KR100590880B1 - System and method for transmitting compressed packet - Google Patents

Abstract

The present invention provides a first apparatus for relaying a compressed packet received from a terminal by performing a decompression extension mode or by performing a decompressor mode to decompress a compressed packet and transmit the decompressed packet to a corresponding destination. In addition, the present invention provides a compressed packet transmission system including a second device relayed through a first device to decompress a received compressed packet and transmit the decompressed packet to a destination of the corresponding packet.

According to the present invention, by performing an operation of decompressing a compressed packet through a decompression server, the router can effectively reduce the load of decompressing a compressed packet, thereby implementing a low-cost router. It can improve the performance of the router.

Router, compression, decompression, CRTP, CID,

Description

Compressed packet transmission system and its method {SYSTEM AND METHOD FOR TRANSMITTING COMPRESSED PACKET}             

1 is a block diagram of a conventional IP header compression packet.

2 is a block diagram of a communication network system using a conventional IP header compression technique.

3 is a block diagram of an IP header compression packet transmission system according to an embodiment of the present invention.

4 is a flowchart illustrating an operation of transmitting an IP header compressed packet in a router according to an embodiment of the present invention.

5 is a diagram illustrating a decompression server discovery request message according to an embodiment of the present invention.

Figure 6 is a form of a response message according to an embodiment of the present invention.

7 is an operation flowchart of a decompression server according to an embodiment of the present invention.

8 is a diagram illustrating a failure response message according to an embodiment of the present invention.

9 is a form of a notification message according to an embodiment of the present invention.

10 is a flowchart illustrating an operation of processing a notification message in a router according to an embodiment of the present invention.

11 is a flowchart illustrating the operation when the router performs the decompression extension mode according to the present invention.

12 illustrates a form of an IP header compressed packet in accordance with the present invention.

Figure 13 is a block diagram of a router according to an embodiment of the present invention.

14 is a block diagram illustrating a decompression server according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100, 200: terminal 300, 400: router

310: router identifier management unit 320: authentication processing unit

330: header compression extension unit 340: control signal unit

350: header decompressor 360: packet transceiver

500: decompression server 510: authentication processing unit

520: router identifier management unit 530: control signal unit

540: header decompressor 550: packet transceiver

The present invention relates to a compressed packet transmission system and a method thereof, and more particularly, when receiving an IP header compressed packet compressed by an IP (Internet Protocol) header compression technique from a wired or wireless communication terminal, by decompressing the received packet. It relates to a compressed packet transmission system and a method for transmitting to the terminal.

Today, there is an increasing demand for real-time transmission of video data or audio data through a network.

To meet this need, Real-time Transport Protocol (RTP) is specified in Request For Comment (RFC) 1889 issued to the Internet Engineering Task Force (IETF), an Internet standardization organization. Alternatively, video data can be transmitted in real time.

In addition, in order to transmit over a network in real time according to RTP, an added IP (Internet Protocol) header is 20 bytes, a UDP (User Datagram Protocol) header is 8 bytes, and an RTP header is 12 bytes.

Therefore, since overheading occurs for a packet for transmitting one data, to solve this problem, IPCP, CRTP, and ROHC have been defined.

IP Compression Protocol (IPCP) is a technique for compressing RTP / UDP / IP headers, UDP / IP headers, and Encapsulation Security Payload (ESP) / IP headers.Compressed RTP (CRTP) and Robust Header Compression (ROHC) are IP / UDP. Compresses the / RTP header.

1 shows a conventional IP header compressed packet.

Referring to FIG. 1, an IP header compressed packet includes a CID (Context Identifier) field, a compressed header field, and a data field. CID may use an 8-bit or 16-bit identifier as an identifier for identifying an IP header compressed packet. The compression header is a compression header that compresses an IP header and uses a compression header defined according to a compression algorithm used, such as IPCP, CRTP, and ROHC. The data field is a data field carried in an IP packet.

2 is a block diagram of a communication network system using a conventional IP header compression technique.

2, conventional IP header compression / decompression techniques have been used in point-to-point communication networks. Compression in the wired / wireless terminal 10 as a starting point is released by the wired / wireless terminal 30 or the wired / wireless router (or base station) 20 as the end point. In the figure, a form of a packet including a compression header and data between the wired / wireless terminals 10 and 30 and the wired / wireless router (or base station) 20 is illustrated, and the CID identifier shown in FIG. 1 is omitted.

