CN114697300B

CN114697300B - Data multicast realization method of high-timeliness communication system

Info

Publication number: CN114697300B
Application number: CN202210395659.6A
Authority: CN
Inventors: 刘台; 胡斌; 王一鸣; 张希杰; 赵瑞峰; 朱超; 程意; 钟海亮; 周君; 边康龙; 汤庆闻; 唐新飞; 向灯
Original assignee: Wuhan Zhongyuan Mobilcom Engineering Co Ltd
Current assignee: Wuhan Zhongyuan Mobilcom Engineering Co Ltd
Filing date: 2022-04-15
Publication date: 2024-06-04
Anticipated expiration: 2042-04-15

Abstract

The application discloses a data multicast realization method of a high-timeliness communication system, which comprises a plurality of nodes; each node comprises a router and a terminal, the terminal is connected with the router, the router comprises a wide area network IP address, and the method comprises: creating unique identity addresses for all terminals of each node respectively; establishing an identity-wide area network mapping table in each node according to the wide area network IP address of the router in each node and the identity address of the terminal; each node obtains an identity-global mapping table according to the identity-wide area network mapping table; and after the router of each node receives the multicast message, forwarding the multicast message according to a preset forwarding strategy and the identity-global mapping table. The application can reduce the transmission delay of data, reduce occupied bandwidth, improve communication efficiency, and has fast recovery time after communication interruption, and is especially suitable for complex tactical communication environment.

Description

Data multicast realization method of high-timeliness communication system

Technical Field

The invention relates to the technical field of multicast communication, in particular to a data multicast realization method of a high-timeliness communication system.

Background

Highly time-sensitive communication systems are also called high-time-sensitive communication systems, which in particular emphasize the ultra-low delay of the transmission and the high availability. The tactical communication system is one of high-timeliness communication systems, in which data communication requirements between various command and combat elements are met by transmitting various tactical communication services, and many tactical communication services are transmitted in a manner of one-to-more and have high timeliness. In order to meet the mobile communication requirement, tactical communication systems generally contain a large number of long-distance wireless links, and have the characteristics of limited bandwidth, large transmission delay and frequent topology change. Based on the service characteristics and the network characteristics, tactical communication is generally required to have high real-time performance, relatively low bandwidth occupation and quick recovery of communication when the network topology changes on the transmission of data services.

In the prior art, a one-to-many or many-to-many information transmission mode is generally realized by adopting a multicast technology, and currently common multicast technologies include an IP multicast technology and an application layer multicast technology, and the basic principles of the multicast technology are that a data transmission tree is established among group members, a transmission path of a data packet is determined through the transmission tree, unnecessary transmission paths and data replication are reduced, and the transmission efficiency of data is improved. However, the existing multicast model superimposes additional protocol interaction and timeout mechanisms in the network to maintain the neighbor relation or the multicast tree, so that the update of the multicast tree is not sensitive enough and the network change cannot be responded in time. In a low bandwidth tactical communications scenario, the more resources are used for multicast protocol messages, the lower the resources reserved for traffic transmission, which will affect the overall performance of the tactical communications network. In addition, the tactical communication network is mainly based on node identity addressing, and in all nodes of a subsystem, members in a multicast group are determined according to identity planning in advance, so that dynamic maintenance of group member information is not needed; the existing multicast technology spends a lot of overhead to maintain the group member information, generates a lot of waste, and also generates unnecessary configuration complexity for the user terminal.

Therefore, when the existing multicast communication technology is used in a high-timeliness communication system, the problems of large communication time delay, large bandwidth occupation and low communication efficiency exist, and the requirement of high-timeliness communication cannot be met.

Disclosure of Invention

In view of this, it is necessary to provide a method for implementing data multicasting in a high-efficiency communication system, so as to solve the problems of large communication delay, large bandwidth occupation and low communication efficiency existing in the conventional high-efficiency communication system during multicasting.

