CN113259499A

CN113259499A - Addressing method for cross-domain network

Info

Publication number: CN113259499A
Application number: CN202110350505.0A
Authority: CN
Inventors: 冯飞; 王建; 张旭; 曹璐; 赵晓飞; 刘勇
Original assignee: Aerospace Dongfanghong Satellite Co Ltd
Current assignee: Aerospace Dongfanghong Satellite Co Ltd
Priority date: 2021-03-31
Filing date: 2021-03-31
Publication date: 2021-08-13
Anticipated expiration: 2041-03-31
Also published as: CN113259499B

Abstract

A cross-domain network-oriented addressing method comprises the following steps for a certain device: the device fixed identification GUID further comprises an organization unique identifier OUI and a randomly generated device unique identifier EI, a certain section of bit position in the OUI is a fixed value, and time and device information are configured according to the GUID address to generate EI; recording unique GUID of each device; the device networking identifier NID further comprises a domain identifier DI, a subnet identifier SNI and a device identifier EI; DI is used for distinguishing the communication segment where different devices are located, SNI is used for distinguishing different sub-networks in the domain, and EI is used for distinguishing nodes in the sub-networks; the network address of the equipment adopts a network address dynamic allocation strategy to carry out network segment dynamic allocation and IP address dynamic allocation; device-readable tags, defining namespaces based on different subnets within different communication segments, each device having a unique device-readable tag within each namespace.

Description

Addressing method for cross-domain network

Technical Field

The invention relates to an addressing method for a cross-domain network, in particular to an addressing method applied to a three-dimensional grid type cross-domain network.

Background

Satellite communication technology has been greatly developed in recent decades, however, at present, the function of the satellite is mainly as a signal relay, providing bent pipe type signal forwarding, and the capabilities of networking and store forwarding are relatively lacking. In order to implement spatial networking and integrated network convergence, a series of technical challenges need to be solved at a physical layer, a data link layer, a network layer and a transmission layer, wherein a unified network layer design is a key point for implementing efficient multi-network convergence and interconnection.

Cross-domain networks also present network problems while having good performance. The dynamic change of network topology is caused by a large number of nodes in a network and the rapid movement among the nodes, meanwhile, the relative motion between the nodes and the ground in a low earth orbit satellite plane is strong, and the connection with a ground terminal is frequently switched. The special mobility characteristic brings dynamic challenges to addressing and routing of the network, and the traditional addressing and routing strategies in the ground network cannot adapt to cross-domain internet application. The method and the device for IP addressing of the polar orbit low orbit satellite network provide an IP addressing strategy of a mobile user in the polar orbit low orbit satellite network, the ground is divided into a plurality of large areas, each large area is allocated with a fixed IP address section, and the IP addresses of the user are all in the IP address sections of the large areas, so that the updating frequency of the IP addresses of the mobile user is greatly reduced, but the work of simultaneously considering the port addressing of an inter-satellite network and on-satellite equipment in the existing research is less.

Therefore, designing a high-efficiency unified addressing system of the system is an important research subject for improving the performance of the stereoscopic grid type cross-domain network. At present, no suitable network addressing design suitable for high-speed cross-domain networks exists.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method overcomes the defects of the prior art, provides an addressing method facing to a cross-domain network, and comprises the following steps for certain equipment: the device fixed identification GUID further comprises an organization unique identifier OUI and a randomly generated device unique identifier EI, a certain section of bit position in the OUI is a fixed value, and time and device information are configured according to the GUID address to generate EI; recording unique GUID of each device; the device networking identifier NID further comprises a domain identifier DI, a subnet identifier SNI and a device identifier EI; DI is used for distinguishing the communication segment where different devices are located, SNI is used for distinguishing different sub-networks in the domain, and EI is used for distinguishing nodes in the sub-networks; the network address of the equipment adopts a network address dynamic allocation strategy to carry out network segment dynamic allocation and IP address dynamic allocation; device-readable tags, defining namespaces based on different subnets within different communication segments, each device having a unique device-readable tag within each namespace.

