CN118695323B - An improved OSPF protocol routing metric method for wireless ad hoc networks - Google Patents

Abstract

The present invention discloses a method for improving OSPF protocol routing metrics for wireless ad hoc networks, including S1. running the OSPF protocol; starting routing protocol software, running the OSPF protocol and configuring routers and interfaces. S2. resetting the interface type; resetting the interface type connected to the wireless broadcast link to the Point‑to‑MultiPoint interface type. S3. link quality detection; the router sends a link detection message to a neighboring router to detect the link quality. S4. setting the link quality; the router sets the link quality for neighboring routers reachable by the Point‑to‑MultiPoint interface respectively. S5. routing calculation. The router performs the shortest path calculation according to the new link quality. The present invention can be used to apply the OSPF protocol in wireless ad hoc networks, to optimize the OSPF link quality setting, and to improve routing metrics.

Description

An improved OSPF protocol routing metric method for wireless ad hoc networks

Technical Field

The invention relates to the technical field of communication networks, in particular to an OSPF protocol routing metric improvement method for wireless ad hoc networks.

Background Art

In recent years, with the widespread application of unmanned platforms such as drones/cars/ships in emergency communications for disaster relief and military confrontation, the demand for the development of wireless ad hoc networks has become stronger. At the same time, the rapid development of wireless communication technology has also brought new opportunities for wireless ad hoc networks. Wireless ad hoc networks do not rely on basic settings such as base stations, and have the characteristics of being centerless, self-organizing, highly dynamic topology, bandwidth-limited, and high-jitter links. Wireless ad hoc networks rely on routing protocols for networking communications. Some researchers have proposed the application of the OSPF protocol to build large wireless ad hoc networks. The OSPF protocol is an autonomous system internal routing protocol based on link state, and one version, OSPFv2, has been widely used in the Internet. However, the OSPF protocol is usually applied to wired networks, and the application of the OSPF protocol in wireless ad hoc networks will bring new problems.

Specifically, for broadcast networks with multiple access points, OSPF uses designated routers (DRs) to reduce resource consumption. In this case, the router in the broadcast network can only configure the link quality of the interface, but cannot set the same link quality for other routers in the multi-point access network.

However, when OSPF is applied in wireless networks, which are usually broadcast networks, since link quality changes frequently and dynamically, when an OSPF router needs to set different link qualities for other routers, it is difficult for the OSPF router to set different link qualities for each neighbor, resulting in incorrect routing metrics in the routing table.

Summary of the invention

In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for improving the OSPF protocol routing metrics for wireless ad hoc networks, which can optimize the OSPF protocol link quality settings for wireless ad hoc networks, optimize the routing metric calculation, and enhance the application capability of wireless links.

To achieve the above object, the present invention proposes a method for improving OSPF protocol routing metrics for wireless ad hoc networks, comprising the following steps:

S1: Run OSPF protocol on all routers and verify OSPF operation status;

S2: For each interface connected to the wireless broadcast link, reset its interface type to Point-to-MultiPoint interface type; modify the network topology and the type of LSA generated by the router to support point-to-point link quality modification;

S3: Link quality detection: Calculate the short-term detection delay based on the time of sending and receiving link detection messages;

S4: Set link quality for neighbor routers; by resetting the new link quality for each neighbor and spreading it in the network with LSA, routers in the entire network can use the differentiated link quality for calculation when calculating the routing table;

S5: Router R calculates the shortest path based on the new link quality.

Further, step S1 specifically includes the following sub-steps:

S1.1. Start the routing protocol software and run the OSPF protocol;

S1.2. Configure the router ID and the area to which the interface belongs.

S1.3. Check and verify the OSPF operation status.

Further, step S2 specifically includes the following sub-steps:

S2.1. For router R _i ( , Refers to the number of routers), use the command "do show ip ospfinterface" to check whether the router interface type 'Network type' field is Broadcast type;

S2.2. For each interface IF _broadcast of type Broadcast, reset the interface type by using the command "IP ospf networkPoint-to-MultiPoint";

S2.3. Use the command "ip ospf cost [cost]" to set the link quality of the Point-to-MultiPoint type interface.

