CN113259244B

CN113259244B - Traffic mapping method for time-sensitive network

Info

Publication number: CN113259244B
Application number: CN202110582468.6A
Authority: CN
Inventors: 全巍; 黄容; 孙志刚; 严锦立; 李军帅; 彭***
Original assignee: National University of Defense Technology
Current assignee: National University of Defense Technology
Priority date: 2021-05-27
Filing date: 2021-05-27
Publication date: 2021-10-08
Anticipated expiration: 2041-05-27
Also published as: CN113259244A

Abstract

The invention discloses a flow mapping method for a time sensitive network, which comprises the following steps: the first equipment sends a request message to a network controller according to the IP address of the second equipment to acquire a TSN label; the first device writes the TSN label into an IP-MAC table; the first device communicates with the second device based on the IP address and TSN tag of the second device. In the technical scheme, when a first device accesses to an opposite-end communication device in a TSN, the communication between the first device and the opposite-end device can be completed only by calling a TSN label which is acquired from a network controller and stored in an IP-MAC table and combining with an IP address of the opposite-end device. And a TSN label does not need to be added to each communicated data message, so that the reduction of the traffic mapping performance caused by the processing mode is avoided. Therefore, the technical scheme is simple and convenient, and can obviously improve the network traffic mapping performance.

Description

Traffic mapping method for time-sensitive network

Technical Field

The invention relates to the technical field of network transmission, in particular to a traffic mapping method for a time-sensitive network.

Background

A Time Sensitive Network (TSN) is a completely new industrial communication technology that is being actively promoted by the international industry at present. The time sensitive network allows periodic and aperiodic data to be transmitted in the same network, so that the standard ethernet has the advantage of deterministic transmission and has become a key technology of wide focus through a vendor independent standardization process. At present, organizations such as IEEE, IEC, etc. are making the bottom interoperability standards and specifications of industrial application networks based on TSN. The TSN is a new generation network standard based on ethernet, and has functions of ensuring real-time performance, such as time synchronization and delay guarantee.

When the standard ethernet packet is transmitted in the TSN switching network, mapping between the application traffic and the network traffic is often required. That is, before entering the TSN switching network, the standard ethernet packet needs to be converted into the TSN packet with the TSN label, so as to complete the mapping from the application traffic to the network traffic; before the message leaves the TSN switching network, the TSN label needs to be removed and inversely converted into a standard ethernet message, so as to complete the mapping from the network traffic to the application traffic.

Currently, TSNs are based on the IEEE 802.1Q Virtual Local Area Network (VLAN) and priority standards that place a 4-byte TSN tag in a VLAN field in a standard ethernet network. Then, the standard ethernet packet is mapped into a TSN packet, and a TSN tag needs to be obtained according to the characteristics of the standard ethernet packet, and then a 4-byte TSN tag is inserted into the standard ethernet packet. This method has the following disadvantages: all data messages need to be subjected to protocol conversion through a proprietary network adapter (such as a TSN network card or a TSN gateway) so as to complete mapping from standard Ethernet messages to TSN messages. If the protocol conversion is implemented by hardware, large-scale traffic mapping is supported by hardware, and the hardware has a large storage resource, which makes the protocol conversion expensive. If the software implementation is used, all application traffic needs to be processed by software before entering the TSN switching network, which may greatly reduce performance. The root causes of this defect are: this method must insert a 4 byte TSN tag in the standard ethernet to complete the mapping of traffic.

Therefore, in the TSN network, it is an urgent need to solve the problem of the art to provide a traffic mapping method that is simple, convenient, and capable of improving the network traffic mapping performance.

Disclosure of Invention

The invention aims to provide a traffic mapping method for a time-sensitive network, which is simple, safe, effective, reliable and simple and convenient to operate and can effectively improve the traffic mapping performance in the network.

