Communication network and method based on on-chain and off-chain interaction

Abstract

The communication network comprises an SDN network and an edge gateway, the SDN network forwards a request of a terminal to the edge gateway, and if the request is an uplink request, the edge gateway carries out decryption, compression and aggregation processing on the uplink request, carries out compliance evaluation and then sends the uplink request to a cloud block chain; and if the request is a downlink request, the edge gateway returns the downlink request to the terminal. According to the method, the end-edge-chain hierarchical efficient communication network with the software-defined edge gateway as the core is constructed, stable and reliable data uplink is achieved, and the method has the advantages of being low in time delay, high in throughput, self-adaptive and capable of being supervised.

Description

Technical Field

[0001] The present invention relates to the technical field of distributed computing systems, and in particular, to a communication network and method based on on-chain and off-chain interaction. Background Art

[0002] A blockchain is a concatenated text record protected by cryptography. A blockchain system is a distributed ledger built on a peer-to-peer network. The ledger consists of blocks composed of transactions and is jointly maintained and updated by user nodes in the network. New transactions are verified by verification nodes in the network, and a consensus algorithm running in the network determines whether to add them to the block.

[0003] With its core features such as distributed ledger, immutability, and decentralization, blockchain technology has been widely applied in fields such as finance, supply chain, and Internet of Things. However, the deep integration of blockchain systems with the off-chain physical world still faces severe challenges at the communication architecture level: the off-chain network usually consists of a large number of heterogeneous terminals such as industrial sensors, mobile devices, and edge servers. Its network topology changes dynamically and the types of transmitted data are diverse, including real-time monitoring data, transactional records, multimedia information, etc. It is necessary to achieve low-latency and reliable transmission of large-scale data in a complex network environment. At the same time, compliance requirements such as financial supervision and data sovereignty make the communication process must have the ability to be supervised throughout the process, including terminal identity tracing, transmission path auditing, and data integrity evidence preservation.

[0004] Since existing blockchain systems are all end-chain architectures, that is, the client directly interacts with the blockchain. In the face of general scenario requirements such as a large number of heterogeneous terminals, low latency, high throughput, adaptability, and supervision, due to the performance limitations and architecture design of the blockchain system itself, there is no general solution. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the present invention provides a communication network and method based on on-chain and off-chain interaction. By constructing an end-edge-chain hierarchical and efficient communication network with a software-defined edge gateway as the core, stable and reliable data can be uploaded to the chain, and it has the characteristics of low latency, high throughput, adaptability, and supervision.

[0006] To achieve the above technical objectives, the present invention adopts the following technical solutions: A communication network based on on-chain and off-chain interaction, including: an SDN network and an edge gateway. The SDN network forwards the request of the terminal to the edge gateway. If it is an on-chain request, the edge gateway decrypts, compresses, and aggregates the on-chain request, and after performing a compliance assessment, sends it to the cloud blockchain; if it is an off-chain request, the edge gateway returns the off-chain request to the terminal.

[0007] Furthermore, the SDN network consists of an SDN data plane and an SDN control plane. The SDN data plane is provided with multiple SDN switches, and the edge gateway is provided with multiple edge gateway units. An SDN switch and an edge gateway unit form a communication link. The SDN control plane consists of an SDN controller, a link calculation module, and an edge gateway status monitoring module.

[0008] The request of the terminal arrives at the SDN switch closest to the terminal. The SDN controller monitors the status of the edge gateway unit, the status of the SDN switch, and the communication link status. If the edge gateway unit associated with the SDN switch fails or has a high load, the link calculation module determines a new communication link based on the global status of the edge gateway unit, and sends the routing information of the new communication link to the corresponding SDN switch through the SDN controller, and forwards the request of the terminal to the new communication link.

[0009] Furthermore, the process of determining the new communication link is as follows:

[0010] (a) When the edge gateway unit is under high load, the link calculation module calculates multiple redundant communication links and distributes part of the traffic to other edge gateway units.

[0011] (b) When the edge gateway unit fails, the link calculation module finds a neighboring edge gateway unit and directs all traffic to the neighboring edge gateway unit.

[0012] (c) When the SDN switch fails, communication is restored according to the backup path and fault repair strategy configured on the SDN switch.

[0013] Furthermore, the edge gateway unit includes: a trusted data processing module and an oracle off-chain module. The trusted data processing module decrypts the on-chain request and compresses and aggregates the on-chain request according to the data type of the on-chain request. The oracle off-chain module performs a compliance assessment on the compressed and aggregated on-chain request and encrypts and sends the compliant on-chain request to the cloud blockchain.

[0014] Furthermore, the specific process of the trusted data processing module compressing the on-chain request according to the data type of the on-chain request is as follows:

[0015] (a) If the data in the on-chain request is raw data and metadata, compress it according to the field semantics of the data.

[0016] (b) If the data of the on-chain request is the storage address of the raw data and metadata, merge multiple data from the same terminal and retain one terminal identifier. Then merge the data with the same timestamp and retain one timestamp.

[0017] Further, the specific process of the trusted data processing module aggregating the on-chain request according to the data type of the on-chain request is as follows: calculating the aggregation digest value of the on-chain request, constructing a hash tree with the aggregation digest value as the leaf node, and uploading the hash tree root to the cloud blockchain.

[0018] Further, during the process of sending the on-chain request to the cloud blockchain, the time delay needs to be controlled within seconds. First, reduce the aggregation batch size of the on-chain request. If the time delay requirement is not met, select a lightweight encryption and decryption algorithm to reduce the computational overhead.

[0019] Further, the edge gateway unit further includes: an audit component, which is composed of a high-order semantics generation module and an original data storage module. The high-order semantics generation module forms an audit summary from the original audit information and provides it for the supervisor to call through an interface; the original data storage module stores the original audit information locally in the edge gateway as a voucher for the audit summary; where the original audit information includes: transport layer protocol, network quadruple, flow start time, flow completion time, number of data packets, and total number of bytes.

[0020] Further, the edge gateway unit further includes: an edge cache service module, which is used to store the processed off-chain requests. If the data corresponding to the off-chain request exists in the edge cache service module, the edge cache service module directly returns the data of the off-chain request to the terminal; if the data corresponding to the off-chain request does not exist in the edge cache service module, the edge gateway unit queries the block number corresponding to the off-chain request in the metadata database, obtains the hash tree and metadata corresponding to the off-chain request, requests the block from the cloud blockchain according to the block number, and then sends the hash tree and the block to the terminal together, and stores the data in the edge cache service module.

[0021] Further, the present invention also provides a communication method based on on-chain and off-chain interaction, which specifically includes the following steps:

[0022] Step S1: The terminal sends an on-chain request or an off-chain request, and the SDN switch closest to the terminal receives the request of the terminal.

[0023] Step S2: The SDN controller monitors the status of the edge gateway unit, the status of the SDN switch, and the communication link status. If a failure or excessive load occurs, the link calculation module determines a new communication link according to the global status of the edge gateway unit, sends the routing information of the new communication link to the corresponding SDN switch through the SDN controller, and forwards the request of the terminal to the new communication link; otherwise, forwards the request to the corresponding edge gateway unit.

[0024] Step S3: If it is an on-chain request, the trusted processing module decrypts, compresses, and aggregates the on-chain request, and sends it to the oracle off-chain module for compliance evaluation. After passing the evaluation, the data is transmitted to the cloud blockchain;

[0025] Step S4: If it is an off-chain request, if the edge cache service module stores the data corresponding to the off-chain request, the edge cache service module directly returns the data of the off-chain request to the terminal; if the edge cache service module does not have the data corresponding to the off-chain request, the edge gateway unit queries the metadata database for the block number corresponding to the off-chain request, and obtains the hash tree and metadata corresponding to the off-chain request. After requesting the block from the cloud blockchain according to the block number, the hash tree and the block are sent to the terminal together, and the data is stored in the edge cache service module.

[0026] Compared with the prior art, the present invention has the following beneficial effects: Based on the communication network and method of on-chain and off-chain interaction, the present invention constructs an end-edge-chain hierarchical and efficient communication network with a software-defined edge gateway as the core, providing a general solution for the requirements of large-scale heterogeneous terminals, low latency, high throughput, adaptability, and supervision. It can utilize the existing blockchain to achieve the performance of millions of data being uploaded to the chain in seconds; at the same time, by adding the SDN network to the edge gateway, the present invention ensures the adaptive ability of on-chain and off-chain interaction, enabling the on-chain and off-chain communication network to still work normally when the edge gateway or the link has an abnormality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is the architecture diagram of the communication network based on on-chain and off-chain interaction of the present invention;

[0028] Figure 2 is the structural schematic diagram of the SDN network in the present invention;

[0029] Figure 3 is the structural schematic diagram of the edge gateway in the present invention;

[0030] Figure 4 is the throughput schematic diagram of data uploading using the communication network based on on-chain and off-chain interaction of the present invention. Among them, Figure 4 in (a) is the throughput schematic diagram of a single edge gateway unit, Figure 4 in (b) is the schematic diagram of the change of throughput with the number of edge gateway units. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The technical solutions of the present invention will be further explained below with reference to the accompanying drawings.

[0032] As Figure 1This is the architecture diagram of the communication network based on on-chain and off-chain interaction of the present invention. The communication network 101 includes: an SDN network 102 and an edge gateway 103. The SDN network 102 forwards the requests of the terminals to the edge gateway 103, and the edge gateway 103 meets the on-chain requests of heterogeneous terminals in different scenarios by setting multiple on-chain interfaces; for an on-chain request, the edge gateway 103 decrypts, compresses, and aggregates the on-chain request, and after performing a compliance assessment, it is sent to the cloud blockchain. The present invention realizes stable and reliable data on-chain by constructing an end-edge-chain hierarchical and efficient communication network with a software-defined edge gateway as the core; for an off-chain request, the edge gateway 103 returns the off-chain request to the terminal. The communication network of the present invention can process the on-chain and off-chain requests of the terminals, and achieve low-latency and high-throughput communication performance under the condition of meeting adaptive and regulatory requirements.

[0033] As Figure 2 , the SDN network 102 consists of an SDN data plane 201 and an SDN control plane 204. The SDN data plane 201 is provided with multiple SDN switches 202, and the edge gateway 103 is provided with multiple edge gateway units 203. An SDN switch 202 and an edge gateway unit 203 form a communication link; the SDN control plane 204 consists of an SDN controller 205, a link calculation module 206, and an edge gateway status monitoring module 207. The edge gateway status monitoring module 207 can monitor the network traffic within the local domain and across domains of the edge gateway, realize the status detection of the communication link and the edge gateway unit 203, and through the analysis and learning of the communication status, realize the reasonable configuration of cross-domain communication resources and the reliability and stability of communication.

[0034] The request of the terminal reaches the SDN switch 202 closest to the terminal. The SDN controller 205 monitors the status of the edge gateway unit 203, the status of the SDN switch 202, and the communication link status. If the edge gateway unit associated with the SDN switch 202 fails or has too high a load, the link calculation module 206 determines a new communication link according to the global status of the edge gateway unit 203, sends the routing information of the new communication link to the corresponding SDN switch 202 through the SDN controller 205, and forwards the request of the terminal to the new communication link. Under the end-edge-chain communication architecture with the edge gateway 103 as the core, the present invention configures the SDN function in the edge gateway 103, constructs a software-defined edge gateway, and at the same time adopts the strategies of repair and predefined protection, ensuring the adaptive ability of the communication network, so that the on-chain and off-chain communication network can still work normally when the edge gateway or the communication link has an abnormality.

[0035] The determination process of the new communication link is as follows:

[0036] (a) When the edge gateway unit 203 is under high load due to sudden traffic or other reasons, resulting in slow response or crashes, etc., the link calculation module 206 calculates multiple redundant communication links to divert part of the traffic to other edge gateway units 203 to achieve load balancing and realize fault tolerance for slow single-point response or failure under high load;

[0037] (b) When the edge gateway unit 203 fails and shuts down, and thus cannot process the upstream request, the link calculation module 206 finds the adjacent edge gateway unit 203 and directs all traffic to the adjacent edge gateway unit 203 to ensure the normal processing of the upstream request and the normal operation of the edge gateway 103, realizing system fault tolerance for single-point failures;

[0038] The load and status monitoring of the edge gateway unit 203 are realized through the agent technology. The relevant services deployed on the edge gateway unit 203 periodically send monitoring data to the edge gateway status monitoring module 207 to master the status and load of each edge gateway unit 203.

[0039] (c) When the SDN switch 202 fails, communication is restored according to the backup path and fault repair strategy configured on the SDN switch 202.

[0040] Such as Figure 3 , each edge gateway unit 203 includes: a trusted data processing module 303 and an oracle off-chain module 304. The trusted data processing module 303 decrypts the upstream request. The decryption process in the present invention adopts an HTTPS communication protocol based on the national cryptographic algorithm; and compresses and aggregates the upstream request according to the data type of the upstream request, so that the compressed and aggregated data matches the consensus performance of the cloud blockchain, greatly improving the throughput upper limit of the original cloud blockchain; the oracle off-chain module 304 conducts a compliance assessment on the compressed and aggregated upstream request, encrypts the compliant upstream request, and sends it to the cloud blockchain using HTTP3 based on the QUIC communication protocol to further reduce the latency.

[0041] The specific process of the trusted data processing module 303 in the present invention for compressing the upstream request according to the data type of the upstream request is as follows:

[0042] (a) If the data in the upstream request is raw data and metadata, it is compressed according to the field semantics of the data to reduce the amount of data;

[0043] (b) If the data requested to be uploaded is the storage address and metadata of the original data, the original data can be stored on the local server or in the local IPFS network. Multiple data from the same terminal are merged and one terminal identifier is retained; then, data with the same timestamp are merged and one timestamp is retained. Without losing the data semantics, data redundancy is eliminated as much as possible, and the amount of data uploaded is reduced, so that one upload request can accommodate more data entries.

[0044] The specific process of the trusted data processing module 303 aggregating the upload request according to the data type of the upload request is as follows: calculate the aggregation digest value of the upload request, construct a hash tree with the aggregation digest value as the leaf node, and upload the hash tree root to the cloud blockchain.

[0045] When sending the upload request to the cloud blockchain, the time delay needs to be controlled within seconds. Therefore, the time delay of each link in the upload process is monitored and estimated in real time, including: the transmission time t1 from the terminal to the edge gateway, the terminal encryption time t α1 , the edge gateway decryption time t α2 , the digest aggregation time t β , the oracle evaluation time t2, the transmission time t3 from the edge gateway to the cloud blockchain, the edge gateway encryption time t α3 and the cloud blockchain decryption time t α4 . Under the target of second-level data upload time delay, by jointly adjusting the total encryption and decryption time delay t α = t α1 + t α2 + t α3 + t α4 and the digest aggregation time t β , so that t α + t β + t1 + t2 + t3 < t target . When situations such as increased transmission time delay caused by network jitter or increased transmission time delay caused by failover occur, first reduce the batch waiting time delay and hash tree calculation time delay by reducing the data aggregation batch size, thereby reducing the digest aggregation time t β ; in the case where simply reducing the data aggregation batch cannot meet the target time delay, reduce the encryption and decryption calculation overhead by using a computationally lighter encryption and decryption algorithm, thereby reducing the total encryption and decryption time delay t α , and further making the total time delay meet the target time delay. After the network is stable or the fault is recovered, the edge gateway adjusts back to the original encryption and decryption algorithm and aggregation batch size according to the time delay monitoring index to ensure the best efficiency and security.

[0046] The edge gateway unit 203 further includes: an audit component 302. To meet the requirements of supervision, the audit component 302 in the edge gateway unit 203 obtains audit information from the transaction level and the communication level respectively, so as to monitor and audit the entire process of the on-chain request initiated by the terminal. The audit component consists of a high-order semantic generation module 306 and an original data storage module 307. The high-order semantic generation module 306 forms an audit summary from the original audit information and provides it for the supervisor to call through an interface; the original data storage module 307 stores the original audit information locally in the edge gateway as a voucher for the audit summary. Among them, the original audit information is obtained through the Conntrack table in the Linux Netfilter kernel component, including: transport layer protocols (tcp, udp), network quadruple (source address, source port, destination address, destination port), flow start time, flow completion time, number of data packets, and total number of bytes.

[0047] The edge gateway unit 203 further includes: an edge cache service module 301. The edge cache service module 301 is used to store the processed off-chain requests. If the data corresponding to the off-chain request exists in the edge cache service module 301, the edge cache service module 301 directly returns the data of the off-chain request to the terminal; if the data corresponding to the off-chain request does not exist in the edge cache service module 301, the edge gateway unit 203 queries the block number corresponding to the off-chain request in the metadata database, and obtains the hash tree and metadata corresponding to the off-chain request. After requesting the block from the cloud blockchain according to the block number, it sends the hash tree and the block to the terminal together, and stores the data in the edge cache service module 301. The edge cache service module 301 can be used to accelerate the off-chain request.

[0048] Based on the communication network of on-chain and off-chain interaction, the present invention realizes on-chain and off-chain interactive communication in practical terms, provides a general solution for the requirements of large-scale heterogeneous terminals, low latency, high throughput, adaptability, and supervision, and can use the existing blockchain to achieve the on-chain of tens of millions of data in seconds.

[0049] The present invention also provides a communication method based on on-chain and off-chain interaction, which specifically includes the following steps:

[0050] Step S1, the terminal sends an on-chain request or an off-chain request, and the SDN switch 202 closest to the terminal receives the request of the terminal;

[0051] Step S2: The SDN controller 205 monitors the status of the edge gateway unit 203, the status of the SDN switch 202, and the communication link status. If a fault occurs or the load is too high, to ensure the timeliness of uploading to the chain, the link calculation module 206 determines a new communication link according to the global status of the edge gateway unit 203, sends the routing information of the new communication link to the corresponding SDN switch 202 through the SDN controller 205, and forwards the request of the terminal to the new communication link; otherwise, forwards the request to the corresponding edge gateway unit 203.

[0052] Step S3: If it is an upload request to the chain, the trusted processing module 303 decrypts, compresses, and aggregates the upload request, and sends it to the off-chain oracle module 304 for compliance evaluation. After passing, the data is transmitted to the cloud blockchain.

[0053] Step S4: If it is a download request to the chain, if the edge cache service module 301 stores the data corresponding to the download request, the edge cache service module 301 directly returns the data of the download request to the terminal; if the edge cache service module 301 does not have the data corresponding to the download request, the edge gateway unit 203 queries the metadata database for the block number corresponding to the download request, and obtains the hash tree and metadata corresponding to the download request. After requesting the block from the cloud blockchain according to the block number, the hash tree and the block are sent to the terminal together, and the data is stored in the edge cache service module 301.