When the first wired / wireless terminal 10 generates the IP header compression packet, if the receiving terminal is the second wired / wireless terminal 20 existing in the header compression operation network using the IP header compression technique, the second wired / wireless terminal 10 Compression is decompressed in the wireless terminal 20, and when the receiving terminal is outside the header compression operation network, the IP packet decompressed and restored by the router is transmitted to the external network.

As described above, in the system for processing the conventional IP header compressed packet, the load for releasing the compressed IP header in the router increases, which may cause a delay in the processing of the entire packet. For example, if the terminal is a VoIP terminal that frequently generates an IP header compressed packet, the degree is more severe, and thus, it is difficult to develop a low-power wired / wireless router (or base station) and causes a delay of voice packets.

Disclosure of Invention The present invention has been made to solve such a conventional problem, and an object thereof is to provide a compressed packet transmission system and a method for reducing a load for releasing compressed packets in a router.

According to an aspect of the present invention for achieving this object, by performing a decompression extension mode to relay the compressed packet received from the terminal, or decompressed and decompressed the compressed packet by performing a decompressor mode Provided is a compressed packet transmission system comprising a first device for transmitting a packet to a corresponding destination, and a second device for decompressing and receiving a compressed packet received through the first device to the destination of the packet.

According to another aspect of the present invention, the compressed packet received from the terminal to the first device to perform the decompression extension mode to relay to the second device, and in the second device of the compressed packet received relayed from the first device A method of transmitting a compressed packet in a compressed packet transmission system, the method comprising: decompressing to transmit a decompressed packet to a corresponding destination.

Hereinafter, an IP header compression packet transmission system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a configuration diagram of an IP header compressed packet transmission system according to an embodiment of the present invention.

Referring to FIG. 3, a packet transmission system according to an embodiment of the present invention compresses and transmits an IP header of a packet using various IP header compression techniques, or decompresses an IP header by receiving a packet in which the IP header is compressed. Decompressor when packet data is received from the first terminal 100 and the second terminal 200 and the first terminal 100 or the second terminal 200 and are received from the corresponding terminal. Connected to the first router 300 and the second router 400 and the first router 300 and the second router 400 to perform the extension mode or the decompression extension mode to decompress the IP header to the external network. It is configured to include a decompression server 500 to transmit to.

The first terminal 100 and the second terminal 200 compresses the IP header of the packet and transmits the packet to the router, and decompresses the compressed IP header from the IP header compression packet received through the router to the original packet. Restore the function.

The first router 300 and the second router 400 receive the compressed packet from the first terminal 100 or the second terminal 200, and when the destination terminal is a terminal in the internal network, according to the destination address of the packet. The compressed packet is transmitted to the terminal. On the other hand, when the destination terminal is not a terminal in the internal network, the compression extension mode is performed to relay and transmit the received compression packet to the decompression server 500 connected through the network, or the decompressor mode itself is performed. The packet is transmitted to the terminal.

The first router 300 and the second router 400 transmit the decompression server discovery request message to the decompression server 500 connected through the network to determine its operation mode, thereby decompressing the server 500. It determines its operation mode according to the result of the response message sent from the.

That is, when the first router 300 and the second router 400 determine that the decompression server 500 is operating normally through a response message received from the decompression server 500, the first router 300 and the second router 400 may enter the compression extension mode. In operation, the IP header compressed packets received from the first terminal 100 and the second terminal 200 are relayed to the decompression server 500 and transmitted.

The decompression server 500 receives an IP header compressed packet relayed and transmitted from the first terminal 100 or the second terminal 200, decompresses the IP header, and transmits the decompressed IP header to the corresponding terminal according to the destination address of the packet. do.

The decompression server 500, which has received the decompression server discovery request message from the first router 300 and the second router 400, determines whether to provide a decompression service according to its system situation, and decompresses normally. If the release service can be performed, the router identifier is provided to the router. In addition, when the system is newly activated, the decompression server 500 transmits a notification message indicating that the current state of the system is in the system boot state to the router connected through the network. In addition, when the system is in a pause state, it transmits a notification message indicating that its current state is in the stopped state. Here, the response message and the notification message generated by the decompression server 500 have respective formats.

Various IP header compression techniques may be used for the IP header compression technique used for compressing and decompressing the IP header in the first terminal 100 and the second terminal 200 and the first router 300 and the second router 400. Can be.

For example, an IP Compression Protocol (IPCP) that compresses an RTP / UDP / IP header, a UDP / IP header, an Encapsulation Security Payload (ESP) / IP header may be used, and a CRTP that compresses an IP / UDP / RTP header. Compressed RTP) and Robust Header Compression (ROHC) may be used.

The packet processing operation of the IP header compression packet transmission system according to the present invention configured as described above will be described.

When there is data to be transmitted, the first terminal 100 or the second terminal 200 compresses the IP header by the IP header compression technique, and then transmits the packet with the IP header compressed to the router. ) Determines whether to transmit the packet as it is to the terminal according to the packet destination information, to operate in the decompressor mode, or to operate in the compressed extension mode. The routers 300 and 400 identify the destination of the packet and transmit the packet to the corresponding destination terminal or relay the packet to the decompression server 500. The decompression server 500 decompresses the IP header compressed packet relayed from the routers 300 and 400 and transmits the decompressed packet to the destination terminal according to the destination address of the packet.

4 is a flowchart illustrating an operation of transmitting an IP header compressed packet in a router according to an embodiment of the present invention.

Referring to FIG. 4, when the router 300 receives an arbitrary IP header compression packet from the first terminal 100, the header compression has a function of decompressing the IP header compression of the destination address of the packet from the corresponding CID information. It is determined whether the terminal in the operating network or the terminal in the external network does not have the function to release the IP header compression (S1). If it is determined that the destination terminal is a terminal in the header compression operation network, the IP header compression packet is transmitted to the corresponding terminal according to the destination address of the corresponding packet (S2). On the other hand, when the determination result, if the destination terminal is not a terminal in the header compression operation network, it is determined whether the decompression server 500 is connected to the network (S3). If the decompression server 500 is connected to the network as a result of the determination, a request message for discovering the decompression server is transmitted to the decompression server 500 (S4). The router 300 determines whether a response message is received from the decompression server in response to the request message transmitted to the decompression server 500 (S5). If there is a response message received from the decompression server as a result of the determination, the router identifier assigned by the decompression server 500 is extracted from the response message and set (S6). Then, based on the set router identifier, the compression extension mode function is performed to transmit the compressed packet to the corresponding decompression server 500 (S7).

Meanwhile, if the decompression server 500 is not connected or there is no response message from the decompression server 500, the router 300 operates in decompressor mode to decompress the compressed packet and transmit the decompressed packet to the corresponding terminal. (S8).

5 illustrates an example of a decompression server discovery request message that a router sends to a decompression server to discover a decompression server connected to a network.

Referring to FIG. 5, the decompression server discovery request message includes a CID (Context ID) field, an operation field, an authentication type field, an authentication field, and a router IP address. It consists of fields.

The CID sets '0', and the operation field uses 1 for IPv4 and 9 for IPv6 according to the IP version. The authentication type field indicates an authentication method, and the authentication field indicates data necessary for authentication. In the case of the IPv4, a 4-byte IP address may be used for the router IP address field and a 16-byte address may be used for the IPv6.

6 shows a response message sent by the decompression server to the router.

Referring to FIG. 6, the response message includes a CID, an operation field, a length field, and a router ID field.

The CID sets '0' and the operation field sets '2' to a value indicating a response (success). The length field indicates the length of the router ID field. The router ID field is set to the router ID issued to the router by the decompression server 500.

7 is an operation flowchart of a decompression server according to the present invention.

Referring to FIG. 7, when the decompression server 500 receives a decompression server discovery request message transmitted from an arbitrary router 300 or 400, the decompression server 500 corresponds to an authentication type field and an authentication field of the decompression server discovery request message. Authentication is performed for the routers 300 and 400 (S11). It is determined whether authentication is successful according to the result of authentication (S12). If authentication is successfully completed, a router identifier is assigned to the corresponding router (S13), and the response message is set by setting an operation, a length, and a router identifier in the response message. It generates (S14). The generated response message is transmitted to the routers 300 and 400 (S15). On the other hand, if authentication fails, a failure response message is transmitted to the router (S16).

8 shows a failure response message transmitted from the decompression server to the router. Referring to FIG. 8, the CID sets a value of '0', the operation sets a value of '3' to indicate a failure response message, and the error type sets a value corresponding to a failure cause.

9 shows a notification message in which the decompression server transmits its operation status to a router. Referring to FIG. 9, the CID sets '0' and the operation sets '4' as a value for displaying a notification. The reason field may correspond to server start or server stop. In this case, the server start refers to a state in which the decompression server is started to perform a service, and the server stop refers to a state in which the decompression server cannot perform a service.

