CN109327377B

CN109327377B - Wide area industrial network interconnection method based on software definition

Info

Publication number: CN109327377B
Application number: CN201811426726.6A
Authority: CN
Inventors: 高明; 王伟明
Original assignee: Zhejiang Gongshang University
Current assignee: Zhejiang Zhonghong Internet Technology Co ltd
Priority date: 2018-11-27
Filing date: 2018-11-27
Publication date: 2021-06-01
Anticipated expiration: 2038-11-27
Also published as: CN109327377A

Abstract

The invention discloses a software definition-based wide area industrial network interconnection method. On one hand, the interconnection of industrial networks is realized based on an SDN networking mode, namely the integration of a factory network and the Internet; on the other hand, the converged network can provide similar connection-oriented real-time transmission capability. The integration of factory network and internet is to generate independent network plane (logic network) for service cooperation between factories in public network, and to flexibly and quickly customize QOS such as bandwidth and time delay.

Description

Wide area industrial network interconnection method based on software definition

Technical Field

The invention belongs to the technical field of network communication, and particularly relates to a software-definition-based wide area industrial network interconnection method.

Background

At present, the integration of new generation scientific technologies such as artificial intelligence, big data, cloud computing and other emerging technologies with the traditional network is accelerated, a new technological revolution of vigorous development and a production mode and a business mode which are continuously emerged enable industrial internet to be developed, research and exploration on the industrial internet are also developed at once at home and abroad, and the development of an industrial system towards intellectualization is promoted. The industrial internet is a convergence of technologies in key communication fields such as an industrial system and the internet, so that people still have a little understanding and limitation on the industrial internet at present, and the development path and the evolution process of the industrial internet are still quite long.

The core of the industrial internet is data-driven intelligence formed based on comprehensive interconnection, and network, data and security are common foundation and support for industrial and internet perspective applications. At present, more and more enterprises adopt internet equipment in the production process, and an industrial information network is moving from a local area network in a factory to an internet outside the factory, namely the popular industrial internet concept at present. In the industrial internet system structure, the 'network' is the basis of industrial system interconnection and data transmission and exchange and is composed of network interconnection, identification analysis and application support. It is first emphasized that, due to the limitation of the "best effort" packet switching mode, the conventional IP internet has genetic defects in Quality of service (QOS) and real-time transmission, and cannot be directly used for industrial network interconnection, so that a new network technology needs to be researched to meet the requirements of the industrial internet.

As for the network interconnection problem in the industrial internet, the problems of network connection and transmission delay become more and more prominent, and even one millisecond of signal delay between devices in the industrial field causes serious damage to the production line and causes loss which is difficult to estimate for enterprises, so that the speed, real-time performance and certainty of communication are very important for the industrial internet of today. The research on the industrial internet in the early days is mainly focused on an intelligent manufacturing application layer and an application layer of physical fusion of industrial information, and the research on the industrial internet itself is far from enough.

The main goal of industrial internetworks is to not only define a dynamically configurable infrastructure, but also to provide interoperability of different applications on a shared communication infrastructure. Needless to say, this will involve more communication technologies, the association of products, machines and operators will be greater and greater, and the industrial network will face more and more heterogeneity. Time Sensitive Network (TSN) and Software Defined Network (SDN) methods are mainly used to design a standard that can be commonly used in different applications, and applications in industrial control mainly include some videos, audios, controls on machines, and the like.

The SDN framework separates a data plane and a control plane of a network, the controller has a global view angle of the network, the current global state of the network and the use condition of resources can be obtained at any time, in addition, the SDN has the advantages of openness and programmability, and flexible control strategies can be formulated according to network information collected in the controller and equipment in the network can be dynamically configured. For different types of data flows, an administrator in the SDN network adopts different coping strategies to perform corresponding control, so that fine-grained management control on each flow can be achieved. QOS technology can obviously take advantage of all of the above SDN features to efficiently meet the ever increasing QOS requirements in a network.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a software-definition-based wide area industrial network interconnection method.

