port (TP) packet transmission is barred.
In an embodiment, the element core switches, and the access switch connected forms a two-tier architecture with a core and an access layer, where the core layer has triple network redundancy with a full mesh architecture and the access layer has dual redundancy with a network element.
In an embodiment, the core switch comprises a summarization table and is updated periodically by the access switch, where if a packet is received at the trunk port (TP) and a destination is available on the summarization table the packet is forwarded to a specific access port (AP) else packet is dropped.
In an embodiment, the packet is received the at trunk port (TP) forwards the packet to all the available listening the access port (AP) based on the summarization table.
In an embodiment, the access switch has a data and the trunk port, the data port (DP) is connected to an end point and the trunk port (TP) is connected to the core switch.
In an embodiment, the access switch is updating the end points details in form of a summarization table to core switches periodically.
In an embodiment, the packet received at Data port (DP) is duplicated and forwarded on all the trunk port (TP) and the packet received at trunk ports (TP) is re-duplicated and forwarded on corresponding Data port (DP).
In an embodiment, the present invention provides a method for a fault tolerant redundant network comprising steps of:
a) forwarding low latency packet based on a user defined forwarding rules by an element core switch;
b) performing duplication and de-duplication of the packet by an access switch it received from the element core switch; and
c) receiving the packet by a trunk port (TP) where trunk port (TP) is connected to the core switches to receive the packet;
wherein any packet received at the access port (AP) will be forwarded to the trunk port (TP) and any packet received at the trunk port (TP) will be forwarded to the access ports (AP), where trunk port (TP) to Trunk port (TP) packet transmission is barred.
Core Switches perform High speed Low Latency packet forwarding based on user defined forwarding rules. It provides a high bandwidth, fault tolerant network backbone for underlying network layers. It has the necessary control plane in a Linux based Real Time OS. The Core switches will be managed switch and controlled by web-based GUI application and CLI.
Access switches perform real-time switching in a deterministic manner, as well as provide the necessary control plane in a Linux based Real Time OS. The Access switches will be managed switch and controlled by web-based GUI application and CLI. It will provide packet duplication and de duplication.
End points may workstation with Ethernet Connections for Network Redundancy.
Network Diagram includes two tier architecture with Core and Access Layer. Core layer will have triple network redundancy with full mesh architecture. Access Layer will have Dual redundancy with network elements.
In an embodiment, the present disclosure envisages a method and an apparatus for achieving fault tolerance in the packet network in case of multiple link/ node failures. Zero network convergence time.
According to the method as disclosed herein, the network systems perform packet forwarding rules in case of Core Switch as per defined rules to mitigate broadcast traffic storm: Core switch having access and trunk port.
According to the method as disclosed herein, Access port (AP) will be connected to access switch and trunk port (TP) will be used to connect others core switches. It will provide triple level redundancy at core level.
According to the method as disclosed herein, any packet received at Access port (AP) will be forwarded to all trunk ports (TP).
According to the method as disclosed herein, any packet received at trunk port (TP) will be forwarded to all Access ports (AP).
According to the method as disclosed herein, trunk port (TP) to Trunk port (TP) packet transmission is barred. Packet will not be forwarded from Trunk port (TP) to another Trunk port (TP) in the same core switch.
According to the method as disclosed herein, no dynamic reconfiguration is allowed. It is a hardwired network, and no routing table will be exchanged among the core switches.
According to the method as disclosed herein, the core switch will have a summarization table and it will be updated periodically by the Access Switch.
According to the method as disclosed herein, if a packet is received at Trunk port (TP) and destination is available on summarization table packet will be forward to that particular Access port (AP) else packet will be dropped.
According to the method as disclosed herein, at Trunk port (TP), if any broadcast (e.g. ARP) packet is received, then it will be forwarded to all the available Access ports (AP).
According to the method as disclosed herein, at Trunk port (TP), if any multicast packet is received from another at Trunk port (TP), then it will be forwarded to all the available listening Access port (AP) based on the summarization table.
In an embodiment, network systems perform packet de-duplication and forward single packet to the end points as per packet forwarding rules for Access Switch.
According to the method as disclosed herein, the access switch has data and trunk port. Data port (DP) will be connected to end points (Workstation, CRA, PC etc.) and trunk port (TP) will be connected core switch. It will provide dual level redundancy at Access level.
According to the method as disclosed herein, access switch will be updating the end points details in form of summarization table to Core Switches periodically.
According to the method as disclosed herein, any packet received at Data port (DP) will be duplicated and forwarded on all the trunk port (TP).
According to the method as disclosed herein, any packet received at trunk ports (TP) will be re-duplicated and forwarded on corresponding Data port (DP).
According to the method as disclosed herein, access switch operation: Access switch learns source address from packet on end term parts.
According to the method as disclosed herein, broadcast traffic (ARP) received on end points ports Forward packet to all end ports except the received port and also on the trunk port (TP).
According to the method as disclosed herein, based on Search DMAC of packet in MAC table, unicast packet received on Data port (DP), traffic will be forwarded to Data Port (If match found) and also to trunk port (TP).
According to the method as disclosed herein, Broadcast packet received on trunk port (TP): Check whether packet is duplicate, if duplicate, Drop the packet. If not duplicate, search SMAC of packet in mac table, Forward the packet to all end points ports except the output.
According to the method as disclosed herein, Unicast packet received on trunk port (TP): If duplicate packet, drop the packet. If not duplicate packet, search DMAC of packet in MAC table. Forward the packet to the Data Port.
In an embodiment, according to the packet forwarding rules for Client Redundant adapter (CRA), data from single Ethernet port is taken and duplicated to 2 port Ethernet in transmit side and receive side reduplication will be done.
Thus, the present disclosure focuses on a method to provide multipath between two end systems and send ingress traffic to all the available paths simultaneously, to provide uninterrupted data communication even in case of multiple fault occurrences in the network simultaneously. The forwarding nodes ensure no broadcast storm in the network. The network devices will remove the duplicate packets and deliver a single copy to the end point.
Thus, at least some of the technical advantages provided by the present disclosure include: avoiding the loops between the network devices at different layers, network recovery even in event on multiple link/ node failures, redundant network recovery with no packet loss, Core Layer of Network will work as rules based packet forwarding and Access Layer will do the packet duplication and de duplication.
The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the invention.
,CLAIMS:We Claim:

1. An apparatus for a fault tolerant redundant network comprising:
a) an element core switches, where the element core switches perform high speed low latency packet forwarding based on a user defined forwarding rules;
b) an access switch, where the access switch receives the packet form the element core switch is configured to provide duplication and de duplication of the packet; and
c) a trunk port (TP), where the trunk port is controlled by the access switch, where an access port (AP) is connected to the access switch and the trunk port (TP) is connected to the core switches to receive the packet;
wherein any packet received at the access port (AP) will be forwarded to the trunk port (TP) and any packet received at the trunk port (TP) will be forwarded to the access ports (AP), where trunk port (TP) to Trunk port (TP) packet transmission is barred.
2. The apparatus for a fault tolerant redundant network as claimed in claim 1, wherein the element core switches, and the access switch connected forms a two-tier architecture with a core and an access layer, where the core layer has triple network redundancy with a full mesh architecture and the access layer has dual redundancy with a network element.
3. The apparatus for a fault tolerant redundant network as claimed in claim 1, wherein the core switch comprises a summarization table and is updated periodically by the access switch, where if a packet is received at the trunk port (TP) and a destination is available on the summarization table the packet is forwarded to a specific access port (AP) else packet is dropped.
4. The apparatus for a fault tolerant redundant network as claimed in claim 1, wherein when packet is received the at trunk port (TP) forwards the packet to all the available listening the access port (AP) based on the summarization table.
5. The apparatus for a fault tolerant redundant network as claimed in claim 1, wherein the access switch has a data and the trunk port, the data port (DP) is connected to an end point and the trunk port (TP) is connected to the core switch.
6. The apparatus for a fault tolerant redundant network as claimed in claim 1, wherein the access switch is updating the end points details in form of a summarization table to core switches periodically.
7. The apparatus for a fault tolerant redundant network as claimed in claim 1, wherein the packet received at Data port (DP) is duplicated and forwarded on all the trunk port (TP) and the packet received at trunk ports (TP) is re-duplicated and forwarded on corresponding Data port (DP).
8. A method for a fault tolerant redundant network comprising steps of:
a) forwarding low latency packet based on a user defined forwarding rules by an element core switch;
b) performing duplication and de-duplication of the packet by an access switch it received from the element core switch; and
c) receiving the packet by a trunk port (TP) where trunk port (TP) is connected to the core switches to receive the packet;
wherein any packet received at the access port (AP) will be forwarded to the trunk port (TP) and any packet received at the trunk port (TP) will be forwarded to the access ports (AP), where trunk port (TP) to Trunk port (TP) packet transmission is barred.