CN115396382A

CN115396382A - Operation method of network device and control chip of network device

Info

Publication number: CN115396382A
Application number: CN202110497961.8A
Authority: CN
Inventors: 庞嘉佑; 刘博伟; 王瑞强
Original assignee: Realtek Semiconductor Corp
Current assignee: Realtek Semiconductor Corp
Priority date: 2021-05-08
Filing date: 2021-05-08
Publication date: 2022-11-25

Abstract

The invention discloses an operation method of a network device and a control chip of the network device. The operation method comprises the following steps: setting a target transmission speed of the network device to a first speed; transmitting and/or receiving data at the first speed; and when the amplitude or the energy of the input signal is not larger than the threshold value, setting the target transmission speed of the network device to be a second speed, wherein the second speed is not equal to the first speed.

Description

Operation method of network device and control chip of network device

Technical Field

The present invention relates to a network device, and more particularly, to a control chip of a network device and a method for operating a network device, which can prevent a network device from being mis-linked.

Background

In the prior art, two network devices (one of which is called a local device (local device) and the other of which is called a link partner (link partner) of the local device) linked by a fiber medium (fiber medium) need to determine that a reliable link-up (link-up) has been established between them before transmitting a packet or user data (user data). That is, the physical layer (PHY layer) of the network device must first determine that a reliable link has been established before providing a service to its upper layer, i.e., a Medium Access Control (MAC) layer.

The self-negotiation (auto negotiation) closed link establishment method comprises the following steps: (1) The home device transmits a code group (e.g., an 8-bit/10-bit (8 b/10 b) code group or a 4-bit/5-bit (4 b/5 b) code group) to its link partner; (2) The link partner confirming the quality of the received signal and confirming whether the code-set was decoded correctly; (3) When the signal quality is acceptable and the code set can be decoded correctly, the link partner declares that a link has been established with the home device.

A reliable link requires both network devices to claim to establish a link with each other, however, only one of the two network devices can establish a link when the optical fiber medium is damaged in one direction. Unfortunately, limited by the specifications defined by IEEE 802.3, a party that does not claim to establish a link cannot notify the other party of its failure, which may result in a unilateral link. Unilateral link status is unacceptable and should be avoided because it may result in packet loss (loss) and even cause problems to the upper layers of the open systems interconnection model (OSI model) of the network.

Disclosure of Invention

In view of the deficiencies of the prior art, it is an object of the present invention to provide a method for operating a network device and a control chip of the network device, so as to improve the deficiencies of the prior art.

The invention discloses an operation method of a network device, the network device receives an input signal through an optical fiber medium, the method comprises the following steps: setting a target transmission speed of the network device to a first speed; transmitting and/or receiving data at the first speed; and when the amplitude or the energy of the input signal is not larger than the threshold value, setting the target transmission speed of the network device to be a second speed, wherein the second speed is not equal to the first speed.

The invention also discloses a control chip of the network device, the network device receives the input signal through the optical fiber medium, and the control chip comprises an analog front-end circuit, a control circuit and a medium selection unit. The analog front-end circuit is used for receiving the input signal. The control circuit is used for generating a speed setting signal according to a first speed and a detection signal, wherein the detection signal represents the amplitude or the energy of the input signal. The medium selection unit is coupled to the control circuit and used for determining a target transmission speed of the network device according to the speed setting signal. When the detection signal indicates that the amplitude or energy of the input signal is greater than a threshold value, the control circuit controls the medium selection unit to use the first speed as the target transmission speed through the speed setting signal, and when the detection signal indicates that the amplitude or energy of the input signal is not greater than the threshold value, the control circuit controls the medium selection unit to use a second speed as the target transmission speed through the speed setting signal, wherein the second speed is not equal to the first speed.

The features, implementations and functions of the present invention are described in detail below with reference to the accompanying drawings.

Drawings

FIG. 1 is a diagram illustrating an embodiment of a control chip of a network device according to the present invention;

FIG. 2 is a flow chart of one embodiment of a method of operation of a network device of the present invention;

FIG. 3 is a flow chart of another embodiment of a method of operation of a network device of the present invention; and

FIG. 4 is a functional block diagram of one embodiment of a control circuit.

