CN101119307A - a routing method - Google Patents

Abstract

The invention relates to a routing method, comprising: receiving a routing request and a bandwidth expectation value; calculating the reserved bandwidth occupancy rate according to its own bandwidth occupancy rate; judging whether the reserved bandwidth occupancy rate belongs to a linear domain, and if so, setting the actual allocated bandwidth value equal to the bandwidth Expected value; allocate reserved bandwidth, and judge whether it is a destination node, if so, generate and forward successful routing response information, if not, forward the routing request; receive routing response information, and judge whether it is a successful routing response information, If yes, forward the successful routing response information, otherwise delete the reserved bandwidth and then forward the failed routing response information. The routing method of the present invention can balance the business load of the network, avoid the problem of network resource bottlenecks in general routing protocols, and distribute the task of routing transmission to the entire network range, thereby reducing the queuing and other control overheads of business transmission of some heavy-load nodes. At the same time, it has the advantage of improving the utilization rate of network resources.

Description

a routing method

technical field

The invention relates to a routing method, in particular to a load balancing routing method with dynamic bandwidth allocation applied to wireless networks, and is suitable for systems such as mobile self-organizing networks and wireless local area networks.

Background technique

Communication nodes in wireless networks have the characteristics of limited resources, limited energy, and limited receiving capabilities. These characteristics require nodes to adopt appropriate routing methods to efficiently realize end-to-end communication between source nodes and destination nodes. The design goal of the wireless network routing method is to consider the scarcity of network resources and time-varying network status as much as possible, adapt to the dynamic and rapid changes of the network topology, and improve the scalability of the network and the robustness of multi-hop routing. The existing routing methods in wireless networks can be divided into two categories: active routing and on-demand routing.

Most active routing protocols of wireless networks follow the routing table-driven routing method of wired networks, and there are still unavoidable defects when applied to wireless networks: no matter whether the routes in the routing table are applied to wireless networks or not, a large amount of control is required. Group maintenance, periodic broadcast of control information and complex routing table maintenance will consume a lot of limited network resources and node energy; rapid changes in topology make a lot of routing information outdated quickly, resulting in waste of resources.

In most on-demand routing protocols, a node only sends a routing request packet to search when it needs a new path to transmit a data packet, and each node that receives a routing request packet will not consider the current traffic load of the node at all. Intensity, the routing request packet is blindly forwarded to the destination node, and after receiving the routing request packet, the destination node returns the response packet in reverse according to the shortest path experienced. When the demand for routing request packets and routing maintenance packets is infrequent, on-demand routing protocols can have lower routing overhead, higher packet delivery rate and operating efficiency than active routing protocols, and are more adaptable to frequent and effective wireless network topology changes. The use of limited bandwidth resources and battery power. The on-demand routing scheme is an effective method when there are few communicating node connections, but it is relatively inefficient when there are frequent requests for routing request packets and routing maintenance packets or when there are many communicating node connections. In most on-demand routing schemes, as the traffic load increases, the loss of routing information caused by congestion will trigger the generation of more routing requests and routing maintenance control packets, thereby further aggravating network congestion. Since control packets usually have a higher priority than data packets, the transmission of more control packets will further aggravate the congestion state in the network.

The main reason for the above wireless network routing problem is that most of the routing protocols in the wireless network fail to consider the balanced distribution of routing tasks among the mobile nodes in the network, so that the result of the protocol operation is that many routes generated converge in the network. A small number of nodes and links in the network will lead to unbalanced overall transmission load of the network. Unbalanced data service flow transmission will quickly deplete the power of heavy-load nodes. With the increase of power-depleted nodes, the connectivity of the network will be weakened, which will eventually lead to large queuing delays and long-term delays for heavy-load nodes. High packet loss rate leads to network congestion and bottlenecks, so that the average end-to-end delay and packet loss rate of routing connections with these heavy-load nodes as intermediate nodes will increase, and the reliability of data transmission in the network is poor.

A better way to solve the limited power and bandwidth in the wireless network is to consider the network congestion of each node in the network in the design of the routing method, and use a reasonable load for the network according to the load and congestion of each node in the network during the routing selection process. The balanced strategy keeps the network running continuously, efficiently, and stably, and optimizes the overall performance of the network, such as the successful delivery rate of packets, the average end-to-end delay of packet transmission, and additional routing control overhead, thereby improving the transmission quality of network traffic.