Based on the above purposes, the technical scheme provided by the invention is as follows:

a traffic mapping method for a time sensitive network, comprising the steps of:

the first equipment sends a request message to a network controller according to the IP address of the second equipment to acquire a TSN label;

the first device writes the TSN label into an IP-MAC table;

the first device communicates with the second device according to the IP address of the second device and the TSN tag.

Preferably, before the first device sends the request packet to the network controller according to the destination IP of the second device to obtain the TSN tag, the method further includes:

presetting a flow mapping table and a flow inverse mapping table;

deploying the traffic mapping table into the network controller;

issuing the traffic inverse mapping table to a TSN switch;

wherein the traffic mapping table comprises: source IP, destination IP, and TSN labels;

the traffic inverse mapping table includes a stream identifier, a source MAC address, a destination MAC address, and an output port number in the TSN label.

Preferably, the TSN switch is provided in plurality, wherein a first switch is connected to the first device, and a second switch is connected to the network controller.

Preferably, the first device sends a request message to the network controller according to the IP address of the second device to obtain the TSN tag, including the following steps:

after receiving the request message, the first switch encapsulates the request message and transmits the request message to the TSN;

after receiving the packaged request message, the second switch transmits the packaged request message to the network controller;

and the network controller analyzes the encapsulated request message to obtain a TSN label.

Preferably, after the network controller analyzes the encapsulated request packet and acquires the TSN tag, the method further includes the following steps:

the network controller constructs a packaged response message according to the TSN label and sends the packaged response message to the second switch;

the second switch transmits the packaged response message to the TSN network;

the first switch receives the packaged response message, restores the packaged response message and transmits the restored response message to the first equipment;

and the first equipment acquires the TSN label according to the restored response message.

Preferably, the first device communicates with the second device according to the IP address of the second device and the TSN tag, comprising the steps of:

the first equipment sends a data message containing the TSN label to the second equipment according to the IP address of the second equipment;

and after receiving the data message, the TSN switch restores the data message according to the reverse traffic mapping table and transmits the restored data message to the second device.

Preferably, after receiving the data packet, the TSN switch restores the data packet according to the inverse traffic mapping table, and transmits the restored data packet to the second device, specifically:

after receiving the data message, the TSN switch searches the flow inverse mapping table according to the flow identification in the TSN label in the data message, and obtains a corresponding source MAC address, a corresponding destination MAC address and a corresponding output port number;

replacing the TSN label in the data message with the destination address;

and transmitting the data message to second equipment according to the output port number.

Preferably, after replacing the TSN tag in the data packet with the destination address, before transmitting the data packet to the second device according to the output port number, the method further includes:

and if the IP-MAC table of the second equipment is updated according to the data message, replacing the source MAC address of the data message as the source MAC address in the flow inverse mapping table.

In the traffic mapping method for the time-sensitive network, in the working process, the first device sends a request message to the network controller according to the destination IP of the opposite-end communication device, and the request message is transmitted in the TSN until the request message reaches the network controller; the network controller generates a response message with a TSN label and transmits the response message to the first equipment; the first device extracts the TSN tag and writes it into its own IP-MAC mapping table.

In a TSN (transport stream network), when a first device accesses an opposite-end communication device, a request message is only needed to be sent to a network controller to obtain a TSN label, the TSN label is written into an IP-MAC (Internet protocol-media access control) table of the first device, and the TSN label in the IP-MAC table is called to combine with an IP address of the opposite-end device to complete communication between the first device and the opposite-end device.

In the technical scheme, the first device already requests the network controller to acquire the TSN label, and only needs to read the IP-MAC table of the first device when accessing the communication device at the opposite end. Therefore, a TSN label does not need to be added to each communicated data message, and the reduction of the traffic mapping performance caused by the processing mode is avoided. Therefore, the technical scheme is simple and convenient, and can obviously improve the network traffic mapping performance.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a flowchart of a traffic mapping method for a time-sensitive network according to an embodiment of the present invention;

fig. 2 is a flowchart of a method before step S1 in a traffic mapping method according to an embodiment of the present invention;

fig. 3 is a flowchart of a method specifically executed in step S1 in the traffic mapping method according to the embodiment of the present invention;

fig. 4 is a flowchart of a method after step B3 in the traffic mapping method according to the embodiment of the present invention;

fig. 5 is a flowchart of a specific method for a TSN switch to restore and send a data packet in a traffic mapping method according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Embodiments of the present invention are written in a progressive manner.

