WO2018222000A1 - Mptcp proxy system, and manufacturing method and operating method therefor - Google Patents

Abstract

Proposed are an MPTCP proxy system, and a manufacturing method and an operating method therefor, which are highly efficient and require low cost and can support data offloading for load balancing of a communication network and a seamless handover between heterogeneous networks. The proposed MPTCP proxy system comprises: a DPFP interworking interface processing unit for receiving a packet, input to an MP board, according to a DPFP communication scheme and outputting the received packet; an MPTCP protocol interworking interface processing unit for reading header information of the packet output from the DPFP interworking interface processing unit so as to determine whether the read header information includes an MPTCP option, and transmitting the packet to an MPTCP protocol layer and application program interworking interface processing unit when the read header information includes the MPTCP option; and the MPTCP protocol layer and application program interworking interface processing unit for generating an MPTCP subflow by processing the packet from the MPTCP protocol interworking interface processing unit.

Description

MCPC proxy system, its production method and operation method

The present invention relates to an MPTCP proxy system, a method for manufacturing the same, and an operation method thereof, and more particularly, to a multicore CPU high performance packet board based MPTCP proxy system for data service on a multiple network interface in a mobile environment. The present invention relates to a method of manufacturing and operating such an MPTCP proxy system.

In the related art, as shown in FIG. 1, a single path TCP communication method is used between a terminal device 2 having a TCP / IP stack 1 and a service server device 4 having a TCP / IP stack 3. . Accordingly, when the terminal device 2 moves from the cellular network to the WiFi network, after the coverage of the cellular network is removed, an IP address is allocated from the WiFi network and the TCP connection is reset. At this time, the user may experience that the service in use is momentarily interrupted due to the additional delay. In FIG. 1, the terminal device 2 may be a mobile device such as a smartphone, and the service server device 4 may be a legacy TCP server.

As a concept of extending the existing TCP as a technique for improving such a problem, a plurality of communication interfaces (MPTCP stack 11, 21) that the terminal device 10 or the service server device 20 has as shown in FIG. TCP / IP stack (12, 13; 22, 23) can be used simultaneously. When connecting, the terminal device 10 and the service server device 20 informs whether or not the MPTCP (Multi-Path TCP) is used, and multiple subflows using multiple IP addresses for one connection ( subflow). In FIG. 2, the terminal device 10 may be a mobile device such as a smartphone, and the service server device 20 may be a server having a multipath transmission protocol. In order to implement the configuration as shown in Figure 2, a high cost MPTCP system construction cost is generated. That is, the configuration of Figure 2 has to replace all the configuration of the existing server and upgrade the OS, a high cost occurs.

The present invention has been proposed to solve the above-described problems, a high performance low-cost MPTCP proxy system capable of supporting data offloading and endless handover between heterogeneous networks for distributing the load of a communication network, a manufacturing method and operation thereof The purpose is to provide a method.

In order to achieve the above object, MPTCP proxy system according to a preferred embodiment of the present invention, the DPFP interworking interface processing unit for receiving the packet entered into the MP board in a DPFP communication method, and outputs the received packet; An MPTCP protocol interworking interface processor that reads header information of the packet output from the DPFP interworking interface processor to determine whether there is an MPTCP option, and transmits the packet to an MPTCP protocol layer and an application program interworking interface processor when the MPTCP option is present; And an MPTCP protocol layer and an application program interworking interface processor for processing a packet from the MPTCP protocol interworking interface processor to generate an MPTCP subflow.

The MPTCP protocol interworking interface processor may transmit the packet to the legacy TCP server if the MPTCP option is not present.

The MP board has its own CPU and can directly process input / output.

On the other hand, the manufacturing method of the MPTCP proxy system according to a preferred embodiment of the present invention, importing the MP library to the existing TCP / IP stack to create a modified TCP / IP stack; And installing an MPTCP stack and connecting to the MP board through a DPFP interface in the modified TCP / IP stack.

The modified TCP / IP stack may include: a DPFP interworking interface processor configured to receive a packet introduced into the MP board through a DPFP communication method and output a received packet; And an MPTCP protocol interworking interface processor for reading the header information of the packet output from the DPFP interworking interface processor to determine whether there is an MPTCP option, and transmitting the packet to the MPTCP stack when the MPTCP option is present. .

On the other hand, the operating method of the MPTCP proxy system according to a preferred embodiment of the present invention, the DPFP interworking interface processing unit, the step of transmitting a packet entered into the MP board to the internal message queue; Extracting, by the DPFP interworking interface processor, the packet in the message queue and outputting the packet; Determining, by an MPTCP protocol interworking interface processor, header information of the packet; Transmitting, by the MPTCP protocol interworking interface processor, the packet to the MPTCP protocol layer and an application program interworking interface processor when the header information of the packet is an MPTCP option; And generating, by the MPTCP protocol layer and the application program interworking interface processor, the MPTCP subflow by processing the packet.

And transmitting, by the MPTCP protocol interworking interface processor, the packet to the legacy TCP server if the header information of the packet is not the MPTCP option.

According to the present invention having such a configuration, it is possible to provide an apparatus for performing a high performance low cost MPTCP proxy function by implementing a multicore CPU high performance packet board (MP board) based MPTCP proxy system.

In addition, since the present invention uses multiple communication paths, it is possible to support data offloading and continuous handover between heterogeneous networks to distribute the load of the communication network. In other words, it can support data offloading and continuous handover between heterogeneous networks to distribute the load of the communication network, and can improve the throughput of data network traffic by using multiple communication paths, and it is possible to use a high-performance packet board (hardware) based It can support simultaneous multiple access session of.

Network traffic performance improves as the number of connections increases under server hardware conditions with PCI slots that allow CPU-based packet PCI boards to be expanded.

1 is a diagram schematically illustrating a conventional single path TCP communication scheme.

2 is a diagram schematically illustrating a conventional multi-path TCP (Multi-Path TCP) communication scheme.

3 is a network configuration to which the MPTCP proxy system according to an embodiment of the present invention is applied.

4 is a view of the MPTCP proxy system shown in FIG. 3 as viewed from a network communication point of view.

FIG. 5 is a diagram illustrating an internal configuration of the MPTCP proxy system shown in FIG. 3.

6 is a diagram illustrating an MPTCP option format.

FIG. 7 is a flowchart for describing an operation of the DPFP interworking interface processor shown in FIG. 5.

FIG. 8 is a flowchart for describing an operation of the MPTCP protocol interworking interface processor shown in FIG. 5.

FIG. 9 is a flowchart illustrating an MPTCP subflow session processing in the MPTCP protocol layer and an application program interworking interface processor shown in FIG. 5.

10 is a flowchart illustrating a method of manufacturing an MPTCP proxy system and an operation method thereof according to an embodiment of the present invention.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description.

However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. In the following description of the present invention, the same reference numerals are used for the same elements in the drawings and redundant descriptions of the same elements will be omitted.

3 is a diagram illustrating a network configuration to which an MPTCP proxy system is applied according to an embodiment of the present invention, and illustrates a concept of a network configuration to which an MPTCP proxy system 30 based on a multicore CPU high performance packet board (hereinafter referred to as an MP board) is applied. It is a figure for following.

The MPTCP proxy system 30 is TCP-connected to the service server device 4 and is connected to the terminal device 10 via a network 40 (including LTE network and WiFi network) such as the Internet for simultaneous use of multiple wireless networks. Here, the terminal device 10 is a terminal device capable of MPTCP, which is the same as the terminal device of FIG. 2, and the service server device 4 may be regarded as a legacy TCP server.

The MPTCP proxy system 30 may support data offloading and continuous handover between heterogeneous networks to distribute the load of the communication network.

In addition, the MPTCP proxy system 30 may process all sessions and traffic between the terminal device 10 and the legacy TCP server 4.

According to the configuration of FIG. 3 described above, since the embodiment of the present invention uses an existing legacy TCP server (that is, a service server device) without modification, an apparatus for performing a high performance low cost MPTCP proxy can be provided.

4 is a view of the MPTCP proxy system 30 shown in FIG. 3 from a network communication point of view.

Looking at the MPTCP proxy system 30 from a network communication point of view, the MPTCP proxy system 30 is a TCP / IP stack for communication with a terminal device 10 to a first communication network (for example, an LTE network), and a terminal device ( 10) with a TCP / IP stack for communication to a second communication network (e.g., WiFi network).

The MPTCP Proxy system 30 will also have a TCP / IP stack for TCP connection with the service server device 4.

In addition, the MPTCP Proxy system 30 will have an MPTCP stack capable of scheduling traffic for MPTCP subflows.

The TCP / IP stack shown in FIG. 4 may be abbreviated as TCP stack.

FIG. 5 is an internal configuration diagram of the MPTCP Proxy system 30 shown in FIG. 3, and FIG. 6 is a diagram illustrating an MPTCP option format.

The MPTCP proxy system 30 includes an MP board 31, an OS 32, a DPFP interworking interface processor 33, an MPTCP protocol interworking interface processor 34, and an MPTCP protocol layer and an application program interworking interface processor 35. can do.

The MP (Multi-Path) board 31 is a multicore CPU high performance packet board.

Since the MP board 31 is equipped with its own CPU to process the input / output without using the CPU of the service server device 4, the MP board 31 can operate independently of the service server device 4. . This may be the reason why the MPTCP proxy system 30 can maintain high performance at low cost.

Although not shown, the MP board 31 includes a pre-classifier in the form of m (m is a natural number) pipe lines, an input terminal (INPUT), and an output terminal (OUTPUT).

The OS 32 is an operating system of the MPTCP proxy system 30. For example, the OS 32 may be configured as a Linux kernel.

The OS 32 may be referred to as an OS section 32.

The DPFP (Data-Plane Fast-Path) interworking interface processor 33 may deliver a packet received through a DPFP communication scheme to an IP layer (not shown) through a predetermined interworking interface (eg, TCPIP_MSG_INPKT interworking interface). Here, the IP layer may be understood as being inside or outside the DPFP interworking interface processor 33.

In other words, the DPFP interworking interface processing unit 33 may receive a network packet introduced into the MP board 31 through the DPFP communication method and transfer the received packet to the IP layer through, for example, the TCPIP_MSG_INPKT interworking interface.

The MPTCP protocol interworking interface processor 34 sends packets received through the IP layer (not shown) and the TCP layer (not shown) in the DPFP interworking interface processor 33 to the MPTCP protocol layer and the application program interworking interface processor 35. I can deliver it.

At this time, the MPTCP protocol interworking interface processor 34 reads the header information of the received packet and determines whether there is an MPTCP option.

If there is an MPTCP option, the MPTCP protocol interworking interface processor 34 transmits the received packet to the MPTCP protocol layer and the application program interworking interface processor 35.

If there is no MPTCP option, the MPTCP protocol interworking interface processor 34 transmits the received packet to the legacy TCP server 4 by determining that the MPTCP protocol interworking interface processor 34 interworks with the general legacy TCP server 4.

The MPTCP protocol layer and the application program interworking interface processor 35 manages the TCP session and the MPTCP session, and traffic scheduling functions for the MPTCP subflow for data transmission to the terminal device 10. Do this.

In other words, the MPTCP protocol layer and the application program interworking interface processing unit 35 interpret the MPTCP protocol in the DPFP interworking interface processing unit 33 and the MPTCP protocol interworking interface processing unit 34, and if the requested protocol is the MPTCP protocol, the MPTCP subflow ( Subflow) Processes the requested packet so that it can be created and managed. In addition, the MPTCP protocol layer and the application program interworking interface processor 35 may perform congestion control.