However, in the existing load balancing routing method, the selected load level measurement is relatively single and static, and the bandwidth utilization and transmission efficiency are less improved, so there are certain limitations in practicality. The existing load balancing routing protocol mainly infers the current path or node load size based on a certain characteristic parameter in network information transmission, such as: the buffer queue length of the routing node, the end-to-end service flow delay or the transmission time of the routing node. number of business flows, etc. Most of the routing protocols selected by the existing load balancing routing protocols are to collect the above-mentioned characteristic parameters of the nodes in the network, and then calculate and select the transmission path. This technical solution will cause the following problems: 1. The characteristic parameters reflect the load characteristics. The utility is limited. For example, the "DLAR" (Dynamic Load-Aware Routing) routing protocol accumulates the buffer queue lengths of each intermediate node and selects the one with the smallest total value as the routing path. Various factors have a great influence, so the reliability of routing is relatively low; 2. Existing routing protocols fail to maximize the transmission capacity of nodes. Existing routing protocols, such as "LBAR" routing protocols, select the most However, in fact, suboptimal but feasible routing paths are also of considerable value. In addition, existing routing protocols often only use binary logic expressions of (0, 1) for node congestion or unblocking, which cannot make full use of Internet resources.

Contents of the invention

The purpose of the present invention is to provide a routing method through some embodiments, overcome the problems existing in the prior art, and solve the problem that the load status of network nodes cannot be fully considered in the existing routing method, it is difficult to achieve load balancing, and thus the utilization efficiency of network resources is poor problems, so as to more effectively utilize network resources, reduce local load levels, and improve network performance.

In order to achieve the purpose of the present invention, some embodiments provide a routing update method, including the following steps:

Step 1. Receive the routing request sent by the superior node, and collect the bandwidth expectation contained in the routing request;

Step 2, detecting the bandwidth occupancy rate of the self, and calculating the reserved bandwidth occupancy rate according to the bandwidth occupancy rate and the bandwidth expectation value;

Step 3. Determine whether the reserved bandwidth occupancy rate belongs to the linear domain. If so, set the actual allocated bandwidth value to be equal to the expected bandwidth value, and perform step 4. If not, generate a failed routing response message, and perform step 8;

Step 4. Allocate the reserved bandwidth according to the actual allocated bandwidth value, and judge whether it is the destination node, if so, generate a successful routing response message, and perform step 8, if not, then perform step 5;

Step 5, forwarding the routing request to its own subordinate node;

Step 6, receiving the routing response information, judging whether the routing response information is a successful routing response information, if so, then performing step 8, otherwise performing step 7;

Step 7, delete the allocated reserved bandwidth;

Step 8: Send the routing response information to the superior node.

The above embodiments of the present invention calculate the load capacity of the node according to the bandwidth occupancy rate of the node itself and the bandwidth expectation in the service flow routing request, and implement dynamic allocation and recovery of the bandwidth occupied by the service flow, so that the service load of the network can be balanced in a timely and accurate manner , to avoid the bottleneck problem of network resources in general routing protocols, by repeatedly implementing the above method to explore all feasible paths, the task of routing transmission is distributed to the entire network, thereby reducing the queuing and other control overhead of service transmission of some heavy-load nodes, It can improve the utilization rate of network resources.

Furthermore, the above step 3 can be specifically:

Step 30, determine whether the reserved bandwidth occupancy rate belongs to the linear domain, if so, set the actual allocated bandwidth value equal to the expected bandwidth value, and perform step 4, if not, then perform step 31;

Step 31, judging whether the reserved bandwidth occupancy rate belongs to the index domain, if so, then calculate the actual bandwidth allocation value, and execute step 32, otherwise, generate a failed routing response message, and execute step 8;

Step 32: Collect the minimum bandwidth value, determine whether the actual bandwidth allocation value is greater than or equal to the minimum bandwidth value, if so, perform step 4, otherwise, generate a failed routing response message, and perform step 8.

By adopting the above technical solution, all paths satisfying at least the minimum value of the bandwidth can be found, not just the best transmission path, so the network resources can be utilized to the maximum extent, and the utilization ratio of the network resources is improved.

The technical solutions of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

Description of drawings

FIG. 1 is a flow chart of Embodiment 1 of the routing method of the present invention.

FIG. 2 is a schematic diagram of a successful routing request process in Embodiment 1 of the routing method of the present invention.

FIG. 3 is a graph of the actual allocated bandwidth function in Embodiment 1 of the routing method of the present invention.

FIG. 4 is a graph of the transmission cost function in Embodiment 1 of the routing method of the present invention.

FIG. 5 is a schematic diagram of a failed routing request process in Embodiment 1 of the routing method of the present invention.

Detailed ways

Embodiment one

As shown in Figure 1, it is a flowchart of a specific embodiment 1 of the routing method of the present invention, and this embodiment 1 includes the following steps:

Step A1, the lower-level node receives the routing request sent by the upper-level node, and collects the expected bandwidth contained in the routing request;

Step A2, the lower-level node detects its own bandwidth occupancy rate, and calculates the reserved bandwidth occupancy rate according to the bandwidth occupancy rate and bandwidth expectation value according to the following formula (1), that is, the calculation formula for the reserved bandwidth occupancy rate:

${\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; K</span>}}{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Among them, U _ij ′ is the reserved bandwidth occupancy rate after the lower-level node allocates the expected bandwidth value for the routing request, U _ij is the bandwidth occupancy rate of the lower-level node before the expected bandwidth value is assigned to the routing request, and K is the routing request. Expected bandwidth value, B _W is the total bandwidth value of this node;

Step A3, determine whether the reserved bandwidth occupancy rate belongs to the linear domain, if so, set the actual allocated bandwidth value equal to the expected bandwidth value, and execute step A4, if not, generate a failed routing response message, and execute step A8;

Step A4. Allocate the reserved bandwidth according to the actual allocated bandwidth value, and judge whether it is the destination node, if so, generate a successful routing response message, and execute step A8, if not, execute step A5;

Step A5, forwarding the routing request to its own subordinate node, where the routing request includes at least an expected bandwidth value;

Step A6, receiving the routing response information sent back by its own subordinate node, judging whether the routing response information is a successful routing response information, if so, performing step A8, otherwise performing step A7;

Step A7, the subordinate node deletes the reserved bandwidth allocated by itself for the routing request;

Step A8, the lower-level node sends the routing response information to its upper-level node.

In step A3 of this embodiment, judge whether it belongs to the linear domain according to the reserved bandwidth occupancy rate, then calculate the actual allocated bandwidth value, and perform admission control on the service flow of the routing request, if so, then this node can transmit the service flow . Further, the actual allocated bandwidth value can also be calculated according to the minimum value of the service flow bandwidth included in the routing request, and admission control can be performed. The specific implementation method is realized through the following steps:

Step A30, judging whether the reserved bandwidth occupancy rate belongs to the linear domain, that is, judging whether the reserved bandwidth occupancy rate U _ij ′ is smaller than the first limit value Δ ₁ of the bandwidth occupancy rate, and if so, setting the actual allocated bandwidth value to be equal to the expected bandwidth value, that is, according to Formula (2) calculates the actual bandwidth allocation value, and executes step A4, if not, then executes step A31;

B(U _ij )＝K 0≤U _ij ′＜Δ ₁ (2)

Wherein, B(U _ij ) is the actual allocated bandwidth value, which is a function of the bandwidth occupancy rate U _ij , and Δ ₁ is the first limit value of the bandwidth occupancy rate, which is a preset constant, and the determination of its value is related to the capacity of the node;

Step A31, judging whether the reserved bandwidth occupancy rate belongs to the exponential domain, that is, judging whether the reserved bandwidth occupancy rate U _ij ′ is smaller than the second limit value Δ ₂ of the bandwidth occupancy rate, and if so, calculate the actual bandwidth allocation according to the reserved bandwidth occupancy rate Value, that is, calculate the actual allocated bandwidth value according to formula (3), and perform step A32, if not, you can set the actual allocated bandwidth value to be equal to "0", that is, the bandwidth cannot be allocated, and a failed routing response message is generated, and step A8 is performed:

$B\left(u_{\mathrm{ij}}\right)=K\frac{1-u_{\mathrm{ij}}^{\&prime;}}{1-{\mathrm{\&Delta;}}_1}$ Δ1≤U _ij ′＜Δ ₂ (3)

Wherein, Δ ₂ is the second limit value of the bandwidth occupancy rate, which is a preset constant, and the determination of its value is related to the capacity of the node;

Step A32, determine whether the actual bandwidth allocation value is greater than or equal to the minimum bandwidth value, the minimum bandwidth value is collected from the routing request, if so, then perform step A4, otherwise, the actual allocated bandwidth value can be set equal to "0", that is If the bandwidth cannot be allocated, a routing reply message of failure is generated, and step A8 is executed.