Further, step S3 specifically includes the following sub-steps:

S3.1. Router R _i obtains the neighbor list of Point-to-MultiPoint type interface { };

in, , is the total number of neighbor routers of router R _i under this interface, is the j-th neighbor router of router R _i ;

S3.2, traverse the neighbor list, starting with the jth neighbor router of router R _i For example, router R _i generates The kth link detection message and send;

in, represent The message type, represent The sending time, represent Serial number;

S3.3. The jth neighbor router of router R _i Receive the kth link detection message After that, send The kth probe reply message To router R _i ;

in, represent The message type, exist Add one to the serial number;

S3.4, router R _i receives After that, record and ;

in, for Address, for Arrival time.

Further, the short-term detection delay t _i =t _rcv-i -t _snd-i ;

Wherein, t _snd-i represents the sending time of the link detection message; t _rcv-i represents the receiving time of the link detection message.

Further, step S4 specifically includes the following sub-steps:

S4.1. Router R _i traverses the neighbor router list and finds the address Neighbor routers;

S4.2, link quality modification, modification arrival The link quality is The kth short-term detection delay ;

S4.3. Use the command "do show ip ospf detail" to check whether the link quality to each neighbor router has been modified.

Furthermore, in step S1.2, router-id is set to the smallest interface address of router R _i .

Furthermore, in step S1.3, the neighbor of each router R _i in the network is checked by the command "do show ip ospf neighbor" to ensure that each router has established a correct adjacency relationship; the routing table of each router R _i in the network is checked by the command "do show ipospf route".

Further, in step S1.3, the routing table of each router _Ri in the network is checked by the command "do show ip ospf route".

Further, in step S3, router _Ri compares the variation of the short-term detection delay to detect the route switching frequency.

The present invention can achieve the following technical effects:

1. The present invention can realize setting differentiated link qualities for multiple neighbor nodes when OSPF is applied to a wireless ad hoc network, thereby avoiding the single link quality problem caused by a DR router.

2. The present invention can realize dynamic update of link quality of Point-to-MultiPoint interface in OSPF and avoid static link quality setting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall flow of the OSPF protocol routing metric improvement method for wireless ad hoc networks of the present invention;

FIG. 2 is a schematic diagram of a link type modification solution proposed by the present invention.

DETAILED DESCRIPTION

The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

As shown in FIG. 1-FIG 2, the present invention provides a method for improving OSPF protocol routing metrics for wireless ad hoc networks to solve the problems caused by the application of OSPF protocol to wireless ad hoc networks.

The present invention changes the interface type of the OSPF router applied to the wireless ad hoc network from the broadcast type to the point-to-multipoint type through link type modification, modifies the network topology and the LSA type generated by the router, thereby supporting point-to-point link quality modification, and resetting the new link quality for each neighbor, and spreading it in the network with LSA, so that the routers in the whole network can use the differentiated link quality for calculation when calculating the routing table. In addition, through link quality detection, a dynamic link quality is set for each neighbor to optimize the routing metric calculation and improve the application capability of the wireless link.

The OSPF protocol routing metric improvement method for wireless ad hoc networks of the present invention mainly includes the following specific steps:

S1: Run OSPF on all routers and verify OSPF operation status, including the following sub-steps:

S1.1. Start the routing protocol software and run the OSPF protocol. Enter the _routing protocol software and , The OSPF protocol is started on the routers (the total number of routers in the network).

S1.2. Configure the router ID and the area to which the interface belongs. Create an OSPF process and enter the OSPF configuration mode. Use the command "ospf router-id [Router-Id]" to configure the router ID, which is used to distinguish different routers in the network. Usually, router-id can be set to the smallest interface address of router R _i . Use the command "ip ospf area [Area]" to configure the area to which the router interface belongs, thereby controlling the propagation range of routing information in the OSPF protocol. For the configuration of router-id and area, refer to RFC2328.

S1.3. Check and verify the OSPF operation status. Use the command "do show ip ospf neighbor" to check the neighbors of each router R _i in the network to ensure that each router has established the correct adjacency relationship. Use the command "doshow ip ospf route" to check the routing table of each router R _i in the network.

S2: for each interface connected to the wireless broadcast link, resetting its interface type to a Point-to-MultiPoint interface type, specifically including the following sub-steps:

S2.1. For router R _i ( ), use the command "do show ip ospf interface" to check whether the 'Network type' field of the router interface type is Broadcast. By default, OSPF sets the interface type of the wireless broadcast link to Broadcast by default. In a wireless broadcast link, one interface corresponds to multiple neighbors. In this type, you can only set the link quality of the interface, and you cannot set the link quality for each neighbor.

S2.2. For each interface connected to a wireless broadcast link, the default type is Broadcast. Reset the interface type by using the command "IPospf network Point-to-MultiPoint". A Point-to-MultiPoint type interface has the link status from the interface to each one-hop reachable neighbor in the link state database of the router, and the link quality can be set in the link state database for each one-hop reachable neighbor of the interface.

S2.3. Set the link quality of the Point-to-MultiPoint type interface through the command "ip ospf cost [cost]". In this way, the link quality values of the one-hop reachable neighbors in the link state database will be modified at the same time. Use the command "do show ip ospf interface" to check whether the interface type 'Network type' field is changed to Point-to-MultiPoint type, and whether the interface link quality 'Cost' field has been modified.

S3: Link quality detection, router R _i ( ) By sending link detection messages to all neighboring routers that are reachable within one hop and receiving detection reply messages, the short-term detection delay is obtained to detect the link quality. Specifically, the following sub-steps are included:

S3.1. Router R _i obtains the neighbor list of Point-to-MultiPoint type interface { }（ , is the total number of neighbor routers of router R _i under this interface), is the j-th neighbor router of router R _i .

S3.2, traverse the neighbor list, starting with the jth neighbor router of router R _i For example, router R _i generates The kth link detection message and send.

in, represent The message type, represent The sending time, represent The serial number of the

S3.3. The jth neighbor router of router R _i Receive the kth link detection message After that, send The kth probe reply message To router R _i .

in, represent The message type, exist The serial number is incremented by one.

S3.4, router R _i receives After that, record and ;

in, for Address, for Arrival time.

S3.4.1. Router R _i calculation The kth short-term detection delay :

S3.4.2. Router R _i records the short-term detection delay two-tuple .

S3.4.3. If the router R _i does not receive , then The kth short-term detection delay If it is set to 10000, it means the link is down.

S3.5, router R _i compares the short-term detection delay variation to detect the routing switching frequency and prevent routing switching from being too frequent.

S3.5.1. Router R _i calculates the short-term detection delay variation . represent The k-1th short-term detection delay.

S3.5.2, router R _i will detect the short-term delay change Short-term detection delay threshold For comparison, if Less than This indicates that the link quality has not changed much. for : .

S4: Router R _i sets the link quality for the neighboring router. This includes the following sub-steps:

S4.1. Router R _i traverses the neighbor router list and finds the address Neighbor router:

S4.1.1. If its IP is the same as your own IP, it means it is your own router and no operation is performed.

S4.1.2, if its IP is different from its own IP, according to the short-term detection delay two-tuple , get the value in step 3 The kth short-term detection delay .

S4.2, link quality modification. Since the Point-to-MultiPoint interface actually contains multiple Point-to-Point type connections in the link state database, each Point-to-Point type connection corresponds to a neighbor router. Each connection has a link quality parameter to mark the link quality of the neighbor router that the connection can reach. Short-term detection delay is an important basis for evaluating the quality of the path. Therefore, modify the arrival The link quality is The kth short-term detection delay .

S4.3. Use the command "do show ip ospf detail" to check whether the link quality to each neighbor router has been modified.

Experimental setup:

This experiment constructs a three-node topology to verify the OSPF protocol routing metric improvement method. Three routers running the OSPF protocol form a wireless broadcast network:

R1 (router-id: 10.59.8.120, area: 0);

R2 (router-id: 10.59.8.100, area: 0);

R3 (router-id: 10.59.8.105, area: 0);

Three routers belong to the same domain. Each router has two neighbors. Take R1 as an example. For R2, This experiment compares the changes in the routing metric values in the routing table before and after the link type is modified.