Here, MPTCP subflow generation control of the MPTCP protocol layer and the application program interworking interface processor 35 will be described in more detail as follows.

Subflow can use a plurality of transmission paths called subflows at the same time as the flow of TCP. Although it is possible to make an arbitrary number set between both hosts that have performed a TCP connection, in the case of the current wireless connection, one subflow may be generated per one air interface.

MPTCP transfers through one primary subflow and another multipath transfer (CMT) method that simultaneously transfers the generated subflows, and the other route acts as its backup subflow. It can be operated by backup method.

In processing packets in MPTCP, the packet order of MPTCP is divided into a data sequence number and a subflow sequence number. The data sequence number indicates the order among the packets transmitted by utilizing the packet order among the transmission data transmitted by the host. The subflow sequence number indicates the order among the packets transmitted by using the corresponding subflow.

Unlike TCP, MPTCP uses a large number of subflows and, in this case, needs to rearrange the packet order due to differences in transmission speed and delay time between each subflow. Use sequence number and Subflow sequence number.

In particular, since MPTCP supports backward TCP, packet headers for MPTCP are added under the packet header form of TCP. That is, MPTCP has a structure in which MPTCP related information is added to a header of an existing TCP packet. As shown in FIG. 6, if MPTCP is specified in the Kind of the TCP option field, the packet is recognized as an MPTCP packet and operated. Length indicates the length of the MPTCP option, and Subtype indicates the MPTCP message type of the packet. Based on this value, MPTCP is classified as a message for connection, address addition, redirection, route disconnection, and so on. Stuck.

Also, the MP_CAPABLE, MP_JOIN, MP_FAIL, and MP_FASTCLOSE headers are used for new subflow connection and disconnection. The ADD_ADDR and REMOVE_ADDR headers are used to add or remove addresses, and the MP_PRIO header is used to switch paths. In addition, a Data Sequence Signal (DSS) header including sequence information is added to all data and ACK packets using MPTCP.

This time, the congestion control function of the MPTCP protocol layer and the application program interworking interface processor 35 will be described in more detail as follows.

Transmission is performed by using a number of subflows, and the transmission rate is distributed in proportion to the size of the cwnd (congestion window) of each subflow. Therefore, new problems arise when TCP's congestion control algorithm is applied as it is. do. Representatively, as MPTCP subflows occupy the bottleneck interval, the issue of equity violation due to bandwidth overcapacity compared to the existing TCP, packet rearrangement due to transmission speed and round trip time (RTT) difference between subflows A problem arises.

The typical congestion control algorithm uses OLIA (Opportunistic LIA), and LIA (Linked-Increased Algorithm) uses a specific transmission path while delivering the transmission rate when the optimal path is used in the existing TCP method when multi-transmission using MPTCP. Algorithm to prevent oligopoly. This can be achieved by passing the amount of transmission allocated to the most congested subflow to the less congested subflow. With OLIA, the congestion level for each path is controlled similarly by adjusting the distribution level of each subflow by reducing the increase when the congestion level of a certain path is high and increasing the increase when the congestion level is low.

The DPFP interworking interface processor 33 and the MPTCP protocol interworking interface processor 34 may correspond to the TCP / IP stack of the MPTCP proxy system 30 of FIG. 4. The conventional TCP / IP stack cannot directly read the packet by directly connecting to the MP board 31, and even if it is read from the MP board 31, there is no function of interpreting the MPTCP protocol request. However, the TCP / IP stack (that is, the DPFP interworking interface processor 33 and the MPTCP protocol interworking interface processor 34) in the embodiment of the present invention can interpret the MPTCP protocol.

The above-described MPTCP protocol layer and the application program interworking interface processor 35 may correspond to the MPTCP stack of the MPTCP proxy system 30 of FIG. 4.

The operation of the above-described DPFP interworking interface processor 33 will be described again with reference to FIG. 7 as follows.

First, the DPFP interworking interface processor 33 inquires a message queue (S10).

Thereafter, if a packet exists in the message queue ("Yes" in S12), the DPFP interworking interface processor 33 transmits the packet in the message queue to the IP layer (S14).

The operation of the above-described MPTCP protocol interworking interface processor 34 will be described with reference to FIG. 8 as follows.

First, the MPTCP protocol interworking interface processor 34 receives the message of the IP layer (S20), and reads the header information of the packet in the message to determine whether there is an MPTCP option (S22).

If the MPTCP option exists, the MPTCP protocol interworking interface processor 34 transmits the received packet to the MPTCP protocol layer and the application program interworking interface processor 35 (S24). Here, the MPTCP protocol layer and the application program interworking interface processor 35 may be an MPTCP layer or an MPTCP protocol layer.

On the contrary, if there is no MPTCP option, the MPTCP protocol interworking interface processor 34 transmits the received packet to the legacy TCP server 4 (S26). Here, the legacy TCP server 4 may be a TCP layer or a TCP protocol layer.

The operation of the MPTCP subflow session processing of the above-described MPTCP protocol layer and the application program interworking interface processor 35 will be described with reference to FIG. 9 as follows.

The terminal device 10 transmits a message (ie, SYN + MP_CAPABLE) to the MPTCP proxy system 30 via the LTE network to inquire whether a sync signal (SYN) and multipath are possible (S30).

The MPTCP proxy system 30 sends an ACK signal (ie, SYN / ACK + MP_CAPABLE) to the terminal device 10 via the LTE network (S32).

In addition, the terminal device 10 transmits an acknowledgment signal (that is, ACK + MP_CAPABLE) to the MPTCP proxy system 30 through the LTE network (S34).

Accordingly, a TCP session is established between the terminal device 10 and the MPTCP proxy system 30 that can use the LTE network (S36).

In addition, the terminal device 10 transmits a sync signal SYN and a message (that is, SYN + MP_JOIN) to the MPTCP proxy system 30 through the WiFi network (SYN + MP_JOIN).

The MPTCP proxy system 30 sends an ACK signal (ie, SYN / ACK + MP_JOIN) to the terminal device 10 via the WiFi network (S40).

In addition, the terminal device 10 transmits an Ack signal (ie, ACK + MP_JOIN) corresponding thereto to the MPTCP proxy system 30 through the WiFi network (S42).

Accordingly, a session capable of MPTCP subflow join is formed between the terminal apparatus 10 and the MPTCP proxy system 30 that can use the WiFi network (S44).

Accordingly, the MPTCP proxy system 30 may transmit single data to the terminal device 10 via the LTE network and the WiFi network, respectively (S46).

6 to 8, it can be seen that the present invention can support data offloading for distributing the load of the communication network and continuous handover between heterogeneous networks because the present invention uses multiple communication paths.

10 is a flowchart illustrating a method of manufacturing an MPTCP proxy system and an operation method thereof according to an embodiment of the present invention.

First, the MP board 31, which is a high-performance CPU-mounted network card, is mounted in a PCI slot of a computer (S100).

Thereafter, the SDK (Software Development Kit; Software Development Kit) for the MP board 31 is installed on the computer (S110).

In addition, the modified TCP / IP stack is created by opening an existing TCP / IP stack and importing the MP library (S120). For example, import means importing data into one's own system from another computer system, so importing an MP library into an existing TCP / IP stack causes the existing TCP / IP stack to become a new TCP / IP stack. Can be changed to stack Since the modified TCP / IP stack means the DPFP interworking interface processor 33 and the MPTCP protocol interworking interface processor 34, the DPFP interworking interface processor 33 and the MPTCP protocol interworking interface processor 34 are created in step S120. .

Thereafter, the MPTCP stack (that is, the MPTCP protocol layer and the application program interworking interface processor 35) is installed, and the MP board 31 is connected through the DPFP interface by the DPFP interworking interface processor 33 and the MPTCP protocol interworking interface processor 34. Modify to connect with (S130).

When the process of steps S100 to S130 described above is performed, the MPTCP proxy system 30 according to the embodiment of the present invention can be manufactured.

In order to operate the MPTCP proxy system 30 manufactured as described above, first, a program capable of operating the MPTCP proxy system 30 is compiled and executed (S140).

Accordingly, the packet introduced into the MP board 31 is transmitted to the DPFP interworking interface processor 33, and the DPFP interworking interface processor 33 delivers the packet to an internal message queue (S150). Accordingly, the packet introduced into the MP board 31 will be temporarily stored in the message queue of the DPFP interworking interface processor 33.

Thereafter, the DPFP interworking interface processor 33 extracts the packet in the message queue and delivers the packet to the IP layer (S160).

Then, the MPTCP protocol interworking interface processor 34 determines whether the header information of the packet received from the IP layer (or in the IP layer) is MPTCP (more specifically, MPTCP option) (S170).

If it is determined that the MPTCP, the MPTCP protocol interworking interface processor 34 transmits the packet to the MPTCP protocol layer and the application program interworking interface processor 35 (that is, the MPTCP stack) (S180). Accordingly, the MPTCP protocol layer and the application program interworking interface processor 35 participate in the MPTCP subflow session and perform TCP processing (S190).

On the contrary, if not MPTCP, the MPTCP protocol interworking interface processor 34 performs TCP processing on the packet (S200).

As described above, the best embodiment has been disclosed in the drawings and the specification. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (8)

1. A DPFP interworking interface processor for receiving a packet inserted into the MP board through a DPFP communication method and outputting the received packet;

   An MPTCP protocol interworking interface processor that reads header information of the packet output from the DPFP interworking interface processor to determine whether there is an MPTCP option, and transmits the packet to an MPTCP protocol layer and an application program interworking interface processor when the MPTCP option is present; And

   And an MPTCP protocol layer and an application program interworking interface processor for processing a packet from the MPTCP protocol interworking interface processor to generate an MPTCP subflow.
2. The method according to claim 1,

   The MPTCP protocol interworking interface processing unit,

   The MPTCP proxy system, if the MPTCP option is absent, sends the packet to a legacy TCP server.
3. The method according to claim 1,

   The MP board,

   MPTCP proxy system, which is equipped with its own CPU and processes input / output directly.
4. Importing the MP library into an existing TCP / IP stack to create a modified TCP / IP stack; And

   And installing an MPTCP stack and connecting to the MP board through a DPFP interface in the modified TCP / IP stack.
5. The method according to claim 4,

   The modified TCP / IP stack,

   A DPFP interworking interface processor configured to receive the packet received in the MP board through a DPFP communication method and output the received packet; And an MPTCP protocol interworking interface processor for reading the header information of the packet output from the DPFP interworking interface processor to determine whether there is an MPTCP option, and transmitting the packet to the MPTCP stack when the MPTCP option is present. The production method of the MPTCP proxy system.
6. The method according to claim 4,

   The MP board,

   A method of manufacturing an MPTCP proxy system, which is equipped with its own CPU and processes input / output directly.
7. Transmitting, by the DPFP interworking interface processor, a packet inserted into the MP board to an internal message queue;

   Extracting, by the DPFP interworking interface processor, the packet in the message queue and outputting the packet;

   Determining, by an MPTCP protocol interworking interface processor, header information of the packet;

   Transmitting, by the MPTCP protocol interworking interface processor, the packet to the MPTCP protocol layer and an application program interworking interface processor when the header information of the packet is an MPTCP option; And

   And generating, by the MPTCP protocol layer and the application program interworking interface processor, the MPTCP subflow by processing the packet.
8. The method according to claim 7,

   And transmitting, by the MPTCP protocol interworking interface processor, the packet to the legacy TCP server if the header information of the packet is not the MPTCP option.

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