WO2018120549A1

WO2018120549A1 - Method and device for processing time stamp in ethernet passive optical network, and storage medium

Info

Publication number: WO2018120549A1
Application number: PCT/CN2017/082284
Authority: WO
Inventors: 张磊; 谢小龙; 陈恒; 臧高勇
Original assignee: 深圳市中兴微电子技术有限公司
Priority date: 2016-12-29
Filing date: 2017-04-27
Publication date: 2018-07-05
Also published as: CN108259106A

Abstract

Disclosed is a method for processing a time stamp in an EPON, the method comprising: detecting a delay in an MPCP packet passing through a PCS and a delay in same passing through an MAC coding layer; acquiring a first time stamp carried in an MPCP frame delivered by an OLT, wherein the MPCP frame comprises a Report frame; and adding the first time stamp, the delay in a data flow of each MPCP packet passing through the PCS and the delay in same passing through the MAC coding layer to obtain a second time stamp, and after the second time stamp is filled into the Report frame, sending the Report frame to the OLT. Further disclosed are a device for processing a time stamp in an EPON, and a storage medium.

Description

Ethernet passive optical network time stamp processing method and device, storage medium

Cross-reference to related applications

The present application is based on a Chinese patent application filed on Jan. 29, 2016, the entire disclosure of which is hereby incorporated by reference.

Technical field

The present invention relates to a time synchronization technology in the field of network communication, and in particular, to a timestamp processing method and apparatus, and a storage medium in an Ethernet Passive Optical Network (EPON).

Background technique

With the continuous development of the Internet, the demand for high-speed access networks is increasing, and EPON technology emerges in this situation. EPON technology is an Ethernet-based Passive Optical Network (PON) technology that combines the technical advantages of Ethernet and PON to provide a high-speed platform for accessing data, voice and video services. The EPON system is composed of an optical line terminal (OLT), an optical network unit (ONU, an optical network unit), and an optical distribution network (ODN), and the EPON system adopts a point-to-multipoint topology. And the transmission mode of passive optical fiber, providing multiple services based on Ethernet.

In order to achieve reasonable allocation of uplink bandwidth resources of each ONU, the EPON system needs to implement the bandwidth management function between EPON devices through the Multi-Point Control Protocol (MPCP). Therefore, MPCP is the core protocol for solving the key technologies of EPON. MPCP is a protocol of the media access control (MAC) control sublayer in the EPON system. The protocol specifies the control mechanism between the OLT and the ONU, and coordinates the effective transmission and reception of data by providing ONU control management information, ONU bandwidth management information, and service monitoring information control.

During the operation of the EPON system, the multi-point MAC control function is the core of the MPCP; the multi-point MAC controls the sending and receiving of the MAC client, so that multiple MAC clients work in the point-to-multipoint optical network, and multiple MAC clients The ends are connected by a shared fiber. Wherein, in the uplink direction, only one MAC is allowed to send an uplink frame in the network at any given moment, so that multiple MACs can operate on the shared medium. Therefore, in order to avoid data conflicts and to consider data compatibility, multi-point MAC control needs to comply with certain delay requirements, that is, based on a strict timestamp (Timestamp), or called a timestamp mechanism, according to system requirements. Strict calculation of timing.

In order to maintain the correctness of the timestamp, in addition to the timestamp carried in the MPCP frame received by the ONU, the actual delay of the ONU processing must be added to obtain the correct new timestamp in order to reset the internal counter of the ONU. However, in the traditional timestamp calculation method, the conventional method of processing the actual delay of the ONU is to set the processing delay of the data stream through the physical layer (PHY, Physical Layer), MAC layer and MPCP layer sub-modules to be fixed. The value of this fixed delay is based on the longest delay of each submodule in the actual situation. Since the processing of the data stream in each module is complicated, a plurality of IPs are also included in the middle, such as Advanced Encryption Standard (AES), triple disturbance, etc., and the delay when the data flows through these IP processing is fixed. This brings a lot of implementation difficulty to some algorithms IP and module processing. Even if the delay is fixed, the required delay will be large.

Summary of the invention

In view of this, the embodiments of the present invention are directed to providing a timestamp processing method and apparatus, and a storage medium in an EPON, aiming at solving the problem that a delay caused by a fixed delay processing is large in the existing timestamp calculation method.

To achieve the above objective, the technical solution of the embodiment of the present invention is implemented as follows:

An embodiment of the present invention provides a method for processing a timestamp in an EPON, where the method includes:

Detecting a delay of each MPCP packet data stream passing through a physical coding sublayer (PCS, Physical Coding Sublayer) and a delay of passing through the MAC coding layer;

Obtaining a first timestamp carried in an MPCP frame sent by the OLT, where the MPCP frame includes a report frame;

Adding the first timestamp, the delay of the respective MPCP packet data stream to the PCS, and the delay of the MAC encoding layer to obtain a second timestamp, and filling the second frame with the second timestamp After the timestamp, the Report frame is sent to the OLT.

In the foregoing solution, the MPCP frame further includes a Gate frame, where the Gate frame includes information about a transmission length of the MPCP packet and a start transmission time.

The first timestamp is a timestamp carried by the Gate frame delivered by the OLT.

In the foregoing solution, after the acquiring the first timestamp carried in the MPCP frame sent by the OLT, the method further includes:

Receiving a Gate frame that matches the ONU, intercepting a transmission length and a start transmission time of the MPCP packet in the Gate frame, and updating a local timing of the ONU according to the first timestamp carried in the Gate frame.

In the foregoing solution, the detecting the delay of the data flow of each MPCP packet through the PCS and the delay of the MAC coding layer include:

Calculating, according to the delay information carried by the MPCP packet, and the current local timing of the ONU, the difference of the local timing when the MPCP packet passes through each processing module in the PCS and the MAC coding layer, to obtain the MPCP packet Delay information of the processing module in the PCS and MAC coding layers;

The method further includes:

The counter of the ONU is updated by the second timestamp by a control character.

In the above solution, after the sending the report frame to the OLT, the method further includes:

Calculating a round trip delay (RTT) between the OLT and the ONU according to the second timestamp, and adjusting an authorization time of each ONU according to the RTT.

The embodiment of the present invention further provides a timestamp processing device in an EPON, where the device includes: a first processor and a second processor; wherein

The first processor is configured to detect a delay of the MPC packet data flow through the PCS and a delay of the MAC coding layer, and obtain a first timestamp carried in the MPCP frame sent by the OLT, where the MPCP frame includes Report frame

The second processor is configured to add the first timestamp, the delay of each MPCP packet data stream to the PCS, and the delay of the MAC encoding layer to obtain a second timestamp, and After the Report frame is filled in the second timestamp, the Report frame is sent to the OLT.

In the above solution, the device further includes: a third processor, configured to: after the first processor acquires the first timestamp carried in the MPCP frame sent by the OLT, receive a Gate frame that matches the ONU, and intercept the Transmitting the length of the MPCP packet in the Gate frame and starting the transmission time, and updating the local timing of the ONU according to the first timestamp carried in the Gate frame.

In the foregoing solution, the first processor is configured to: calculate, according to the delay information carried by the MPCP packet, and the current local timing of the ONU, the MPCP packet to pass through each processing module in the PCS and the MAC coding layer. And the time difference of the local timing, the delay information of the MPCP packet passing through the processing module in the PCS and the MAC coding layer is obtained; and the second timestamp is updated by the control symbol to update the counter of the ONU.

In the above solution, the device further includes: a fourth processor, configured to calculate, after the second processor sends the Report frame to the OLT, according to the second timestamp, between the OLT and the ONU RTT, and adjust the authorization time of each ONU according to the RTT.

An embodiment of the present invention further provides a timestamp processing apparatus in an EPON, including:

a memory for storing an executable program;

a processor for implementing the following steps by executing an executable program stored in the memory:

Detecting the delay of the MPCP packet passing through the PCS and the delay of the MAC encoding layer after the medium access control;

Adding the first timestamp, the delay of the MPCP packet to the PCS, and the delay of the MAC encoding layer to obtain a second timestamp, and after filling the second timestamp into the Report frame Sending the Report frame to the OLT.

The embodiment of the invention further provides a readable storage medium, which stores an executable program, and when the executable program is executed by the processor, the following steps are implemented:

Obtaining a first timestamp carried in an MPCP frame sent by the OLT, where the MPCP frame includes a report Report frame;

The timestamp processing method and device in the EPON provided by the embodiment of the present invention, and the storage medium, detecting the delay of each MPCP packet passing through the PCS and the delay of the MAC coding layer; acquiring the first time carried in the MPCP frame delivered by the OLT The MPCP frame includes a Report frame, and the first timestamp, the delay of the respective MPCP packets passing through the PCS, and the delay of the MAC encoding layer are added to obtain a second timestamp, and the After the report frame is filled in the second timestamp, Sending the Report frame to the OLT. In this way, the actual processing delay of the ONU can be flexibly processed to avoid the problem that the delay caused by the fixed delay processing in the existing timestamp calculation method is large, and the processing delay can be effectively reduced, and the internal processing time is optimized. Embodiments can also make the method of calculating the timestamp more accurate to better achieve synchronization between the ONU and the OLT.

DRAWINGS

1 is a schematic flowchart of a method for processing a timestamp in an EPON according to an embodiment of the present invention;

2 is a schematic diagram of a format of an MPCP frame according to an embodiment of the present invention;

3 is a schematic diagram of a format of a time synchronization mechanism between an OLT and an ONU according to an embodiment of the present invention;

4 is a schematic diagram of data flow of a PCS and a MAC coding layer according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a structure of a timestamp processing apparatus in an EPON according to an embodiment of the present invention.

detailed description

The embodiments of the present invention are described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the implementation process of the timestamp processing method in the EPON in the embodiment of the present invention includes the following steps:

Step 101: Detect a delay of each MPCP packet data stream passing through the PCS and a delay of passing through the MAC encoding layer;

The step specifically includes: calculating, according to the delay information carried by the current MPCP packet data stream and the local timing of the current ONU, the difference between the local timing of each MPCP packet data stream passing through each processing module in the PCS and the MAC coding layer, and obtaining the PCS through the PCS The final delay information of the processing module is processed in the MAC coding layer, and the final delay information of the processing module in the PCS and MAC coding layers is carried in the counter by the control character.

Here, the delay of each MPCP packet data stream passing through the MAC coding layer is mainly the MPCP packet. The data stream passes through the delay of the decryption module in the MAC coding layer.

Here, the local timing of the current ONU can be directly measured and obtained by the counter, which belongs to the prior art and will not be further described herein.

The MPCP packet is included in the MPCP frame, and only one MPCP packet is encapsulated in one MPCP frame, that is, one MPCP packet corresponds to one MPCP frame. In general, the MPCP packet operates on the network layer and the transport layer in the Open System Interconnection (OSI), and the MPCP frame operates on the data link layer in the OSI.

It should be noted that in EPON systems and even in 10G Ethernet passive optical networks (XEPON, 10Gigabit-EPON) systems, the concept of timestamps has been clearly defined in the IEEE802.3 standard protocol: within the OLT and ONU. Set a 32-bit counter and count it every 16 ns; that is, the counter provides a timestamp to uniquely identify the time of the OLT or ONU at a certain time. The timestamp identifies the count value of the OLT when the MAC control frame is uploaded to the MAC layer, and the timestamp is mapped to the corresponding area of the MPCP frame sent by the OLT or ONU (see MPCP frame format).

Figure 2 shows the MPCP frame format. As shown in Figure 2, the MPCP frame format mainly includes: destination address (DA, Destination Address), source address (SA, Source Address), length or type (Length/Type), operation. Code (Opcode), Timestamp, Date/Reserved/Pad, and Frame Check Sequence (FCS). The DA occupies 6 bytes in the MPCP frame, the SA occupies 6 bytes in the MPCP frame, the Length/Type occupies 2 bytes in the MPCP frame, and the Opcode occupies 2 bytes in the MPCP frame, and the Timestamp occupies 4 bytes in the MPCP frame, Date/Reserved/Pad occupies 40 bytes in the MPCP frame, and the FCS occupies 4 bytes in the MPCP frame. In particular, the 8 bits (b0-b7) in each byte are transmitted in order from left to right, that is, from low to high; at the same time, the bytes in each frame are sent in order from top to bottom. .

Figure 3 shows the format of the OLT and ONU time synchronization mechanism, which can be seen from Figure 3. Out: After the ONU receives the Gate frame, it does not delay until the time frame T3 is filled in before the Report frame is sent to the Report frame. To ensure the accuracy of the timestamp T3, Tn and Tn' must be guaranteed. The correct processing of this delay between.

According to the EPON/XEPON protocol, data is sent from the serializer/deserializer (SerDes, Serializer/Deserializer) link. The delay during this time will be composed of the processing time of the PCS and MAC coding layers.

Depending on the function of each module, the PCS can usually be divided into five modules: a bit-width conversion module (denoted as a gearbox module), a 66-bit sync header lock module (denoted as a SYNC module), and forward error correction (FEC). , Forward Error Correction) module, 66bit data descrambling module (denoted as DESCRAM module), 66b64b decoding module (denoted as 66b64b_DECODE module). When the data flows through the above modules in the PCS, the delay of each module is recorded and transmitted backwards together with the data stream, so that when the current module records the current delay, it can refer to the data stream before the record is carried. Module delay.

Figure 4 shows the data flow direction of the PCS and MAC coding layers. As shown in Figure 4, after the data flows through the SerDes IP output, it passes through the gearbox module and then delimits through the SYNC module. After error correction by the FEC module, Then perform data descrambling operation, and finally enter the 66b64b decoding module. Since the data of the first four modules only has the concept of data stream and codeword, and there is no fixed format of the MPCP packet to conveniently carry the delay information of each module, the actual start of the recording delay should be after the 66b64b decoding module. In this way, after 66b64b decoding, you can get the delay of the Start control character (the beginning of a packet) carrying each module, mark it as S0 or S4, at this time, you can record the current delay of the MPCP packet processing module, and The packet data that follows the parsing is passed along to the subsequent modules.

Here, the data format outputted by the 66b64b is a standardized 10Gb media independent interface (XGMII interface, 10Gigabit Media Independent Interface), where X corresponds to the Roman numeral 10. At this time, the delay of the data stream passing through the MAC coding layer is mainly delayed by the decryption module. When the data stream is parsed according to the data stream, it is determined whether the data stream enters the AES decryption module, the triple disturbance module, or the non-decryption module. The decryption module generally calls IP, and the processing of the data is complicated, and different IP types or different MPCP packet lengths will affect the processing of the delay. Therefore, the delay between the lengths of the MPCP packets is very different.

Step 102: Acquire a first timestamp carried in an MPCP frame sent by the OLT, where the MPCP frame includes a Report frame.

Here, the MPCP frame further includes a Gate frame, where the Gate frame includes information about a transmission length of the MPCP packet and a start transmission time;

The first timestamp is a timestamp carried by the Gate frame in the MPCP frame delivered by the OLT.

Here, after obtaining the first timestamp carried in the MPCP frame delivered by the OLT in this step, the method further includes:

Specifically, the OLT sends an MPCP frame to the specified ONU, where the MPCP frame contains the transmission information and the start time of the transmission. The Gate information in the transmission process is added with a local timestamp, that is, the transmission time is started. The first timestamp is mapped to the corresponding area in the MPCP frame format (corresponding to the Timestamp field). After receiving the Gate frame matching with itself, the ONU intercepts the transmission length and the start transmission time, and uses the timestamp (first timestamp) carried in the received Gate frame to update the local timing of the ONU, thereby eliminating the possibility. The clock drifts to ensure synchronization between the ONU and the OLT.

The ONUs in the EPON system use the broadcast mode in the downlink direction and the time division multiple access (TDMA) in the uplink direction. To avoid data collision, the clock of the OLT and the clock of the ONU must be communicated. Initial stage, one It needs to be synchronized until the end of the communication. In other words, the EPON needs to keep the synchronization of the entire network by using a timestamp, that is, the timestamp is first generated by the OLT, and the timestamp is sent to each ONU through the MPCP frame, and each ONU adjusts the timestamp by receiving the timestamp. The deviation between the local clock and the OLT clock, so as to achieve the effect that each ONU synchronizes with the OLT.

In addition to the Report frame and the Gate frame mentioned above, the OLT and the ONU need to complete the automatic registration process through the interaction of the other three types of MPCP control frames - REGISTER_REQ frame, REGISTER frame, and REGISTER_ACK frame.

Specifically, the registration process is as follows: the Gate frame is sent by the OLT, and the ONU that receives the Gate frame is allowed to send data immediately or within a specified time period; the ONU reports its state to the OLT through the Report frame, including where the ONU is synchronized. A timestamp, and whether there is data to be sent, etc.; the ONU sends a REGISTER_REQ frame to the OLT, that is, requests registration during the registration procedure; the OLT sends a REGISTER frame to notify the ONU that the registration request has been identified during the registration procedure; the ONU passes Sending a REGISTER_ACK frame indicates the registration confirmation during the registration procedure processing.

Step 103: Add the first timestamp, the delay of each MPCP packet data stream to the PCS, and the delay of the MAC encoding layer to obtain a second timestamp, and fill in the report frame. After the second timestamp is described, the Report frame is sent to the OLT.

Here, after the report frame is sent to the OLT in this step, the method further includes:

Calculating an RTT between the OLT and the ONU according to the second timestamp, and adjusting an authorization time of each ONU according to the RTT.

Specifically, FIG. 3 shows the calculation process of the RTT: 1. The OLT sends a Gate frame from the MPCP layer to the ONU at time T1, and fills in the timestamp T1, and in actuality, the time when the Gate frame is officially sent from the SERDES link is T1', there is a time difference between T1 and T1'; 2. ONU receives the Gate frame from the SERDES link at time T2', and the data arrives at MPCP at time T2. Layer, reset the local counter, and set the timestamp at this time to T2; 3. ONU sends a Report frame at time T3, and fills the report frame with timestamp T3. The time when the Report frame is officially sent from the SERDES link is T3. '; 4. The OLT receives the Report frame from the SERDES link at time T4', and the time when the data reaches the MPCP layer in the actual situation is T4; thus the formula for calculating the RTT is: RTT=T2'-T1'+ T4'-T3'. In the actual situation, the RTT is calculated at the MPCP layer. As can be seen from Figure 3, there is a delay when the recorded timestamp is officially transmitted on the SERDES link.

Here, the ONU and the OLT will rely on the timestamp to implement unique clock synchronization. The OLT inserts the value of its local counter into the timestamp field, and the ONU inserts its own local count value into the timestamp field; the ONU is based on the received OLT. The timestamp, updating its own counter, the OLT calculates the RTT according to the timestamp of the received ONU, and then the OLT adjusts the authorization time of each ONU according to the RTT.

In summary, the method for calculating the timestamp according to the embodiment of the present invention obtains the actual used delay according to the count of the internal counters recorded when each MPCP packet passes each module, without setting the maximum delay in advance. Fixed delay. Compared with the traditional timestamp calculation method, the calculation method of the embodiment of the present invention greatly reduces the processing delay, optimizes the internal processing time, and is flexible and simple to implement, and also reduces some algorithm IP and module. The difficulty of implementation.

To implement the above method, an embodiment of the present invention further provides a timestamp processing apparatus in an EPON. As shown in FIG. 5, the apparatus includes a first processor and a second processor.

The second processor is configured to add the first timestamp, the delay of each MPCP packet data stream to the PCS, and the delay of the MAC encoding layer to obtain a second timestamp, and After the second timestamp is filled in the Report frame, the Report frame is sent to the OLT.

The first processor is configured to calculate, according to the delay information carried in the current MPCP packet data stream and the local timing of the current ONU, each MPCP packet data stream is locally processed through each processing module in the PCS and MAC coding layers. The time difference is obtained, and the final delay information of the processing module in the PCS and MAC coding layers is obtained, and the final delay information of the processing module in the PCS and MAC coding layers is carried in the counter by the control character.

Here, the apparatus further includes: a third processor, configured to: after the first processor acquires the first timestamp carried in the MPCP frame sent by the OLT, receive a Gate frame matching the ONU, and intercept the Gate The transmission length of the MPCP packet in the frame and the start transmission time, and updating the local timing of the ONU according to the first timestamp carried in the Gate frame.

The device further includes: a fourth processor, configured to: after the second processor sends the Report frame to the OLT, calculate an RTT between the OLT and the ONU according to the second timestamp, and according to The RTT adjusts the authorization time of each ONU.

In an actual application, the first processor, the second processor, the third processor, and the fourth processor may be implemented on the OLT device or on the ONU device.

The embodiment of the present invention detects a delay of the data flow of each MPCP packet through the PCS and a delay of the MAC coding layer; and obtains a first timestamp carried in the MPCP frame sent by the OLT, where the MPCP frame includes a Report frame; The first timestamp, the delay of the respective MPCP packet data streams passing through the PCS, and the delay of the MAC encoding layer are added to obtain a second timestamp, and after the second timestamp is filled in the Report frame Sending the Report frame to the OLT. So, you can The processing time delay of the ONU is flexibly processed to avoid the problem that the delay is large due to the fixed delay processing in the existing timestamp calculation method, and the processing delay is optimized, and the internal processing time is optimized. The method of calculating the timestamp can be made more precise to better achieve synchronization between the ONU and the OLT.

The embodiment of the present invention provides a timestamp processing device in an EPON, which can be applied to an ONU, and is applicable to a time synchronization scenario between an ONU and an OLT:

The OLT sends an MPCP frame to the designated ONU. The MPCP frame contains the transmission length and the start transmission time, carries the local timestamp of the OLT, and is mapped to the corresponding area of the MPCP frame. After receiving the Gate frame matching with itself, the ONU intercepts the transmission length and starts the transmission time, and updates the ONU local timing. This is mainly done by the timestamp in the received Gate frame, thereby eliminating possible clock drift. Synchronization with the OLT is guaranteed. In the EPON system, each ONU uplink is accessed by TDMA, and the clock of the OLT and the clock of the ONU are kept synchronized at the time when the communication does not start until the end of the communication to avoid data collision.

For example, for an ONU that sets up a timestamp processing device, the MPCP packet will come from the SerDes link and will pass through the physical layer PCS and the coding layer MAC.

The physical layer PCS can be divided into five modules as shown in FIG. 5 according to the function. After the 66b64b decoding module, the Start control character (start of a packet) can be obtained with the flag S0 or S4, and the counter of the MPCP packet processing module is recorded at this time. Count1, the MPCP packet obtained by the parsing is transmitted to the subsequent module in FIG. 5, and when the MPCP packet reaches the MPCP packet processing module of the encoding layer MAC, the counter count2 of the MPCP packet processing module is subtracted from the count1. The delay of the MPCP packet from the decoding module to the MPCP packet processing module can be obtained. Adding the delay of this part to the delay of FEC decoding, and adding the timestamp in the Gate frame sent by the OLT, you can get a new timestamp and update the local counter inside the ONU to this new one. Timestamp, complete a time synchronization, repeat the above steps to continue the synchronization.

This timestamp processing method is based on the time when each recorded MPCP packet arrives at each module. The counter is counted to get the actual delay, without the need to calculate the maximum delay as a fixed delay. Relatively speaking, this solution is flexible and convenient, and the delay is greatly reduced. The internal processing delay.

For example, the hardware structure of the time stamp processing device may include:

a memory for storing an executable program;

The processor is configured to implement the timestamp processing method provided by the embodiment of the present invention by executing the executable program stored in the memory, for example, including at least the following steps:

Detecting the delay of the MPCP packet passing through the CS and the delay of passing through the MAC coding layer;

Embodiments of the present invention provide a storage medium storing an executable program, and the executable program is executed by a processor, for example, a time stamp processing method as shown in FIG. 1 . The storage medium of the embodiment of the present invention may be a storage medium such as an optical disk, a hard disk, or a magnetic disk, and may be a non-transitory storage medium.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention can take the form of a hardware embodiment, a software embodiment, or a combination of software and hardware. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) including computer usable program code.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each of the processes and/or blocks in the flowcharts and/or block diagrams, and in the flowcharts and/or block diagrams, can be implemented by computer program instructions. / or a combination of boxes. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in Within the scope of protection of the present invention.

Claims

A timestamp processing method in an Ethernet passive optical network EPON, the method comprising:

Detecting the delay of the multi-point control protocol MPCP packet passing through the physical coding sub-layer PCS and the delay of the medium access control MAC coding layer;

Obtaining a first timestamp carried in an MPCP frame sent by the optical line terminal OLT, where the MPCP frame includes a report Report frame;

Adding the first timestamp, the delay of the MPCP packet to the PCS, and the delay of the MAC encoding layer to obtain a second timestamp, and after filling the second timestamp into the Report frame Sending the Report frame to the OLT.
The method of claim 1 wherein

The MPCP frame further includes a strobe Gate frame, where the Gate frame includes a transmission length of the MPCP packet and a start transmission time;

The first timestamp is a timestamp carried in the Gate frame by the OLT.
The method according to claim 2, wherein after the acquiring the first timestamp carried in the MPCP frame delivered by the OLT, the method further includes:

Receiving a Gate frame that matches the optical network unit ONU, intercepting the transmission length and the start transmission time of the MPCP packet in the Gate frame, and updating the local timing of the ONU according to the first timestamp carried in the Gate frame.
The method according to claim 1, wherein the detecting the delay of the MPCP packet passing through the PCS and the delay of the MAC encoding layer include:

Calculating, according to the delay information carried by the MPCP packet, and the current local timing of the ONU, the difference of the local timing when the MPCP packet passes through each processing module in the PCS and the MAC coding layer, to obtain the MPCP packet Delay information of the processing module in the PCS and MAC coding layers;

The method further includes:

The counter of the ONU is updated by the second timestamp by a control character.
The method of claim 1, wherein after the transmitting the frame to the OLT, the method further comprises:

Calculating a round-trip delay RTT between the OLT and the ONU according to the second timestamp, and adjusting an authorization time of the ONU according to the RTT.
A timestamp processing device in an Ethernet passive optical network EPON, the device comprising: a first processor and a second processor; wherein

The first processor is configured to detect a delay of the multi-point control protocol MPCP packet passing through the physical coding sub-layer PCS and a delay of the medium access control MAC coding layer, and obtain an MPCP frame sent by the optical line terminal OLT a first timestamp carried in the MPCP frame, including a report report frame;

The second processor is configured to add the first timestamp, the delay of the MPCP packet to the PCS, and the delay of the MAC encoding layer to obtain a second timestamp, and in the report frame After filling in the second timestamp, the Report frame is sent to the OLT.
The apparatus according to claim 6, wherein the MPCP frame further comprises a gated Gate frame, wherein the Gate frame includes a transmission length and a start transmission time of the MPCP packet;

The first timestamp is a timestamp carried by the Gate frame delivered by the OLT.
The apparatus of claim 7 wherein said apparatus further comprises:

The third processor is configured to: after the first processor acquires the first timestamp carried in the MPCP frame sent by the OLT, receive a Gate frame that matches the ONU, and intercept the MPCP packet in the Gate frame. The transmission length and the start transmission time are updated according to the first timestamp carried in the Gate frame, and the local timing of the ONU is updated.
The apparatus according to claim 6, wherein

The first processor is configured to: calculate, according to the delay information carried by the MPCP packet, and the current local timing of the ONU, the MPCP packet is subjected to PCS and MAC coding. The difference between the local timings of each processing module in the layer, and the delay information of the processing module of the MPCP packet passing through the PCS and the MAC encoding layer is obtained;

The counter of the ONU is updated by the second timestamp by a control character.
The apparatus of claim 6, wherein the apparatus further comprises: a fourth processor configured to, after the second processor sends the Report frame to the OLT, according to the second timestamp Calculating a round trip delay RTT between the OLT and the ONU, and adjusting an authorization time of the ONU according to the RTT.
A timestamp processing device in an Ethernet passive optical network EPON, comprising:

a memory for storing an executable program;

a processor for implementing the following steps by executing an executable program stored in the memory:

Detecting the delay of the multi-point control protocol MPCP packet passing through the physical coding sub-layer PCS and the delay of the medium access control MAC coding layer;

Obtaining a first timestamp carried in an MPCP frame sent by the optical line terminal OLT, where the MPCP frame includes a report Report frame;

Adding the first timestamp, the delay of the MPCP packet to the PCS, and the delay of the MAC encoding layer to obtain a second timestamp, and after filling the second timestamp into the Report frame Sending the Report frame to the OLT.
A storage medium storing an executable program, the executable program being executed by a processor to implement the following steps:

Detecting the delay of the multi-point control protocol MPCP packet passing through the physical coding sub-layer PCS and the delay of the medium access control MAC coding layer;

Obtaining a first timestamp carried in an MPCP frame sent by the optical line terminal OLT, where the MPCP frame includes a report Report frame;

The first timestamp, the delay of the MPCP packet passing through the PCS, and the MAC encoding The delays of the layers are added to obtain a second timestamp, and after the second timestamp is filled in the Report frame, the Report frame is sent to the OLT.