In order to solve the above problems, the present invention provides a method for implementing data multicasting in a high-aging communication system, the high-aging communication system including a plurality of nodes; each node comprises a router and a terminal, the terminal is connected with the router, the router comprises a wide area network IP address, and the method comprises:

Creating unique identity addresses for all terminals of each node respectively;

Establishing an identity-wide area network mapping table in each node according to the wide area network IP address of the router in each node and the identity address of the terminal;

obtaining an identity-global mapping table according to the identity-wide area network mapping table of each node;

and after the router of each node receives the multicast message, forwarding the multicast message according to a preset forwarding strategy and the identity-global mapping table.

Further, the step of establishing an identity-wide area network mapping table in each node according to the wide area network IP address of the router in each node and the identity address of the terminal comprises the following steps:

According to the wide area network IP address of the router in each node, a unicast route interaction table of the router between adjacent nodes is established;

The terminal of each node registers an identity address and a local area network address to the router of the node, and establishes an identity address-local area network relation table in each node;

and the router of each node establishes an identity-wide area network mapping table in each node according to the unicast routing interaction table and the identity address-local area network relation table.

Further, according to the identity-wide area network mapping table of each node, an identity-global mapping table is obtained, including:

the routers of two adjacent nodes synchronize the identity-wide area network mapping tables in the respective nodes through a preset interaction protocol;

The preset interaction protocol is used for defining message messages between adjacent nodes.

Further, the message comprises a node request message, a node regular message and a node update message;

the router of any node requests the router of the adjacent node for the message record of the adjacent node through the node request message;

The router of any node sends the information record owned by the node to the router of the adjacent node through the conventional information message;

the router of any node updates the content of the message record of the node through the node update message.

Further, the service data comprises a target address, and the target address comprises a target terminal identity address or a target multicast address;

Wherein the target multicast address includes an identity address of each multicast member terminal.

Further, after receiving the multicast message, the router of each node forwards the multicast message according to a preset forwarding policy and the identity-global mapping table, including:

after any node receives the service data, judging whether a target address of the service data is a multicast address;

When the target address is a multicast address, forwarding is performed through a preset multicast forwarding method; and when the target address is not the multicast address, forwarding through a preset unicast forwarding method.

Further, when the target address is not a multicast address, forwarding by a preset unicast forwarding method includes:

When a router in any node receives the service data, extracting a target address of the service data, and judging whether the target address is an identity address of a terminal in the node;

And when the target address is the identity address of the terminal in the node, the router in the node encapsulates the service data into a local area network message corresponding to the node, and sends the local area network message to the target terminal corresponding to the target address.

Further, when the target address is a multicast address, forwarding by a preset multicast forwarding method includes:

A multicast address-identity address mapping table is established in advance;

when the destination address is a multicast address, the destination address includes a multicast header;

and after the router in any node receives the service data, determining a target terminal according to a multicast header and the multicast address-identity address mapping table in the service data, and forwarding the service data by a preset multicast forwarding method.

Further, the multicast header includes a point-to-point link multicast header and a broadcast link multicast header;

The point-to-point link multicasting head is used in the point-to-point link type and comprises the number of group members and the group member identity address;

The broadcast link multicast header is used in a broadcast link type and comprises a next hop node indication field, the number of group members and the group member identity address.

Further, when the link type is a point-to-point link, forwarding is performed by a preset multicast forwarding method, including:

After the router of any node receives the multicast header of the point-to-point link, extracting a multicast target membership address in the multicast header of the point-to-point link, and judging whether the identity address of the terminal of the node contains the multicast target membership address or not;

If the identity address of the terminal of the node contains the multicast target member identity address, sending the service data to the multicast target member terminal in the node;

And deleting the identity address of the multicast target member of the node from the multicast target member identity address.