The embodiment of the invention provides a traffic mapping method for a time-sensitive network. The method mainly solves the technical problems that in the prior art, the flow mapping cost is high and the performance is low.

In the actual application process, each method step has specific use details according to different use requirements or required effects, and the specific equipment adopted in each step can be selected according to actual needs. In this embodiment, the request message initially sent by the first device to the control is a standard ethernet arp request message.

Referring to fig. 1, a traffic mapping method for a time sensitive network includes the following steps:

s1, first equipment sends an ARP request message to a network controller according to an IP address of second equipment to obtain a TSN label;

s2, the first equipment writes the TSN label into an IP-MAC table;

and S3, the first equipment communicates with the second equipment according to the IP address and the TSN label of the second equipment.

In step S1, the first device sends an ARP request message to the network controller according to the destination IP of the peer communication device, and the request message is transmitted in the TSN network until reaching the network controller; the network controller generates a response message with a TSN label and transmits the response message to the first device.

In step S2, the first device extracts the TSN tag and writes it into its IP-MAC mapping table.

In step S3, the first device invokes the TSN tag in the IP-MAC mapping table to communicate with the peer device in combination with the destination IP of the peer communication device.

It should be noted that the IP protocol is a protocol designed for communication with computer networks. In the internet, it is a set of rules that enable all computer networks connected to the network to communicate with each other, defining rules that computers should follow when communicating over the internet.

A very important aspect of the IP protocol is that each computer and other device on the internet is assigned a unique address, called the "IP address". Due to the unique address, the user can select the needed objects from thousands of computers efficiently and conveniently when operating on the networked computers.

The IP address is just like our home address, and if you want to write a letter to a person, you know his (her) address so that the carrier can send the letter. The computer sends the message as if it were a postman who must know the unique "home address" so as not to send the message wrong. Except that our addresses are represented by words and the computer addresses are represented by binary digits.

MAC address: each device in the network has a unique network identifier, which is called a MAC address or network card address, written inside the hardware when produced by the network device manufacturer.

The key to packet delivery is to map the IP address of the destination node to the MAC address of the intermediate node. The mapping of the IP address to the MAC address is performed by the ARP address resolution protocol, which can map the IP address in the network to the MAC address of the host, e.g., the switch can find the MAC address of the local host according to the IP address in the network. The specific process is as follows: when the exchanger receives a data packet from the network, whether the inner part of the exchanger has the MAC address corresponding to the IP address or not is checked according to the target IP address of the data packet, and if the inner part of the exchanger has the corresponding MAC address reserved last time, the data packet is forwarded to the host computer corresponding to the MAC address. If there is no MAC address corresponding to the target address in the switch, the switch maps the target IP address to the MAC address according to the corresponding relation in the 'table' according to the ARP protocol, and the data packet is transferred to the host with the corresponding MAC address.

The address Resolution protocol (arp) is a TCP/IP protocol for acquiring a physical address according to an IP address. When the host sends information, the ARP request containing the target IP address is broadcasted to all the hosts on the local area network, and the return message is received, so that the physical address of the target is determined; after receiving the return message, the IP address and the physical address are stored in the local ARP cache and are kept for a certain time, and the ARP cache is directly inquired when the next request is made so as to save resources. The address resolution protocol is established on the basis that all hosts trust each other in the network, the hosts on the local area network can independently send ARP response messages, and other hosts can not detect the authenticity of the messages and can record the messages into the ARP cache of the local hosts when receiving the response messages.