The technical scheme adopted by the invention for solving the technical problem comprises the following steps:

the wide area industrial network interconnection layer in the step (1) consists of a control sublayer and a network sublayer, wherein the entity of the control sublayer is a controller, and the entity of the network sublayer is a physical network device and a virtual switch;

the controller creates a logic network for a group of factories participating in the same service cooperation, and the logic network consists of logic nodes and logic links;

step (3) each logical node corresponds to a factory, and when the controller creates a logical node for the factory 1, a VPN instance is created on an external Gateway (GW) of the factory 1 in a network sub-layer; although the VPN instance is a routing process in the GW, the GW and the VPN instance belong to different routing spaces and are two different routers;

the VPN instance attributes include: the VPN system comprises a current VPN instance number ID-1, an output mark List-1, an input permission List-2, an inner layer Label Label-1 and an intranet routing table RT; ID-1 is used to uniquely identify a VPN instance; a Label-1 is mapped to an ID-1, and the mapping relation is maintained by the controller; the RT is used for recording how to reach the internal network segment of the factory;

when RT synchronization is carried out between VPN instances in step (4), an originating VPN instance sends an update message MSG, and the message contains List-1 and RT; each VPN instance receiving the MSG checks its own List-2, and if the List-2 and the List-1 in the MSG have intersection, the VPN instance receives the RT in the MSG and updates its own RT;

step (5) recording that the VPN instance corresponding to the logical node 1 is Vpn1, the GW where the logical node is located is GW1, the VPN instance corresponding to the logical node 2 is Vpn2, and the GW where the logical node is located is GW 2; when the controller creates a logical link between logical node 1 and logical node 2, first, the controller will assign a Label to Vpn1 and Vpn2 and write to the Label-1 respectively, and then the following steps are included:

5-1, judging whether a VXLAN tunnel exists between GW1 and GW2, if not, entering step 5-2, and if so, entering step 5-3;

the 5-2 controller will establish a VXLAN tunnel between GW1 and GW2, VXLAN being a local area network extension technology common in the network field.

The 5-3 controller records the mapping relation between the VXLAN tunnel and the logical links, and a plurality of logical links can correspond to the same VXLAN tunnel;

and (6) the controller ensures the transmission quality of each VXLAN tunnel, and the method comprises the following steps:

the 6-1 controller obtains the network sub-layer topology (underlay) corresponding to each VXLAN tunnel from the existing routing protocol;

the 6-2 controller identifies a data packet in a logical link in a VXLAN tunnel as a stream, and a plurality of streams can exist in one VXLAN at the same time;

and the 6-3 controller maps the service quality requirement of the logical link into a configuration strategy of the flow and issues the configuration strategy to each network device in the underlay topo.

The invention has the following beneficial effects:

according to the wide area industrial network interconnection method based on software definition, on one hand, interconnection of industrial networks is achieved based on an SDN networking mode, namely fusion of a factory network and the Internet; on the other hand, the converged network can provide similar connection-oriented real-time transmission capability. The integration of factory network and internet is to generate independent network plane (logic network) for service cooperation between factories in public network, and to flexibly and quickly customize QOS such as bandwidth and time delay.

Drawings

FIG. 1 is a schematic diagram of a logical network node construction;

Detailed Description

The invention is further illustrated by the following figures and examples.

the VPN instance attributes include: current VPN instance number (ID-1), output tag List (List-1), input permission List (List-2), inner Label (Label-1), and Intranet Routing Table (RT); ID-1 is used to uniquely identify a VPN instance; a Label-1 is mapped to an ID-1, and the mapping relation is maintained by the controller; the RT is used for recording how to reach the internal network segment of the factory; when RT synchronization is carried out among VPN instances in the step (4), an originating VPN instance sends an update Message (MSG) which contains List-1 and RT; each VPN instance receiving the MSG checks its own List-2, and if the List-2 and the List-1 in the MSG have intersection, the VPN instance receives the RT in the MSG and updates its own RT;

Examples

In order to facilitate the understanding and implementation of the present invention for those skilled in the art, the technical solutions of the present invention will be further described with reference to the accompanying drawings, and a specific embodiment of the present invention is provided.

