CDP / LLDP frame reader

Abstract

The utility model relates to devices for reading CDP / LLDP frames. The technical result is a reduction in labor intensity during operational switching of IP telephony subscribers and users of a local data transmission network. A device for reading CDP / LLDP frames, comprising a control unit equipped with an indicator module, an Ethernet module and an RJ-45 connector. The control unit is implemented on the basis of a microcontroller containing a microprocessor core connected via a system bus to program FLASH memory, data SRAM memory, general-purpose bidirectional GPIO input / output ports, and the first and second serial peripheral SPI interfaces. The output of the first SPI interface is electrically connected to the indicator module, the output of the second SPI interface is electrically connected to the network Ethernet module, the output of which is electrically connected to the RJ-45 connector. A push-button keyboard is connected to one of the GPIO input / output ports.The microcontroller is configured to establish a connection to a switch via an Ethernet network module, receive a packet of CDP / LLDP frames, read them, decode them, and display service information on the display module screen in text form. 4 pp. f-ly, 2 figs.

Description

[0001] The utility model relates to devices for transmitting information and can be used for testing telecommunications equipment, in particular for interrogating switches operating in a local network, including determining their basic parameters.

[0002] A network topology management device is known from the prior art (RU 2598317C1, IPC H04L 12 / 751, H04L 12 / 717, published 09 / 20 / 2016), which provides the ability to distinguish Link Layer Discovery Protocol (LLDP) packets for network topology discovery with centralized control from LLDP packets flowing into the network as user traffic. To achieve the specified result, the communication system according to the patent includes a control device configured to specify control information that allows each target control switch to distinguish an LLDP packet of a first network from an LLDP packet of a second network.

[0003] The disadvantage of the known device is the difficulty of adapting it for testing network equipment connected to a local network, in particular, for determining the name of the nearest switch or gateway.

[0004] The closest technical solution to the proposed device and the one selected as the prototype was a device for receiving configuration data from a transmission protocol selection system (RU2598293C1, IPC H04L 12 / 911, published September 20, 2016). The device comprises a receiving module and three analyzing modules.The receiving module is configured to receive a data packet of the Link Layer Discovery Protocol (LLDP), the first analyzing module is configured to analyze the first field in the LLDP packet and determine whether the value of each byte in the first field corresponds to a specified range, the second analyzing module is configured to analyze the value of the first bit segment of each byte in the first field and determine an operational scheduling algorithm used to set internal priorities of the traffic class corresponding to each byte in the first field, depending on the value of the first bit segment, and the third analyzing module is configured to analyze the value of the second bit segment of each byte in the first field and determine an additional parameter corresponding to the priority.

[0005] The disadvantage of the known technical solution is its low manufacturability, due to the complex design of the device, which makes its practical implementation based on microcontrollers impossible.

[0006] The technical problem that the utility model is aimed at solving is the development of a device for testing telecommunications equipment of local networks.

[0007] The device for reading CDP / LLDP frames comprises a control unit equipped with an indication module, an Ethernet module and an RJ-45 connector, wherein the control unit is based on a microcontroller containing a microprocessor core connected via a system bus to FLASH program memory, SRAM data memory, first and second serial peripheral SPI interfaces, wherein the output of the first SPI interface is electrically connected to the indication module, and the output of the second SPI interface is electrically connected to the network Ethernet module, the output of which is electrically connected to the RJ-45 connector.

[0008] The positive technical result achieved by the combination of features characterizing the device is a reduction in labor intensity during operational switching of IP telephony subscribers and local data network users. This positive technical result is ensured by the following design features of the device:

[0009] 1. The microcontroller-based control unit, equipped with an RJ-45 connector, enables the device to be connected to a local area network. The microprocessor core, using the control program stored in the microcontroller's FLASH memory, buffers data in the data SRAM memory and implements a hardware and software tester that determines the name and model of the nearest switch, port number, IP address, and virtual local area network (VLAN) parameters by reading CDP / LLDP frames;

[0010] 2. The display module allows the received data to be displayed to the user, making it possible to use the device as a portable device that can be used by system administrators when configuring local area networks.

[0011] The device is explained by drawings, where

[0012] Fig. 1 shows the structural diagram of the device,

[0013] Fig. 2 shows its appearance during operation.

[0014] The CDP / LLDP frame reader has the following structure.

[0015] It contains a housing 1, with an indicator module 2, an RJ-45 connector (3) and a power button 4 attached to it. Inside the housing 1, a device control unit 5 is fixed, made on the basis of a microcontroller 6, containing a microprocessor core 7, connected by means of a system bus 8 to a FLASH program memory 9, an SRAM data memory 10, universal bidirectional GPIO input-output ports 11 (GPIO port B is shown in Fig. 1), each of the lines of which can perform alternative functions, the first and second serial peripheral SPI interfaces 12, 13. In this case, the output of the first SPI interface 12 is electrically connected to the indicator module 2, and the output of the second SPI interface 13 is electrically connected to the network Ethernet module 14, the output of which is electrically connected to the RJ-45 connector (3).

[0016] A push-button keypad 15 containing sixteen keys can be additionally connected to one of the GPIO input / output ports, with the help of which the user can configure the operating parameters of the device.

[0017] The indicator module 2, microcontroller 6 and Ethernet module 14 are powered by a stabilized DC 3.3V / 200mA power supply, and the power button 4 is connected to the positive power supply circuit.

[0018] The STM32F401CD microcontroller, based on the Cortex-M4 core, can be used as the microcontroller 6 of the device control unit 5. The 2.4-inch TFT LCD 320x240 color display model ST7789V can be used as the display module 2, and the W5500 TCP / IP (Ethernet) network module is recommended as the network Ethernet module 14.

[0019] If the STM32F401CD microcontroller and ST7789V color display are used in the device design, the latter can be controlled via a four-digit serial interface, while the PA5 (SPI1_SCK), PA7 (SPI1_MOSI) lines of GPIO port A of the microcontroller perform an alternative function of the first SPI interface and are connected, respectively, to the DCX (Clock signal), SDA (Serial input / output data) lines of the display chip.To supply the display chip enable signal (Chip selection signal), the PB1 line of the GPIO port B of the microcontroller is connected to the CSX line of the chip; to switch the command or data transfer mode (logical 0 - commands, logical 1 - parameters or data), the PA12 line of the GPIO port A of the microcontroller is connected to the WRX line of the chip; to reset the chip and initialize it correctly, the PA10 line of the GPIO port A of the microcontroller is connected to the RESX line of the chip; and to turn the display backlight on or off, the PA11 line of the GPIO port A of the microcontroller is connected to the LED_EN line of the chip.

[0020] When using the W5500 TCP / IP (Ethernet) network module, the PB13 (SPI2_SCK), PB14 (SPI2_MISO), and PB15 (SPI2_MOSI) lines of the microcontroller's GPIO port B serve as an alternative second SPI interface and are connected to the corresponding lines of the network module chip. To supply the network module enable signal (Chip Select for SPI bus), the PA9 line of the microcontroller's GPIO port A is connected to the CSC line of the chip.

[0021] Eight free lines (PB2–PB9) of the microcontroller's GPIO port B can be used to connect a push-button keypad. These lines form an eight-bit interface for implementing the "running one" algorithm when scanning the keyboard: the first four low-order lines (PB2–PB5) are used to scan rows, and the four high-order lines (PB6–PB9) are used to scan columns.

[0022] The CDP / LLDP frame reader works as follows.

[0023] When preparing the device for operation, a network cable connected to one of the ports of the local area network equipment, for example, a switch, is connected to the RJ-45 connector (3); if it is necessary to configure the device, a push-button keyboard 15 is connected to the GPIO port B, then a DC source, for example, a battery, is connected to the power lines of the microcontroller 16, the indicator module 2 and the Ethernet module 14, after which the device is turned on using button 4.

[0024] When the device is turned on, the control program of microcontroller 6, stored in the FLASH memory of programs 9, is automatically launched, performing the initialization of the display module 2 (TFT display) and the network Ethernet module 14, after which the user of the device, using the keyboard connected to it, using the interface implemented by the control program of microcontroller 6, can configure the operating parameters of the control unit, for example, the modes of displaying service information output by the device on the screen of the display module 2.

[0025] When the device is operating, microcontroller 6 establishes a connection to the switch via network Ethernet module 14. If the connection is successfully established, the microcontroller enters frame translation standby mode. After receiving a CDP / LLDP frame packet, a subroutine for reading and decoding them is executed, after which service information is displayed on the display module 2 in text form. If the connection to the switch is lost or if CDP / LLDP frames are not being translated, the control program terminates.

[0026] Thus, the device described in the utility model is a simple-to-use device that facilitates the maintenance of local data networks. Network maintenance often requires subscriber switching, for example, when moving automated workstations (AWS) to other rooms or relocating equipment (IP phones, printers). The port configurations of the switches used to connect various equipment often vary significantly, so when switching equipment, it is necessary to know the exact name of the required switch and the port number, which is not always possible to determine visually, since switches with a high port density are typically used at the access layer of the data network. Using a device for reading CDP / LLDP frames for automatic switch parameter detection (Fig. 2) eliminates the need for a visual inspection of the switch, significantly simplifying the task of subscriber switching.

Claims

1. A device for reading CDP / LLDP frames, comprising a control unit equipped with an indication module, an Ethernet module and an RJ-45 connector, characterized in that the control unit is based on a microcontroller containing a microprocessor core connected via a system bus to FLASH program memory, SRAM data memory, universal bidirectional GPIO input / output ports, first and second serial peripheral SPI interfaces, wherein the output of the first SPI interface is electrically connected to the indication module, the output of the second SPI interface is electrically connected to the network Ethernet module, the output of which is electrically connected to the RJ-45 connector, and a push-button keyboard is connected to one of the GPIO input / output ports; The microcontroller is designed with the ability to establish a connection with a switch using a network Ethernet module, receive a packet of CDP / LLDP frames, read them, decode them, and display service information on the display module screen in text form.

2. The device according to paragraph 1, characterized in that the push-button keyboard contains sixteen keys.

3. The device according to paragraph 1, characterized in that the STM32F401CD microcircuit is used as the microcontroller.

4. The device according to paragraph 1, characterized in that the W5500 network module is used as the network Ethernet module.

5. The device according to paragraph 1, characterized in that a color display of the ST7789V model is used as the display module.

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