Experimental results:

As shown in Figure 2, before the link type is modified, the routers form a star network, and the link quality from router R1 to R2 and R3 is the same and cannot be distinguished. (R2) and The link quality of (R3) is 100. After the link type is modified, the nodes form a fully connected network. After link quality detection, R1 to The short-term detection delay of (R2) is 10, R1 to The short-term detection delay of (R3) is 100. Therefore, R1 to (R2) and The link quality of (R3) is set to 10 and 100 respectively.

The following shows the OSPF neighbors and routing tables of each node after routing convergence. The OSPF neighbors and routing tables of node R1 (10.59.8.120) are as follows:

(config)#do show ip ospf neighbor

Neighbor ID Pri State Up Time Dead Time Address Interface

10.59.8.100 1 Full/DROther 11m28s 31.270s 10.59.8.100 eno1:10.59.8.120

10.59.8.125 1 Full/DROther 4m36s 31.807s 10.59.8.125 eno1:10.59.8.120

(config)#do show ip ospf route

============OSPF network routing table==============

N 10.59.8.100/32 [10]area:0.0.0.0

Via 10.59.8.100,eno1

N 10.59.8.120/32 [0]area:0.0.0.0

directly attached to eno1

N 10.59.8.125/32 [60]area:0.0.0.0

Via 10.59.8.100,eno1

The OSPF neighbors and routing table of node R2 (10.59.8.100) are as follows:

(config)#do show ip ospf neighbor

Neighbor ID Pri State Up Time Dead Time Address Interface

10.59.8.120 1 Full/DROther 10m59s 33.050s 10.59.8.120 enx2:10.59.8.100

10.59.8.125 1 Full/DROther 3m59s 31.064s 10.59.8.125 enx2:10.59.8.100

(config)#do show ip ospf route

============OSPF network routing table==============

N 10.59.8.100/32 [0]area:0.0.0.0

Directly attached to enx2

N 10.59.8.120/32 [50]area:0.0.0.0

Via 10.59.8.120, enx2

N 10.59.8.125/32 [50]area:0.0.0.0

Via 10.59.8.125, enx2

The OSPF neighbors and routing table of node R3 (10.59.8.125) are as follows:

(config)#do show ip ospf neighbor

Neighbor ID Pri State Up Time Dead Time Address Interface

10.59.8.100 1 Full/DROther 11m33s 36.253s 10.59.8.100 enx0:10.59.8.125

10.59.8.120 1 Full/DROther 11m41s 39.026s 10.59.8.120 enx0:10.59.8.125

(config)#do show ip ospf route

============OSPF network routing table==============

N 10.59.8.100/32 [1000]area:0.0.0.0

Via 10.59.8.100, enx0

N 10.59.8.120/32 [1000]area:0.0.0.0

Via 10.59.8.120, enx0

N 10.59.8.125/32 [0]area:0.0.0.0

Directly attached to enx0

The next hop of the route from router R1 (10.59.8.120) to router R3 (10.59.8.125) is R2 (10.59.8.100), and the route metric is 60, which means that the link quality value of 50 between R2 and R3 has been successfully spread to R1, and the shortest path calculation has been performed at this node. In addition, there are three Router-LSAs in the link state database of each router, and there is no Network-LSA in the broadcast type network. This shows that the OSPF protocol route metric optimization is successful, and the router has successfully adapted to the wireless networking environment.

Any process or method description in the flowchart of the present invention or described in other ways herein can be understood as a module, segment or part of a code including one or more executable instructions for implementing the steps of a specific logical function or process, which can be implemented in any computer-readable medium for use by an instruction execution system, device or equipment, and the computer-readable medium can be any medium containing storage, communication, propagation or transmission programs for use by execution systems, devices or equipment, including read-only memories, magnetic disks or optical disks, etc.

In the description of this specification, the description with reference to the terms "embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, those skilled in the art can combine or combine different embodiments or examples described in this specification and the features therein without causing any contradiction.