The purpose of the invention is realized by the following technical scheme:

a cross-domain network-oriented addressing method comprises the following steps for a certain device:

the device fixed identification GUID further comprises an organization unique identifier OUI and a randomly generated device unique identifier EI, a certain section of bit position in the OUI is a fixed value, and time and device information are configured according to the GUID address to generate EI; recording unique GUID of each device;

the device networking identifier NID further comprises a domain identifier DI, a subnet identifier SNI and a device identifier EI; DI is used for distinguishing the communication segment where different devices are located, SNI is used for distinguishing different sub-networks in the domain, and EI is used for distinguishing nodes in the sub-networks;

the network address of the equipment adopts a network address dynamic allocation strategy to carry out network segment dynamic allocation and IP address dynamic allocation;

device-readable tags, defining namespaces based on different subnets within different communication segments, each device having a unique device-readable tag within each namespace.

According to the addressing method, a 24-bit random hash code is generated as EI according to the GUID address configuration time, the configuration equipment type and the equipment production number.

In the addressing method, the 2 nd bit position from the lower bit position of the first byte of the OUI is set as 1.

In the addressing method, the method for determining the networking identifier NID of the device comprises the following steps:

intercepting a certain section of byte of the GUID as a temporary NID for the new network access equipment, and allowing the new network access equipment to use if the temporary NID does not conflict with the existing NID; otherwise, selecting the NID which is closest to the temporary NID and is not used for the new network access equipment; and after the NID is determined by the new network access equipment, the network access equipment confirms the new network access equipment through forwarding.

The addressing method adopts an approximation degree searching method to select the NID closest to the temporary NID.

According to the addressing method, the equipment in the subnet addresses the server, judges whether the temporary NID conflicts with the existing NID or not, and confirms the NID which is finally determined.

In the addressing method, the last two bytes of the GUID are intercepted as the temporary NID for the new network access device.

The addressing method establishes a database for storing addressing information of the equipment.

Compared with the prior art, the invention has the following beneficial effects:

(1) the high-efficiency fusion of network layers is realized, and the system has good expandability, usability, stability and controllability;

(2) the uniqueness and the effectiveness of the addressing of the equipment ensure that the physical network access can realize the addressing communication, and the lengthy network planning and parameter distribution configuration processes in the early stage of task execution are reduced. (ii) a

(3) All the network nodes are dynamically and quickly indexed for various addressing, so that addressing conflict is prevented;

(4) and the equipment addressing root server performs validity confirmation, uniqueness detection and collision avoidance on the addressing allocation of the whole cross-domain Internet.

Drawings

FIG. 1 is a unified addressing architecture for cross-domain interconnect network devices;

FIG. 2 is a diagram of a quadbit addressing mapping relationship;

FIG. 3 is a flow chart of cross-domain internetworking autonomous address assignment;

FIG. 4 is a flow chart of NID assignment;

FIG. 5 is a schematic diagram of IP address allocation based on space domain subnet address planning;

FIG. 6 is a schematic diagram of dynamic allocation of network segments;

FIG. 7 is a flow of dynamic IP address assignment for a new network-accessing node device;

fig. 8 is a flow of dynamic IP address allocation for a mobile network access node device.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Aiming at the requirements of a 'grid type' networking mode and a service scene of a cross-domain internet, the invention firstly carries out uniform distribution on four types of equipment addressing such as equipment fixed identification, equipment networking identification, equipment network address, equipment readable label and the like; secondly, designing a uniform access management mechanism for equipment addressing, providing dynamic and rapid indexes for all kinds of addressing at the network nodes, and preventing addressing conflict. The technical approach of the part is shown in figure 1.

The invention uniformly distributes four types of equipment addressing, such as equipment fixed identification, equipment networking identification, equipment network address, equipment readable label and the like, and simultaneously adopts an equipment addressing uniform access management mechanism to provide dynamic rapid index for all types of addressing at network nodes so as to prevent addressing conflict. The address mapping relationship is shown in fig. 2.

