Method for testing high-low priority scheduling mechanism of A664 switch

Abstract

According to the test method for the high-low priority scheduling mechanism of the A664 switch, a minimum test environment is established, an A664 tester with four physical ports is used, and verification cases of high-priority data frame priority forwarding, priority data integrity and the number of high-low priority buffer areas in a congestion scene are designed. The integrity and accuracy of high-low priority transmission function verification are ensured, and the problem of verification test of the high-low priority working mechanism of the A664 network in the prior art is effectively solved. The method is high in universality and can be suitable for various A664 network devices and application scenes.

Description

Technical Field

[0001] This invention belongs to the technical field of computers, and in particular relates to a test method for a high and low priority scheduling mechanism of an A664 switch. Background Technology

[0002] The avionics full-duplex switched Ethernet (A664) network consists of dual-redundant switches and end systems to achieve distributed communication. Each switch port has buffers for high-priority and low-priority queues to temporarily store data frames waiting to be processed or forwarded. When the destination address of a data frame is not on the same port, it will be temporarily stored in the buffer of the corresponding output port until forwarding. The buffer is mainly used to resolve queuing conflicts when the network data transmission rate is inconsistent and multiple devices send data simultaneously.

[0003] To optimize data transmission, modern switches employ a high-priority and low-priority queuing mechanism: high-priority queues handle urgent data frames, while low-priority queues handle regular data frames. The former are stored and scheduled first. However, there is currently a lack of complete and feasible verification and testing methods for the effectiveness of the high-priority and low-priority functions of A664 network switches.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The present invention provides a testing method for the high-low priority scheduling mechanism of A664 switches, used to evaluate whether the high-low priority function of A664 network switches is correctly implemented according to the protocol standard, solving the problem of verifying and testing the high-low priority working mechanism of A664 networks in the prior art. The technical solution of this invention has many beneficial effects, as described below: A testing method for the high-low priority scheduling mechanism of an A664 switch is disclosed. This method establishes a switch test structure and constructs multiple scenarios to adapt to the high-low priority functional requirements of the A664 switch, and tests whether the A664 switch can execute the high-low priority processing mechanism. The testing method includes... S1: For testing the priority processing of high-priority data frames in the buffer under congestion scenarios, a scenario is designed in which traffic from two ports of the switch is forwarded to the same port, and a scenario is designed in which traffic from three ports of the switch is forwarded to the same port, so as to realize the construction of congestion scenarios. S2: To test whether low-priority data frames will not be interrupted by high-priority data frames during forwarding, design a test scenario in which high-priority data frames are received during the forwarding of low-priority data frames. S3: For testing A664 switches with different speeds, at least calculate the number of virtual links (VLs) with modified configurations.

[0006] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: This testing method clarifies the testing procedures and parameter requirements for the high-priority scheduling mechanism of A664 network switches. A minimal testing environment was established, using an A664 tester with four physical ports. Verification cases were designed under congestion scenarios, including priority forwarding of high-priority data frames, priority data integrity, and the number of high-priority and low-priority buffers. This ensures the completeness and accuracy of the verification of high-priority transmission functions, effectively solving the difficulties in verifying the high-priority working mechanism of A664 networks in existing technologies. This method is highly versatile and applicable to various A664 network devices and application scenarios. Attached Figure Description

[0007] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0008] Figure 1 This is a test environment diagram for the high and low priority scheduling mechanism of the A664 network switch. Figure 2 This is a test flowchart for the high and low priority scheduling mechanism of the A664 network switch. Detailed Implementation

[0009] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0010] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this invention, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0011] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0012] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that aspects can be practiced without these specific details. To enable those skilled in the art to better understand the invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of that feature. In the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0013] See Figures 1 to 2 The test method for the high-low priority scheduling mechanism of the A664 switch, as shown, establishes a switch test structure and constructs multiple scenarios to adapt to the high-low priority functional requirements of the A664 switch, and tests whether the A664 switch can execute the high-low priority processing mechanism, thereby evaluating whether the high-low priority meets the protocol requirements. The test method includes... S1: To test the priority processing of high-priority data frames in the buffer under congestion scenarios, we designed a scenario in which traffic from two ports of the switch is forwarded to the same port and a scenario in which traffic from three ports of the switch is forwarded to the same port, so as to build congestion scenarios and conduct tests. S2: To test whether low-priority data frames will not be interrupted by high-priority data frames during forwarding, design a test scenario in which high-priority data frames are received during the forwarding of low-priority data frames, and conduct the test. S3: For testing A664 switches with different speeds, at least calculate the number of virtual links (VLs) with modified configurations.

[0014] In one embodiment, the scenario in S1 where traffic from both ports of the switch is forwarded to the same port includes, Step 1: Define the configuration table of the switch, in which the tester's ports i and i+1 send virtual link (VL) to the switch port i+3 in sequence, and use a high-priority and low-priority alternating sending method, where i is a positive integer; Step 2: Calculate the number of virtual links (VLs) required to achieve line-rate transmission. Taking a minimum frame length of 64 bytes (L=64) as an example, and using BAG=1ms, each virtual link (VL) occupies a bandwidth of 0.672 Mbit / s. If full bandwidth transmission is required, at least 100 / 0.672=148.8095 different virtual links (VLs) need to be defined for filling. Step 3: Determine the expected results. Tester port i and tester port i+1 should each send at least 3000 data frames. Switch port i+3 is expected to receive a total of 3000 high-priority data frames. Low-priority data frames will be lost due to the buffer being full, but at least 512 low-priority data frames should be received (determined according to the number of low-priority buffers in the configuration table). Step 4: Port Traversal. Steps 1 through 3 are repeated sequentially, with the value of i increasing from 1 to 24. This completes the traversal test of all switch ports. When i+n>24, the port value changes from i+n to i+n-24. It should be noted that n is the number of switch ports selected for the test. -- Ports i, i+1, i+2, and i+3 are four consecutive ports, not random. For example, if ports 1, 2, 3, and 4 are selected the first time, and ports 2, 3, 4, and 5 are selected the second time, the value of i is changed, and all ports are traversed. i is the port number of the first of the four ports selected in this test, and n takes values ​​from 1 to 3.

[0015] In one implementation, a scenario where traffic from all three ports of switch S1 is forwarded to the same port includes the following steps: Step 1: Define the switch configuration table, in which ports i, i+1, and i+2 of the tester send virtual link (VL) to port i+3 of the switch in sequence, and use a high-priority and low-priority alternating sending method; Step 2: Calculate the number of Virtual Links (VLs) required to achieve line-speed transmission. Taking a minimum frame length of 64 bytes (L=64) as an example, with BAG=1ms, each VL occupies a bandwidth of 0.672 Mbit / s. Therefore, if full bandwidth transmission is required, at least 100 / 0.672=148.8095 different VLs need to be defined for filling. Step 3: The expected results are clear. The tester's i port, i+1 port, and i+2 port will each send 3000 data frames. The switch's i+3 port is expected to receive a total of 3000 + 512 (determined by the number of high-priority buffers in the configuration table) high-priority data frames. Low-priority data frames will be lost due to the buffer being full, but at least 512 low-priority data frames will be received (determined by the number of low-priority buffers in the configuration table). Step 4: Port traversal. Repeat the above steps in sequence, with i ranging from 1 to 24, to complete the traversal test of all ports of the switch. When i+n>24, change the port value from i+n to i+n-24.

[0016] Furthermore, S4 includes, (1) After the rate change, for test cases 1 and 2, with a fixed data frame length, when the number of virtual links (VL) required to construct the congestion scenario changes, the bandwidth (L, BAG) occupied by one virtual link (VL) after the change is calculated using the following formula, where, (L,BAG)=[8*(8+64+12) / Bandwidth] / (BAG / 1000), then calculate the number of VLs required after the change: VLNumber =[Bandwidth / (L,BAG)]; In one implementation, S2 includes, (1) Switch configuration table definition, wherein a low priority VL is defined on port i of the tester with a frame length of 1518 bytes, and a high priority VL is defined on port i+1 of the tester. Both VLs are forwarded to port i+2 of the switch. (2) Data frame transmission, wherein a data frame with a frame length of 1518 is sent to switch port i according to the parameters in the configuration table, and after waiting for 50μs, a high-priority VL frame with a frame length of 1518Bytes is sent to switch port i+1. (3) The expected result is clear: the test platform of switch port i+2 received a total of 2 frames, with the low-priority frame arriving before the high-priority frame; (4) Port traversal: Repeat the above steps in sequence, with i ranging from 1 to 24, to complete the traversal test of all ports of the switch. When i+n>24, the port value of the switch is changed from i+n to i+n-24.

[0017] Furthermore, S4 includes the following: after the rate change, for test case 3, the duration for which the switch processes a data frame changes. The processing time of the data frame is calculated as L = 8 * (8 + 1518) / Bandwidth, where a high-priority data frame is sent first, and a low-priority data frame is sent within the processing time of the high-priority data frame.

[0018] Establish such as Figure 1 The A664 network test environment shown includes an A664 network tester with more than four physical ports. The four ports are numbered 1, 2, 3, and 4, and connected to four physical ports i, i+1, i+2, and i+3 of the A664 switch, respectively. When i is 1, it corresponds to ports 1, 2, 3, and 4, as detailed below: The first step, for testing the priority processing of high-priority data frames in the buffer under congestion scenarios, involves designing a scenario where traffic from both ports of the switch is forwarded to the same port to construct congestion. The steps are as follows: (1) According to the description in the test environment definition, see Figure 1 Connect the four physical ports of the switch to the four physical ports of the tester, check the port connection status between the tester and the switch, and confirm that the physical connection status is correct. (2) Ports 1 and 2 of the tester send VL to port i and port i+1 of the switch in turn, with high and low priority alternating. In order to send as many data frames as possible to create a congestion scenario under the condition of fixed bandwidth, the data frame length is configured to a minimum of 64 bytes, and the data frames of each VL are sent in turn according to the minimum frame interval (IFG) conforming to the IEEE 1620 standard, with each port sending 3000 data frames; (3) Because the configuration table of the A664 switch defines that the data frames received by port i and port i+1 will be forwarded to port i+3, and both port i and port i+1 send at line speed, a congestion scenario will occur when the traffic converges to port i+3. The high priority traffic on port i and port i+1 accounts for 50% of the port bandwidth, and the sum of the high priority traffic sent by the two ports at the same time is equal to the port line speed; (4) Repeat the above steps in sequence, with i ranging from 1 to 24, to complete the traversal test of all ports of the switch. When i+n>24, the port value is changed from i+n to i+n-24.

[0019] (5) Passing the standard: High-priority data frames are forwarded first and no packet loss occurs. A total of 3,000 high-priority data frames are received. Low-priority data frames will be lost due to the buffer being full, but at least 512 low-priority data frames are received (the number of low-priority buffers in the configuration table).

[0020] The second step involves testing the priority processing of high-priority data frames in the buffer under congestion scenarios. This is achieved by designing a scenario where traffic from all three ports of the switch is forwarded to the same port to create congestion. The steps are as follows: (1) According to the description in the test environment definition, see Figure 1 Connect the four physical ports of the switch to the four physical ports of the tester, and check the port connection status between the tester and the switch. If all ports are successfully connected, the physical connection status is confirmed to be correct. (2) Ports 1, 2, and 3 of the tester send VLs to ports i, i+1, and i+2 of the switch in turn, alternating between high and low priority. In order to construct a congestion scenario by sending as many data frames as possible under the condition of fixed bandwidth, the data frame length is configured to a minimum of 64 bytes. The data frames of each VL are sent in turn according to the minimum frame interval (IFG) conforming to the IEEE 1620 standard, and 3000 data frames are sent by each of the three ports. (3) Because the configuration table of the A664 switch defines that the data frames received by port i, port i+1 and port i+2 will be forwarded to port i+3, and ports i, i+1 and i+2 are all sent at line speed, congestion will occur when the traffic converges to port i+3. In the line speed scenario, the high priority traffic on ports i, i+1 and i+2 accounts for 50% of the port bandwidth respectively. The high priority traffic sent by the three ports at the same time is equal to 150% of the port line speed after aggregation; (4) Repeat the above steps in sequence, with i ranging from 1 to 24, to complete the traversal test of all ports of the switch. When i+n>24, the port value is changed from i+n to i+n-24.

[0021] (5) According to the standard: high-priority data frames are forwarded first, but packet loss may occur due to full buffer. At least 3000+512 high-priority data frames are received. Low-priority data frames may be lost due to full buffer, but at least 512 low-priority data frames are received (the number of low-priority buffers in the configuration table).

[0022] The third step involves testing how low-priority data frames are not interrupted by high-priority data frames during forwarding. Test cases are designed where high-priority data frames are received during the forwarding of low-priority data frames. The steps are as follows: (1) According to the description in the test environment definition, see Figure 1 Connect the four physical ports of the switch to the four physical ports of the tester, and check the port connection status between the tester and the switch. If all ports are successfully connected, the physical connection status is confirmed to be correct. (2) A low-priority VL frame is sent to switch port i with a frame length of 1518 bytes. The time for switch port i with a speed of 100 Mbps to process this data frame is approximately 122 μs. (3) After waiting for 50μs, a high-priority VL frame is sent to port i+1 with a frame length of 1518Bytes. The configuration table specifies that the VL frames of both ports are forwarded to port i+3 of the switch. That is, a scenario is constructed in which a high-priority data frame is received while the switch is receiving a low-priority data frame. The high-priority data frame that arrives late will not interrupt the processing of the low-priority data frame and will be forwarded correctly without loss. (4) Repeat the above steps in sequence, with i ranging from 1 to 24, to complete the traversal test of all ports of the switch. When i+n>24, the port value is changed from i+n to i+n-24.

[0023] (5) According to the standard: the test platform of port i+3 received a total of 2 frames, with the low-priority data frame arriving before the high-priority data frame.

[0024] The fourth step, when performing high and low priority tests on A664 switches with different speeds, requires recalculating the number of VLs (Variable Levels). The steps are as follows: (1) After the rate is changed, for test items that prioritize scheduling high-priority data frames, the number of VLs required to construct a congestion scenario changes when the data frame length is fixed. Refer to the following formula to calculate the bandwidth occupied by a VL: (L,BAG)=[8*(8+64+12) / Bandwidth] / (BAG / 1000), and then calculate the number of VLs to be configured: VLNumber=[Bandwidth / (L,BAG)]; After the switch speed changes, the duration for the switch to process a data frame changes for the test item of low-priority data frame forwarding integrity. The processing time of a data frame is calculated with reference to the following time: 8*(8+1518) / Bandwidth. High-priority data frames are sent first, and low-priority data frames are sent within the processing time of the high-priority data frames. The change after the speed change is due to the switch's own configuration attributes.

[0025] This method establishes a minimal test environment using an A664 tester with four physical ports. Verification test cases were designed for high-priority data frame forwarding, priority data integrity, and the number of high and low priority buffers under congestion scenarios. This ensures the completeness and accuracy of the verification of high and low priority transmission functions, effectively solving the challenge of verifying the high and low priority working mechanism of A664 networks in existing technologies. This method is highly versatile and applicable to various A664 network devices and application scenarios.

[0026] The product provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from the principles of the invention, and these improvements and modifications also fall within the protection scope of the invention claims.

Claims

1. A test method for a high-low priority scheduling mechanism of an A664 switch, characterized in that, A switch test structure is established and multiple scenarios are constructed to adapt to the high and low priority functional requirements of the A664 switch, and to test whether the A664 switch can execute the high and low priority processing mechanism. The test method includes... S1: For testing the priority processing of high-priority data frames in the buffer under congestion scenarios, design a scenario where traffic from two ports of the switch is forwarded to the same port and a scenario where traffic from three ports of the switch is forwarded to the same port, so as to realize the construction of congestion scenarios. S2: To test whether low-priority data frames will not be interrupted by high-priority data frames during forwarding, design a test scenario in which high-priority data frames are received during the forwarding of low-priority data frames. S3: For testing A664 switches with different speeds, calculate the number of virtual links (VLs) with modified configurations.

2. The test method according to claim 1, characterized in that, In S1, scenarios where traffic from both ports of a switch is forwarded to the same port include: Step 1: Define the configuration table of the switch, in which the tester's port i and port i+1 send virtual link (VL) to the switch's port i+3 in sequence, and use a high-low priority alternating sending method, where i is a positive integer; Step 2: Calculate the number of virtual link (VL) required to achieve line-speed transmission. If the shortest frame length is 64 bytes and BAG=1ms is used, each virtual link (VL) occupies a bandwidth of 0.672 Mbit / s. If full bandwidth transmission is required, at least 100 / 0.672=148.8095 different virtual link (VL) need to be defined for filling. Step 3: The tester's port i and port i+1 each send at least 3000 data frames. The switch's port i+3 is expected to receive a total of 3000 high-priority data frames. Low-priority data frames will be lost due to the buffer being full, but at least 512 low-priority data frames can be received. Step 4: Port traversal. Steps 1 to 3 are repeated sequentially, with the value of i increasing from 1 to 24. This completes the traversal test of all ports of the switch. When i+n>24, the switch port value is changed from i+n to i+n-24, where n is the number of switch ports selected for the test.

3. The test method according to claim 1, characterized in that, In S1, scenarios where traffic from all three ports of the switch is forwarded to the same port include: Step 1: Define the switch configuration table, in which ports i, i+1, and i+2 of the tester send virtual link (VL) to port i+3 of the switch in sequence, and use a high-priority and low-priority alternating sending method; Step 2: Calculate the number of Virtual Links (VLs) required to achieve line-rate transmission. The minimum frame length is 64 bytes, and each VL occupies a bandwidth of 0.672 Mbit / s. If full bandwidth transmission is required, at least 100 / 0.672 = 148.8095 different VLs need to be defined for filling. Step 3: The tester sends 3000 data frames each from port i, port i+1 and port i+2. The switch's port i+3 is expected to receive a total of 3000+512 high-priority data frames. Low-priority data frames will be lost due to the buffer being full, but at least 512 low-priority data frames will be received. Step 4: Port traversal. Repeat the above steps in sequence, with the value of i ranging from 1 to 24 to complete the traversal test of all ports of the switch. When i+n>24, the port value is changed from i+n to i+n-24.

4. The test method according to claim 2 or 3, characterized in that, S4 includes, When the number of virtual links (VLs) required to construct a congestion scenario changes, the bandwidth (L, BAG) occupied by each virtual link (VL) after the change is calculated using the following formula, where, (L,BAG)=[8*(8+64+12) / Bandwidth] / (BAG / 1000), then calculate the number of VLs required after the change: VLNumber =[Bandwidth / (L,BAG)].

5. The test method according to claim 1, characterized in that, S2 includes, The switch configuration table defines a low-priority virtual link (VL) with a frame length of 1518 bytes on port i of the tester, and a high-priority virtual link (VL) on port i+1 of the tester. Both virtual links (VL) are forwarded to port i+2 of the switch. Data frame transmission: a data frame with a length of 1518 bytes is sent to switch port i according to the parameters in the configuration table. After waiting for 50μs, a high-priority VL frame with a length of 1518 bytes is sent to switch port i+1. The test platform on port i+2 of the switch received a total of 2 frames, with the lower priority frame arriving before the higher priority frame; Port traversal: Repeat the above steps in sequence. The value of i ranges from 1 to 24 to complete the traversal test of all ports of the switch. When i+n>24, the switch port value is changed from i+n to i+n-24.

6. The test method according to claim 5, characterized in that, S4 includes, When the switch speed changes, the duration for which the switch processes a data frame changes. The calculated processing time for the changed data frame is L = 8 * (8 + 1518) / Bandwidth.

Images