Compared with the prior art, the invention has the beneficial effects that: the node of the high-timeliness communication system has the identity address and the wide area network IP address, and the identity address of the node and the wide area network IP address are separated, so that the node can be directly addressed through the identity address of the node during data communication, and the details of an IP layer are shielded. Because the identity address is often shorter than the length of the wide area network IP address, the overhead of the IP header can be saved, and more control information can be transmitted by the same length of message. By changing multicast addressing from IP address to identity address of node, multicast members are managed according to the identity address, and information of multicast members is not required to be maintained dynamically, so that deployment and management are more flexible. Meanwhile, the terminal is addressed through the service data and the identity-wide area network mapping table of the terminal, the data is forwarded, complex network configuration is simplified, the network is easy to understand, no extra interaction mechanism is needed to be introduced, when the network changes, new multicast forwarding information can be immediately generated, the waiting time generated by the message transmission of the reconstructed multicast tree is completely eliminated, and the communication efficiency is improved. The invention can reduce the transmission delay of data, reduce occupied bandwidth, improve communication efficiency, and has fast recovery time after communication interruption, thereby being applicable to complex tactical communication environments with limited bandwidth, large transmission delay and frequent topology change.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of an application system where a method for implementing data multicasting in a high-aging communication system according to the present invention is located;

fig. 2 is a schematic flow chart of a method for implementing a data multicast of a high-aging communication system according to an embodiment of the present invention;

fig. 3 is a schematic flow chart of a method for implementing data multicast in a high-aging communication system according to another embodiment of the present invention;

FIG. 4 is a flow chart of an embodiment of a Request message interaction flow provided by the present invention;

fig. 5 is a schematic diagram of an embodiment of a multicast object list format of a point-to-point link according to the present invention;

Fig. 6 is a schematic diagram of an embodiment of a multicast object list format of a broadcast link according to the present invention.

Detailed Description

The following detailed description of preferred embodiments of the application is made in connection with the accompanying drawings, which form a part hereof, and together with the description of the embodiments of the application, are used to explain the principles of the application and are not intended to limit the scope of the application.

The invention provides a data multicasting realization method of a high-timeliness communication system, which can well cope with the characteristic requirements of high real-time performance, low bandwidth, high dynamic performance and the like of the high-timeliness communication system such as a tactical communication system and the like through a name and address separation technology and a custom interaction protocol, and improves the communication efficiency of multicast service in the high-timeliness communication system.

The embodiment of the invention provides a data multicast implementation method of a high-timeliness communication system, as shown in fig. 1, fig. 1 is a schematic structural diagram of the high-timeliness communication system, and the high-timeliness communication system comprises a plurality of nodes; each node comprises a router and a terminal, the terminal is connected with the router, the router comprises a wide area network IP address, and the method comprises:

Creating unique identity addresses for all terminals of each node respectively;

In the method of this embodiment, the highly-timeliness node has an identity address and a wide area network IP address, and by separating the identity address of the node from the wide area network IP address, addressing can be directly performed through the identity address of the node during data communication, thereby shielding details of the IP layer. Because the identity address is often shorter than the length of the wide area network IP address, the overhead of the IP header can be saved, and more control information can be transmitted by the same length of message. Meanwhile, the terminal is addressed through the service data and the identity-wide area network mapping table of the terminal, and the data is forwarded, so that complex network configuration is simplified, and the method is easy to understand. The method of the embodiment can reduce the transmission delay of data, reduce occupied bandwidth, improve communication efficiency, and has fast recovery time after communication interruption, and is particularly suitable for complex high-timeliness communication systems with limited bandwidth, large transmission delay and frequent topology change, such as tactical communication systems and the like.

As a specific embodiment, the highly time-efficient communication system includes a tactical communication system, where a unique identity address is created for all terminals of each node, and a router of each node has a wide area network IP address. The wide area network IP address is only used for IP networking, and the route is maintained to be reachable; the upper layer traffic is addressed by the identity address of the user terminal. The identity address of the terminal is unbinding with the network IP address, and the source address and the destination address are both identity addresses in the data sent by the upper layer application. In a communication network, an IPv4 address generally needs to occupy 4 bytes, an IPv6 address generally needs to occupy 16 bytes, and an identity address generally needs only 1 byte after being reduced to an identity number, so that the cost of an IP header can be greatly saved by addressing the identity address. Meanwhile, the address allocation of the local area network is not affected by the external network, and the use is simpler and more convenient. In addition, the multicast members are managed according to the identity addresses, and the information of the multicast members is not required to be dynamically maintained, so that the deployment and management are more flexible.

As a preferred embodiment, the step of establishing an identity-wide area network mapping table in each node according to the wide area network IP address of the router in each node and the identity address of the terminal includes:

As a specific embodiment, firstly, information is interacted among all nodes, and a unicast route interaction table among adjacent nodes and an identity-IP mapping table of a computer in the nodes are established; after the unicast routing interactive table and the identity-IP mapping table are established, the computers of different nodes can carry out service communication.

As shown in fig. 2, the node #1 includes a router #1 and a computer #1, where the identity address of the computer #1 is 01020304H, and the wide area network IP address of the router #1 is 1.1.1.1; node #2 includes router #2 and computer #2, the identity address of computer #2 is 05060708H, and the wide area network IP address of router #2 is 2.2.2.2. In the local area network of the node #1, the local area network IP address of the computer #1 is 192.168.1.2; in the lan of node #2, the lan IP address of computer #2 is 192.168.1.2.

The above scheme will be described in detail below by taking the example of data transmitted by the computer #1 and the computer # 2.

The first step: the computer #1 sends a local area network message with a local area network target IP address of 192.168.1.1 to the router #1, wherein the target address is the identity address of the computer #2 in service data of the local area network message.

And a second step of: after receiving the local area network message sent by the computer #1, the router #1 searches a wide area network IP address of the router #2 in the node #2 corresponding to a target address (namely, an identity address of the computer # 2) in service data to be 2.2.2.2 (a wide area network IP address of a next hop node) according to the identity-IP mapping table, then matches a unicast routing interactive table according to the wide area network IP address, finds a routing out interface, and forwards the service data; the destination address of the traffic data is still the identity address 05060708H of computer # 2.

And a third step of: and after receiving the service data, the router #2 searches the local area network IP address of the corresponding computer #2 in the node according to the target identity address. Because the local area network IP address of the computer #2 belongs to the local area network, the router #2 adds the local area network IP header corresponding to the local area network to obtain the local area network message, and sends the local area network message to the computer #2.

Fourth step: the computer #2 receives the service data, and this time the transmission and reception process is completed.

The processing procedure can show that the data transmitted between the routers only comprises service data, the source address and the destination address are identity addresses, the overhead of a header is saved, the occupied bandwidth is reduced, the communication efficiency is improved, and the method has strong practicability in a tactical communication system.

As a preferred embodiment, establishing an identity-wide area network mapping table of the terminal in each node further includes:

As a specific embodiment, the flow from network provisioning to normal forwarding of traffic data is shown in figure 3,

The first step: the routers of each node will firstly exchange routing protocols, unicast routing exchange tables are established between adjacent routes,

And a second step of: the computer of each node registers the information such as the identity address and the local area network IP address of the computer with the router of the node.

And a third step of: after the computers in the nodes register with the router, the router binds the identity address of the node computer with the wide area network IP (core IP) address of the router, and establishes a corresponding relation.

Fourth step: the routers of different nodes interact through a preset interaction protocol to generate a corresponding relation table (an identity-wide area network mapping table) of the computer identity address and the wide area network IP address, so that all forwarding tables are established, and the forwarding of service data can be started.

The process of transmitting business data in the tactical system is as follows:

The first step: the source computer encapsulates the service data into a local area network IP message and sends the service data to a source router of the node through the local area network;

And a second step of: the source router analyzes the local area network IP message, extracts a destination terminal identity address in the service data, searches a corresponding wide area network IP address according to the destination terminal identity address, uses the searched wide area network IP address to carry out route matching, obtains a next hop router IP address and an outgoing interface, and forwards the service data to the next hop router.

And a third step of: and after receiving the service data, the target router corresponding to the destination terminal searches the registration terminal of the node according to the destination terminal address in the service data, acquires the local area network IP address of the destination terminal according to the local area network registration information after finding the matched terminal, and if the user IP address is the local area network IP address, the router packages the service data into a corresponding local area network IP message and sends the corresponding local area network IP message to the destination terminal.

Fourth step: and the destination terminal receives the message and then sends the message to an upper application program for receiving.