The basic idea of network autonomous address allocation is that the cross-domain interconnection unit of each subnet takes charge of the function of a subnet addressing server, a device addressing server in the subnet is responsible for address allocation in the subnet, the uniqueness and the effectiveness of the device addressing in the subnet ensure that the physical network access can realize addressing communication, and the tedious network planning and parameter distribution configuration processes in the early stage of task execution are reduced. The equipment addressing server in the sub-network is periodically connected with the space-based or foundation equipment addressing root server, the equipment addressing root server is registered to confirm the addressing information allocated to the access node equipment, and the equipment addressing root server performs validity confirmation, uniqueness detection and collision avoidance on the addressing allocation of the whole cross-domain internet. The basic flow is shown in fig. 3.

(1) Device fixed identity allocation mechanism

The device fixed Identifier, i.e. a Global Unique Identifier (GUID), is a permanently assigned, non-modifiable identification tag before each device leaves the factory. The format of the GUID is specified as shown in table 1.

TABLE 1

Field(s)	Length of	Means of
			OUI	24bit	Unique Identifier of organization (organization Unique Identifier)
EI	24bit	Randomly generated device Unique Identifier (Equipment Unique Identifier)

When generating a new GUID for a new device, the OUI organizationally unique identifier is first assigned. In order to ensure that the GUID can identify that the address is self-configured when being read by other devices, the 2 nd bit position from the lower bit of the first byte of the OUI needs to be 1, which indicates that the GUID is a custom address.

And then, in the process of configuring the last 24 bits, generating a 24-bit random hash code as the number of the equipment by using a special address allocation computer according to the GUID address configuration time, the configuration equipment type and the random number generation algorithm and parameter corresponding to the equipment production number configuration in the series of types, establishing a database to record all the equipment information configured with the GUID, and ensuring the uniqueness and the disorder of the fixed identifier of the equipment configured each time.

(2) Equipment networking identification distribution mechanism

The device networking Identifier, i.e. Node Identifier (NID), is a unique Identifier of the Node for link layer transmission. In consideration of the particularity of the application scenario of the integration of space, air, ground and sea, the device needs to identify each device of the cross-domain internet by the NID and acquire identification information of the subnet where the device is located based on the NID. Therefore, the invention designs a double-byte NID, and divides the NID into three parts of a domain identifier, a subnet identifier and an equipment identifier, wherein the domain identifier is used for distinguishing the communication segments where different equipment is positioned, the subnet identifier is used for distinguishing different subnets in the domain, and the equipment identifier is used for distinguishing nodes in the subnets.

NID field specification, as shown in table 2.

TABLE 2

The structure can extract information such as the subnet and the subnet interior, and is convenient for the link layer to directly perform data processing analysis on the ID. According to the format, at present, each communication segment can support 4096 nodes at most, in subsequent research, the domain identification segment can be expanded as required for subnet identification, 65536 devices are supported at most, and the requirement of large-scale networking addressing is met.

The NID setting includes two steps of node pre-selection and interactive determination after network access, and the specific NID setting flow is shown in fig. 4.

The new network-accessing node device intercepts the last two bytes of the GUID as a temporary NID, sends a NID notification application to the network-accessing node device, and requests the network-accessing node device to assist in forwarding the NID notification application to a device addressing server on a cross-domain interconnection unit in the subnet so as to determine whether the NID can be used for link layer communication. And the equipment addressing server in the subnet inquires whether the NID conflicts with the existing NID according to the temporary NID information carried in the NID notice, if not, the equipment in the subnet allows the equipment in the network to use the NID to carry out link layer communication, otherwise, the NID is subjected to approximation degree search, one unused NID which is closest to the NID is selected as the distributed NID, and NID confirmation information is replied. And the in-network node equipment makes the new network access node equipment clearly determine the distributed NID by forwarding the NID confirmation information to the new network access node equipment, so that the process of dynamically distributing the NID is completed.