[0054] As Figure 4 is a throughput schematic diagram of uploading to the chain using the communication method based on on-chain and off-chain interaction of the present invention. The experimental environment configuration adopted is: including 45 x86 servers, the CPU of each server is Intel Xeon Silver 4214 dual-way, the memory is 256GB, and the servers are connected to the switch through a 1Gbps bandwidth. 1 server runs the SDN controller 205 and the blockchain program, 34 servers run the SDN switch 202 and the edge gateway unit 203, and another 10 servers run the upload transaction generation test program. The servers running the SDN switch 202 and the edge gateway unit 203 use the VXLAN technology to generate virtual SDN switches 202 on the servers using the system kernel SDN; the SDN controller 205 uses the open-source software OpenDayLight, and the transaction generation test server uses the distributed performance test platform Lucas. The parameter configuration of the upload request adopted is: the metadata length of each upload request is 1 - 100 random bytes, and the transaction content is 1 - 400 random bytes. For comparison with Hyperledger Fabric, 100Byte random content is written to a random key of Hyperledger Fabric for each upload request. From Figure 4As shown in (a), the throughput comparison between a single edge gateway unit 203 of the present invention and HyperLedger Fabric can be seen. Due to the advantages brought by data aggregation and compression in terms of high throughput, the throughput of the edge gateway unit 203 of the present invention is about 100 times that of HyperLedger Fabric. Figure 4 (b) shows the scenario of the total throughput varying with the number of edge gateway units 203 in the present invention. It can be seen that the total system throughput basically increases linearly with the increase in the number of edge gateway units 203, and finally meets the high throughput requirement of 10 million data being uploaded to the blockchain when there are 34 servers. At the same time, it can be seen that the communication network of the present invention has high scalability. By continuously expanding the edge gateway unit 203, the total throughput can be further increased before reaching the processing capacity of the cloud blockchain, so as to achieve the ability to upload tens of millions of data to the blockchain in one second.

[0055] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. Any technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, several improvements and refinements made without departing from the principle of the present invention should be regarded as within the protection scope of the present invention.

Claims

1. A communication network based on on-chain and off-chain interactions, characterized in that: include: An SDN network (102) and an edge gateway (103), wherein the SDN network (102) forwards the request of the terminal to the edge gateway (103); if it is an uplink request, the edge gateway (103) decrypts, compresses and aggregates the uplink request, and after a compliance assessment, sends it to the cloud blockchain; if it is a downlink request, the edge gateway (103) returns the downlink request to the terminal.

2. A communication network based on on-chain and off-chain interaction according to claim 1, characterized in that: The SDN network (102) is composed of an SDN data plane (201) and an SDN control plane (204); the SDN data plane (201) is provided with a plurality of SDN switches (202); the edge gateway (103) is provided with a plurality of edge gateway units (203); an SDN switch (202) and an edge gateway unit (203) form a communication link; the SDN control plane (204) is composed of an SDN controller (205), a link calculation module (206) and an edge gateway status monitoring module (207); The request of the terminal arrives at the SDN switch (202) closest to the terminal. The SDN controller (205) monitors the status of the edge gateway unit (203), the status of the SDN switch (202) and the status of the communication link. If the edge gateway unit associated with the SDN switch (202) fails or the load is too high, the link calculation module (206) determines a new communication link according to the global status of the edge gateway unit (203), sends the routing information of the new communication link to the corresponding SDN switch (202) through the SDN controller (205), and forwards the request of the terminal to the new communication link.

3. A communication network based on on-chain and off-chain interaction according to claim 2, characterized in that: The process of determining the new communication link is as follows: (a) when the edge gateway unit (203) is under high load, the link calculation module (206) distributes part of the traffic to other edge gateway units (203) by calculating multiple redundant communication links; (b) when the edge gateway unit (203) fails, the link calculation module (206) finds an adjacent edge gateway unit (203) and directs all traffic to the adjacent edge gateway unit (203); (c) When the SDN switch (202) fails, communication is restored according to the backup path and fault repair strategy configured on the SDN switch (202).

4. A communication network based on on-chain and off-chain interaction according to claim 1, characterized in that: The edge gateway unit (203) includes: a trusted data processing module (303) and an oracle off-chain module (304), wherein the trusted data processing module (303) decrypts the on-chain request and compresses and aggregates the on-chain request according to the data type of the on-chain request; the oracle off-chain module (304) performs compliance assessment on the compressed and aggregated on-chain request and encrypts the compliant on-chain request and sends it to the cloud blockchain.

5. A communication network based on on-chain and off-chain interaction according to claim 4, characterized in that: The specific process of the trusted data processing module (303) compressing the uplink request according to the data type of the uplink request is as follows: (a) If the data in the on-chain request is raw data and metadata, it is compressed according to the field semantics of the data; (b) If the data requested on the chain is the storage address and metadata of the original data, multiple data from the same terminal are merged and a terminal identifier is retained; Then merge the data with the same timestamp and keep one timestamp.

6. A communication network based on on-chain and off-chain interaction according to claim 5, characterized in that: The specific process of the trusted data processing module (303) aggregating the on-chain requests according to the data types of the on-chain requests is as follows: calculating the aggregated summary value of the on-chain requests, and using the aggregated summary value as a leaf node to construct a hash tree, and uploading the hash tree root to the cloud blockchain.

7. A communication network based on on-chain and off-chain interaction according to claim 6, characterized in that: In the process of sending the chain request to the cloud blockchain, the latency needs to be controlled at the second level, and the aggregate batch size of the chain request should be reduced first. If the latency requirement is not met, a lightweight encryption and decryption algorithm should be selected to reduce the computing overhead.

8. A communication network based on on-chain and off-chain interaction according to claim 4, characterized in that: The edge gateway unit (203) also includes: an audit component (302), which is composed of a high-level semantic generation module (306) and a raw data storage module (307), wherein the high-level semantic generation module (306) forms an audit summary from the original audit information and provides it to the regulator for invocation through an interface; the raw data storage module (307) stores the original audit information locally on the edge gateway as a voucher for the audit summary; wherein the original audit information includes: transport layer protocol, network quadruple, flow start time, flow completion time, number of data packets and total number of bytes.

9. A communication network based on on-chain and off-chain interaction according to claim 4, characterized in that: The edge gateway unit (203) further comprises: an edge cache service module (301), wherein the edge cache service module (301) is used to store processed downlink requests. If the edge cache service module (301) stores data corresponding to the downlink request, the edge cache service module (301) directly returns the data of the downlink request to the terminal; if the edge cache service module (301) does not store data corresponding to the downlink request, the edge gateway unit (203) queries the metadata database for the block number corresponding to the downlink request, obtains the hash tree and metadata corresponding to the downlink request, and after requesting a block from the cloud blockchain according to the block number, sends the hash tree and the block to the terminal together, and stores the data in the edge cache service module (301).

10. A communication method based on on-chain and off-chain interaction, characterized in that: The specific steps include: Step S1: The terminal sends an uplink request or a downlink request, and the SDN switch (202) closest to the terminal receives the request from the terminal; Step S2, the SDN controller (205) monitors the status of the edge gateway unit (203), the status of the SDN switch (202) and the status of the communication link. If a fault occurs or the load is too high, the link calculation module (206) determines a new communication link according to the global status of the edge gateway unit (203), sends the routing information of the new communication link to the corresponding SDN switch (202) through the SDN controller (205), and forwards the request of the terminal to the new communication link; otherwise, forwards the request to the corresponding edge gateway unit (203); Step S3: If it is a request to upload to the blockchain, the trusted processing module (303) decrypts, compresses and aggregates the request to upload to the blockchain, and sends it to the oracle off-chain module (304) for compliance assessment. If it passes the compliance assessment, the data is transmitted to the cloud blockchain. Step S4: If it is a downlink request, if the edge cache service module (301) stores data corresponding to the downlink request, the edge cache service module (301) directly returns the data of the downlink request to the terminal; If there is no data corresponding to the downlink request in the edge cache service module (301), the edge gateway unit (203) queries the metadata database for the block number corresponding to the downlink request, obtains the hash tree and metadata corresponding to the downlink request, and requests the block from the cloud blockchain according to the block number, then sends the hash tree and the block to the terminal together, and stores the data in the edge cache service module (301).

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