As a preferred embodiment, the message packet includes a node request message packet, a node regular message packet, and a node update message packet;

As a specific embodiment, the message mainly includes a Request message, a Normal message, and an Update message.

The router sends a Request message to the neighbor node, and is used for requesting all the message records held by the router from the neighbor node. After the router is started or restarted, the message is sent, so that the message record of the whole network can be quickly obtained.

And the Normal message is sent to the neighbor node by the router and is used for periodically notifying the neighbor node of the message record owned by the node.

As shown in fig. 4, when the node #1 is started (or restarted), only the message record of the present node is currently recorded. Node #1 sends out a Request message through each interface (route enabling interface), node #2 is directly connected with node #1, after receiving the Request message of node #1, node #2 sends Normal message to node #1, and simultaneously records information of node # 1. The Normal message sent by node #2 contains the message record of node #2 itself and the message record that was not learned from the receiving interface (i.e., the Normal message). Node #1 updates its own message record table after receiving these message records.

The interaction mode of the Normal message comprises the following steps:

1. And (5) sending at fixed time. The node periodically sends Normal messages out through the interface, and typically uses horizontal bisection (i.e., a message record learned from an interface is not sent back from the interface), encapsulates the message record in an active state allowed to be sent from the interface into Normal messages and sends them out.

2. Responding to the Request message. After receiving the Request message, the interface receiving the Request message will send an active status message record (i.e. normal message with horizontal segmentation) allowed to be sent from the interface.

Update messages are used to make the message record content change information propagate as fast as possible within the network. The Update message is divided into: deleting message, adding message, updating message, the content is single message record with variation. And after receiving the Update message, other nodes directly Update the message record of the node.

The interaction flow of Update message is as follows:

The first step: after the node obtains the information of the message record change of the node through the interface protocol, the message record table is updated.

And a second step of: the node announces the message record change to each direct-connected node through an Update message.

And a third step of: after receiving the notification, the direct connection node updates the corresponding message record content and sends out the Update message through each interface (excluding the message source interface).

The node only diffuses and updates the Update message when receiving the Update message for the first time, and directly discards the Update message when receiving the Update message for the second time.

Since in the high-timeliness communication system, there is a one-to-one, one-to-many or many-to-many situation, as a preferred embodiment, the service data includes a target address, and the target address includes a target terminal identity address or a target multicast address;

According to the technical scheme, the data transmitted between the routers only comprise service data, a destination address in unicast service data is an identity address of a node, and a destination address of multicast service data is a multicast address planned by a tactical communication system. Therefore, before the communication of the high-timeliness system starts, a corresponding relation table of the multicast address planned by the high-timeliness system and the identity address of the multicast member contained in the multicast address can be written into the router in advance, so that the identity address of the multicast member is obtained according to the multicast address when the message is forwarded. By defining the multicast address, the target address can be set as a plurality of terminals, so that the same service data can be forwarded to the plurality of target terminals conveniently.

When the target address comprises a single target terminal identity address or a target multicast address, the forwarding logic of the router changes, and whether the target address of each packet of data among the routers is the target multicast address is judged; if yes, executing the preset multicast forwarding strategy, otherwise, executing the unicast forwarding strategy.

As a preferred embodiment, when the target address is not a multicast address, forwarding by a preset unicast forwarding method includes:

As a preferred embodiment, when the target address is a multicast address, forwarding by a preset multicast forwarding method includes:

A multicast address-identity address mapping table is established in advance;

As a preferred embodiment, the multicast header includes a point-to-point link multicast header and a broadcast link multicast header;

As a specific embodiment, the router is responsible for generating multicast forwarding information at the first forwarding of multicast data and appends it as a multicast header before traffic data. The multicast header and forwarding policy are different according to the link type in order to minimize header overhead. The link types are classified into point-to-point links and broadcast links.

In a point-to-point link, the multicast header contains only one multicast object list, as shown in fig. 5, fig. 5 is a message format of the multicast object list of the point-to-point link. It consists of a membership field and a series of group membership numbers. Each identity number is 1 byte in length, is programmed according to the address, is converted from the identity address, and is unique in each tactical communication subsystem, so that a group member can be uniquely identified in multicast service. The multicast object list is used for indicating a destination node list to which multicast data sent from a certain interface needs to be sent.

In the broadcast link, a next hop node indication field is added to the multicast object list compared with the point-to-point link, the next hop node indication field is used for identifying nodes in a plurality of multicast object lists, if the nth bit of the flag is 1, the nth node of the multicast object list is marked, only the marked node can forward the data, and the unmarked node only receives the data and does not forward the data. This is done to avoid repeated forwarding of messages by other nodes of the multicast path tree. The message format of the multicast object in the broadcast link is shown in fig. 6.

As a preferred embodiment, when the link type is a point-to-point link, forwarding by a preset multicast forwarding method includes:

As a specific embodiment, for a certain router, there are three types of multicast messages received: multicast messages of terminals in the node, multicast messages of point-to-point links and multicast messages of broadcast links. The routers perform different forwarding policies for them, respectively.

When the router receives the multicast message of the terminal in the node, the forwarding strategy is as follows:

the first step: removing the IP part of the local area network, extracting service data, and acquiring the identity numbers of all group members according to the target multicast address and the group member mapping table in the service data;

And a second step of: obtaining a corresponding wide area network IP address for each identity number through a name and address separation mechanism;

and a third step of: carrying out unicast routing table matching on each wide area network IP address to obtain an interface and the IP address of the next hop node;

Fourth step: classifying the identity addresses of group members corresponding to the wide area network IP addresses with the same outgoing interfaces into a class, and constructing a new multicast object list according to the interface types and referring to the identity addresses corresponding to the next hop wide area network IP addresses to obtain new service data (comprising a multicast object list and content data);

Fifth step: and forwarding the constructed new service data to all outgoing interfaces.

When the router receives the multicast message of the point-to-point link, the forwarding strategy is as follows:

the first step: extracting each identity address in the message, checking whether the identity address belongs to a local area network, if so, turning to the second step, otherwise, turning to the third step;

And a second step of: constructing an IP header with the local area network IP address corresponding to the identity address as a target, encapsulating service data to obtain a local area network IP message, forwarding the local area network IP message to a local area network, deleting the identity address from a multicast object list, and forwarding to a third step;

And a third step of: and (3) sequentially executing the second, third, fourth and fifth steps in the ' when the router receives the forwarding strategy of the multicast message of the terminal in the node ' on the rest nodes of the multicast object list ', and ending.

When the router receives the multicast message of the broadcast link, the forwarding strategy is as follows:

The first step: extracting each identity address in the message, checking whether the identity address belongs to a local area network, if so, turning to a second step, otherwise, discarding the message, and ending;

And a third step of: checking whether the identity address of the local area network is marked in the multicast object list, if so, turning to a fourth step, otherwise, ending;

Fourth step: and (3) sequentially executing the second, third, fourth and fifth steps of the forwarding strategy of the multicast message received by the router from the terminal in the node for the rest nodes in the multicast object list, and ending.

As can be seen from the above-mentioned forwarding policy, in the forwarding process of multicast, the first hop router (source router) is responsible for generating a multicast object list according to the group members and unicast routes, and the subsequent routers step by step perform split forwarding on the nodes of the multicast object, so that the final effect is that the multicast data is forwarded along the forwarding tree generated according to the unicast routes, which is similar to the forwarding of the existing IP multicast based on the multicast forwarding tree.

In order to verify the effect of the technical scheme, a test network shown in fig. 1 is built. The nodes are all routing exchange nodes in physical form, parameters such as bandwidth, speed and the like of wireless access equipment for accompanying measurement are set to be close to parameter values in an actual tactical communication scene, and a tactical communication system multicast service network environment is simulated by constructing a multicast network physical topology.