That is, in the TSN network, the TSN tag is regarded as the MAC address of the peer device, and communication with the peer device can be completed by combining the IP address of the peer device according to the ARP protocol. In the actual application process, the TSN label can be obtained only by configuring parameters in the offline network to realize the intercommunication between the first device and the network controller. When accessing the opposite-end communication equipment, the MAC address of the opposite-end equipment can be obtained only by reading the IP-MAC table of the opposite-end equipment, and the access can be completed according to the IP address and the MAC address. Therefore, a TSN label does not need to be added to each communicated data message, and the reduction of the traffic mapping performance caused by the processing mode is avoided.

Referring to fig. 2, before the first device sends the request packet to the network controller according to the destination IP of the second device to obtain the TSN tag, the method further includes:

A1. presetting a flow mapping table and a flow inverse mapping table;

A2. deploying a traffic mapping table into a network controller;

A3. issuing a traffic inverse mapping table to a TSN switch;

wherein, the flow mapping table includes: source IP, destination IP, and TSN labels;

the traffic reverse mapping table includes the flow identification, source MAC address, destination MAC address, and output port number in the TSN label.

In step a1, a traffic mapping table is used to map application traffic to network traffic, and a traffic mapping table entry includes three parts: source IP, destination IP, and TSN label. The source IP represents the IP address of the message sending end equipment, the destination IP represents the IP address of the message receiving end equipment, and the TSN label represents the TSN network identification information of the message flow;

the flow inverse mapping table is used for mapping the network flow to the application flow, and the flow inverse mapping table entry comprises four parts: the flow identification, source MAC address, destination MAC address, and output port number in the TSN tag. The stream id in the TSN tag is a field of the TSN tag that is used to uniquely identify the stream in the TSN network. The source MAC address (smac) indicates a TSN label transmitted in the reverse direction of the flow, that is, a TSN label corresponding to a packet flow from the receiving end device of the flow to the transmitting end device of the flow. The destination MAC address (dmac) represents the real physical address of the device at the receiving end of this stream. The egress port number (outport) indicates from which physical port of the TSN switch this stream is outgoing. Similarly, since the TSN network is mainly applied to a relatively closed network, and the resources, network topology, network traffic path, etc. in the network are known in advance, the network controller may deploy the traffic inverse mapping table to the switch in an offline environment.

The presetting of the flow mapping table and the flow inverse mapping table is not required to be carried out every time, but is required to be preset in advance when the method is used for the first time, but the presetting can be finished in an off-line environment.

In steps a2 and A3, the traffic mapping table is deployed in the network controller. In actual operation, the network controller deploys its own existing traffic mapping table and issues the deployed traffic inverse mapping table to the TSN switch.

Because the TSN network is mainly applied to a relatively closed network, and resources, network topology, network traffic paths, and the like in the network are known in advance, the TSN network controller can plan all application traffic in the network offline, and each application traffic corresponds to one TSN label.

Preferably, the TSN switch is provided in plurality, wherein the first switch is connected to the first device, and the second switch is connected to the network controller.

It should be noted that the first-hop switch is a switch that receives the message traffic first after the message traffic enters the TSN switching network; the last hop switch refers to the switch that processes the message traffic last before the message traffic leaves the TSN switch network. The first hop switch and the last hop switch can be switched with each other according to different transmission directions of message flow.

In this embodiment, in the process of sending the request message to the network controller by the first device, the first-hop switch is the first switch, and the last-hop switch is the second switch. And in the process that the network controller sends the response message to the first equipment, the first-hop switch is the second switch, and the last-hop switch is the first switch.

Referring to fig. 3, preferably, the first device sends a request message to the network controller according to the IP address of the second device to obtain the TSN tag, including the following steps:

B1. after receiving the request message, the first switch encapsulates the request message and transmits the request message to the TSN network;

B2. after receiving the packaged request message, the second switch transmits the packaged request message to the network controller;

B3. the network controller analyzes the encapsulated request message to obtain the TSN label.