An SDN controller of a control plane in an industrial internet layer controls an underwlay network consisting of various routing switching devices on a data plane through a southbound interface, and generates an Overlay network (namely a logic network) according to the requirements of an upper industrial cloud platform. The logical network construction mode is very flexible, but the suggested principle in the specific operation is as follows:

(1) network transport service types, such as IPv4 connectionless service, MPLS label switching, VPLS two-layer virtual circuit service, etc.;

(2) presenting types of industrial internet collaborative services, such as design collaboration, supply collaboration, and formulation collaboration;

(3) the access types of the industrial cloud platforms are greatly different from the technologies used by the cloud platforms of different manufacturers, the network configuration modes are different, and the network complexity can be simplified by constructing a logic network based on a cloud platform provider for the sake of simplicity;

(4) the QOS type and QOS guarantee in the era of industrial internet are the necessary capabilities of the network, but the QOS requirements are various, and a logic network cannot be constructed for each QOS, so that the management of the logic network can be simplified by reasonably classifying QOS parameters, such as bandwidth, time delay, reliability, jitter and the like.

The presentation mode of the logical network is very similar to that of the physical network, and both the logical network and the physical network are composed of nodes and links, but the logical network node is essentially a VPN example on the physical node, exists in the physical equipment, and has an independent routing forwarding table and various service strategies, just like a virtual network equipment; the reason why the logical network link is a tunnel based on VXLAN is that a large number of non-virtualized non-SDN devices widely exist in consideration of the heterogeneity of the current internet, and the non-virtualized non-SDN devices cannot sense and support the logical link, so that the problem can be well solved through the VXLAN tunnel, and the method is a feasible technical scheme at present.

A Virtual Private Network (VPN) means a Virtual Private Network, can provide flexible networking spanning a public Network for large-scale Private Network users, and has very good Network privacy and isolation. As shown in fig. 1, the network design for industrial interconnection divides the roles of network elements in a physical network into the following categories:

(1) access equipment (User Edge, UE). One or more interfaces are connected directly to an industrial internet service provider. The UE may be a physical router or a virtual switch. The factory users and their networks need not be aware of the existence of the VPN in the design.

(2) Network Edge devices (PEs) of industrial interconnection service providers. The PEs are directly connected to the CEs, provide network virtualization capabilities based on VPN instances, are important bearers for nodes in the logical network, and are also endpoints of VXLAN tunnels.

(3) Core devices (P) of industrial internet service Provider networks. The equipment only needs to have the transparent transmission capability of VXLAN and can provide the label switching capability similar to MPLS when providing the connection-oriented service, and the problem of VPN does not need to be considered.

In the network topology shown in fig. 1, 3 intelligent factories are connected to the industrial internet through their UE devices and perform production coordination for order 1. The SDN controller constructs the same logical network for order 1. In order to realize the functions, the PE-1 and the PE-2 need to configure VPN examples, wherein the VPN examples are VPN route forwarding tables. A router having a VPN instance is connected to both an industrial networking network (public network) and a factory internal network (referred to as a site in fig. 1), so that routing information of both a public network and an internal network exists on the router while maintaining a route forwarding table facing the public network and a VPN route forwarding table facing the VPN site (i.e., VPN instance).

In the process of constructing the logical network, as shown in fig. 1, a VXLAN tunnel (as a logical link) is created for each plant < - > plant connection for each order, and a VPN instance (logical node) group is created on the PE as an end point of the logical link.

Each physical PE can virtualize a plurality of logic nodes, and the routing tables maintained by each logic node are independent from each other and are independent from the public network routing table. Each logical node can be seen as a virtual router: and maintaining independent address space, and forming a logical link with the connection of other VPN sites.

The controller obtains a network sub-layer topology (underlay) corresponding to each VXLAN tunnel from an existing routing protocol, the data packet in a logical link in the VXLAN tunnel is identified as a stream, then the controller maps the service quality requirement of the logical link into a configuration strategy of the stream, and the configuration strategy is issued to each network device in the underlay, so that the controller can guarantee the transmission quality of each VXLAN tunnel.

Claims

1. A wide area industrial network interconnection method based on software definition is characterized by comprising the following steps:

step (3) each logical node corresponds to a factory, and when the controller creates a logical node for the factory 1, a VPN instance is created on an external gateway GW of the factory 1 in a network sub-layer; although the VPN example is a routing process in the GW, the GW and the VPN example belong to different routing spaces, the VPN example is a virtual router with an independent routing space, and a data packet forwarding process of the VPN example is irrelevant to the GW;

the 5-2 controller will establish a VXLAN tunnel between GW1 and GW 2;

the 6-1 controller obtains the network sublayer topology underlay corresponding to each VXLAN tunnel from the existing routing protocol;