Each node in the network consists of a router, a computer terminal, wireless access equipment and wired access equipment. The router has realized the functions of unicast routing forwarding, PIM-SM routing protocol and the multicast forwarding scheme of the method of the application, and is used for comparing and verifying the functions and performances of the multicast forwarding strategy of the method of the application. The wireless access device and the wired access device are respectively used for realizing the access of the wireless broadcast link and the wired point-to-point link. And running high-timeliness communication system multicast service test software on the computer terminal, and transmitting and receiving multicast service data.

Enabling unicast routing protocol at each interface of router, and starting to test function and performance of multicast strategy after route convergence in network is completed.

Three multicast groups are used for multicast test, and the three multicast groups are respectively:

Multicast identity number 0xF1, member is node # 1\node # 2\node # 3\node #4;

multicast identity number 0xF3, member is node # 5\node # 6\node # 7\node # 8\node # 9\node #10;

Multicast identity number 0xFF, members are all nodes.

The end-to-end delay and the multicast recovery time are tested separately as follows.

(1) End-to-end delay testing

In the network of fig. 1, multicast service data of multicast identification numbers 0xF1, 0xF2, and 0xFF are transmitted to computer terminals of nodes #1, #5, and #2, respectively, at intervals of 250ms, 1000 times. Meanwhile, other test data with 50% of broadcast link bandwidth are added in the network by using test software, and the condition of certain link load is simulated. And respectively recording data receiving conditions in the node #3, the node #6 and the node #7, and counting the maximum time delay and the average time delay. For a single data transmission, if the number of packets received within the time window τ of the test delay is n, the measured average delay ET can be expressed as:

The test was repeated 10 times, i.e., n=20, and the average value of the test results is shown in table 1. Table 1 shows the delay test results of the multicast strategy according to the present invention.

TABLE 1

Recording point	Maximum time delay (ms)	Average time delay (ms)
			Node #3	155	131
Node #6	15	11
			Node #7	162	131

And then, correspondingly adding three groups of IP multicast groups, running PIM-SM on each node router, configuring node #1 as RP, repeating the above test by using an IP multicast test tool, and repeating the test 10 times, namely, when n=20, wherein the average value of the test results is shown in table 2. Table 2 shows the delay test results using IP multicast.

TABLE 2

It can be seen that the maximum delay after applying the multicast strategy of the present invention is significantly shorter than that of IP multicast. This is because in PIM-SM, before the multicast tree is switched to SPT, data is first aggregated to RP and then distributed to members, and there is a duplicate transmission path, which increases the maximum delay.

(2) Multicast recovery time test

In the network of fig. 1, the slave node #5 continuously transmits multicast service data with a multicast identity number of 0xFF, at intervals of 125ms. After receiving the data, all members disconnect the wired link between the node #5 and the node #3, record the packet loss number from the moment when the received data is recovered, estimate the recovery time of the multicast service data after the network changes, and record the estimated recovery time. And then, correspondingly adding an IP multicast group, running PIM-SM on each node router, configuring the node #1 as RP, and repeating the test by using an IP multicast test tool.

The test was repeated 20 times, and the average value of the test results is shown in table 3. Table 3 shows the multicast recovery time test results.

TABLE 3 Table 3

Multicast scheme	Unicast recovery time (ms)	Multicast recovery time (ms)
			The method of the invention	375	375
PIM-SM	375	1250

It can be seen that in the multicast method of the present invention, the multicast data communication immediately returns to normal after the unicast route is recovered, and no additional waiting time is required. In the IP multicast method, communication is recovered after about 875ms is additionally waited, because the PIM-SM needs to prune or graft the message again in the process of disconnection and recovery of the unicast route, which generates transmission delay overhead.

The test results show that no extra waiting time delay is generated in the process of recovering the multicast communication after the network topology changes, and the method has better time delay performance in a narrow-band link, has better performance than PIM-SM in the two aspects, and can meet the requirements of a tactical communication system on the multicast service communication.