In step B1, the first switch encapsulates the request packet according to a preset rule, and the encapsulation process specifically includes: adding a TSN message header containing a TSN label, a source MAC address and a message type to the request message data, and adding a port number field before the request message data. The encapsulated request message is sent through the first switch, transmitted in the TSN network and finally arrives at the second switch.

It should be noted that adding the message header and the port number field is to add the TSN tag, the source MAC address, the message type, and the port number, but the TSN tag, the source MAC address, and the message type are logically used as the TSN message header, and the port number is used as the data field of the TSN message. This port number is added in order to reserve the arp request message input port number so that in a later step the first switch knows from which port number to send the arp response message to the first device.

In step B2, the encapsulated request message is a TSN network arp request message. And the second switch receives the message and transmits the message to the network controller.

In step B3, the network controller parses the packet, and the parsing process specifically includes: the method comprises the steps of firstly storing TSN message head and port number information, then removing the TSN message head and the port number information, obtaining a standard Ethernet arp request message, then analyzing the standard Ethernet arp request message to obtain a source IP and a target IP, and finally searching a flow mapping table according to the obtained source IP and the target IP to obtain a corresponding TSN label.

Referring to fig. 4, preferably, after the network controller parses the encapsulated request packet and obtains the TSN tag, the method further includes the following steps:

C1. the network controller constructs a packaged response message according to the TSN label and sends the packaged response message to the second switch;

C2. the second switch transmits the packaged response message to the TSN network;

C3. the first switch receives the packaged response message, restores the packaged response message and transmits the restored response message to the first equipment;

C4. and the first equipment acquires the TSN label according to the restored response message.

In step C1, the network controller constructs a response packet according to the TSN tag, and the construction process specifically includes: the TSN message header is constructed firstly, the stored TSN message header information is taken out, the TSN label and the source address are exchanged, and then the exchanged TSN message header is used as the TSN message header of the TSN network arp response message. And then constructing a TSN message data domain, taking the stored port number and the standard Ethernet arp response message as the TSN message data domain, and filling the obtained TSN label into the source MAC address and sending end Ethernet address domain of the standard Ethernet arp response message. And after the construction process is completed, sending the packaged response message to the second switch.

In step C2, the encapsulated response message is sent through the second switch, transmitted in the TSN network, and finally arrives at the first switch.

In step C3, the first switch receives the encapsulated response packet, and restores the packet, which includes the following steps: firstly extracting port number information, then removing a TSN message header and a port number of a TSN network arp response message, and finally sending a standard Ethernet arp response message from a designated port to a first device according to the port number

In step C4, after receiving the standard ethernet arp response message, the first device extracts the TSN tag from the standard ethernet arp response message.

Preferably, the first device communicates with the second device according to the IP address and TSN tag of the second device, comprising the steps of:

the first equipment sends a data message containing a TSN label to the second equipment according to the IP address of the second equipment;

and after receiving the data message, the TSN switch restores the data message according to the flow inverse mapping table and transmits the restored data message to the second equipment.

In actual operation, after the first device requests the network controller to obtain the TSN tag, the first device can access the second device.

The specific process is as follows: after writing the acquired TSN label into the IP-MAC mapping table according to the preamble step, the first device transmits a data message communicated with the first device to the TSN network in the process of communication between the first device and the second device, wherein the data message is equivalent to one of network flow. After the network traffic enters the TSN, the first hop switch is reached firstly, then the first hop switch forwards the packet to other switches, finally the network traffic reaches the last hop switch, and the last hop switch restores the data packet according to the traffic inverse mapping table. And the last hop switch transmits the restored data message to the second equipment. The restoration process is the mapping of the network traffic to the application traffic.

Referring to fig. 5, preferably, after receiving the data packet, the TSN switch restores the data packet according to the reverse traffic mapping table, and transmits the restored data packet to the second device, which specifically includes:

after receiving the data message, the TSN switch searches a flow inverse mapping table according to a flow identifier in a TSN label in the data message, and obtains a corresponding source MAC address, a corresponding destination MAC address and a corresponding output port number;

D2. replacing the TSN label in the data message with a destination address;

D3. and transmitting the data message to the second equipment according to the output port number.

In step D1, the TSN switch searches the traffic inverse mapping table according to the stream identifier in the TSN label, and obtains the corresponding source MAC address, destination MAC address, and output port number. It should be noted that, there is a corresponding relationship between the flow identifier, the source MAC address, the destination MAC address, and the output port number in the traffic inverse mapping table, which is determined in the offline deployment process. Other items may be queried by any of them as desired. In this embodiment, other corresponding items need to be queried through the flow identifier of the TSN tag, mainly to obtain the target MAC address, and implement communication between the first device and the second device in combination with the target IP.

In step D2, the TSN label of the network traffic is replaced with the destination address dmac, thereby completing the mapping from the network traffic to the application traffic.

In step D3, the mapped application traffic is sent to the second device according to the designated output port number, so as to implement the access of the first device to the second device.

In the actual application process, whether a source address of network flow needs to be replaced by a source MAC address (smac) in a flow inverse mapping table is judged, the source address needs to be replaced according to a specific application scene, and if an IP-MAC table of second equipment can be updated at any time according to received data messages, the source address needs to be replaced; if the IP-MAC table of the second device is only updated according to the received arp message, the IP-MAC table does not need to be replaced.

In the embodiments provided in the present application, it should be understood that the disclosed method and apparatus may be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the modules is only one division of logical functions, and other divisions may be realized in practice, such as: multiple modules or components may be combined, or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the coupling, direct coupling or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between the devices or modules may be electrical, mechanical or other.

In addition, all functional modules in the embodiments of the present invention may be integrated into one processor, or each module may be separately used as one device, or two or more modules may be integrated into one device; each functional module in each embodiment of the present invention may be implemented in a form of hardware, or may be implemented in a form of hardware plus a software functional unit.

Those of ordinary skill in the art will understand that: all or part of the steps for implementing the method embodiments may be implemented by program instructions and related hardware, where the program instructions may be stored in a computer-readable storage medium, and when executed, the program instructions perform the steps including the method embodiments; and the aforementioned storage medium includes: various media that can store program codes, such as a removable Memory device, a Read Only Memory (ROM), a magnetic disk, or an optical disk.

The traffic mapping method for the time-sensitive network provided by the invention is described in detail above. The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A traffic mapping method for a time sensitive network, comprising the steps of:

the first device writes the TSN label into an IP-MAC table;

2. The traffic mapping method according to claim 1, wherein before the first device sends the request packet to the network controller according to the destination IP of the second device to obtain the TSN label, the method further comprises:

presetting a flow mapping table and a flow inverse mapping table;

deploying the traffic mapping table into the network controller;

issuing the traffic inverse mapping table to a TSN switch;

3. The traffic mapping method of claim 2, wherein the TSN switch is provided in plurality, wherein a first switch is connected to the first device and a second switch is connected to the network controller.

4. The traffic mapping method according to claim 3, wherein the first device sends a request message to the network controller according to the IP address of the second device to obtain the TSN tag, comprising the steps of:

after receiving the request message, the first switch encapsulates the request message and transmits the request message to a TSN (time delay network);

5. The traffic mapping method according to claim 4, wherein the network controller parses the encapsulated request packet, and after acquiring the TSN tag, further comprises the following steps:

the second switch transmits the packaged response message to the TSN network;

6. The traffic mapping method of claim 2, wherein the first device communicates with the second device based on the IP address and the TSN tag of the second device, comprising the steps of:

7. The traffic mapping method according to claim 6, wherein after receiving the data packet, the TSN switch restores the data packet according to the reverse traffic mapping table, and transmits the restored data packet to the second device, specifically:

replacing the TSN label in the data message with the destination address;

8. The traffic mapping method according to claim 7, wherein after replacing the TSN tag in the data packet with the destination address, before transmitting the data packet to the second device according to the output port number, further comprising: