WO2012126424A2

WO2012126424A2 - Method and device for forwarding data packet

Info

Publication number: WO2012126424A2
Application number: PCT/CN2012/075715
Authority: WO
Inventors: 刘怡
Original assignee: 华为技术有限公司
Priority date: 2012-05-18
Filing date: 2012-05-18
Publication date: 2012-09-27
Also published as: WO2012126424A3; CN102823207A

Abstract

Provided are a method and device for forwarding a data packet. The implementation of the method comprises: a data packet forwarding device receives a data packet, with the data packet being a data packet encapsulated by a communication protocol which requires undamaged and ordered arrival of data packets at the receiving end; the data packet forwarding device judges whether or not the data packet arrives at the data packet forwarding device in accordance with the correct order; if it does not, then the data packet will be stored in a cache queue corresponding to the link to which the data packet belongs; and the data packet forwarding device sends the data packets in the cache queue to the receiving end according to the serial number of the data packet from small to big successively. By way of adjusting the sequence of the data packets before the data packets are sent to the receiving end in the above method, the sending sequence of the data packets is closer to the original sequence thereof, which can lower the disordered sequence rate of the data packets and reduce the problem of bandwidth occupation by the repeated sending of the ACK request and the retransmission of the data packets by the receiving end, thus improving the throughput rate of the network.

Description

Data packet forwarding method and device

The present invention relates to the field of communications technologies, and in particular, to a data packet forwarding method and device. Background technique

At present, there are many types of network communication protocols, some of which provide reliable data transmission services. Reliable data transmission services require data packets to arrive at the receiving end without loss. TCP ( Transmission Control Protocol) is the most widely used one. , which provides a connection-oriented, reliable byte stream service. The transmission reliability of TCP packets is mainly reflected in two aspects. First, the data cannot be damaged. Second, the order of the data must be consistent with the originating and receiving ends. When the above two situations are abnormal, the sender of the TCP packet will actively reduce the sending traffic.

The networking of commercial network systems is very complicated. For example, the transmission from the core network to the base station is usually transmitted by the public network, and the public network is combined by a large number of switching devices in a mesh structure. Due to the complexity of the networking, it is easy to cause the delay of the data packets to arrive at the receiving end after being transmitted on the transmission path, which results in the disorder of the data packets received by the receiving end.

According to the TCP regulations, the sender sends the packets according to the sequence number of the TCP packets. For example, the sender sends the TCP packets with sequence numbers 1 to 9 to the receiver. Since the TCP packets of the above 1~9 have different delays on the transmission path, the TCP packets received by the receiving end may have an out-of-order problem. For example, the serial number of the received TCP packet is 1, 2, 3, 5, 6, 7, 4, 8, 9, and the delay of the packet of sequence number 4 is longer, resulting in the TCP received by the receiver. Packets are out of order.

According to the provisions of TCP, at present, the receiving device cannot distinguish the out-of-order and loss of TCP packets. Therefore, the way in which the receiving end handles the problem of TCP packet out-of-order is: When the receiving end finds the sequence number of the received TCP packet, the sequence is out of order. Sending an Acknowledgement (ACK) request to the sender of the TCP data, and requesting the sender of the TCP packet to send the TCP packet of the next sequence number of the last sequence number currently correctly received. Taking the serial number of the received TCP packet as 123567489 as an example, when receiving the TCP packet with sequence number 3, it is determined that the sequence number of the next TCP packet is 4 and the ACK request 4 is sent, but the actual received is 5 , so send another ACK Requesting and continuing to determine whether the next received TCP packet is a TCP packet with sequence number 4, and finds that the TCP packet with sequence number 4 is still sent an ACK request and continues to determine whether the next received TCP packet is a sequence number. The TCP packet of 4, and so on, in the above example, the receiving end will send 3 repeated ACK requests after receiving the data packet with the sequence number of 123567489, which will cause the sending end to repeatedly send the TCP packet with sequence number 4.

In the process of implementing the embodiments of the present invention, the inventor finds that: according to the provisions of the TCP, the TCP packets received by the receiving end are repeatedly sent ACK request, resulting in too many TCP packet retransmissions and occupying bandwidth, so the network The throughput rate is low. SUMMARY OF THE INVENTION The embodiments of the present invention provide a data packet forwarding method and device, which are used to reduce the out-of-order rate of data packets, thereby improving network throughput.

A method for forwarding data packets, including:

The packet forwarding device receives the data packet, and the data packet is a data packet encapsulated by the communication protocol that requires the data packet to arrive at the receiving end without loss;

The data packet forwarding device determines whether the data packet arrives at the data packet forwarding device in order, and if not, stores the data packet in a cache queue corresponding to the link to which the data packet belongs;

The data packet forwarding device sends the data packets in the buffer queue to the receiving end in sequence according to the sequence number of the data packet.

A packet forwarding device includes:

a receiving unit, configured to receive a data packet, where the data packet is a data packet encapsulated by a communication protocol that requires the data packet to arrive at the receiving end without loss;

a determining unit, configured to determine whether the data packet arrives at the data packet forwarding device in sequence; and a storage control unit, configured to store the data packet and the data packet if the determining unit determines that the result is negative The cache queue corresponding to the link;

And a sending unit, configured to send the data packet in the cache queue to the receiving end in sequence according to the sequence number of the data packet.

The above technical solution has the following beneficial effects: By adjusting the order of the data packets before the data packets are sent to the receiving end, the order of sending the data packets is closer to the original order of the data packets, and the out-of-order rate of the data packets can be reduced. , reducing the receiving end repeatedly sending ACK request and retransmitting the packet occupation band </ RTI></RTI></RTI></RTI></RTI></RTI></RTI></RTI></RTI></RTI></RTI></RTI></RTI></RTI><RTIgt; The drawings are only some of the embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive labor.

1 is a schematic flowchart of a method according to an embodiment of the present invention;

2A is a schematic diagram of a network structure of an application scenario of a solution according to an embodiment of the present invention;

2B is a schematic diagram showing an example of sorting by using an embodiment of the present invention;

3 is a schematic flow chart of another method according to an embodiment of the present invention;

4 is a schematic structural diagram of a forwarding device according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of another forwarding device according to an embodiment of the present invention;

6 is a schematic structural diagram of another forwarding device according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of another forwarding device according to an embodiment of the present invention. 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 only a part of the embodiments of the present invention, and not all of the embodiments. example. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative work are within the scope of the present invention.

An embodiment of the present invention provides a method for forwarding a data packet of a transmission control protocol, as shown in FIG. 1 , including:

101: The data packet forwarding device receives the data packet, where the data packet is a data packet encapsulated by a communication protocol that requires the data packet to arrive at the receiving end without loss;

It should be noted that the foregoing data packet may be a TCP data packet in a Long Term Evolution (LTE) network, or may be a data packet encapsulated by a communication protocol that requires the data packet to arrive at the receiving end in sequence, and the present invention. The embodiment does not limit this.

102: The foregoing packet forwarding device determines whether the data packet arrives in the foregoing packet forwarding in order. And the device, if not, storing the data packet in a cache queue corresponding to the link to which the data packet belongs; determining whether the data packet arrives at the data packet forwarding device in sequence, and an implementation manner may include: acquiring the data packet Link identification information and the serial number of the data packet; determining, by the link identification information, the link to which the data packet belongs; determining whether the serial number of the data packet is greater than a next serial number of the serial number of the largest serial number in the data packet to which the data packet belongs If yes, it is determined that the foregoing data packet does not arrive at the foregoing packet forwarding device in order.

The above link identification information may be: a source internet protocol IP address, a destination IP address, a source port number, and a destination port number of the above data packet. Taking TCP packets as an example, this information can be obtained by reading the corresponding fields in the TCP header. It should be noted that the purpose of obtaining the link identification information is to determine the link to which the data packet belongs. The specific content of the specific optional information is not limited to the above four examples, and thus the above examples are not to be construed as limiting the embodiments of the present invention.

Optionally, the cache queue may be pre-established, or may be established when it is determined that the data packet needs to be reordered and sent, and may also be determined after the data packet is not sequentially arrived at the data packet forwarding device. A cache queue corresponding to the link to which the above data packet belongs is established. By establishing a cache queue after determining that the data packet does not arrive at the packet forwarding device in sequence, unnecessary cache queues can be prevented from occupying storage resources.