The equipment address allocation server plans for the second-layer networking ID and the third-layer IP address, and stores readable label definitions of the equipment for the user to form a complete equipment unified addressing system.

(3) Device network address assignment mechanism

The device network address, i.e. the device IP address, is used as an identification number of the device in the network during the application transmission process, and plays an important role in the network transmission. In order to ensure that the equipment can be allocated to obtain a proper IP address after being accessed to the network, reliable transmission can be ensured, and the IP address does not conflict with the network addresses of other equipment, the invention adopts a network address dynamic allocation strategy which comprises network segment dynamic allocation and IP address dynamic allocation, ensures that a cross-domain interconnection unit (backbone node) can temporarily use an IP network segment to perform dynamic IP allocation on the node equipment, and realizes the quick and flexible allocation of the network address.

The equipment addressing system easy to distinguish and manage is the premise of ensuring the normal operation of the network. The invention designs a unified addressing system of equipment aiming at the requirements of a rasterization networking mode and a service scene of a cross-domain internet, and the basic idea is that a preset network addressing distribution scheme is stored by an equipment addressing root server, a two-layer networking ID domain identifier and a three-layer one-level subnet IP network segment of each subnet domain of a space segment and a ground segment are covered and transmitted to a cross-domain internet unit address distribution server, and the server uniformly distributes the IP network segment and the domain identifier to each subnet in each subnet domain, so that the unified addressing of the equipment in the subnets is realized. The basic flow of unified addressing of devices is shown in fig. 5.

Network segment dynamic allocation

The network segment dynamically allocates a specific flow, as shown in fig. 6.

A subnet address allocation server exists in a cross-domain interconnection unit (backbone node) of each subnet, the subnet address allocation server randomly selects an IP network segment through a predefined algorithm, provides IP address dynamic allocation for newly added node equipment, performs network access address conflict detection, and reallocates the IP network segment if the IP network segment conflicts with the newly added node equipment. The cross-domain interconnection unit (backbone node) and the distributed server or the root server send a network segment address confirmation message, the subnet address allocation server sends a network segment allocation information application to the equipment addressing root server, and the equipment addressing root server performs network segment conflict query. If not, replying network segment distribution information confirmation and agreeing to the subnet address distribution server to continue using the network segment; if conflict occurs, a network segment with the same number of hosts and unused is allocated when the network segment allocation information is replied for confirmation, and the subnet address allocation server needs to notify all nodes to reset IP addresses according to the newly allocated IP network segment. If the IP network segment address pool of a certain subnet has used up all IP addresses, the same IP network segment application process needs to be carried out again.

IP address dynamic allocation

The node access network is divided into two types, namely a new node which is added into the network after being started and a mobile access network in which the node moves from the previous subnet to another subnet.

a) Dynamic IP address allocation of new network access node equipment

When a new node accesses the network, a subnet address allocation server on the backbone node allocates addresses. If the subnet address allocation server can be connected to the space-based or foundation-based equipment addressing root server, the allocation information is reported to the equipment addressing root server at the same time, and the equipment addressing root server performs unified information processing. The IP address of the node device newly joining the subnet is dynamically allocated to a specific flow, as shown in fig. 7.

1) After the node equipment joins the network, according to the information such as the subnet number, one IP address of the network segment is selected as an application IP, and an IP request is initiated to the network address server.

2) After receiving the request, the network address server inquires the request IP in the local IP table. If the request IP can be found, executing the step 3; if the request IP is not found, step 4 is executed.

3) And if the request IP conflicts with other allocated IPs, the request IP is considered to be unreasonable, and at the moment, the network address server selects an idle IP from the idle IP pool as reply content, sends the reply content to the request node equipment and executes the step 5.

4) And verifying the feasibility of the IP in the local network segment. If the request is feasible, the IP is used as reply content and is sent to the request node equipment, and the step 5 is executed; if not, go to step 3.

5) And the node equipment receives the reply, stores the reply IP as a transmission IP in the local, sends an ACK response and executes the step 6.

6) And the network address server receives the ACK response, adds the IP of the request node into a local IP table and ends the dynamic allocation process.

b) Dynamic IP address allocation for mobile network access node equipment

The dynamic IP address assignment process of the mobile network access node device is shown in fig. 8.

If the node device moves from the previous subnet to a new subnet, the destination subnet allocates the address according to the IP address allocation flow of the new network access node device, reports the address allocation information to the device addressing root server, the device addressing root server notifies the subnet address allocation server of the original subnet, recovers the original IP address of the mobile network access node device and notifies the new IP address and the subnet section of the device of the node in the subnet.

(4) Device-readable label assignment mechanism

Because the device fixed identifier, the device networking identifier, and the device network address identifier are machine-readable identifiers for mutual device identification used for device transmission communication, it may be difficult for an actual user to understand a specific device in a task process. Therefore, the user-oriented device readable label needs to be designed, and the user performs personalized label distribution on the device of the current task, so that a complex and tedious format setting mode is omitted, and the user can conveniently and intuitively perform communication and operation control.

A plurality of namespaces are defined aiming at different subnets in different communication segments, and the namespaces are named by using character tags which are maximum 128 bytes in length and can be dynamically configured. Except that node devices under the same namespace are specified to not use the same label, node devices may reuse the same label between different namespaces.

The label multiplexing mode increases the maneuverability and flexibility of executing multiple tasks by the cross-domain internet, and meanwhile, the naming space is divided according to the subnets, and the naming space is directly distributed to the equipment through the subnets of the naming space. And each node is ensured to have a unique label, the probability of error identification of the user on the equipment can be reduced, and the fault tolerance of the whole cross-domain internet on the equipment is improved.

In the cross-domain internet, the whole network information is dynamically managed by the subnet address allocation server, and each node device can complete the query management of the whole network information only by interacting with a server program. Information such as equipment identifier access is stored in an information database in a root server, and a cross-domain interconnection unit (backbone node) information management server has the authority of accessing an operation information database, so that operation such as query application of general node equipment to network information in a network is completed by interacting with the cross-domain interconnection unit information management server.

The table format in the database is shown in table 3.

TABLE 3

Content of field	Abbreviations	Byte number (byte)	Description of field
				Fixed mark	GUID	6	As a unique identification of a device
Networking identification	NodeID	1	Application to link layer transport communications
				Readable label	Tag	128	Character string in namespace
Network address	IP	4	IP service transport address
				Type of device	Type	1	Type of device
Node authority	Auth	1	Priority authority to which node belongs

The data access flow is as follows: the new node device finds the IP address of the information management server closest to the node by inquiring the addressing server of the cross-domain Internet device. And then establishing a link with the information management server, and after the link is completed, the node equipment initiates an information request service to the server. And the server searches the information database according to the request of the node equipment and obtains a query result. And finally, the information management server replies the query result to the node equipment and releases the link. The whole information access process is completed.

Those skilled in the art will appreciate that those matters not described in detail in the present specification are well known in the art.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications of the present invention without departing from the spirit and scope of the present invention by using the methods and technical contents disclosed above.

Claims

1. A cross-domain network-oriented addressing method is characterized in that for a certain device, the method comprises the following steps:

2. The addressing method as claimed in claim 1, wherein a 24-bit random hash code is generated as EI based on GUID address configuration time, configuration device type, device production number.

3. The addressing method according to claim 1, characterized in that the 2 nd bit position from the lower byte of the OUI is set to 1.

4. The addressing method according to claim 1, wherein the device networking identifier NID is determined by:

5. The addressing method according to claim 4, characterized in that the NID closest to the tentative NID is selected using an approximation search method.

6. Addressing method according to claim 4, characterized in that the device addressing server in the subnet determines if the tentative NID conflicts with an existing NID and confirms the NID finally determined.

7. The addressing method according to claim 4, wherein the last two bytes of the GUID are intercepted for the new network-enabled device as the tentative NID.

8. Addressing method according to one of claims 1 to 7, characterized in that a database is established for storing addressing information of the devices.