When further judging whether the actual bandwidth allocation value meets the requirements of the minimum bandwidth, when sending or forwarding the routing request, the minimum bandwidth should be further included in the routing request, and the minimum bandwidth should be considered, so that the searched feasible path is not only kept The optimal transmission path with smooth transmission can also be searched for other feasible transmission paths, which can improve the utilization rate of network resources.

An example of the above-mentioned technical solution is: according to the specific situation of network transmission capacity, set Δ ₁ =0.3, Δ ₂ =0.66, the bandwidth expectation value of a certain routing request is 3Mbps, the minimum bandwidth value is 2Mbps, and the total bandwidth value of this node is 10Mbps, and the current bandwidth occupancy rate is 10%, then the reserved bandwidth occupancy rate can be calculated according to formula (1) $u_{\mathrm{ij}}^{\&prime;}=u_{\mathrm{ij}}+\frac{K}{B_W}=0.1+3/10=0.43,$ Because 0.3<0.43<0.66, the reserved bandwidth occupancy rate belongs to the exponential domain, and the actual allocated bandwidth value should be calculated according to formula (3) $B\left(u_{\mathrm{ij}}\right)=K\frac{1-u_{\mathrm{ij}}^{\&prime;}}{1-{\mathrm{\&Delta;}}_1}=3\&times;(1-0.43)/(1-0.3)=2.44\mathrm{Mbps},$ Also, if 2.44>2, the minimum bandwidth requirement is met, and the reserved bandwidth can be allocated to it.

In the above-mentioned technical solution for calculating the actual allocated bandwidth value, the bandwidth occupancy rate of the node has been divided into three areas by the preset first and second limit values Δ ₁ and Δ ₂ of the bandwidth occupancy rate, and respectively correspond to the transmission cost function curve Corresponding to the three areas in , it reflects the link congestion status described by the node. The first and second limit values Δ ₁ and Δ ₂ of the bandwidth occupancy rate are preset according to the specific conditions of the node, and the determination of the value is related to The capacity of the node is related to meet different network transmission requirements. The curve diagram of the transmission cost function is shown in Figure 4, and the transmission cost function formula is shown in the following formula (4):

Among them, C(U _ij ) is the transmission fee, C(Δ ₁ ) is a constant value set according to the specific transmission conditions of the network, and N/A can be set to 0, because the "other" value range of U _ij can be ignored.

It can be seen from Fig. 4 that the intermediate node acts as a subordinate node when receiving a routing request, and its link transmission cost function curve is divided into three regions: linear domain, exponential domain and unavailable domain. Specifically, in the linear domain, that is, within the linear domain of 0≤U _ij ≤Δ ₁ , the transmission cost C(U _ij ) increases linearly with the bandwidth occupancy rate U _ij of the service flow; when Δ ₁ ≤U _ij ≤ In the exponent range of Δ ₂ , the transmission cost C(U _ij ) increases exponentially with the bandwidth occupancy rate U _ij of the service flow; in the unavailable range of Δ ₂ ≤ U _ij ≤ 1, since this part of It is assigned to the rerouting business flow, so the source node, that is, the business flow of the superior node cannot directly apply for this part of the bandwidth, so there is no need to consider the transmission cost C(U _ij ) of this domain.