Although the above contents have shown and described the embodiments of the present invention, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims (10)

1. A method for improving OSPF protocol routing metrics for wireless ad hoc networks, characterized in that it comprises the following steps: S1: Run OSPF protocol on all routers and verify OSPF operation status; S2: For each interface connected to the wireless broadcast link, reset its interface type to Point-to-MultiPoint interface type; modify the network topology and the type of LSA generated by the router to support point-to-point link quality modification; S3: Link quality detection: Calculate the short-term detection delay based on the time of sending and receiving link detection messages; S4: Set link quality for neighbor routers; by resetting the new link quality for each neighbor and spreading it in the network with LSA, routers in the entire network can use the differentiated link quality for calculation when calculating the routing table; S5: Router R calculates the shortest path based on the new link quality. 2. The method for improving OSPF protocol routing metrics for wireless ad hoc networks according to claim 1, wherein step S1 specifically comprises the following sub-steps: S1.1. Start the routing protocol software and run the OSPF protocol; S1.2. Configure the router ID and the area to which the interface belongs. S1.3. Check and verify the OSPF operation status. 3. The method for improving OSPF protocol routing metrics for wireless ad hoc networks according to claim 1, wherein step S2 specifically comprises the following sub-steps: S2.1. For router R _i , use the command “do show ip ospf interface” to check whether the router interface type ‘Network type’ field is Broadcast type; S2.2. For each interface IF _broadcast of type Broadcast, reset the interface type by using the command "IP ospf networkPoint-to-MultiPoint"; S2.3. Use the command "ip ospf cost [cost]" to set the link quality of the Point-to-MultiPoint type interface. 4. The method for improving OSPF protocol routing metrics for wireless ad hoc networks according to claim 1, wherein step S3 specifically comprises the following sub-steps: S3.1. Router R _i obtains the neighbor list of Point-to-MultiPoint type interface { }; in, , is the total number of neighbor routers of router R _i under this interface, is the j-th neighbor router of router R _i ; S3.2, traverse the neighbor list, router R _i generates neighbor routers The kth link detection message and send; in, represent The message type, represent The sending time, represent Serial number; S3.3. The jth neighbor router of router R _i Receive the kth link detection message After that, send The kth probe reply message To router R _i ; in, represent The message type, exist Add one to the serial number; S3.4, router R _i receives After that, record and ; in, for Address, for Arrival time. 5. The OSPF protocol routing metric improvement method for wireless ad hoc networks according to claim 4, characterized in that the short-term detection delay t _i =t _rcv-i -t _snd-i ; Wherein, t _snd-i represents the sending time of the link detection message; t _rcv-i represents the receiving time of the link detection message. 6. The method for improving OSPF protocol routing metrics for wireless ad hoc networks according to claim 4, wherein step S4 specifically comprises the following sub-steps: S4.1. Router R _i traverses the neighbor router list and finds the address Neighbor router: S4.1.1. If its IP is the same as your own IP, it means it is your own router and no operation is performed; S4.1.2, if its IP is different from its own IP, according to the short-term detection delay two-tuple , get the value in step S3 The kth short-term detection delay ; S4.2, link quality modification, modification arrival The link quality is The kth short-term detection delay ; S4.3. Use the command "do show ip ospf detail" to check whether the link quality to each neighbor router has been modified. 7. A method for improving OSPF protocol routing metrics for wireless ad hoc networks as described in claim 2, characterized in that in step S1.2, router-id is set to the smallest interface address of router _Ri . 8. A method for improving OSPF protocol routing metrics for wireless ad hoc networks as described in claim 2, characterized in that in step S1.3, the neighbors of each router R _i in the network are checked by command "do show ip ospf neighbor" to ensure that each router has established an adjacency relationship. 9. A method for improving OSPF protocol routing metrics for wireless ad hoc networks as claimed in claim 8, characterized in that in step S1.3, the routing table of each router _Ri in the network is viewed through the command "do show ip ospf route". 10. The OSPF protocol routing metric improvement method for wireless ad hoc networks as claimed in claim 4, characterized in that in step S3, router _Ri compares the short-term detection delay variation to detect the routing switching frequency.