Further, before the data packet is stored in the cache queue of the link to which the link belongs, the method may further include: if the sequence number of the data packet is less than or equal to the next sequence number of the sequence number with the largest serial number in the data packet that the link to which the data packet belongs Determining whether the cache queue corresponding to the link to which the data packet belongs is empty. If it is empty, sending the data packet to the receiving end. If not, storing the data packet in a cache corresponding to the link to which the data packet belongs. queue. The embodiment is based on the establishment of a cache queue after determining that the data packet does not arrive in sequence with the data packet forwarding device, and the next sequence number with the largest serial number in the data packet that has been sent than the link to which the data packet belongs is Packets with a small serial number may not be delayed by the time delay caused by the delay. These packets can be sent directly to the receiver.

Preferably, the storing, by the foregoing 102, the data packet in the cache queue corresponding to the link to which the data packet belongs includes: storing the data packet in a cache queue corresponding to the link to which the data packet belongs, and the cache queue is sorted according to the serial number from small to large. . In this step, the sequence numbers of the data packets stored in the buffer queue are sorted from small to large and can be compatible with the transmission scheme of the original data packet of the protocol. The ordering in this step is a preferred embodiment and should not be construed as limiting the embodiments of the present invention. 103: The foregoing packet forwarding device sends the data packet in the cache queue to the receiving end in sequence according to the sequence number of the data packet.

Optionally, the sending, in the foregoing 103, the data packet in the buffer queue to the receiving end according to the sequence number of the data packet is: when the timer timing reaches a predetermined value or when the data packet in the buffer queue reaches a predetermined number And sending the data packet in the cache queue to the receiving end according to the sequence number of the data packet in the cache queue. It should be noted that the foregoing examples of the timers and the data packets reaching a predetermined number are all the conditions for the triggering forwarding device to send the data packets. The triggering conditions may be many, and are not limited to the foregoing two types. This is not limited. Specifically, the above predetermined value can be set to 2 milliseconds (ms).

According to the solution of the embodiment of the present invention, before the data packet is sent to the receiving end, the order of the data packet is adjusted, so that the sending order of the data packet is closer to the original order of the data packet, and the out-of-order rate of the data packet can be reduced. Reduce the problem that the receiving end repeatedly sends ACK requests and retransmits the bandwidth occupied by the data packets, thereby improving the network throughput.

In addition, according to the TCP protocol, when the three ACK requests of the same TCP packet are received, the sender of the TCP packet confirms that the network has a reliability abnormality, and will actively take the initiative after confirming the reliability abnormality at the transmitting end. The packet transmission rate is reduced by half. Therefore, for TCP packet transmission, the out-of-order TCP packet causes the sender to actively reduce the transmission rate, thereby reducing the network throughput. With the embodiment of the present invention, the out-of-order rate of the data packet can be reduced, thereby reducing the situation that the transmitting end actively reduces the transmission rate by receiving the ACK request, thereby improving the network throughput rate.

For example, the forwarding entity of the above embodiment may be any forwarding device, such as a base station, between the sending end and the receiving end of the TCP data packet. As shown in FIG. 2A, in the downlink direction, the transmitting end of the TCP packet is in the core network, and the core network sends a TCP packet to the base station, and the base station sends the TCP packet to the receiving end. The receiving end shown in FIG. 2A is a mobile phone, and the forwarding device is a base station. It can be understood that the receiving end can have more than four types, which may be terminal devices or other network side devices, and the forwarding devices may also have many types. This embodiment of the present invention does not limit this.

For example, a TCP processing module may be added to a network element of a Long Term Evolution (LTE) system, such as an evolved base station (eNodeB), to perform the method provided by the embodiment of the present invention. The TCP processing module may perform downlink data. The package is processed. The TCP processing module detects whether each downlink TCP packet arrives at the eNodeB in order. If it is detected that the sequence numbers of the two TCP packets are not consecutive, it can be determined that the TCP packet does not arrive at the eNodeB in order, then the The eNodeB caches out-of-order packets and buffers and sorts the packets arriving at the eNodeB for a period of time.

For example, in FIG. 2B, when the packet arrives at the eNodeB when the out-of-order occurs, the following is the case where the data packet arrives at the receiving end after being processed by the method of the embodiment of the present invention, where the receiving end is the destination end of the TCP packet. An example is a mobile phone in FIG. 2A. In Fig. 2B, time is the arrival time of the TCP packet, tcp_seq is the serial number of the TCP packet, and info is other information (shown in Figure 2 as the length of the file transfer protocol data). It can be seen from the upper part of Fig. 2 that the data packet with the serial number 3284316717 should appear between the data packets with the serial numbers 3284325257 and 3284318177 when it arrives at the eNodeB. It appears behind the 3284132097 due to the out-of-order. After the processing of this scheme, the data packet Going back to the right place. Therefore, the method of the embodiment of the present invention can reduce the out-of-order rate.

The inventor has measured the effect of the embodiment of the present invention, and the test scenario is as shown in FIG. 2A: In the LTE network, the test object is a TCP packet transmitted by the core network to reach the base station, and the base station performs the solution of the embodiment of the present invention as a packet forwarding device. Forward the TCP packet to the phone. In this scenario, the solution of the embodiment of the present invention can improve the average throughput rate of the LTE network. The specific gain effect is related to the out-of-order rate, out-of-order range, out-of-order delay, and Round-Trip Time (RTT) of the wired transmission side (core network to base station). The greater the out-of-order rate, the larger the RTT is, the more obvious the gain is. It should be noted that the data packet encapsulated by the communication protocol that requires the data packet to arrive at the receiving end without loss can be applied to many types of networks. The example of the LTE network should not be construed as limiting the embodiment of the present invention. The inventor measured the effect of the above embodiment, and the test scenario is: the bandwidth of the cell where the mobile phone is located is 20 MHz, the peak rate of the LTE network is 148 Mbps, the manufacturing disorder rate is 1/10000, the out-of-order average distribution, and the out-of-order range are 2~5 data stream, the mobile phone uses the File Transfer Protocol (FTP) to download 5 times 1G files from the core network. The test results are as follows: The average throughput of the LTE network that does not use the method of the embodiment of the present invention is 40.367 Mbps, and the average throughput of the LTE network is 126.912 Mbps and the maximum is 137.568 Mbps. The method gain of the embodiment of the invention is 214.3% to 241.3%. Therefore, the experiment proves that the scheme of the embodiment of the present invention can effectively improve the LTE network throughput rate.

The forwarding of the TCP packet is described as an example. Specifically, as shown in FIG. 3, the following steps are included:

301: The packet forwarding device receives the data packet, and checks whether it is a TCP data packet. If not, enter 302, if it is a TCP data packet, enter 303; 302: directly transparently transmit the foregoing TCP packet, and then return to 301;

303: Obtain link identification information of the TCP packet and determine a link to which the TCP packet belongs (ie, a TCP link), and check whether the TCP link to which it belongs has sort information;

The above sorting information includes: source, destination IP address, source, destination port number, and may also include: a timer timing value, and a currently transmitted maximum sequence number CurrSeq. If there is sorting information, go to 305, if there is no sorting information, go to 304;

304: Establish sorting information for the above data packet, and then enter 305;

305: Perform preprocessing of TCP packets;

The pre-processing may include: initializing CurrSeq to the sequence number of the first TCP packet received; it should be noted that if CurrSeq itself has an initial value (ie, has been initialized), then the initialization of CurrSeq is not performed, and directly enters 306. ;

It should be noted that: 301~305 above adopts that the first TCP packet is received, and the sorting information is directly established; if the sorting information is established after determining that the TCP packet is out of order, the CurrSeq initialization in this step is performed. The serial number of the current TCP packet to establish the sorting information. It can be understood that if the TCP packet does not appear out of order, the TCP packet will be sent directly.

306: Calculate the sequence number NxtSn of the next TCP packet sent in sequence; parse the sequence number of the TCP packet, and compare the sequence number obtained by the analysis with NxtSn: If the sequence number of the TCP packet is less than or equal to NxtSn, enter 307; The sequence number of the above TCP packet is greater than NxtSn, and enters 308;

307: Check whether the cache queue corresponding to the link to which the TCP packet belongs is empty. If the cache queue is empty, enter 302, and update CurrSeq to the maximum sequence number of the currently forwarded TCP data, and calculate and update NxtSn as a new CurrSeq. The sequence number of the next TCP packet; if the cache queue is not empty, enter 308;

There are two cases in which the check cache queue is empty in the above 307: one is that there is no cache queue corresponding to the link to which the above TCP packet belongs, and the other is that there is a cache queue corresponding to the link to which the above TCP packet belongs, and There are no packets in this cache queue. The reason for the above "there is no cache queue corresponding to the link to which the above TCP packet belongs" is as follows: If the scheme established after determining that the TCP packet is out of order is used before step 306, then in the case where no disorder occurs The cache queue corresponding to the link to which the TCP packet belongs does not exist; that is, when the check cache queue is empty in the above 307, there is no cache queue corresponding to the link to which the TCP packet belongs.

308: Check if the timer is started, if the timer is not started, start the timer, and the above TCP packets are stored in the cache queue;

In this step, if the timer is started, the TCP packet is directly stored in the buffer queue. It should be noted that, in this step, the TCP in the cache queue is preferably sorted according to the sequence number of the TCP packet from small to large. data pack.

309: After the timer expires, all the TCP packets in the buffer queue are sequentially sent (that is, according to the serial number of the TCP packet from small to large) to the receiving end, regardless of whether the packet causing the out-of-order is received. The CurrSeq is updated to the maximum sequence number of the currently forwarded TCP data, and the sequence number of the next TCP packet whose NxtSn is the new CurrSeq is calculated and updated, and then proceeds to 301. In this step, after the TCP packet in the buffer queue is sent to the receiving end, the already sent TCP packet can be deleted from the buffer queue.

It should be noted that: The principle of setting the timer duration: The longer the timer duration, the higher the out-of-order ratio that can be corrected, the better the sorting effect, but the RTT delay of the data will increase, and the peak value may be reduced for the packet loss scenario. The rate may also increase the delay of the hypertext transport protocol (http) service; the shorter the timer duration, the lower the out-of-order ratio that can be corrected, the worse the sorting effect, but the smaller the impact on the RTT delay of the data. The packet loss scenario has a small impact on the peak rate and has little impact on the http service delay. The default time of the timer sets different timer values according to the scenario to cope with different out-of-order delays. The specific time is not limited in the embodiment of the present invention. In this step, the timer can be set to 2ms.

In addition, it should be noted that, in the execution of any step of the above step 3, if it is determined that the linked data service is completed, the process will end. In addition, it can be understood that the cache queue can be emptied after all TCP packets in the cache queue are sent.

An embodiment of the present invention provides an example of the implementation of the corresponding embodiment in FIG. 3, and the following is assumed: the maximum length of the TCP packet: 100;

The TCP packet numbers are: 3012, 3112, 3212, 3312, 3362, 3462, 3562, 3662, 3762, 3862, 3962;

The order in which the packet forwarding device receives the TCP data packet is: 3012, 3112, 3212, 3312, 3362, 3562, 3662, 3762, 3862, 3462, 3962;

Observations can be found: The packet that caused the out-of-order is a packet with the sequence number 3462.

Then implement the scheme of Figure 3, specifically:

The packet 3012 arrives at the packet forwarding device in step 301 and determines it as a TCP packet, and then The ordering information is established in step 304, and CurrSeq is initialized to 3012 in step 305. At step 306, NxtSn = current CurrSeq + 100 is calculated. Since the current buffer queue is empty and the received 3112, then the comparison in step 306 is performed to determine that 3112 is equal to NxtSn, so it can be determined that the TCP packet is sent directly to the receiving end, updating the CurrSeq and NxtSn. Similarly, for packet 3212, CurrSeq is updated to 3312, and NxtSn is calculated to be 3312.

Since sometimes the server does not send packets according to the maximum packet length, for example, the packet of 3312, the next packet sequence number is 3362. Since the packet length of 3312 is only 50 bytes, when the packet is received, the buffer queue is still empty. At this time, CurrSeq<3362<3412, will not be considered as out of order, 3362 will still be forwarded, and update CurrSeq to 3362, and calculate NxtSn to get 3462.

When a 3562 packet is received, it is considered out of order because it is greater than NxtSn, the packet will be stored in the buffer queue, and the sort timer will be started. For packets with the following sequence numbers: 3662, 3762, 3862, 3462, if they arrive before the timer expires, they will be stored in the cache queue and reordered in the cache queue. The timer will be issued after the timer expires and updated. CurrSeq is 3862. If the packet timer with the sequence number 3462 is received after receiving the data packet with the sequence number 3762, the 3624, 3662, and 3762 in the buffer queue are issued in order, and the CurrSeq is updated to 3762 (currently sent. The maximum sequence number of the data packet); subsequent reception of 3862, judging not to be out of order, direct forwarding, updating CurrSeq; receiving 3462, less than the current CurrSeq, direct forwarding. When a packet with sequence number 3962 is received, it is determined to be equal to NxtSn, forwarded directly, and CurrSeq and NxtSn are updated.

If the sorting information is established after determining that the TCP packets are out of order, then the preceding serial numbers are 3012, 3112, 3212, 3312, 3362. These packets are not out of order, so they are directly forwarded, and the data with the serial number is 3362. After the packet is sent, the CurrSeq is 3362 and the NxtSn is 3462. When the data packet with the sequence number 3562 arrives, it is larger than NxtSn, so the out-of-order is determined. At this time, the sorting information is established; when the data packets with the sequence numbers 3562, 3662, 3762, and 3862 arrive, the sequence number is larger than NxtSn, and the data is larger. The packet will be stored in the cache queue; the sequence number of the packet with the sequence number 3462 is equal to NxtSn. Since the buffer queue is not empty at this time, the packet with the sequence number 3462 will still be cached and sorted. If the timer expires before receiving 3462, the packets in the buffer queue will be all forwarded in order, and the CurrSeq will be updated to 3862, and the value calculated by NxtSn is 3962.

The embodiment of the present invention further provides a data packet forwarding device. As shown in FIG. 4, the method includes: a receiving unit 401, configured to receive a data packet, where the data packet is a data packet encapsulated in a communication protocol that requires the data packet to arrive at the receiving end without loss. package; It should be noted that the foregoing data packet may be a TCP data packet in the LTE network, or may be a data packet encapsulated by the communication protocol that requires the data packet to arrive at the receiving end in sequence, which is not limited in this embodiment of the present invention.

The determining unit 402 is configured to determine whether the data packet arrives at the data packet forwarding device in sequence; and the storage control unit 403 is configured to: if the determining unit 402 determines that the result is negative, store the data packet in the link with the data packet Corresponding cache queue;

The sending unit 404 is configured to send the data packet in the cache queue to the receiving end in sequence according to the sequence number of the data packet.

Optionally, the sending unit 404 is configured to send the data packet in the buffer queue to the receiving end according to the sequence number of the data packet, and the method includes: configured to: when the timer timing reaches a predetermined value or in the cache queue When the data packet reaches a predetermined number, the data packets in the cache queue are sent to the receiving end in sequence according to the sequence number of the data packet in the cache queue. It should be noted that, the foregoing examples of the timer and the data packet reaching a predetermined number are all the conditions for the triggering forwarding device to send the data packet. The triggering condition may be many, and is not limited to the foregoing two types. This is not limited. Specifically, the above predetermined value can be set to 2 milliseconds (ms).

Optionally, as shown in FIG. 5, the determining unit 402 includes: an obtaining subunit 501, a link determining subunit 502, and a determining subunit 503;

The obtaining subunit 501 is configured to obtain link identification information of the data packet and a sequence number of the data packet.

The link determining subunit 502 is configured to determine the data packet by using the link identification information Dependent link

The determining subunit 503 is configured to determine whether the serial number of the data packet is greater than a next serial number of the serial number of the data packet that has been sent by the link to which the data packet belongs, and if yes, determining that the data packet does not arrive in the data sequentially Packet forwarding device.

Further, as shown in FIG. 6, the foregoing apparatus further includes:

The queue control unit 601 is configured to establish, after the determining subunit 503, that the data packet does not arrive in sequence with the data packet forwarding device, to establish a cache queue corresponding to the link to which the data packet belongs.

After determining that the above data packet does not arrive in sequence with the above packet forwarding device, establishing a cache queue can prevent unnecessary cache queues from occupying storage resources.

Further, as shown in FIG. 7, the foregoing apparatus further includes:

The cache information obtaining unit 701 is configured to determine, if the sequence number of the data packet is less than or equal to the next sequence number of the sequence number with the largest sequence number in the data packet to which the link to which the data packet belongs, determine whether the cache queue corresponding to the link to which the data packet belongs Is empty;

The sending unit 404 is further configured to: if the cache information acquiring unit 701 determines that the cache queue corresponding to the link to which the data packet belongs is empty, send the data packet to the receiving end;

The storage control unit 403 is further configured to: if the cache information obtaining unit 701 determines that the cache queue corresponding to the link to which the data packet belongs is not empty, store the data packet in a cache queue corresponding to the link to which the data packet belongs.

The embodiment is based on the establishment of a cache queue after determining that the data packet does not arrive in sequence with the data packet forwarding device, and the next sequence number with the largest serial number in the data packet that has been sent than the link to which the data packet belongs is Packets with a small serial number may not be delayed by the time delay caused by the delay, and such packets may be sent directly to the receiving end.

More specifically, the sending unit 404 is specifically configured to receive, according to the sequence number of the data packet in the cache queue, the sequence number of the data packet in the cache queue from the small to the large when the timer reaches a predetermined value or when the data packet in the buffer queue reaches a predetermined number. The terminal sends the data packet in the above cache queue. It should be noted that the foregoing examples of the timers and the data packets reaching a predetermined number are all the conditions for the triggering forwarding device to send the data packets. The triggering conditions may be many, and are not limited to the foregoing two types. This is not limited.

More specifically, the storage control unit 403 is specifically configured to store the data packet in a cache queue corresponding to the link to which the data packet belongs, and the cache queue is sorted according to the sequence number from small to large.

It should be noted that, when the sending unit 404 sends a data packet, it can be sent according to the sequence number from small to large to implement the technical purpose of the embodiment of the present invention. Therefore, in the embodiment, the scheme for sorting before sending may be the original protocol. Some packets are sent in a compatible scheme. The use of the storage control unit 403 to sort the data packets in the buffer queue in the present embodiment is a preferred embodiment and should not be construed as limiting the embodiments of the present invention.

For example, in the case of forwarding a TCP packet, the above packet forwarding device may be any forwarding device, such as a base station, between the sender and the receiver of the TCP packet. As shown in FIG. 2A, in the downlink direction, the transmitting end of the TCP packet is in the core network, and the core network sends a TCP packet to the base station, and the base station sends the TCP packet to the receiving end. The receiving end shown in FIG. 2A is a mobile phone, and the forwarding device is a base station. It can be understood that the receiving end can have more than four types, which may be terminal devices or other network side devices, and the forwarding devices may also have many types. This embodiment of the present invention does not limit this.

For example, a TCP processing module may be added to a network element of the LTE system, such as an eNodeB, to implement the functions of each component in the data packet forwarding device, and the TCP processing module may process the downlink data packet. The TCP processing module detects whether each downlink TCP packet arrives at the eNodeB in order. If it is detected that the sequence numbers of the two TCP packets are not consecutive, it can be determined that the TCP packet does not arrive at the eNodeB in order, and then the cache can be cached on the eNodeB. Out-of-order packets, and buffers and sorts packets arriving at the eNodeB over a period of time.

For example, in FIG. 2B, when the packet arrives at the eNodeB when the out-of-order occurs, the following is the case where the data packet arrives at the receiving end after being processed by the apparatus of the embodiment of the present invention, where the receiving end is the destination end of the TCP packet. An example is a mobile phone in FIG. 2A. In FIG. 2B, time is the arrival time of the TCP packet, tcp_seq is the serial number of the TCP packet, and info is other information (shown as the length of the file transfer protocol data in FIG. 2). It can be seen from the upper part of Fig. 2 that the data packet with the serial number 3284316717 should appear between the data packets with the serial numbers 3284325257 and 3284318177 when it arrives at the eNodeB. It appears behind the 3284132097 due to the out-of-order. After the processing of this scheme, the data packet Going back to the right place. Therefore, the apparatus of the embodiment of the present invention can reduce the out-of-order rate. It should be noted that, in the embodiment of the foregoing device, each unit included is only divided according to functional logic, but is not limited to the foregoing division, as long as the corresponding function can be implemented; The names are also for convenience of distinction from each other and are not intended to limit the scope of protection of the present invention. The functions of each functional unit can be implemented by components such as a receiver, a memory, a processor, and a transmitter.

A person skilled in the art can understand that all or part of the steps of implementing the above embodiments can be completed by a program to instruct related hardware, and the above program can be stored in a computer readable storage medium, the above mentioned storage medium. It can be a read-only memory, a disk or a disc, and the like. The description of the examples is only for helping to understand the method of the present invention and its core ideas; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific embodiments and application scopes. The contents of this specification are not to be construed as limiting the invention.

Claims

Rights request

A method for forwarding a data packet, comprising:

The method according to claim 1, wherein the determining whether the data packet arrives at the data packet forwarding device in an order comprises:

Obtaining link identification information of the data packet and a sequence number of the data packet;

Determining, by the link identification information, a link to which the data packet belongs;

Determining whether the sequence number of the data packet is greater than a next sequence number of a sequence number having the largest sequence number in the data packet to which the data packet belongs, and if yes, determining that the data packet does not arrive at the data packet forwarding device in order .

3. The method according to claim 2, wherein after determining that the data packet does not arrive in sequence with the data packet forwarding device, a cache queue corresponding to the link to which the data packet belongs is established.

4. The method according to claim 3, further comprising:

If the sequence number of the data packet is less than or equal to the next sequence number of the sequence number with the largest sequence number in the data packet to which the data packet belongs, determine whether the cache queue corresponding to the link to which the data packet belongs is empty, if If it is empty, the data packet is sent to the receiving end. If it is not empty, the data packet is stored in a buffer queue corresponding to the link to which the data packet belongs.

The method according to any one of claims 1 to 4, wherein the transmitting the data packet in the buffer queue to the receiving end according to the sequence number of the data packet from small to large comprises:

When the timer reaches a predetermined value or the data packet in the buffer queue reaches a predetermined number, the data packet in the buffer queue is sent to the receiving end according to the sequence number of the data packet in the buffer queue. .

The method according to any one of claims 1 to 4, wherein the storing the data packet in a cache queue corresponding to the link to which the data packet belongs includes: The data packet is stored in a cache queue corresponding to the link to which the data packet belongs, and the cache queue is sorted according to the sequence number from small to large.

The method according to any one of claims 1 to 4, wherein the data packet is a Transmission Control Protocol TCP data packet in a Long Term Evolution LTE network.

8. A packet forwarding device, comprising:

9. Apparatus according to claim 8 wherein:

The determining unit includes: an obtaining subunit, a link determining subunit, and a determining subunit; the obtaining subunit, configured to acquire link identification information of the data packet and a sequence number of the data packet;

The link determining subunit, configured to determine, by the link identification information, the link to which the data packet belongs;

The determining subunit is configured to determine whether the sequence number of the data packet is greater than a next sequence number of a sequence number having the largest serial number in the data packet that the link to which the data packet belongs, and if yes, determining that the data packet is not pressed The sequence arrives at the packet forwarding device.

10. The device according to claim 9, further comprising:

And a queue control unit, configured to: after the determining subunit determines that the data packet does not arrive at the packet forwarding device in order, establish a cache queue corresponding to the link to which the data packet belongs.

11. The device according to claim 10, further comprising:

a cache information obtaining unit, configured to determine a cache corresponding to the link to which the data packet belongs if the sequence number of the data packet is less than or equal to a next sequence number of a sequence number having the largest sequence number in the data packet to which the link to which the data packet belongs Whether the queue is empty;

The sending unit is further configured to: if the cache information obtaining unit determines that the cache queue corresponding to the link to which the data packet belongs is empty, send the data packet to the receiving end; The storage control unit is further configured to: if the cache information obtaining unit determines that the cache queue corresponding to the link to which the data packet belongs is not empty, store the data packet in a cache queue corresponding to the link to which the data packet belongs.

12. Apparatus according to any of claims 8 to 11, characterized in that

The sending unit is specifically configured to send, according to the sequence number of the data packet in the buffer queue, the sequence number of the data packet in the buffer queue to the receiving end when the timer reaches a predetermined value or when the data packet in the buffer queue reaches a predetermined number. The data packet in the cache queue.

13. Apparatus according to any of claims 8 to 11 wherein:

The storage control unit is configured to store the data packet in a cache queue corresponding to a link to which the data packet belongs, and the cache queue is sorted according to a sequence number from small to large.