The invention discloses a data multicast realization method of a high-timeliness communication system, which comprises a plurality of nodes; each node comprises a router and a terminal, the terminal is connected with the router, the router comprises a wide area network IP address, the identity address of the node and the wide area network IP address are separated, the node can be directly addressed through the identity address of the node during data communication, and details of an IP layer are shielded. Because the identity address is often shorter than the length of the wide area network IP address, the overhead of the IP header can be saved, and more control information can be transmitted by the same length of message. Meanwhile, the terminal is addressed through the service data and the identity-wide area network mapping table of the terminal, and the data is forwarded, so that complex network configuration is simplified, and the method is easy to understand. The method of the embodiment can reduce the transmission delay of data, reduce occupied bandwidth, improve communication efficiency, and has fast recovery time after communication interruption, and is particularly suitable for complex tactical communication environments with limited bandwidth, large transmission delay and frequent topology change. The method of the invention attaches the multicast information header to the multicast data message header, and cooperates with the corresponding multicast forwarding strategy to carry out multicast forwarding scheme, thereby solving the problems of frequent network change and large influence of low link bandwidth on multicast service in high-timeliness communication systems such as tactical communication systems and the like, and being better applied to high-timeliness communication scenes with high real-time, low bandwidth and high dynamic.

The method of the invention uses a name and address separation mechanism to change multicast addressing from IP to node identity, manages group members according to the node identity, and does not dynamically maintain the group member information. The user terminal receives and transmits the multicast information directly according to the node identity, and does not need to join the multicast group. By appending multicast forwarding information in the custom header, there is no additional interaction mechanism. When the network changes, the subsequent data packet can immediately generate new multicast forwarding information according to the new unicast routing information, so that the waiting time generated by the message transmission of the reconstructed multicast tree is completely eliminated. The method can well meet the characteristic requirements of the tactical communication system, such as high real-time performance, low bandwidth, high dynamic performance and the like, effectively improves the transmission efficiency of multicast data in the high-timeliness communication system, and provides reference for the design of a general multicast scheme of the high-timeliness communication system.

The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention.

Claims

1. A data multicast implementation method of a high-timeliness communication system comprises a plurality of nodes; each node comprising a router and a terminal, the terminal being connected to the router, the router comprising a wide area network IP address, the method comprising:

Creating unique identity addresses for all terminals of each node respectively;

After the router of each node receives the multicast message, forwarding the multicast message according to a preset forwarding strategy and the identity-global mapping table;

Obtaining an identity-global mapping table according to the identity-wide area network mapping table of each node, wherein the identity-global mapping table comprises:

The preset interaction protocol is used for defining message messages between adjacent nodes;

the multicast message comprises service data;

The length of the identity address is shorter than the length of the wide area network IP address;

After receiving the multicast message, the router of each node forwards the multicast message according to a preset forwarding strategy and the identity-global mapping table, including:

when the target address is a multicast address, forwarding is performed through a preset multicast forwarding method;

When the target address is a multicast address, forwarding by a preset multicast forwarding method, including:

A multicast address-identity address mapping table is established in advance;

After a router in any node receives the service data, determining a target terminal according to a multicast header and the multicast address-identity address mapping table in the service data, and forwarding the service data by a preset multicast forwarding method;

The multicast header comprises a point-to-point link multicast header and a broadcast link multicast header;

2. The method for implementing data multicasting in a highly aged communication system according to claim 1, wherein establishing an identity-wide area network mapping table in each node based on the wide area network IP address of the router in each node and the identity address of the terminal comprises:

3. The method for implementing data multicasting in a highly aged communication system according to claim 1, wherein the message packet includes a node request message packet, a node regular message packet, and a node update message packet;

4. The method for implementing data multicasting in a highly aged communication system according to claim 1, wherein the service data comprises a destination address, and the destination address comprises a destination terminal identity address or a destination multicast address;

5. The method for implementing data multicasting in a highly aged communication system according to claim 4, further comprising:

and when the target address is not the multicast address, forwarding through a preset unicast forwarding method.

6. The method for implementing data multicasting in a highly aged communication system according to claim 5, wherein when the target address is not a multicast address, forwarding is performed by a preset unicast forwarding method, comprising:

7. The method for implementing data multicasting in a high-efficiency communication system according to claim 1, wherein when the link type is a point-to-point link, forwarding is performed by a preset multicast forwarding method, including: