CN114124720A - Method for testing time-triggered service gating characteristic of TTE switch - Google Patents

Abstract

The invention provides a method for testing time-triggered service gating characteristics of a TTE (time to equipment) switch, which comprises the following steps of: firstly, setting a network topology; secondly, designing a test sending flow meter; thirdly, generating an expected receiving flow table; fourthly, starting a test and sending test flow; fifthly, comparing results; and sixthly, outputting a result. The testing method can accurately control the sending time of the flow and can effectively verify the correctness of the gating characteristic. The TT flow sending time of the test method is controllable, and the test flow meeting different service test scenes can be designed. The test method has the advantages of simple verification process, high verification accuracy and high verification reusability.

Description

Method for testing time-triggered service gating characteristic of TTE switch

Technical Field

The invention belongs to the technical field of computer networks, relates to TTE (time to equipment), and particularly relates to a method for testing time-triggered service gating characteristics of a TTE switch.

Background

In recent years, the real-time network transmission demand brings new demands and challenges to the real-time network, and becomes a hot issue for research in the industry of various countries. In intense competition, Time Triggered Ethernet (TTEthernet) stands out, combines the certainty, fault tolerance mechanism and real-Time performance of the Time Triggered technology with the flexibility, dynamic performance and best effort of the common Ethernet, and provides support for synchronous and highly reliable embedded computing and network and fault tolerance design. TTE adds clock synchronization function to traditional Ethernet, can transmit time-deterministic data (TT data frame) which is not available on traditional Ethernet, and is fully compatible with IEEE 802.3.

Facing the requirements of future cloud combat systems and mosaic combat, national defense equipment is developing towards the systematic combat direction of flexible networking, rapid combination and intelligent control, and is required to have the capabilities of mass calculation, ultrahigh bandwidth and capacity, control and information fusion transmission, task cooperative scheduling and the like. This requirement requires that the new equipment network must be a flexible open network architecture with high reliability, strong real-time, deterministic, high bandwidth, large capacity, control and information fusion. Then, the time triggered ethernet technology can just meet the requirement, and the TTE technology has been applied to the fields of aerospace carrying platforms, satellite control, deep space probe and the like.

TTEthernet can simultaneously meet application requirements of different real-time and security levels in a single network, and supports three different message types, namely Time Trigger (TT), Rate Constraint (RC) and Best Effort (BE). The TT message applies a time trigger mechanism, all TT messages are sent in the network according to specific time, and the priority is higher than all other types of messages. RC messages are suitable for systems with less stringent real-time requirements than TT messages. The RC message ensures that the message bandwidth of each corresponding virtual link in the system is deterministic and the time delay does not exceed the expected limit. The BE message adopts a well-known common ethernet mode, and whether or when the message is successfully sent cannot BE guaranteed in the transmission process.

The TTE network is a star network, and the TTE switch is the core of the whole network and is the center of the TTE network for realizing distributed clock synchronization and communication, so the TTE switch is the core device for realizing the time trigger function.

As shown in fig. 1, the TTE switch divides different time slots for implementing the time-triggered function, each time slot allows only TT messages of corresponding vl to pass through, and TT messages arriving before or after the time slot do not allow TT messages to pass through; and the output end forwards data in a set time slot, so that the time certainty is ensured. This time slot is called gating and there is a corresponding input gate and output gate for each TT message at the TTE switch.

As shown in fig. 2, only TT frames in the input gating range can be received and forwarded by the switch, and TT frames in the non-input gating range are discarded. And the output gating is a time slot when the TTE switch forwards the message, so that the TT can ensure that the message is forwarded within the time specified by the receiver, the message can be ensured to be received in the receiving gating of the receiver, and the time certainty of the message is achieved.

To ensure that the TTE switch can achieve time certainty of a message, it must be guaranteed that the TTE switch triggers traffic gating is in compliance with design requirements. Therefore, a method for testing the time-triggered traffic gating characteristic of the TTE switch is needed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method for testing the time-triggered service gating characteristic of a TTE switch, which solves the technical problems that the direct time certainty test of the TTE switch in the prior art is difficult and no testing scheme aiming at gating exists at present.

In order to solve the technical problems, the invention adopts the following technical scheme:

a TTE exchanger time-triggered service gating characteristic test method includes the following steps:

step one, setting a network topology:

setting TTE exchanger test network topology, and all analog end systems and exchangers use AS6802 time synchronization protocol to carry out time synchronization;

secondly, designing a test sending flow meter:

designing a test sending flow meter according to the gating characteristic of the switch to be tested;

thirdly, generating an expected receiving flow table:

predicting the receiving condition of a receiving end according to the generated test sending flow meter and the gating range of the switch, generating an expected receiving flow meter, storing the expected receiving flow meter as a local file, and performing result verification by using the file after the execution to be tested is finished;

step four, starting the test, and sending test flow:

in the TTE switch testing network topology, a simulated sending module sends flow to the TTE switch one by one according to a designed testing sending flow table, data is sent to a simulated receiving module through the TTE switch to be received, and actually received flow data is stored in a file;

fifthly, comparing results:

step S51, verifying the correctness of the content:

comparing the actual receiving flow with the expected receiving data frame content one by one, if the contents are consistent, carrying out step S52, if not, the test is failed;

step S52, time certainty verification:

after the data content is consistent, judging whether the receiving time is within an expected receiving range, if so, proving to be in accordance with time certainty, otherwise, proving not to satisfy the gating characteristic, thereby not satisfying the time certainty characteristic;

sixthly, outputting a result:

and (4) storing the statistical data compared with the results of the fifth step into a file, feeding back the test result, and completing the test.

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

the testing method can accurately control the sending time of the flow and can effectively verify the correctness of the gating characteristic.

And (II) the TT flow sending time of the test method is controllable, and the test flow meeting different service test scenes can be designed.

(III) the test method has simple verification process, high verification accuracy and high verification reusability.

Drawings

Fig. 1 is a schematic diagram of a triple redundant end system and switch cascading topology.

Fig. 2 is a schematic diagram of TTE switch gating.

Fig. 3 is a schematic diagram of a data traffic scheduling timing sequence.

Fig. 4 is a schematic diagram of a TTE switch test network topology.

Fig. 5 is an input gated data frame pass case.

Fig. 6 is an output gated data frame pass case.

The present invention will be explained in further detail with reference to examples.

Detailed Description

It is to be noted that all the devices in the present invention are those known in the art, unless otherwise specified.

In the present invention, it is to be noted that:

TTE, TTEthernet, Time Triggered Ethernet, refers to Time Triggered Ethernet.

TT refers to time triggering.

RC refers to a rate constraint.

BE refers to best effort.

VL refers to a virtual link.

The following embodiments of the present invention are provided, and it should be noted that the present invention is not limited to the following embodiments, and all equivalent changes based on the technical solutions of the present invention are within the protection scope of the present invention.

Example (b):

the embodiment provides a method for testing a time triggered service gating characteristic of a TTE switch, which comprises the following steps:

step one, setting a network topology:

setting TTE exchanger test network topology, and all analog end systems and exchangers use AS6802 time synchronization protocol to carry out time synchronization;

service scheduling timing sequence: as shown in fig. 3, TT traffic is scheduled according to a cluster cycle, which performs the same actions all around. The cluster cycle comprises a plurality of integration cycles, each integration cycle starts to carry out clock synchronization of the whole network equipment, and data transceiving of TT service is carried out after the clock synchronization.

TTE switch test network topology: as shown in fig. 4, the TTE switch test network topology includes a tested switch and a test module, where the test module includes a simulation end system, and the simulation end system simulates a sending module and a receiving module.

The test module can simulate a plurality of TTE end systems, two of the TTE end systems are connected with the tested switch, and the TTE end systems respectively simulate the sending module and the receiving module. The analog end system adopts an analog end system which is conventional in the field, and the sending module and the receiving module are conventional in the field.

After the network environment is built, an AS6802 time synchronization function is operated on all switches and simulation end systems on the network, so that the time of each node is synchronized.

Secondly, designing a test sending flow meter:

designing a specific test sending flow meter according to the gating characteristic of the switch to be tested;

setting TTE switch gating: in TTE switches, the data messaging process of real-time deterministic traffic needs to rely on a scheduling schedule. The scheduling schedule represents input gating and output gating of different VLs, for example, setting the gating parameters as shown in table 1:

table 1 switch gating example

In the parameters specified in the above list, it is shown that there are 4 VL TT message arrangements in one cluster cycle, and their input and input gating ranges are both 30 us. The time of input-output gating is relative to the start of the cluster cycle.

Testing a data frame: and designing a test sending flow meter according to input gating. The test delivery flow meter was designed for table 1 and the test flow meter contents are shown in table 2.

TABLE 2 test data frame information

In the test frame data specified in the above list, the data field is filled with characters in the content, and different VLs are tested with different contents, so that the correctness of input gating can be quickly judged.

Because the test data are arranged according to the cluster cycle, the test data can be repeatedly sent according to the repetition of the cluster cycle, and the flow of the fixed packet number is realized by setting the sending times in the test module.

Thirdly, generating an expected receiving flow table:

predicting the receiving condition of a receiving end according to the generated test sending flow meter and the gating range of the switch, generating an expected receiving flow meter, storing the expected receiving flow meter as a local file, and performing result verification by using the file after the execution to be tested is finished;

step four, starting the test, and sending test flow:

in the TTE switch testing network topology, a simulated sending module sends flow to the TTE switch one by one according to a designed testing sending flow table, data is sent to a simulated receiving module through the TTE switch to be received, and actually received flow data is stored in a file;

fifthly, comparing results:

step S51, verifying the correctness of the content:

comparing the actual receiving flow with the expected receiving data frame content one by one, if the contents are consistent, carrying out step S52, if not, the test is failed;

step S52, time certainty verification:

after the data content is consistent, judging whether the receiving time is within an expected receiving range, if so, proving to be in accordance with time certainty, otherwise, proving not to satisfy the gating characteristic, thereby not satisfying the time certainty characteristic;

in this embodiment, an expected receive flow table may be generated for the receive flow based on the designed test flow table and the input gating characteristics of the switch. And the receiving end compares the received flow with the expected received flow so as to judge the time conformity of the data frame. Data frames as in table 2 in the example through table 1, the input gated data frame pass case is shown in fig. 5 and the output gated data frame pass case is shown in fig. 6. Table 2 table 3 shows the expected received traffic table of the test data frame information according to the input-output gating characteristic of the TTE switch.

Table 3 expected received flow meter

In this embodiment, after the test module sends data in the flow meter, an actual received flow is received through the TTE switch, and a specific actual received flow meter is shown in table 4, and the test module compares the received data with data in an expected flow meter to verify the correctness of TT (time triggered), especially time information.

Table 4 actual received flow meter

Sixthly, outputting a result:

and (4) storing the statistical data compared with the results of the fifth step into a file, feeding back the test result, and completing the test.

Claims (1)

1. A TTE switch time-triggered service gating characteristic test method is characterized by comprising the following steps:

step one, setting a network topology:

setting TTE exchanger test network topology, and all analog end systems and exchangers use AS6802 time synchronization protocol to carry out time synchronization;

secondly, designing a test sending flow meter:

designing a test sending flow meter according to the gating characteristic of the switch to be tested;

thirdly, generating an expected receiving flow table:

predicting the receiving condition of a receiving end according to the generated test sending flow meter and the gating range of the switch, generating an expected receiving flow meter, storing the expected receiving flow meter as a local file, and performing result verification by using the file after the execution to be tested is finished;

step four, starting the test, and sending test flow:

in the TTE switch testing network topology, a simulated sending module sends flow to the TTE switch one by one according to a designed testing sending flow table, data is sent to a simulated receiving module through the TTE switch to be received, and actually received flow data is stored in a file;

fifthly, comparing results:

step S51, verifying the correctness of the content:

comparing the actual receiving flow with the expected receiving data frame content one by one, if the contents are consistent, carrying out step S52, if not, the test is failed;

step S52, time certainty verification:

after the data content is consistent, judging whether the receiving time is within an expected receiving range, if so, proving to be in accordance with time certainty, otherwise, proving not to satisfy the gating characteristic, thereby not satisfying the time certainty characteristic;

sixthly, outputting a result:

and (4) storing the statistical data compared with the results of the fifth step into a file, feeding back the test result, and completing the test.

Images