In this embodiment, the reserved bandwidth occupancy rate cannot be less than zero, so the value range of the above-mentioned reserved bandwidth occupancy rate is correspondingly divided into three areas, and the formula for calculating the actual allocated bandwidth value within the three value ranges can be summarized For formula (5):

$\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="K"\; filenames="A20071012025600181.png,A20071012025600191.png"\; state="\{\{state\}\}">K</figure-callout></span>}& \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; \&Delta;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ \mathrm{<span\; class="notranslate">\; K</span>}\frac{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}& {\mathrm{<span\; class="notranslate">\; \&Delta;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&le;</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; \&Delta;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ \mathrm{<span\; class="notranslate">\; 0</span>}& {\mathrm{<span\; class="notranslate">\; \&Delta;</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}^{<span\; class="notranslate">\; \&prime;</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

As shown in Figure 2, it is a schematic diagram of the routing request process of the specific embodiment of the routing method of the present invention. In the specific execution process of the above-mentioned embodiment, the source node S sends the routing request to the intermediate node A, and then the intermediate node A sends the routing request in turn. To the intermediate nodes B and C, and finally sent to the destination node D, in the above process, the nodes that send the routing request can be collectively referred to as the superior node, and the nodes that receive the routing request are collectively referred to as the subordinate node, then the source node S is the superior node , the destination node D is a lower-level node, and the intermediate nodes A, B, and C are both upper-level nodes and lower-level nodes because they forward routing requests, and perform different operations at different stages.

In the specific implementation process of this embodiment, when a service is initiated, the source node S first calculates the bandwidth expectation value and the bandwidth minimum value according to its own service flow transmission information, and the bandwidth expectation value corresponds to the bandwidth requirement that can smoothly transmit network video streams or data streams , and the minimum bandwidth value refers to the minimum bandwidth requirement under the hard quality of service of the business, and then sends a routing request to the intermediate node A, that is, a lower-level node, including the expected bandwidth value and the minimum bandwidth value. Then in step A1, the lower-level node receives the routing request from the upper-level node, and receives the expected bandwidth value and the minimum bandwidth value at the same time.

In the technical solution of this embodiment, the graph of the above calculation of the actual allocated bandwidth function is shown in Figure 3, the horizontal axis is the bandwidth occupancy rate of the node, which is divided into three sections by _Δ1 and _Δ2 , and the vertical axis is the actual allocated bandwidth value, and the corresponding bandwidth occupancy rate is also divided into three areas. The shaded area 1 is the difference between the reserved bandwidth occupancy rate and the existing bandwidth occupancy rate after the node reserves bandwidth for this routing request, that is, this routing request The routing requirements of , project this segment onto the curve of the actual allocated bandwidth value, forming a shaded area 2, which is the admission bandwidth allocated by the node for this routing request. The values of Δ ₁ and Δ ₂ divide the bandwidth occupancy rate into three value ranges, and the values of Δ ₁ and Δ ₂ can be further set according to the specific situation of the node to meet different network transmission requirements.

The advantage of not allocating bandwidth in Δ ₂ ≤ U _ij ≤ 1 and other unavailable domains is that due to the particularity of the wireless network environment, factors such as node movement often lead to link disconnection, resulting in rerouting services flow. The rerouting service flow will cause great interference to the ongoing normal transmission service flow, so it is necessary to allocate a relatively fixed bandwidth for the rerouting service flow, so when Δ ₂ ≤ U _ij ≤ 1 Within the availability domain, bandwidth is reserved for rerouting service flows.

After the admission control is completed, in step A4, firstly, the bandwidth is reserved according to the actual allocated bandwidth value, and then the lower-level node judges whether it is the destination node of this routing request. Replying a successful routing reply message, if the subordinate node is not the destination node, continue to forward the routing request including the expected bandwidth value and the minimum bandwidth value to the subordinate node of the subordinate node. After forwarding the routing request, the node waits for the routing response information replied by its subordinate nodes. If it succeeds, it forwards the successful routing response information to its upper-level node and waits to receive the service flow. Otherwise, if it receives a failed routing response information, it deletes The bandwidth reserved for this service flow, and forwards the failed routing response information to its upper-level node.

In the schematic diagram of the routing request process shown in Figure 2, each intermediate node and destination node executes the process of the routing method embodiment 1 of the present invention as a subordinate node when receiving the routing request, and Figure 2 shows a schematic diagram of a successful routing request . The source node S intends to transmit a data stream of a specified traffic volume to the destination node D. Among them, A, B, and C are intermediate nodes, responsible for routing and transmitting service flows. The source node first calculates the expected value and the minimum value of the bandwidth request according to the size of the traffic, and writes these two values into the packet header field of the routing request 3 . After node A receives the routing request 3, it executes the process of this embodiment as a subordinate node, calculates the actual allocated bandwidth value according to the actual bandwidth allocation function shown in FIG. Then the intermediate nodes B and C receive the routing request 3 sequentially, and execute the technical solutions of the above-mentioned embodiments of the routing method of the present invention. When the intermediate nodes A, B, and C receive the routing request 3, they can at least meet the requirement of the minimum bandwidth, so they send the routing request 3 to the destination node D step by step, and the destination node D returns the routing response success message 4. The intermediate nodes C, B, and A return to the source node S step by step, and the path S-A-B-C-D is a feasible transmission path, which can be used for service flow transmission. After receiving the successful request response message 4, the source node S starts to transmit the service information flow according to the allocated bandwidth value.

FIG. 5 is a schematic diagram of another routing request process in Embodiment 1 of the routing method of the present invention, which is a schematic diagram of a routing request failure. When the intermediate node C receives the forwarded routing request 5, it cannot meet the minimum bandwidth requirement, so it returns the routing response failure information 6, and the intermediate node returns the routing response failure information 6 to the source node S step by step, and deletes the intermediate node accordingly B and A themselves reserve information for the bandwidth that has been reserved for the service flow and release the bandwidth, and the path S-A-B-C-D forms a link where the routing request fails. Another failed link may fail to allocate bandwidth at the destination node, forming a failed link path.

The advantage of the technical solution of this embodiment is: through the dynamic allocation and recovery of the pre-occupied bandwidth of the service flow, the bandwidth can be allocated to the service flow according to the bandwidth occupancy rate of the node in real time, the service load of the network is balanced, and the network resources in the general routing protocol are avoided. The bottleneck problem disperses the task of routing transmission to the entire network, thereby reducing the queuing and other control overheads of service transmission of some heavy-load nodes, and at the same time has the advantage of improving the utilization of network resources. In addition, the intermediate node plays the functions of routing transmission and network management at the same time. After the intermediate node accesses or transmits the service flow, it actively updates its own information, and the load information has high validity and reliability. When an intermediate node acts as a subordinate node to allocate bandwidth for a service flow, it is not a simple binary logic expression, but is calculated according to the actual bandwidth allocation function based on the bandwidth occupancy rate, and reasonably allocates bandwidth for the service flow. The source node and the intermediate node in the routing request path calculate whether they can meet the requirement of the minimum bandwidth, and iteratively search the next hop node until all effective paths to the destination node are found. Then the business flow of the source node can not only find an optimal transmission path, but also obtain all feasible transmission paths that can meet the minimum requirements of business transmission. Other paths in the transmission path set are used as backup paths, so that network resources can be fully utilized.

Embodiment two

The difference between the second embodiment of the routing method of the present invention and the first embodiment above is that after the lower-level node sends the routing request, that is, after step A5 is executed, the following steps are added:

Step B1, cumulative recording time;

Step B2, judging whether the routing response information is received, if so, clear the accumulated time, otherwise execute step B3;

Step B3, judging whether the cumulative time is greater than the threshold value, if so, execute step B4;

In step B4, the node defaults that the next hop node is unreachable, and then executes step A7.

The specific execution process of this embodiment is: in the information transmission process of the network, the clock is set in the routing request process, within the specified time range, that is, the cumulative time reaches a certain threshold and the routing response information cannot be obtained, then use The method in step A7 reversely deletes the corresponding bandwidth information on the transmission path and releases the link. Further, a threshold value can also be set during the transmission of the service flow. When the cumulative time has reached the threshold value after the service flow is transmitted, but the transmission response information about the information transmission is still not received, the service occurs. In the case of stream transmission timeout, etc., the intermediate nodes do not use the method of active inquiry, but when the specified time limit is reached, the business stream that cannot be successfully transmitted normally is regarded as a transmission failure. Using this method of bandwidth management in the form of non-active intervention, the bandwidth of abnormally transmitted business flows and nodes with broken links can be dynamically released, so that they can be redistributed to other routing requests, which can reduce additional network control information and prevent further increase. network load.

