WO2017206306A1 - Data frame transmitting or receiving method and apparatus - Google Patents

Abstract

The embodiment of the invention provides a data frame transmitting method comprising: receiving, from a first PON channel, a data frame sequence, wherein a data rate in the first PON channel is a sum of data rates in N second PON channels, and the data frame sequence comprises a first data frame; determining that a data frame in the data frame sequence is forwarded via M second PON channels, if a length of the first data frame exceeds a first length, slicing the first data frame to obtain a plurality of slices of the first data frame; adding overhead information to each of the slices to obtain a plurality of sliced data frames, wherein the overhead information comprises a slice field and a frame serial number, the slice field is used to indicate a number of the sliced data frames and a serial number of a corresponding sliced data frame with respect to the first data frame, and the frame serial number is a serial number of the first data frame in the data frame sequence; and forwarding, via the M second PON channels, the plurality of sliced data frames. The invention can resolve a problem of large latency variation owing to a large transmission latency caused by a jumbo frame.

Description

Method and device for transmitting and receiving data frames Technical field

The present invention relates to the field of Passive Optical Network (PON), and in particular, to a method and device for transmitting and receiving data frames.

Background technique

As users' demand for network access bandwidth increases significantly, 100G Ethernet Passive Optical Network (EPON), XG Passive Optical Network (XGPON) and time division wavelength division Systems such as the Time Wavelength Division Multiplexing Passive Optical Network (TWDM-PON) have attracted widespread attention in the industry.

Among them, 100G-EPON, XGPON and TWDM-PON systems have multiple transmission channels, which can support channel bonding technology, that is, multiple transmission channels are used as one logical channel to achieve higher rate transmission. However, when the Ethernet service is transmitted, because the Ethernet frame contains jumbo frames, in the channel bonding state, jumbo frames are transmitted on any transmission channel, which will result in unbalanced traffic on each transmission channel, resulting in increased delay and bandwidth utilization. The rate is reduced, and the frequency of jumbo frames is not fixed, which increases the jitter of the delay and affects the service experience.

Summary of the invention

The embodiment of the invention provides a method for transmitting a data frame, which solves the problem that the transmission of the jumbo frame on any transmission channel causes an increase in delay, a decrease in bandwidth utilization, and a large delay jitter.

A first aspect provides a method for transmitting a data frame, where the method is used in a passive optical network PON system, including: receiving a sequence of data frames from a first PON channel, where the rate of the first PON channel is N a rate sum of the second PON channel, wherein the data frame sequence includes a first data frame, N is a positive integer greater than 1, and determining that the data frame in the data frame sequence is forwarded from the M second PON channels, if The length of the first data frame exceeds the first length, and the first data frame is fragmented to obtain multiple fragments of the first data frame, where M is a positive integer, 2≤M≤ And adding the overhead information to each fragment to obtain a plurality of fragmented data frames, where the overhead information includes a fragmentation field and a frame sequence number, where the fragmentation field is used to indicate the number of fragmented data frames and corresponding a sequence number of the fragment data frame in the first data frame, the frame sequence number is a sequence number of the first data frame in the data frame sequence; and the plurality of the second PON channels are used The fragmented data frames are forwarded out.

The embodiment of the present invention solves the problem that the jumbo frame is fragmented, which causes the delay of the jumbo frame transmission on any transmission channel to increase the delay, the bandwidth utilization is reduced, the delay jitter is increased, and the service experience is affected; The fragmentation operation of the embodiment is implemented above the Media Access Control (MAC) layer, regardless of the specific number of channel bindings, and thus is compatible with all multi-channel PON systems.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the first data frame and the fragment data frame are both Ethernet frames, and the fragment data frame includes a first length type length a /type field, configured to indicate that the fragment data frame carries the fragmentation field, where the fragmentation field is adjacent to the first length/type field, and is located after the first length/type field.

With reference to the first aspect, in a second possible implementation manner of the first aspect, the first data frame and the fragment data frame are both a Gigabit Gigabit passive optical network encapsulation mode XGEM frame, and the XGEM The frame includes an XGEM frame header, wherein the slice field and the frame sequence number replace all or part of a selected options field in the XGEM frame header.

In conjunction with the second possible implementation of the first aspect, in a third possible implementation manner of the first aspect, the fragment field is replaced by all or part of the selected options field in the XGEM frame header. The options field includes a first field, a second field, and a third field, where the first field is used to indicate a sequence number of the first data frame in the data frame sequence, and the second field is used to indicate the The sequence number of the fragmented data frame in the corresponding fragmented data frame, the third field and the last fragment indicating that the LF field collectively indicates the number of slices.

With reference to the first aspect or any one of the possible implementation manners of the first or the second possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, the fragment field includes The fragment identifier and the fragment sequence number, the fragment identifier is the number of fragments, and the fragment sequence number is a sequence number of the corresponding fragment data frame in the first data frame. The embodiment of the invention can solve The data frame received by the receiving end has a problem of out of order.

With reference to the first aspect, or any one of the possible implementation manners of the first or the second possible implementation of the first aspect, in a fifth possible implementation manner of the first aspect, the fragment field includes a slice identifier and a slice sequence number, the slice identifier being used to indicate a slice data frame formed by a last slice in the first data frame; the slice sequence number is a corresponding slice data frame in the The sequence number in the first data frame.

With reference to the fifth possible implementation manner of the first aspect, in a sixth possible implementation manner of the first aspect, the fragment identifier is used to indicate that the last fragment in the first data frame is formed. The fragment data frame specifically includes: when the value of the fragment identifier is a first value, the fragment data frame is formed by a first fragment of the first data frame; When the value is the second value, the fragment data frame is formed by the intermediate fragment of the first data frame; when the value of the fragment identifier is the third value, the fragment data frame is The last slice of the first data frame is formed, wherein the first to third values are three different values.

In conjunction with the sixth possible implementation of the first aspect, in a seventh possible implementation manner of the first aspect, the fragment identifier is configured by a fragment header indication field and a fragment tail indication field.

With reference to the first aspect or any one of the possible implementation manners of the first or the second possible implementation manner of the first aspect, in the eighth possible implementation manner of the first aspect, the number of fragments is M . The embodiment of the invention can utilize the second PON channel more effectively and improve the bandwidth utilization.

In conjunction with the eighth possible implementation of the first aspect, in a ninth possible implementation manner of the first aspect, before the fragmenting the first data frame, the method further includes: according to the M The remaining space of the transmission queue of the second PON channel, the number of the fragments and the length of the first data frame, determine the length of each slice.

A second aspect provides a method for receiving a data frame, where the method is used in a passive optical network PON system, including: receiving a data frame from a second PON channel, where the data frame has a frame number, wherein the frame The sequence number is a sequence number of the data frame in the sequence of data frames; determining, according to the frame sequence number and the expected sequence number, whether the data frame is a data frame to be processed, and if the data frame is a data frame to be processed, Whether the data frame to be processed is a fragmented data frame; if the data frame to be processed is a fragmented data frame, according to the fragmentation field of the fragmented data frame, it is determined whether all the frames having the same frame have been received a fragmented data frame of a sequence number, wherein the fragmentation field For indicating the number of fragmented data frames and the sequence number of the fragmented data frame in the corresponding fragmented data frame; if all the fragmented data frames having the same frame number have been received, according to all of the same And a fragmentation field of the fragment data frame of the frame sequence, recombining all the fragment data frames having the same frame sequence, recovering the fragmented data frame, and adding the expected sequence number to 1.

The method provided by the embodiment of the invention can ensure that the fragment data frame is correctly received, the fragment data frame is reorganized, and the corresponding fragmented data frame is restored.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the data frame and the fragment data frame are both Ethernet frames, and the fragment data frame includes a first length type length/type a field, configured to indicate that the fragment data frame carries the fragment field, where the fragment field is adjacent to the first length/type field, and is located after the first length/type field.

With reference to the second aspect, in a second possible implementation manner of the second aspect, the data frame and the fragment data frame are both a Gigabit Gigabit passive optical network encapsulation mode XGEM frame, and the XGEM frame includes An XGEM frame header, wherein the slice field and the frame sequence number replace all or part of a selected options field in the XGEM frame header.

With reference to the second possible implementation of the second aspect, in a third possible implementation manner of the second aspect, the fragment field is replaced by all or part of the selected options field in the XGEM frame header, including: The options field includes a first field, a second field, and a third field, where the first field is used to indicate a sequence number of the data frame in a sequence of data frames, and the second field is used to indicate the fragment data frame The sequence number in the corresponding fragmented data frame, the third field and the last fragment indicate that the LF field collectively indicates the number of slices.

With reference to the second aspect or any one of the possible implementation manners of the first or the second possible implementation manner of the second aspect, in the fourth possible implementation manner of the second aspect, the determining the data Whether the frame is a data frame to be processed specifically includes: comparing the frame sequence number and the expected sequence number, and if the frame sequence number is greater than the expected sequence number, saving the data frame to the first cache, from the second Receiving, by the PON channel, a data frame; if the frame sequence number is smaller than the expected sequence number, discarding the data frame, and receiving a data frame from the second PON channel; if the frame sequence number is equal to the expected sequence number, the data frame The data frame to be processed.

With reference to the fourth possible implementation of the second aspect, in a fifth possible implementation manner of the second aspect, before the receiving the data frame from the second PON channel, the method further includes: if the If the buffer is not empty, the data frame is extracted from the first cache, and according to the frame sequence number and the expected sequence number, it is determined whether the data frame extracted from the first cache is a data frame to be processed, if The first buffer is empty, and the data frame is received from the second PON channel.

With reference to the fifth possible implementation manner of the second aspect, in a sixth possible implementation manner of the second aspect, after determining whether the data frame extracted from the first buffer is a data frame to be processed, the method The method further includes: if the data frame extracted from the first cache is not a data frame to be processed, continue to extract a data frame from the first cache, if all data frames extracted from the first cache are not to be processed The processed data frame receives a data frame from the second PON channel.

With reference to the second aspect, or any one of the possible implementation manners of the first or the second possible implementation manner of the second aspect, in the seventh possible implementation manner of the second aspect, Whether the processed data frame is a fragmented data frame includes: detecting whether the fragmentation field is included in the to-be-processed data frame, and if the fragmentation field is included, the to-be-processed data frame is a fragmented data frame. .

A third aspect provides a data frame sending device, where the device is used in a passive optical network PON system, and includes: a receiving module, a fragmentation module, an identification module, and a forwarding module.

The receiving module is configured to receive a sequence of data frames from a first PON channel, where the rate of the first PON channel is a rate sum of N second PON channels, and send the sequence of data frames to the fragmentation module. The data frame sequence includes a first data frame, where N is a positive integer greater than 1. The fragmentation module is configured to receive the data frame sequence from the receiving module, and determine data in the data frame sequence. The frame is forwarded from the M second PON channels. If the length of the first data frame exceeds the first length, the first data frame is fragmented to obtain multiple fragments of the first data frame. Transmitting, by the identifier module, the information of the M second PON channels to the forwarding module, where M is a positive integer, 2 ≤ M ≤ N; And receiving, by the fragmentation module, a plurality of fragments of the first data frame, inserting overhead information into each fragment, obtaining a plurality of fragmented data frames, and sending the multiple fragmented data frames. Giving the forwarding module, wherein the overhead information includes a fragmentation field and Serial number, field for indicating the slice sliced data frame and the corresponding frame number of sliced data in the first data frame, the The frame number is a sequence number of the first data frame in the data frame sequence; the forwarding module is configured to receive information about the M second PON channels from the fragmentation module, from the identifier module Receiving the plurality of fragment data frames, and forwarding the plurality of fragment data frames through the M second PON channels.

The device provided by the embodiment of the present invention solves the problem that the jumbo frame is fragmented, and the delay of the jumbo frame transmission on any transmission channel is increased, the bandwidth utilization is reduced, the delay jitter is increased, and the service experience is affected. Since the fragmentation operation of the embodiment of the present invention is implemented above the MAC layer, regardless of the specific number of channel bindings, it can be compatible with all multi-channel PON systems.

With reference to the third aspect, in a first possible implementation manner of the third aspect, the first data frame and the fragment data frame are both Ethernet frames, and the fragment data frame includes a first length type length a /type field, configured to indicate that the fragment data frame carries the fragmentation field, where the fragmentation field is adjacent to the first length/type field, and is located after the first length/type field.

With reference to the third aspect, in a second possible implementation manner of the third aspect, the first data frame and the fragment data frame are both a Gigabit Gigabit passive optical network encapsulation mode XGEM frame, and the XGEM The frame includes an XGEM frame header, wherein the slice field and the frame sequence number replace all or part of a selected options field in the XGEM frame header.

In conjunction with the second possible implementation of the third aspect, in a third possible implementation manner of the third aspect, the options field includes a first field, a second field, and a third field, where the first field is used by And indicating a sequence number of the first data frame in the sequence of data frames, where the second field is used to indicate a sequence number of the fragment data frame in a corresponding fragmented data frame, the third field and the last The fragment indicates that the LF field collectively indicates the number of slices.

With reference to the third aspect, or any one of the possible implementation manners of the first or the second possible implementation manner of the third aspect, in a fourth possible implementation manner of the third aspect, the fragment field includes The fragment identifier and the fragment sequence number, the fragment identifier is the number of fragments, and the fragment sequence number is a sequence number of the corresponding fragment data frame in the first data frame. The embodiment of the invention can solve the problem that the data frames received by the receiving end are out of order.

With reference to the third aspect, or any one of the possible implementation manners of the first or the second possible implementation manner of the third aspect, in the fifth possible implementation manner of the third aspect, the fragmenting The field includes a slice identifier and a slice sequence number, where the slice identifier is used to indicate a slice data frame formed by a last slice in the first data frame; the slice sequence number is a corresponding slice data frame. The sequence number in the first data frame.

In conjunction with the fifth possible implementation of the third aspect, in a sixth possible implementation manner of the third aspect, the fragment identifier is used to indicate that the last fragment in the first data frame is formed. The fragment data frame specifically includes: when the value of the fragment identifier is a first value, the fragment data frame is formed by a first fragment of the first data frame; When the value is the second value, the fragment data frame is formed by the intermediate fragment of the first data frame; when the value of the fragment identifier is the third value, the fragment data frame is The last slice of the first data frame is formed, wherein the first to third values are different values.

In conjunction with the sixth possible implementation of the third aspect, in a seventh possible implementation manner of the third aspect, the fragment identifier is configured by a fragment header indication field and a fragment tail indication field.

With reference to the third aspect or any one of the possible implementation manners of the first or second possible implementation manner of the third aspect, in the eighth possible implementation manner of the third aspect, the number of fragments is M .

In conjunction with the eighth possible implementation of the third aspect, in a ninth possible implementation manner of the third aspect, the fragmentation module is specifically configured to: according to the remaining space of the sending queues of the M second PON channels The number of the slices and the length of the first data frame determine the length of each slice.

A fourth aspect provides a receiving device for a data frame, where the device is used in a passive optical network PON system, including: a receiving module, an identifying module, a processing module, and a recombining module,

The receiving module is configured to receive a data frame from the second PON channel, and send the data frame to the identification module, where the data frame has a frame serial number, and the frame serial number is the data frame in the data frame The serial number in the sequence;

The identification module is configured to receive the data frame from the receiving module, determine, according to the frame serial number and the expected sequence number, whether the data frame is a data frame to be processed, if the data frame is data to be processed Sending, to the processing module, the data frame to be processed;

The processing module is configured to receive the data frame to be processed from the identification module, and determine whether the data frame to be processed is a fragmented data frame, if the data frame to be processed is fragmented Determining, according to the fragmentation field of the fragment data frame, whether all the fragment data frames having the same frame sequence number have been received, and whether the fragment data frame and all the packets have been received have the same The result of the determination of the fragmented data frame of the frame sequence is sent to the reassembly module, where the fragmentation field is used to indicate the number of fragmented data frames and the sequence number of the fragmented data frame in the corresponding fragmented data frame. ;

The reassembly module is configured to receive, according to the processing module, the fragment data frame and the determination result, if all the fragment data frames having the same frame sequence number have been received, according to the all having the same A fragmentation field of the fragment data frame of the frame number, recombining all the fragment data frames having the same frame number, recovering the fragmented data frame, and adding the expected sequence number to 1.

With reference to the fourth aspect, in a first possible implementation manner of the fourth aspect, the data frame and the fragment data frame are both Ethernet frames, and the fragment data frame includes a first length type length/type a field, configured to indicate that the fragment data frame carries the fragment field, where the fragment field is adjacent to the first length/type field, and is located after the first length/type field.

With reference to the fourth aspect, in a second possible implementation manner of the fourth aspect, the data frame and the fragment data frame are both a Gigabit Gigabit passive optical network encapsulation mode XGEM frame, and the XGEM frame includes An XGEM frame header, wherein the slice field and the frame sequence number replace all or part of the selection options field in the XGEM frame header.

In conjunction with the second possible implementation of the fourth aspect, in a third possible implementation manner of the fourth aspect, the options field includes a first field, a second field, and a third field, where the first field is used by And indicating a sequence number of the data frame in a sequence of data frames, where the second field is used to indicate a sequence number of the fragment data frame in a corresponding fragmented data frame, and the third field and a last segment indicate an LF field. Commonly indicate the number of shards.

With reference to the fourth aspect, or any one of the possible implementation manners of the first or the second possible implementation manner of the fourth aspect, in a fourth possible implementation manner of the fourth aspect, the Comparing the frame sequence number and the expected sequence number, if the frame sequence number is greater than the expected sequence number, saving the data frame to the first cache; if the frame sequence number is smaller than the expected sequence number, the data is Frame discarding; if the frame number is equal to the expected sequence number, the number The frame is a data frame to be processed; the device further includes the first buffer, configured to store the data frame whose frame number is greater than the expected sequence number.

In conjunction with the fourth possible implementation of the fourth aspect, in a fifth possible implementation manner of the fourth aspect, the receiving module is further configured to extract a data frame from the first cache, and extract the data The frame is sent to the identification module, wherein the receiving module extracts a data frame from the first cache with a higher priority than receiving a data frame from the second PON channel.

With reference to the fourth aspect, or any one of the possible implementation manners of the first or the second possible implementation manner of the fourth aspect, in a sixth possible implementation manner of the fourth aspect, And detecting whether the fragmentation field is included in the data frame to be processed, and if the fragmentation field is included, the data frame to be processed is a fragmented data frame.

A fifth aspect provides a data frame transmission and reception system, where the system is used in a PON field of a passive optical network, including: the device described in any one of the foregoing third aspect or the third aspect And the apparatus as described in the above fourth aspect or any one of the fourth aspects.

The embodiment of the present invention solves the problem that the jumbo frame is fragmented, which causes the delay of the jumbo frame transmission on any transmission channel to increase the delay, the bandwidth utilization is reduced, the delay jitter is increased, and the service experience is affected; The fragmentation operation of the embodiment is implemented above the MAC layer, independent of the specific number of channel bindings, and thus is compatible with all multi-channel PON systems.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any inventive labor.

1 is a system architecture diagram of an embodiment of the present invention;

2 is a flow chart of a method according to an embodiment of the present invention;

3 is a block diagram of a frame header of an XGEM frame;

4 is a flow chart of a method according to another embodiment of the present invention;

Figure 5 (a) is a schematic diagram of reception delay without using the solution of the present invention;

FIG. 5(b) is a schematic diagram of a receiving delay according to an embodiment of the present invention;

Figure 6 is a structural diagram of a device according to an embodiment of the present invention;

Figure 7 is a structural diagram of a device according to another embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

In the following description, for purposes of illustration and description, reference However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the invention.

When the embodiments of the present invention refer to ordinal numbers such as "first", "second" and the like, unless they are intended to express the order according to the context, it should be understood as merely distinguishing.

As is known, a typical PON system is mainly composed of three parts: an optical line terminal (OLT), an optical distribution network (ODN), and an optical network unit/Terminal (ONU/ONT). ). The OLT is located at the central office and is responsible for allocating and controlling the connection of the channel, and real-time monitoring, management, and maintenance of the entire PON network; the ONU/ONT is located at the user end (or the user premises side) to implement access of the user terminal; It consists of a Passive Optical Splitter (POS) and an optical fiber line to implement network connection between the OLT and each ONU. The difference between the ONU and the ONT is that the ONT is directly located at the user end, and there are other networks between the ONU and the user, but no distinction is made in this patent, and the ONU is always used.

As users' demand for network access bandwidth increases significantly, they can support higher-speed 100G-EPON, XGPON and TWDM-PON systems, which have become the focus of the industry. The system has multiple transmission channels, which can support channel bonding technology, and realize multiple transmissions by using multiple transmission channels as one logical channel, that is, binding multiple second PON channels together to reach the first The transmission rate of the PON channel, wherein the rate of the first PON channel is the rate sum of the plurality of second PON channels. However, when Ethernet packets are transmitted, because the Ethernet frames contain jumbo frames, in the channel bonding state, jumbo frames are transmitted on any transmission channel, which will cause unbalanced traffic on each transmission channel, resulting in increased delay and bandwidth. The utilization rate is reduced, and the frequency of jumbo frames is not fixed, which increases the delay jitter and affects the service experience.

In order to facilitate the understanding of those skilled in the art, the present invention describes the specific implementation process of the technical solution provided by the present invention through the following embodiments.

In the embodiment of the present invention, a system architecture diagram is provided, which is applicable to the method provided by the embodiment of the present invention, and may include an OLT, an ODN, and an ONU. The channel binding technology can be used for both downlink transmission and uplink transmission. That is to say, the channel binding technology can be implemented in the OLT or in the ONU. . Among them, the OLT to the ONU is called the downlink, and the ONU to the OLT is called the uplink.

The following describes the downlink transmission using the 100G-EPON system as an example. In the downlink, the OLT sends data frames to all ONUs in a Single Copy Broadcast (SCB) manner. Through the Discovery and Registered Process (DRP), the OLT assigns a Logical Link ID (LLID) to the successfully completed ONU. An ONU supports at least one LLID, and then the OLT transmits the data frame of the downlink. The LLID of the destination ONU is placed in the frame preamble, where LLID is the stream identifier of the frame. After the data frame arrives at the ONU, all ONUs judge according to the LLID and its own LLID contained in the preamble to determine whether to receive the data frame, and ensure that only the destination ONU will correctly receive the data frame.

It should be understood that the embodiments of the present invention are applicable not only to a 100G-EPON system, but also to a PON system such as an XGPON, a TWDM-PON, and a Wavelength Division Multiplexing Passive Optical Network (WDM-PON). The embodiments of the present invention are not limited thereto. For convenience of description, the following embodiments of the present invention are described as an example of transmission.

The embodiment of the invention provides a method for sending a data frame, as shown in FIG. 2, the method can include:

201. Receive a sequence of data frames, and determine an available channel of the sequence of data frames, where the sequence of data frames includes a first frame of data.

Specifically, the data frame sequence is received from the first PON channel, where the available channel is a second PON channel that can be actually forwarded, the rate of the first PON channel is the rate of the N second PON channels, and N is greater than 1 Integer.

The method for determining the available channel of the data frame sequence may be: searching the channel binding table according to the flow identifier of the first data frame, obtaining a forwarding channel of the first data frame, and obtaining the first data frame according to the remaining space of the sending queue of the forwarding channel The available channel is the available channel of the data frame sequence. The channel binding table is a corresponding table of the pre-configured flow identifier and the forwarding channel, and the available channel is the channel with the remaining space of the sending queue in the forwarding channel.

That is, the channel binding table is searched according to the flow identifier of the first data frame, and the second PON channel that can be forwarded by the first data frame can be obtained, and then the first data frame is obtained according to the remaining space of the sending queue of the second PON channel. The second PON channel that can actually be forwarded, wherein the channel binding table is a correspondence table between the flow identifier and the second PON channel.

Specifically, the 100G-EPON is taken as an example, and the destination MAC address and the LLID are in one-to-one correspondence. The unique LLID can be determined according to the destination MAC address of the data frame, and the channel binding table is searched according to the LLID to obtain an available channel of the first data frame. The second PON channel that can be forwarded; the channel binding table is pre-configured according to actual conditions. For example, it can be configured according to the processing speed of the destination ONU in the 100G-EPON system. If the destination ONU supports the 100G rate, the corresponding The data frame can be forwarded simultaneously in four channels. If the destination ONU only supports 50G rate, the corresponding data frame can only be forwarded from two channels at the same time. The specific configuration of the channel binding table is not limited in the embodiment of the present invention.

202. If the length of the first data frame exceeds the first length, the first data frame is fragmented to obtain multiple fragments of the first data frame, where the number of fragments is determined by the number of available channels. The length of a data frame is the full length of the frame.

Optionally, as another embodiment, after determining an available channel of the data frame sequence, the method further includes: determining whether a length of the first data frame exceeds a first length, where a length of the first data frame is The full length of the frame.

Specifically, if the length of the first data frame does not exceed the first length, the first data frame is not fragmented, and the unsliced first data frame is forwarded through the available channel.

Optionally, if the length of the first data frame exceeds the first length, the method further includes: determining whether the number of the available channels is greater than 1, and if the number of the available channels is greater than 1, dividing the first data frame sheet.

Optionally, before step 202, the method further includes: determining that the data frame in the sequence of data frames is forwarded from the M second PON channels, where M is a positive integer, 2≤M≤N.

It should be noted that if the number of available channels is equal to 1, that is, if the data frames in the sequence of data frames are only forwarded from one second PON channel, the effect of splitting the first data frame is the same. Assuming that the first data frame can only be forwarded from one channel, even if the first data frame is fragmented, all the fragments must be forwarded from this channel, and the other channels are completely unused, which cannot reduce the delay and reduce The effect of small delay jitter.

Optionally, the number of the fragmented data frames is an integer multiple of the number of available channels, and preferably, the number of the fragmented data frames is equal to the number of the available channels, that is, the number of fragments is determined according to the M The actual situation of the two PON channels is determined. Preferably, the number of slices is M.

Optionally, determining a length of each fragment according to a remaining space of the sending queue of the available channels (the M second PON channels), a number of fragments, and a length of the first data frame, for example, M is 4, The available channels are four. The remaining space of the sending queue of the first channel is smaller than the second length. If the sending queue space of the other three channels is sufficient, the first data frame may be cut off first, and the overhead information is added in the cutting part. A fragmented data frame is obtained, the length of the fragmented data frame is equal to the remaining space of the first channel, and the remaining first data frame is further divided into three pieces and respectively forwarded from the other three channels, so that all available data can be fully utilized. Channel, which improves bandwidth utilization, wherein the second length is 1/4 of the sum of the lengths of 4 fragmented data frames.

It should be noted that, in the uplink transmission, the time division multiplexing access mode is adopted, and each ONU obtains a corresponding transmission window according to the transmission time slot allocated by the OLT, and the data is transmitted to the OLT through the transmission window. Therefore, in the uplink transmission, the length of each fragment can be determined according to the remaining space of the transmission window, the number of fragments, and the length of the first data frame. In addition, the embodiments of the present invention are completely consistent in uplink transmission and downlink transmission.

It should be understood that there are many ways to determine the length of the slice, and the embodiment of the present invention does not do this. limited.

203. Adding overhead information to each fragment to obtain multiple fragment data frames, where the overhead information includes a fragmentation field and a frame sequence, and the fragmentation field is used to indicate the number of fragmented data frames and the corresponding fragmented data frame. The sequence number in the first data frame, the frame number is the sequence number of the first data frame in the sequence of data frames.

Optionally, in another embodiment, the first data frame and the fragmented data frame are both Ethernet frames, and the fragmented data frame includes a first length type length/type field, which is used to indicate that the fragment data frame is carried. A fragmentation field, the fragmentation field being adjacent to the first length/type field, located after the first length/type field.

The embodiment of the present invention is applied to a PON system for transmitting an Ethernet frame, such as a 100G-EPON, a WDM-PON, etc., after the Ethernet frame is fragmented, adding overhead information for each fragment to form a fragmented Ethernet frame, and fragmenting The Ethernet frame includes a fragmentation field to ensure that the receiving end can correctly receive and reassemble the fragmented Ethernet frames, where the fragmentation field and the first length/type field can be anywhere in the fragmented Ethernet frame, in the embodiment of the present invention. There is no limit to this.

Optionally, in another embodiment, the first data frame and the fragmented data frame are both a Gigabit Gigabit Encapsulation Method (XGEM) frame, and the XGEM frame includes an XGEM frame header, where The slice field and frame sequence number replace all or part of the options field in the XGEM frame header.

Optionally, the options field includes a first field, a second field, and a third field, where the first field is used to indicate the sequence number of the first data frame in the data frame sequence, and the second field is used to indicate that the fragment data frame is correspondingly The sequence number in the sliced data frame, the third field and the Last Fragment (LF) field together indicate the number of slices.

The embodiment of the present invention is applied to a PON system for transmitting XGEM frames, such as XGPON, TWDM-PON, etc. In the above PON system, a single Ethernet frame is encapsulated in a single XGEM, and therefore, a JGEM frame also has a jumbo frame, therefore, It is also necessary to slice XGEM frames whose length exceeds the first length. After the XGEM frame is fragmented, overhead information is added for each slice to form a fragmented XGEM frame. The frame header structure of the XGEM frame is as shown in FIG. 3, including a 14-bit Payload Length indication (PLI) field, a 2-bit Key Index field, and a 16-bit XGEM port identifier (XGEM port). -ID) field, 18-bit options Field, 1-bit LF field and 13-bit Hybrid Error Correction (HEC) field.

The options field is an idle field and has no function. Therefore, the fragment field and the frame number can replace part or all of the options field of the XGEM frame. The LF field can also be used to indicate whether the fragment is formed by the last fragment. Data frame; or use the third field in the options field to augment the LF field, so that the LF field can respectively indicate which segment of the first slice, the middle slice or the last slice is the current slice data frame. The slice is formed or the LF field indicates the number of slices. In this way, the overhead of the fragmented data frame can be reduced while ensuring normal reception of the fragmented data frame.

Optionally, in another embodiment, the fragmentation field includes a fragment identifier and a fragment sequence number, where the fragment identifier is the number of fragments, and the fragment sequence number is a sequence number of the corresponding fragment data frame in the first data frame. .

The fragment number of each fragment is different. For example, the first data frame is divided into four pieces, and the overhead information is inserted in the four fragments to obtain four fragment data frames, and the first fragment is obtained. The fragment number of the formed fragment data frame is 1, and the fragment sequence number of the fragment data frame formed by the second fragment is 2, and so on.

In a 100G-EPON system, when transmitting a 100G data frame sequence, it needs to be transmitted simultaneously from four 25G rate channels. The processing of the data frame sequence on the channel by the physical layer of the four channels is not completely synchronized, which may result in reception. The data frame received by the terminal has a problem of out of order. Specifically, it is assumed that the fragment numbers of the fragmented data frames sequentially entering the four channels are 1, 2, 3, and 4, respectively, and the receiving end may sequentially receive the fragment data of the fragment numbers 1, 3, 2, and 4. The frame, that is, the channel in which the second fragmented data frame is located may take a long time to process. Although the second fragmented data frame enters the channel first than the third fragmented data frame, the receiving end receives the first The three fragmented data frames cause the fragmented data frames received by the receiving end to be out of order, and the four channels here are four second PON channels.

Therefore, the fragmentation field is used to indicate the number of fragmented data frames and the sequence number of the corresponding fragmented data frame in the first data frame, and it can be determined whether all the fragments are received by the receiving end, and all the fragments can be ensured to be correct. The order is reorganized.

Specifically, the value of the fragment identifier is greater than 0, and when the fragment identifier is equal to 1, the first data frame For an unfragmented data frame, when the value of the fragment identifier is greater than 1, the value of the fragment identifier is the number of fragment data frames.

Optionally, as another embodiment, the slice identifier is used to indicate a slice data frame formed by the last slice of the first data frame. Specifically, when the value of the fragment identifier is the first value, the fragment data frame is formed by the first fragment of the first data frame; and when the value of the fragment identifier is the second value, the fragment data frame is Formed by the intermediate slice of the first data frame; when the value of the slice identifier is the third value, the slice data frame is formed by the last slice of the first data frame; the value of the slice identifier is the fourth value The first data frame is an unfragmented data frame.

The number of fragments can be obtained according to the fragment sequence number of the fragment data frame formed by the last fragment. The first to fourth values are any four different values, for example, 1, 2, 3, and 4. This embodiment of the present invention does not limit this.

Specifically, the fragmentation identifier may be composed of a fragmentation header indication field and a fragmentation tail indication field, where the fragmentation header indication field and the fragmentation tail indication field have various values, for example, the fragmentation header indication field takes 1 and the fragmentation tail indication When the field is 0, the value of the fragment identifier is the first value, and the fragment data frame is formed by the first fragment of the first data frame; when the fragment header indication field and the fragment tail indication field are both 0, the fragmentation is performed. The value of the identifier is a second value, and the fragment data frame is formed by an intermediate fragment of the first data frame; when the fragmentation header indication field is 0, and the fragmentation tail indication field is 1, the fragmentation identifier value is a third value. The fragment data frame is formed by the last fragment of the first data frame; when both the fragment header indication field and the fragment tail indication field are taken as 1, the fragment identification value is the fourth value, and the first data frame is unfragmented. Data frame.

It should be understood that the embodiment of the present invention provides an implementation form of several fragment identifiers, and the use of the fragment identifiers is given, but the specific names, lengths, and values are not limited.

Optionally, in another embodiment, the fragmented data frame and the unfragmented data frame include: a fragmented frame identifier, configured to indicate whether the corresponding data frame is a fragmented data frame.

For example, if the length of the first data frame exceeds the first length, the first data frame is fragmented, and the value of the fragment frame identifier included in each fragment data frame is the fifth value, if the first data frame is The length does not exceed the first length, and the value of the fragmented frame identifier is the sixth value. It should be understood that the fifth value and the sixth value may have a plurality of values, which are not limited in the embodiment of the present invention.

204. Forward, by using the available channel, a plurality of fragmented data frames, where The available channels are the M second PON channels.

Optionally, as another embodiment, after determining that the data frame in the data frame sequence is forwarded from the M second PON channels, the method further includes: determining whether the length of the first data frame exceeds the first length, where The length of the first data frame is the full length of the frame. Specifically, if the length of the first data frame does not exceed the first length, the first data frame is not fragmented, and the unfragmented first data frame is forwarded through the M second PON channels.

The embodiment of the present invention solves the problem that the jumbo frame is fragmented, which causes the delay of the jumbo frame transmission on any transmission channel to increase the delay, the bandwidth utilization is reduced, the delay jitter is increased, and the service experience is affected; The fragmentation operation of the embodiment is implemented above the MAC layer, independent of the specific number of channel bindings, and thus is compatible with all multi-channel PON systems.

Another embodiment of the present invention provides a method for receiving a data frame. As shown in FIG. 4, the method may include:

401. Receive a data frame, where the data frame has a frame sequence number, where the frame sequence number is a sequence number of the data frame in the data frame sequence.

The data frame is received from the second PON channel.

402. Determine, according to the frame sequence number and the expected sequence number, whether the data frame is a data frame to be processed. If the data frame is a data frame to be processed, determine whether the data frame to be processed is a fragmented data frame.

Optionally, determining whether the data frame is a data frame to be processed is: comparing a frame sequence number and an expected sequence number. If the frame sequence number is greater than an expected sequence number, saving the data frame to the first buffer, and continuing to receive the data frame; The frame number is smaller than the sequence number, the data frame is discarded, and the data frame is continuously received. If the frame number is equal to the expected sequence number, the data frame is the data frame to be processed.

Before the step 401, if the first cache is not empty, the data frame is extracted from the first cache, and according to the frame serial number and the expected sequence number, it is determined whether the data frame extracted from the first cache is a data frame to be processed, if The data frame extracted in a buffer is not a data frame to be processed, and the data frame is continuously extracted from the first buffer. If all data frames extracted from the first buffer are not data frames to be processed, the data frame continues to be received. If the first buffer is empty, continue to receive data frames.

The specific manner of determining whether the data frame to be processed is a fragmented data frame may be: (1) detecting a fragmented frame identifier in the to-be-processed data frame, if the value of the fragmented frame identifier is Five values, the data frame to be processed is a fragmented data frame; (2) if there is no fragmentation field in the unfragmented data frame, detecting whether the fragmented field is included in the data frame to be processed, if the fragment is included a slice field, the data frame to be processed is a fragmented data frame; (3) if there is a fragmentation field in the unfragmented data frame, the data frame to be processed may be determined according to the value of the fragmentation field. Fragmented data frames.

403. If the data frame to be processed is a fragmented data frame, determine, according to the fragmentation field of the fragmented data frame, whether all the fragmented data frames having the same frame sequence number have been received, where the fragmentation field is used to indicate The number of fragmented data frames and the sequence number of the fragmented data frame in the corresponding fragmented data frame.

If the data frame to be processed is an unfragmented data frame, the expected sequence number is incremented by one; if all the fragment data frames having the same frame sequence number are not received, the receiving from the first buffer or the second PON channel is continued. Data Frame.

Specifically, the data frame and the fragmented data frame may be an Ethernet frame, and the fragmented data frame includes a first length/type field, which is used to indicate that the fragmented data frame carries the fragmentation field, and the fragmentation field and the first length/ The type field is adjacent to the first length/type field; the data frame and the fragmented data frame may also be XGEM frames, and the XGEM frame includes an XGEM frame header, where the fragmentation field and the frame sequence number are replaced by the XGEM frame header. All or part of the options field.

The options field includes a first field, a second field, and a third field, where the first field is used to indicate the sequence number of the data frame in the data frame sequence, and the second field is used to indicate that the fragment data frame is in the corresponding fragmented data. The sequence number in the frame, the third field and the LF field together indicate the number of slices.

Optionally, as another embodiment, the fragmentation field includes a fragment identifier and a fragment sequence number, where the fragment identifier is the number of fragments or is used to indicate that the last fragment in the fragmented data frame is formed. The fragmented data frame, the fragment number is the sequence number of the fragmented data frame in the corresponding fragmented data frame. It should be understood that the number of slices can be obtained according to the slice number of the slice data frame formed by the last slice. The present invention has been described in detail in the foregoing embodiments, and the embodiments of the present invention are not described herein.

404. If all the fragment data frames having the same frame sequence number have been received, all the fragment data frames having the same frame sequence number are all according to the fragment field of all the fragment data frames having the same frame sequence number. Reorganize and recover the fragmented data frame, and the expected sequence number is increased by 1.

The overhead information is removed before the fragment data frame is reorganized.

The method provided by the embodiment of the present invention is the receiving method of the previous embodiment. The method of fragmenting a jumbo frame solves the problem that the jumbo frame transmission on any transmission channel causes an increase in delay, a decrease in bandwidth utilization, and an increase in delay jitter. Large, affecting the problem of the service experience; since the fragmentation operation of the embodiment of the present invention is implemented above the MAC layer, regardless of the specific number of channel bindings, it can be compatible with all multi-channel PON systems.

Specifically, in the 100G-EPON system, the data frame sequence is the same service flow, and the transmission queues of the four channels are all empty, and the data frame sequence can be forwarded from any channel as an example, wherein the OLT device is from 100G. A sequence of data frames received by the first PON of the rate, the sequence of data frames being forwardable from any of the four PON channels of the 25G rate. As can be seen from FIG. 5(a) and FIG. 5(b), the second data frame is a jumbo frame. After the second data frame is fragmented, the delay of the receiving end is significantly reduced, because the jumbo frame pair is reduced. The effect of the delay, therefore, the embodiment of the invention can also reduce the delay jitter.

The operations such as decoding and demapping at the receiving end must be performed in order, because if the data is not sequentially performed in sequence, the data information cannot be correctly recovered and the service experience is affected. In FIG. 5(a) and FIG. 5(b), the data frame sequence of the 100G reception decoding instruction is a sequence of data frames obtained after recombining the fragment data frames.

It should be noted that since the data frame sequence of the 100G rate is forwarded through the channel of the 25G rate, the transmission time of each data frame is extended by 4 times, and in the example given here, each data frame is in the channel. In the case of the idle state, the channel with a small number is preferentially selected for forwarding. This is a channel selection mode, and there are many options.

Another embodiment of the present invention provides a data frame sending device, as shown in FIG. 6, including: a receiving module 601, a fragmenting module 602, an identifying module 603, and a forwarding module 604.

The receiving module 601 is configured to receive a sequence of data frames, determine an available channel of the data frame sequence, send the available channel information to the fragmentation module 602 and the forwarding module 604, and send the first data frame in the data frame sequence to the fragment. Module 602.

Optionally, the receiving module 601 is specifically configured to receive a data frame sequence from the first PON channel, where the rate of the first PON channel is a rate of the N second PON channels, and the data frame sequence packet Including the first data frame, N is a positive integer greater than one.

The fragmentation module 602 is configured to receive the first data frame and the available channel information from the receiving module 601. If the length of the first data frame exceeds the first length, the first data frame is fragmented to obtain the first data frame. The plurality of fragments send the plurality of fragments of the first data frame to the identification module 603, wherein the number of fragments is determined by the number of available channels, and the first length is a preset value.

Optionally, the fragmentation module 602 is further configured to: determine whether the number of the available channels is greater than 1, and if the number of the available channels is greater than 1, and the length of the first data frame exceeds the first length, the first data is The frame is sliced.

Wherein, if the number of available channels is equal to 1, the effect of splitting the first data frame is the same. Assuming that the first data frame can only be forwarded from one channel, even if the first data frame is fragmented, all the fragments must be forwarded from this channel, and the other channels are completely unused, which cannot reduce the delay and reduce The effect of small delay jitter.

The identifier module 603 is configured to receive multiple fragments of the first data frame from the fragmentation module 602, insert overhead information into each fragment, obtain multiple fragment data frames, and send multiple fragment data frames to the forwarding. The module 604, where the overhead information includes a fragmentation field and a frame number, where the fragmentation field is used to indicate the number of the fragmented data frames and the sequence number of the corresponding fragmented data frame in the first data frame, and the frame sequence number is the first data frame. The sequence number in the sequence of data frames;

The forwarding module 604 is configured to receive the available channel information from the receiving module 601, receive a plurality of fragmented data frames from the identifier module 603, and forward the plurality of fragmented data frames through the available channel.

It should be noted that, in the embodiment of the present invention, the available channel is a second PON channel that can be actually forwarded.

The device provided by the embodiment of the present invention solves the problem that the jumbo frame is fragmented, and the delay of the jumbo frame transmission on any transmission channel is increased, the bandwidth utilization is reduced, the delay jitter is increased, and the service experience is affected. Since the fragmentation operation of the embodiment of the present invention is implemented above the MAC layer, regardless of the specific number of channel bindings, it can be compatible with all multi-channel PON systems.

Optionally, as another embodiment, the fragmentation module 602 is further configured to: determine whether the length of the first data frame exceeds the first length, if it is determined that the length of the first data frame does not exceed the first length The first data frame is not fragmented, and the unsliced first data frame is sent to the forwarding module 604. The forwarding module 604 is further configured to receive the unfragmented first data frame from the fragmentation module. The available channel is used to forward the first data frame that is not fragmented.

The length of the first data frame represents the full length of the first data frame.

Preferably, the fragmentation module 602 is further configured to: determine whether the number of the available channels is greater than 1, and if the number of the available channels is greater than 1, and the length of the first data frame exceeds the first length, the first data frame is Perform the sharding.

Wherein, if the number of available channels is equal to 1, the effect of splitting the first data frame is the same. Assuming that the first data frame can only be forwarded from one channel, even if the first data frame is fragmented, all the fragments must be forwarded from this channel, and the other channels are completely unused, which cannot reduce the delay and reduce The effect of small delay jitter.

Optionally, the number of fragments is an integer multiple of the number of available channels, and preferably, the number of fragments is equal to the number of available channels, that is, the number of fragments is determined according to actual conditions of the M second PON channels. Preferably, the number of shards is M. The length of each slice is determined according to the remaining space of the transmission queues of the M second PON channels, the number of fragments, and the length of the first data frame.

Optionally, the length of each slice may be determined according to the remaining space of the transmit queue of the available channel, the number of slices, and the length of the first data frame.

Specifically, the first data frame and the fragmented data frame may be an Ethernet frame, and the fragmented data frame includes a first length/type field, configured to indicate that the fragmented data frame carries the fragmentation field, and the fragmented field and the first length The /type field is adjacent to the first length/type field; the first data frame and the fragmented data frame may also be XGEM frames, and the XGEM frame includes an XGEM frame header, wherein the fragment field and the frame sequence number replace the XGEM frame header All or part of the options field in .

The options field includes a first field, a second field, and a third field, where the first field is used to indicate the sequence number of the first data frame in the data frame sequence, and the second field is used to indicate that the fragment data frame is correspondingly fragmented. The sequence number in the data frame, the third field and the LF field together indicate the number of slices.

Optionally, as another embodiment, the fragmentation field includes a fragment identifier and a fragment sequence number, where the fragment identifier is the number of fragments or is used to indicate that the last fragment in the fragmented data frame is formed. Fragmented data frame, the fragment sequence number is the sequence of the fragmented data frame in the corresponding fragmented data frame number. It should be understood that the number of slices can be obtained according to the slice number of the slice data frame formed by the last slice. The fragment identification and the fragment sequence number have been implemented in various manners, which have been described in detail in the previous embodiments, and the embodiments of the present invention are not described herein again.

Optionally, in another embodiment, the fragmented data frame and the unfragmented data frame include: a fragmented frame identifier, configured to indicate whether the corresponding data frame is a fragmented data frame.

For example, if the length of the first data frame exceeds the first length, the first data frame is fragmented, and the value of the fragment frame identifier included in each fragment data frame is a fifth value; if the first data frame is The length does not exceed the first length, and the value of the fragmented frame identifier is the sixth value. It should be understood that the fifth value and the sixth value may have a plurality of values, which are not limited in the embodiment of the present invention.

Optionally, as another embodiment, the fragmentation module 602 is specifically configured to: find a channel binding table according to a flow identifier of the first data frame, and obtain a forwarding channel of the first data frame, according to a remaining space of the sending queue of the forwarding channel, Obtaining the available channel of the first data frame, that is, the available channel of the data frame sequence, wherein the channel binding table is a pre-configured correspondence table between the flow identifier and the forwarding channel, and the forwarding channel is a second PON channel that can be forwarded theoretically. The available channel is the second PON channel that can actually be forwarded.

Another embodiment of the present invention provides a receiving device for a data frame. As shown in FIG. 7, the method includes: a receiving module 701, an identifying module 702, a processing module 703, and a reassembly module 704.

The receiving module 701 is configured to receive a data frame, and send the data frame to the identification module 702, where the data frame has a frame serial number, and the frame serial number is a sequence number of the data frame in the data frame sequence;

The receiving module 701 is specifically configured to extract a data frame from the second PON channel.

The identification module 702 is configured to receive the data frame from the receiving module 701, and determine whether the data frame is a data frame to be processed according to the frame serial number and the expected sequence number. If the data frame is a data frame to be processed, the to-be-processed data frame is to be processed. The data frame is sent to the processing module 703;

Optionally, the identification module 702 is specifically configured to: compare the frame sequence number and the expected sequence number, and save the data frame to the first cache 705 if the frame sequence number is greater than the expected sequence number; and discard the data frame if the frame sequence number is smaller than the expected sequence number; If the frame number is equal to the expected sequence number, the data frame is the data frame to be processed.

The device further includes a first cache 705, configured to store a data frame whose frame number is greater than an expected sequence number; the receiving module 701 is further configured to extract a data frame from the first cache 705, and extract the data frame. The incoming data frame is sent to the identification module 702, wherein the data frame extracted from the first cache 705 has a higher priority than the data frame received from the second PON channel.

The processing module 703 is configured to receive the data frame to be processed from the identification module 702, and determine whether the data frame to be processed is a fragmented data frame. If the data frame to be processed is a fragmented data frame, according to the fragment data. a fragmentation field of the frame, determining whether all the fragment data frames having the same frame number have been received, and determining whether the fragment data frame and all the fragment data frames having the same frame sequence have been received Sending to the reassembly module 704, where the fragmentation field is used to indicate the number of fragmented data frames and the sequence number of the fragmented data frame in the corresponding fragmented data frame;

Optionally, the processing module 703 is further configured to: if the data frame to be processed is an unfragmented data frame, increase the expected sequence number by one.

The method for determining whether the data frame to be processed is a fragmented data frame may be: (1) detecting a fragmented frame identifier in the to-be-processed data frame, and if the value of the fragmented frame identifier is a fifth value, The data frame is a fragmented data frame; (2) if there is no fragmentation field in the unfragmented data frame, detecting whether the data frame to be processed includes a fragmentation field, and if the fragmentation field is included, the data frame is (3) If there is also a fragmentation field in the unfragmented data frame, it may be determined according to the value of the fragmentation field whether the to-be-processed data frame is a fragmented data frame.

The reassembly module 704 is configured to receive the fragment data frame and the determination result from the processing module 703, and if all the fragment data frames having the same frame sequence number have been received, according to all the fragments having the same frame sequence number The field reorganizes all the fragmented data frames having the same frame number to recover the fragmented data frame, and the expected sequence number is incremented by one.

It should be noted that the overhead information is removed before the fragment data frame is reorganized.

The device provided by the embodiment of the invention can ensure that the fragment data frame is correctly received, reassembles the fragment data frame, and recovers the corresponding fragmented data frame.

Specifically, the data frame and the fragmented data frame may be an Ethernet frame, and the fragmented data frame includes a first length/type field, which is used to indicate that the fragmented data frame carries the fragmentation field, and the fragmentation field and the first length/ The type field is adjacent to the first length/type field; the data frame and the fragmented data frame may also be XGEM frames, and the XGEM frame includes an XGEM frame header, where the fragmentation field and the frame sequence number are replaced by the XGEM frame header. All or part of the options field.

The options field includes a first field, a second field, and a third field, where the first field is used to indicate the sequence number of the data frame in the data frame sequence, and the second field is used to indicate that the fragment data frame is in the corresponding fragmented data. The sequence number in the frame, the third field and the LF field together indicate the number of slices.

Optionally, as another embodiment, the fragmentation field includes a fragment identifier and a fragment sequence number, where the fragment identifier is the number of fragments or is used to indicate that the last fragment in the fragmented data frame is formed. The fragmented data frame, the fragment number is the sequence number of the fragmented data frame in the corresponding fragmented data frame. It should be understood that the number of slices can be obtained according to the slice number of the slice data frame formed by the last slice. The fragment identification and the fragment sequence number have been implemented in various manners, which have been described in detail in the previous embodiments, and the embodiments of the present invention are not described herein again.

A further embodiment of the invention provides a system for transmitting and receiving data frames, comprising: the device according to any one of claims 19 to 28, and the device according to any one of claims 29 to 35.

The apparatus according to any one of claims 23 to 34, configured to receive a sequence of data frames, determine an available channel of a sequence of data frames, wherein the sequence of data frames includes a first data frame; if the length of the first data frame exceeds The first length, the data frame is fragmented to obtain a plurality of fragments of the first data frame, wherein the number of fragments is determined by the number of available channels; adding overhead information in each fragment, a plurality of fragmented data frames, wherein the overhead information includes a fragmentation field and a frame number, and the fragmentation field is used to indicate the number of the fragmented data frames and the sequence number of the corresponding fragmented data frame in the first data frame, the frame serial number a sequence number of the first data frame in the sequence of data frames; and the plurality of slice data frames are forwarded through the available channels.

That is, the apparatus according to any one of claims 23 to 34, for receiving a sequence of data frames from a first PON channel, the rate of the first PON channel being a rate of N second PON channels, wherein, the data The sequence of frames includes a first data frame, where N is a positive integer greater than one; determining that data frames in the sequence of data frames are forwarded from the M second PON channels, and if the length of the first data frame exceeds the first length, the first The data frame is fragmented to obtain a plurality of fragments of the first data frame, where M is a positive integer, 2 ≤ M ≤ N; and the overhead information is added to each fragment to obtain a plurality of fragmented data frames, where The overhead information includes a fragmentation field and a frame sequence number, and the fragmentation field is used to indicate the number of the fragmented data frames and the sequence number of the corresponding fragmented data frame in the first data frame, and the frame sequence number is the first data frame in the data frame sequence. Serial number; multiple fragmented data frames through the M second PON channels Forward out

The apparatus according to any one of claims 23 to 30, configured to receive a data frame from a second PON channel, the data frame having a frame number, wherein the frame number is a sequence number of the data frame in the sequence of data frames; a sequence number and an expected sequence number, determining whether the data frame is a data frame to be processed, and if the data frame is a data frame to be processed, determining whether the data frame to be processed is a fragmented data frame; if the data frame to be processed is Defragmenting a data frame according to the fragmentation field of the fragment data frame, determining whether all the fragment data frames having the same frame sequence number have been received, wherein the fragmentation field is used to indicate the number of fragmented data frames and the fragmentation data frame The sequence number of the fragmented data frame in the corresponding fragmented data frame; if all the fragmented data frames having the same frame number have been received, according to the fragmentation fields of all the fragmented data frames having the same frame number, All the fragmented data frames having the same frame number are reorganized to recover the fragmented data frame, and the expected sequence number is incremented by one.

The system provided by the embodiment of the present invention solves the problem that the transmission of the jumbo frame on any transmission channel causes the delay to increase, the bandwidth utilization decreases, the delay jitter increases, and the service experience is affected by adopting the method of fragmenting the jumbo frame. Problem; since the fragmentation operation of the embodiment of the present invention is implemented above the MAC layer, regardless of the specific number of channel bindings, it can be compatible with all multi-channel PON systems.

It is to be understood that the phrase "one embodiment" or "an embodiment" or "an embodiment" or "an embodiment" means that a particular feature, structure, or characteristic relating to an embodiment is included in at least one embodiment of the invention. Thus, "in one embodiment" or "in an embodiment" or "an" In addition, these particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the various embodiments of the present invention, the sequence numbers of the above processes do not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not constitute the implementation process of the embodiments of the present invention. Any restrictions.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both, for clarity of hardware and software. Interchangeability, the composition and steps of the various examples have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. Professionals can use different methods to implement the described functions for each specific application, but this It should not be considered as far from the scope of the invention.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, or an electrical, mechanical or other form of connection.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the embodiments of the present invention.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

In summary, the above description is only a preferred embodiment of the technical solution of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims (36)

A method for transmitting a data frame, wherein the method is used in a passive optical network PON system, including: Receiving, by the first PON channel, a sequence of data frames, where the rate of the first PON channel is a rate sum of N second PON channels, where the data frame sequence includes a first data frame, and N is a positive integer greater than one; Determining that the data frame in the data frame sequence is forwarded from the M second PON channels. If the length of the first data frame exceeds the first length, the first data frame is fragmented to obtain the first data frame. a plurality of fragments, wherein M is a positive integer, 2 ≤ M ≤ N; The overhead information is added to each fragment to obtain a plurality of fragmented data frames, where the overhead information includes a fragmentation field and a frame serial number, and the fragmentation field is used to indicate the number of fragmented data frames and the corresponding fragmentation. a sequence number of the data frame in the first data frame, where the frame sequence number is a sequence number of the first data frame in the sequence of data frames; And transmitting, by the M second PON channels, the plurality of fragmented data frames. The method according to claim 1, wherein the first data frame and the fragment data frame are both Ethernet frames, and the fragment data frame includes a first length type length/type field for And indicating that the fragment data frame carries the fragment field, where the fragment field is adjacent to the first length/type field, and is located after the first length/type field. The method according to claim 1, wherein the first data frame and the fragment data frame are both a Gigabit Gigabit passive optical network encapsulation mode XGEM frame, and the XGEM frame includes an XGEM frame header. The fragment field and the frame sequence number replace all or part of the selection options field in the XGEM frame header. The method according to claim 3, wherein the replacing the all or part of the option field in the XGEM frame header by the fragment field includes: The options field includes a first field, a second field, and a third field, where the first field is used to indicate a sequence number of the first data frame in the data frame sequence, and the second field is used to indicate The sequence number of the fragmented data frame in the corresponding fragmented data frame, the third field and the last fragment indicating that the LF field together indicate the number of fragments. Method according to any one of claims 1 to 3, characterized in that said slice word The segment includes a slice identifier and a slice sequence number, and the slice identifier is a number of fragments, and the slice sequence number is a sequence number of the corresponding slice data frame in the first data frame. The method according to any one of claims 1 to 3, wherein the fragmentation field comprises a slice identifier and a slice sequence, and the slice identifier is used to indicate the last in the first data frame a sliced data frame formed by a slice; the slice sequence number is a sequence number of the corresponding sliced data frame in the first data frame. The method according to claim 6, wherein the slice identifier is used to indicate that the slice data frame formed by the last slice in the first data frame comprises: And when the value of the fragment identifier is a first value, the fragment data frame is formed by a first fragment of the first data frame; When the value of the fragment identifier is a second value, the fragment data frame is formed by an intermediate slice of the first data frame; When the value of the slice identifier is a third value, the slice data frame is formed by the last slice of the first data frame, wherein the first to third values are three different values. The method according to claim 7, wherein the slice identifier is composed of a slice header indication field and a slice tail indication field. The method according to any one of claims 1 to 3, characterized in that the number of tiles is M. The method according to claim 9, wherein before the fragmenting the first data frame, the method further comprises: The length of each slice may be determined according to the remaining space of the transmission queues of the M second PON channels, the number of the fragments, and the length of the first data frame. A method for receiving a data frame, wherein the method is used in a passive optical network PON system, including: Receiving, by the second PON channel, a data frame, where the data frame has a frame sequence number, wherein the frame sequence number is a sequence number of the data frame in a sequence of data frames; Determining, according to the frame sequence number and the expected sequence number, whether the data frame is a data frame to be processed, and if the data frame is a data frame to be processed, determining whether the data frame to be processed is a fragmented data frame; If the data frame to be processed is a fragmented data frame, determining, according to the fragmentation field of the fragmented data frame, whether all the fragmented data frames having the same frame sequence number have been received, wherein the fragmentation The field is used to indicate the number of the fragmented data frames and the sequence number of the fragmented data frame in the corresponding fragmented data frame; If all the fragmented data frames having the same frame number have been received, all the fragmented data frames having the same frame number are used according to the fragmented fields of all the fragmented data frames having the same frame number. Reorganizing to recover the fragmented data frame, the expected sequence number is incremented by one. The method according to claim 11, wherein the data frame and the fragment data frame are both Ethernet frames, and the fragment data frame includes a first length type length/type field for indicating The fragmented data frame carries the fragmentation field, and the fragmentation field is adjacent to the first length/type field, and is located after the first length/type field. The method according to claim 11, wherein the data frame and the fragment data frame are both a Gigabit Gigabit passive optical network encapsulation mode XGEM frame, and the XGEM frame includes an XGEM frame header, where The slice field and the frame sequence number replace all or part of the selected options field in the XGEM frame header. The method according to claim 13, wherein the replacing the all or part of the selection of the options field in the XGEM frame header by the fragmentation field comprises: The options field includes a first field, a second field, and a third field, where the first field is used to indicate a sequence number of the data frame in a sequence of data frames, and the second field is used to indicate the fragment data. The sequence number of the frame in the corresponding fragmented data frame, the third field and the last fragment indicating that the LF field collectively indicates the number of slices. The method according to any one of claims 11 to 13, wherein the determining whether the data frame is a data frame to be processed specifically includes: Comparing the frame sequence number and the expected sequence number, if the frame sequence number is greater than the expected sequence number, saving the data frame to a first buffer, and receiving a data frame from the second PON channel; if the frame sequence number And less than the expected sequence number, discarding the data frame, and receiving a data frame from the second PON channel; if the frame sequence number is equal to the expected sequence number, the data frame is the data frame to be processed. The method according to claim 15, wherein before receiving the data frame from the second PON, the method further comprises: If the first buffer is not empty, extract a data frame from the first cache, and determine, according to the frame serial number and the expected sequence number, whether the data frame extracted from the first cache is data to be processed. frame; If the first buffer is empty, receiving a data frame from the second PON pass. The method according to claim 16, wherein after determining whether the data frame extracted from the first buffer is a data frame to be processed, the method further includes: If the data frame extracted from the first cache is not a data frame to be processed, continue to extract data frames from the first cache, if all data frames extracted from the first cache are not pending data a frame that receives a data frame from the second PON pass. The method according to any one of claims 11 to 13, wherein the determining whether the data frame to be processed is a fragmented data frame comprises: Detecting whether the fragmentation field is included in the data frame to be processed, and if the fragmentation field is included, the data frame to be processed is a fragmented data frame. A device for transmitting a data frame, wherein the device is used in a PON system of a passive optical network, and includes: a receiving module, a fragmentation module, an identification module, and a forwarding module, The receiving module is configured to receive a sequence of data frames from a first PON channel, where the rate of the first PON channel is a rate sum of N second PON channels, and send the sequence of data frames to the fragmentation module. The data frame sequence includes a first data frame, where N is a positive integer greater than one; The fragmentation module is configured to receive the data frame sequence from the receiving module, and determine that the data frame in the data frame sequence is forwarded from the M second PON channels, if the length of the first data frame exceeds a length The first data frame is fragmented to obtain a plurality of fragments of the first data frame, and the plurality of fragments of the first data frame are sent to the identifier module, and the M The information of the two PON channels is sent to the forwarding module, where M is a positive integer, 2 ≤ M ≤ N; The identifier module is configured to receive a plurality of fragments of the first data frame from the fragmentation module, insert overhead information into each fragment, and obtain a plurality of fragment data frames, and divide the plurality of fragments The slice data frame is sent to the forwarding module, where the overhead information includes a fragmentation field and a frame sequence number, where the fragmentation field is used to indicate the number of fragmented data frames and the corresponding fragmented data frame is in the first number. The frame number is a sequence number of the first data frame in the sequence of data frames according to a sequence number in the frame; The forwarding module is configured to receive information about the M second PON channels from the fragmentation module, and receive the multiple fragment data frames from the identifier module, and pass the M second PON channels. Transmitting the plurality of fragmented data frames. The device according to claim 19, wherein the first data frame and the fragment data frame are both Ethernet frames, and the fragment data frame includes a first length type length/type field for And indicating that the fragment data frame carries the fragment field, where the fragment field is adjacent to the first length/type field, and is located after the first length/type field. The device according to claim 19, wherein the first data frame and the fragment data frame are both a Gigabit Gigabit passive optical network encapsulation mode XGEM frame, and the XGEM frame includes an XGEM frame header. The fragment field and the frame sequence number replace all or part of the selection options field in the XGEM frame header. The device according to claim 21, wherein the options field comprises a first field, a second field and a third field, wherein the first field is used to indicate that the first data frame is in the data frame sequence The serial number in the second field is used to indicate the sequence number of the fragment data frame in the corresponding fragmented data frame, and the third field and the last fragment indicate that the LF field together indicates the number of fragments. The device according to any one of claims 19 to 21, wherein the fragmentation field includes a slice identifier and a slice sequence number, and the slice identifier is a number of fragments, and the slice sequence number is corresponding to The sequence number of the fragmented data frame in the first data frame. The device according to any one of claims 19 to 21, wherein the fragmentation field comprises a slice identifier and a slice sequence, the slice identifier being used to indicate the last in the first data frame a sliced data frame formed by a slice; the slice sequence number is a sequence number of the corresponding sliced data frame in the first data frame. The apparatus according to claim 24, wherein the fragmentation identifier is used to indicate that the fragmented data frame formed by the last slice in the first data frame comprises: And when the value of the fragment identifier is a first value, the fragment data frame is formed by a first fragment of the first data frame; When the value of the slice identifier is a second value, the fragment data frame is formed by an intermediate slice of the first data frame; When the value of the slice identifier is a third value, the slice data frame is formed by the last slice of the first data frame, wherein the first to third values are three different values. The device according to claim 25, wherein the slice identifier is composed of a slice header indication field and a slice tail indication field. Apparatus according to any one of claims 19 to 21, wherein the number of tiles is M. The device according to claim 27, wherein the fragmentation module is specifically configured to: The length of each slice may be determined according to the remaining space of the transmission queues of the M second PON channels, the number of the fragments, and the length of the first data frame. A receiving device for a data frame, wherein the device is used in a passive optical network PON system, and includes: a receiving module, an identifying module, a processing module, and a recombining module, The receiving module is configured to receive a data frame from the second PON channel, and send the data frame to the identification module, where the data frame has a frame serial number, and the frame serial number is the data frame in the data frame The serial number in the sequence; The identification module is configured to receive the data frame from the receiving module, determine, according to the frame serial number and the expected sequence number, whether the data frame is a data frame to be processed, if the data frame is data to be processed Sending, to the processing module, the data frame to be processed; The processing module is configured to receive the data frame to be processed from the identification module, and determine whether the data frame to be processed is a fragmented data frame, and if the data frame to be processed is a fragmented data frame, Determining, according to the fragmentation field of the fragment data frame, whether all the fragment data frames having the same frame sequence number have been received, and whether the fragment data frame and all the frame numbers having the same frame number have been received And determining, by the fragmentation data frame, the number of the fragmented data frames and the sequence number of the fragmented data frame in the corresponding fragmented data frame; The reassembly module is configured to receive, according to the processing module, the fragment data frame and the determination result, if all fragment data frames having the same frame sequence number have been received, according to the All the fragmented fields of the fragmented data frame having the same frame number are reassembled for all the fragmented data frames having the same frame number, and the fragmented data frame is restored, and the expected sequence number is incremented by one. The device according to claim 29, wherein the data frame and the fragment data frame are both Ethernet frames, and the fragment data frame includes a first length type length/type field for indicating The fragmented data frame carries the fragmentation field, and the fragmentation field is adjacent to the first length/type field, and is located after the first length/type field. The device according to claim 29, wherein the data frame and the fragment data frame are both a Gigabit Gigabit passive optical network encapsulation mode XGEM frame, and the XGEM frame includes an XGEM frame header, where The slice field and the frame sequence number replace all or part of the selection options field in the XGEM frame header. The device according to claim 31, wherein the options field comprises a first field, a second field and a third field, wherein the first field is used to indicate a sequence number of the data frame in a sequence of data frames. The second field is used to indicate the sequence number of the fragment data frame in the corresponding fragmented data frame, and the third field and the last fragment indicate that the LF field together indicates the number of fragments. Apparatus according to any one of claims 29 to 31, wherein The identification module is specifically configured to: compare the frame serial number and the expected sequence number, if the frame sequence number is greater than the expected sequence number, save the data frame to a first cache; if the frame sequence number is smaller than the frame number The sequence number is discarded, and the data frame is discarded; if the frame sequence number is equal to the expected sequence number, the data frame is a data frame to be processed; The device further includes a first cache, configured to store the data frame whose frame sequence number is greater than the expected sequence number. The device according to claim 22, wherein the receiving module is further configured to: extract a data frame from the first cache, and send the extracted data frame to the identification module, where the receiving module Extracting a data frame from the first cache has a higher priority than receiving a data frame from the second PON channel. The device according to any one of claims 29 to 31, wherein the processing module is specifically configured to: Detecting whether the fragmentation field is included in the data frame to be processed, and if the fragmentation field is included, the data frame to be processed is a fragmented data frame. A system for transmitting and receiving data frames, characterized in that the system is used in the field of passive optical network PON, comprising: the apparatus according to any one of claims 19 to 28, and as claimed in claims 29 to 35 A device as described.

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