Detailed Description

The technical terms of the following description are the terms commonly used in the technical field, and if the specification explains or defines a part of the terms, the explanation of the part of the terms is based on the explanation or definition of the specification.

The disclosure of the present invention includes a method of operating a network device and a control chip of the network device. Since some of the components included in the control chip of the network device of the present invention may be known components alone, the following description will omit details of the known components without affecting the full disclosure and the feasibility of the invention of the device. Furthermore, part or all of the flow of the operation method of the network device of the present invention may be in the form of software and/or firmware, and may be executed by a control chip of the network device of the present invention or an equivalent device thereof, and the following description of the method invention will be focused on the contents of steps rather than hardware without affecting the full disclosure and feasibility of the method invention.

Fig. 1 is a schematic diagram of a control chip of a network device according to an embodiment of the invention. The network device may be a router, a switch, or a terminal device (e.g., a server, a computer, etc. networking device). The control chip 100 implements the OSI model, however, fig. 1 only depicts a portion of the mac layer 110, the coordination Sublayer (RS) 120, and the physical layer 130, and omits other layers that are less relevant to the present technology. The control chip 100 further includes a medium selection unit 140, a control circuit 150, and an analog front end circuit 160. The control chip 100 transmits an output signal Vout and receives an input signal Vin through an optical module (optical module) 210 and an optical fiber medium 200. One of the functions of the optical module 210 is to perform conversion between an optical signal and an electrical signal, and therefore the optical module 210 may also be referred to as a photoelectric conversion element.

The analog front end circuit 160 receives an input signal Vin through the optical module 210 and the optical fiber medium 200, and detects an amplitude or energy of the input signal Vin to generate a detection signal SD representing the amplitude or energy of the input signal Vin. Techniques for detecting the amplitude or energy of a signal are well known to those of ordinary skill in the art and will not be described in detail. When the amplitude or energy of the input signal Vin is greater than a threshold value (e.g., the detection signal SD corresponds to a first level), the input signal Vin may be determined as a meaningful signal; conversely, when the amplitude or energy of the input signal Vin is not greater than the threshold (e.g., the detection signal SD corresponds to the second level), the input signal Vin may be determined as a meaningless signal (possibly representing a link-failure of the local device).

The control circuit 150 generates a speed setting signal SS according to the preset speed SK and the detection signal SD. The medium selection unit 140 selects one of the PHY layer transfer data (transmit data) (the PHY layer transfer data SPD-a PHY (transmission speed is SPD-a), the PHY layer transfer data SPD-B PHY (transmission speed is SPD-B), \ 8230;, and the PHY layer transfer data SPD-X PHY (transmission speed is SPD-X)) of a plurality of transmission speeds as the target transfer data TD of the control chip 100, according to the speed setting signal SS. The transmission speed of the target transfer data TD is the target transmission speed ST of the control chip 100. In some embodiments, media selection unit 140 may be a multiplexer.

In other embodiments, the detection signal SD may be replaced with the detection signal SD'. The detection signal SD' is generated by the optical module 210 in the optical fiber medium 200 by measuring the LOSs of signal (LOS), and can also be used to represent the amplitude or energy of the input signal Vin (the larger the LOSs of signal, the smaller the amplitude or energy of the input signal Vin).

Referring to fig. 2, fig. 2 is a flowchart illustrating an operation method of a network device according to an embodiment of the invention. The flow of fig. 2 is executed by the control circuit 150. First, after the system of the network device is started up or restarted (step S210, at which time the control circuit 150 performs some initial procedures), the control circuit 150 controls the medium selection unit 140 to set the transmission speed of the network device to the first speed by the speed setting signal SS (for example, if the first speed = the preset speed SK = SPD-a, the selection unit 140 selects the physical layer transmission data SPD-a PHY) (step S220), and then the control circuit 150 controls the analog front end circuit 160 to transmit and/or receive data at the first speed by the speed setting signal SS (step S230). Next, the control circuit 150 determines whether the detection signal SD is at the first level (step S240). Detecting the signal SD as a first level (e.g. high level) represents that the amplitude or energy of the input signal Vin is greater than a threshold value; the detection signal SD not being at the first level (e.g., the detection signal SD being at a low level) represents that the amplitude or energy of the input signal Vin is not greater than the threshold. In other words, step S240 is equivalent to monitoring whether the detection signal SD changes level, and is also equivalent to determining whether the amplitude or energy of the input signal Vin is greater than a threshold value.

When the detection signal SD is at the first level (yes judgment in step S240, that is, the amplitude or energy of the input signal Vin is greater than the threshold), the control circuit 150 maintains the transmission speed of the network device at the first speed (step S220), and continues to transmit and/or receive data (step S230).

When the detection signal SD is not at the first level (no at step S240, i.e., when the detection signal SD changes from the first level to the second level), the control circuit 150 controls the medium selection unit 140 to set the transmission speed of the network device to the second speed, which is not equal to the first speed, by the speed setting signal SS (step S250). For example, if the first speed is 2500BASE-FX (i.e., 2500M bps), the second speed can be 1000BASE-X (i.e., 1000M bps) or 100BASE-FX (i.e., 100 Mbps), etc., but not limited thereto. Alternative combinations of first speed and second speed include 5000BASE-X (i.e., 5000M bps), 2500BASE-FX (i.e., 2500M bps), 1000BASE-X (i.e., 1000M bps), or 100BASE-FX (i.e., 100M bps), among others. The transfer speeds 1000BASE-X and 100BASE-FX are defined and described in detail in IEEE 802.3, and the definitions of 5000BASE-X and 2500BASE-X can be adjusted or extended by the designer or manufacturer according to the definition of 1000BASE-X and the actual requirements.

Step S250 includes sub-step S255: the transmission control circuit 150 transmits preset data, such as Idle code groups (4 b/5b code groups defined under the 100BASE-X protocol) or Idle ordered sets (8 b/10b code groups defined under the 1000BASE-X protocol), to the link partner. One of the functions of the idle code-set or idle ordered set is to inform the link partner that the home device is currently idle (i.e., not transmitting data packets) but still processing the link state. Since the local device has changed speed in step S250, the link partner cannot correctly decode the received default data, and thus the link partner changes the state to off-line. When the state changes from link to disconnection, the link partner will not continue to transmit packets, thereby avoiding packet loss and problems to the upper layers of the OSI model.

After step S250 is completed, the control circuit 150 continues to determine whether the detection signal SD is at the first level (step S240). When the receiving path of the local device is recovered to be normal (yes in step S240, that is, the local device can receive the signal transmitted by the link partner again), the control circuit 150 sets the transmission speed of the local device to the first speed (step S220), so that the link partner can establish a link with the local device again, and both can recover normal packet transmission and/or reception.

In some embodiments, the second speed of step S250 is less than the first speed. For example, if the first speed is 2500BASE-X, the second speed may be 1000BASE-X or 100BASE-FX.

When the connection quality of the network device is poor, the network device implements a down speed (down speed) function, and tries to establish a network link by using a lower signal transmission rate (data rate) to improve the signal transmission quality, thereby increasing the probability of establishing a link between two network devices. For example, a local device and link partner that also support 1000BASE-X or 100BASE-FX, if they cannot establish a link at 1000BASE-X, both will be slowed down to 100BASE-FX and re-linked.

Based on the above speed reduction function, the present invention further provides an operation method of a network device, and a flowchart thereof is shown in fig. 3. The flow of fig. 3 is also executed by the control circuit 150. Steps S210 to S240 in fig. 3 are the same as those in fig. 2, and therefore are not described again. In the present embodiment, the second speed is 100BASE-FX, and step S250 includes sub-step S257: the control circuit 150 sends a Far-End Fault (FEF) indication (this indication is defined only under the agreement of 100 BASE-FX). Since the link partner performing the speed-down function will reduce its own transmission speed to 100BASE-FX (therefore, the link partner and the local device have the same transmission speed) after step S250, the control circuit 150 of the local device can send a remote failure indication to the link partner at the speed of 100BASE-FX to notify the link partner that the local device has failed. Compared to fig. 2, in the embodiment of fig. 3, the link partner can quickly know the failure and/or the reason of the failure of the local device, so that the link partner can quickly respond.

Referring to fig. 4, fig. 4 is a functional block diagram of an embodiment of the control circuit 150. Control circuit 150 includes a processing unit 152 and a memory 154. The processing unit 152 may be a circuit or an electronic component with program execution capability, such as a central processing unit, a microprocessor, or a micro-processing unit, which executes the steps of fig. 2 or 3 by executing program instructions or program codes stored in the memory 154.

In other embodiments, the control Circuit 150 can be designed by one of ordinary skill in the art based on the above disclosure, that is, the control Circuit 150 can be an Application Specific Integrated Circuit (ASIC) or a Circuit or hardware implementation such as a Programmable Logic Device (PLD) or a Finite State Machine (FSM).

The control chip of the network device and the operation method of the network device can prevent unilateral link state, thereby effectively avoiding packet loss or avoiding causing problems to the upper layer of an OSI model.

Since the details and variations of the method and the invention can be understood by those skilled in the art from the disclosure of the apparatus and the invention of the present invention, the repeated descriptions are omitted here for avoiding the redundancy and without affecting the disclosure requirements and the implementability of the method and the invention. It should be noted that the shapes, sizes and proportions of the elements in the drawings are merely schematic and intended to convey an understanding of the present invention to those skilled in the art, and are not intended to limit the present invention. In addition, in some embodiments, the steps mentioned in the flowcharts of the foregoing disclosure may be adjusted in sequence according to actual operations, and may even be executed simultaneously or partially simultaneously.

Although the embodiments of the present invention have been described above, these embodiments are not intended to limit the present invention, and those skilled in the art can make variations on the technical features of the present invention according to the explicit or implicit contents of the present invention, and all such variations may fall into the scope of the patent protection sought by the present invention.

Description of reference numerals:

100 control chip

110 medium access control layer

120 coordination sublayer

130 physical layer

140 medium selecting unit

150 control circuit

160 analog front-end circuit

200 optical fiber medium

210 optical module

Vout output signal

Vin is an input signal

SD, SD' detection signal

SK preset speed

SS speed setting signal

SPD-A PHY, SPD-B PHY, SPD-X PHY, physical layer transmitting data

TD target transfer data

ST target Transmission speed

152 processing unit

154 memory

S210, S220, S230, S240, S250, S255, S257

Claims

1. A method of operation of a network device that receives an input signal over a fiber optic medium, the method comprising:

setting a target transmission speed of the network device to a first speed;

transmitting and/or receiving data at the first speed; and

setting the target transmission speed of the network device to a second speed when the amplitude or energy of the input signal is not greater than a threshold, the second speed not equal to the first speed.

2. The method of claim 1, wherein the second speed is less than the first speed.

3. The method of claim 2, wherein the second speed is 100BASE-FX, the method further comprising:

a remote fault indication is transmitted.

4. The method of claim 1, further comprising:

transmitting an idle code group or an idle ordered set at the second speed.

5. A control chip of a network device, the network device receiving an input signal through a fiber optic medium, the control chip comprising:

an analog front end circuit for receiving the input signal;

a control circuit for generating a speed setting signal according to a first speed and a detection signal, wherein the detection signal represents the amplitude or energy of the input signal; and

a medium selection unit, coupled to the control circuit, for determining a target transmission speed of the network device according to the speed setting signal;

wherein the control circuit controls the medium selecting unit to have the first speed as the target transmission speed by the speed setting signal when the detection signal indicates that the amplitude or energy of the input signal is greater than a threshold, and controls the medium selecting unit to have a second speed as the target transmission speed by the speed setting signal when the detection signal indicates that the amplitude or energy of the input signal is not greater than the threshold, the second speed being not equal to the first speed.

6. The control chip of claim 5, wherein the second speed is less than the first speed.

7. The control chip of claim 6, wherein the second speed is 100BASE-FX, and the control circuit further transmits a far-end fault indication through the analog front-end circuit.

8. The control chip of claim 5, wherein the control circuitry is to transmit an idle code group or an idle ordered set at the second speed.

9. The control chip of claim 5, wherein the control circuit comprises a memory and a processing unit, the processing unit executing a plurality of program instructions or program codes stored in the memory to generate the speed setting signal according to the first speed and the detection signal.

10. The control chip of claim 5, wherein the detection signal is generated by the analog front end circuit by detecting an amplitude or energy of the input signal.