Those of ordinary skill in the art can understand that all or part of the steps for realizing the above-mentioned method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the It includes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other various media that can store program codes.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (10)

1. A routing method, comprising the following steps: Step 1. Receive the routing request sent by the superior node, and collect the bandwidth expectation contained in the routing request; Step 2, detecting the bandwidth occupancy rate of the self, and calculating the reserved bandwidth occupancy rate according to the bandwidth occupancy rate and the bandwidth expectation value; Step 3. Determine whether the reserved bandwidth occupancy rate belongs to the linear domain. If so, set the actual allocated bandwidth value to be equal to the expected bandwidth value, and perform step 4. If not, generate a failed routing response message, and perform step 8; Step 4. Allocate the reserved bandwidth according to the actual allocated bandwidth value, and judge whether it is the destination node, if so, generate a successful routing response message, and perform step 8, if not, then perform step 5; Step 5, forwarding the routing request to its own subordinate node; Step 6, receiving the routing response information, judging whether the routing response information is a successful routing response information, if so, then performing step 8, otherwise performing step 7; Step 7, delete the allocated reserved bandwidth; Step 8: Send the routing response information to the superior node. 2. The routing method according to claim 1, characterized in that: said step 2 is specifically to calculate the reserved bandwidth occupancy rate according to the following formula: ${\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; K</span>}}{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; W</span>}}}$ Among them, U _ij ′ is the reserved bandwidth occupancy rate after the expected bandwidth value is allocated for the routing request, U _ij is the bandwidth occupancy rate before the expected bandwidth value is allocated to the routing request, K is the expected bandwidth value of the routing request, B _W is the total bandwidth value of this node. 3. The routing method according to claim 1, wherein the step 3 is specifically: Step 30, determine whether the reserved bandwidth occupancy rate belongs to the linear domain, if so, set the actual allocated bandwidth value equal to the expected bandwidth value, and perform step 4, if not, then perform step 31; Step 31, determine whether the reserved bandwidth occupancy rate belongs to the index domain, if so, calculate the actual bandwidth allocation value according to the reserved bandwidth occupancy rate, and perform step 32, otherwise, generate a failed routing response message, and perform step 8; Step 32. Determine whether the actual bandwidth allocation value is greater than or equal to the minimum bandwidth value included in the routing request. If yes, execute step 4; otherwise, generate a failed routing response message and execute step 8. 4. The routing method according to claim 1, wherein the step of judging whether the reserved bandwidth occupancy rate belongs to the linear domain is specifically: judging whether the reserved bandwidth occupancy rate is less than the first limit value of the bandwidth occupancy rate, if so, then The reserved bandwidth occupancy rate belongs to the linear domain. 5. The routing method according to claim 3, wherein the step of judging whether the reserved bandwidth occupancy rate belongs to the index domain is specifically: judging whether the reserved bandwidth occupancy rate is less than the second limit value of the bandwidth occupancy rate, if so, then The reserved bandwidth occupancy rate belongs to the exponential domain. 6. The routing method according to claim 3, wherein the step of calculating the actual allocated bandwidth value in the step 31 is specifically: calculate the actual allocated bandwidth value according to the following formula: $\mathrm{<span\; class="notranslate">\; B</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; K</span>}\frac{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; ij</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&Delta;</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}$ Among them, B(U _ij ) is the actual allocated bandwidth value, K is the expected bandwidth value of the routing request, U _ij ' is the reserved bandwidth occupancy rate after the routing request is assigned the expected bandwidth value, and Δ ₁ is the bandwidth occupancy rate No. A limit value is a preset constant, and its value is determined related to the capacity of the node. 7. The routing method according to any one of claims 1-6, further comprising: the source node calculates the expected bandwidth value and the minimum bandwidth value according to the service flow transmission information, and uses the expected bandwidth value and the minimum bandwidth value as the bandwidth requirement The value is set in the packet header field of the routing request, and the routing request is sent to the subordinate node. 8. The routing method according to any one of claims 1-6, further comprising: setting a first limit value and a second limit value of the bandwidth occupancy rate. 9. The arbitrary routing method according to claims 1 to 6, further comprising: after sending the routing request, accumulative recording time, judging whether the routing response information is received, if so, clearing the accumulated time, Otherwise, it is judged whether the accumulated time reaches the threshold value, and if so, the reserved bandwidth is deleted, and a route reply message of failure is sent to the superior node. 10. The routing method according to any one of claims 1 to 6, further comprising: sending the service flow, accumulating the recording time, and judging whether the transmission response information is received, if so, clearing the accumulated time to zero, otherwise judging Whether the accumulated time reaches the threshold value, if so, delete the occupied bandwidth and service flow, and send the failed service flow transmission information to the upper node.

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