10 is a flowchart illustrating an operation of processing a notification message in a router according to an embodiment of the present invention.

Referring to FIG. 10, when the router 300 receives a notification message from the decompression server 500 (S21), the router 300 determines whether the cause field of the notification message is server start or server stop (S22). If it is determined that the cause field is set to start the server, a request message for detecting the decompression server is transmitted to the decompression server 500 (S23). The router 300 determines whether a response message is received from the decompression server corresponding to the request message transmitted to the decompression server 500 (S24). If there is a response message received from the decompression server as a result of the determination, the router identifier assigned by the decompression server 500 is extracted from the response message and set (S25). Then, based on the set router identifier, the compression extension mode function is performed to transmit the compressed packet to the corresponding decompression server 500 (S6).

Meanwhile, if the decompression server 500 is not connected or there is no response message from the decompression server 500, the router 300 operates in decompressor mode to decompress the compressed packet and transmit the decompressed packet to the corresponding terminal. (S27).

11 is a flowchart illustrating operations when the router performs the decompression extension mode according to the present invention.

Referring to FIG. 11, when the router 300 or 400 performs the decompression extension mode, when the IP header compression packet is received from the terminal 100 or 200 (S31), the router 300 or 400 adds its identifier to the IP header compression packet. (S32). The addition of its identifier at the router is to let the decompression server 500 know at which router the IP header compression packet was sent. That is, the decompression server 500 needs to know from which router the IP header compression packet is transmitted so that the packet can be retransmitted when there is a packet loss during packet transmission. The router 300 or 400 adds its identifier to the IP header compression packet received from the terminal, and then transmits the packet to the decompression server 500 (S33).

12 is a diagram of an IP header compressed packet according to the present invention.

Referring to FIG. 12, the IP header compression packet transmitted from the routers 300 and 400 to the compression header server 500 includes a router ID added by the routers 300 and 400, a CID received from the terminal, Compressed header, consisting of data.

13 is a block diagram of a router 300 according to an embodiment of the present invention.

Referring to FIG. 13, the router 300 includes a router identifier management unit 310, an authentication processing unit 320, a header compression extension unit 330, a control signal unit 340, a header decompression unit 350, It comprises a packet transceiver 360.

The router identifier manager 310 manages a router identifier allocated from the decompression server 500.

When the packet is received from the first terminal 100, the authentication processor 320 determines whether to provide a routing service to the first terminal 100 by performing authentication on the first terminal 100 that has transmitted the packet. do.

The header compression extension unit 330 performs an operation for transmitting the packet received from the first terminal 100 to the decompression server 500 for decompression according to the control signal of the control signal unit 320.

When the IP header compression packet is received from the first terminal 100, the control signal unit 340 determines the destination of the packet, and within the header compression operation network having the function of decompressing the IP header. If there is a terminal that performs the control to transmit to the terminal. On the other hand, if the destination of the packet is a terminal outside the header compression operation network that does not have a function to decompress the IP header, it is determined whether to use the decompression server 500 to control the transmission of the packet. Perform.

That is, the control signal unit 340 transmits the decompression server discovery request message to the decompression server 500, and uses the decompression server 500 in response to the response message received from the decompression server 500. Control may be performed to perform a compression extension mode for transmitting to a destination terminal, and decompresses an IP header without using a decompression server 500 to perform a decompressor mode for transmission to a corresponding terminal. Control may be performed.

The header decompressor 350 decompresses the compressed header by referring to the CID from the IP header compressed packet received from the terminal when the control signal unit 340 performs the decompressor mode, and restores the compressed header into an uncompressed packet.

The packet transmitter / receiver 360 transmits the packet received from the first terminal 100 to the corresponding terminal in the header compression operation network having the function of decompressing the IP header under the control of the control signal unit 340. According to the operation of the header compression extension unit 330, the packet received from the first terminal 100 is transmitted to the decompression server 500, or the decompressed packet according to the operation of the header decompression unit 350 is applied. Send to the terminal.

The IP header compression packet transmission operation of the router 300 configured as described above will be described.

When the IP header compression packet is received from the first terminal 100 through the packet transceiver 360, the control signal unit 340 extracts the CID information of the corresponding packet and transmits the CID information to the authentication processor 320. The authentication processor 320 performs authentication on the packet based on the CID of the packet. If authentication is successfully performed in the authentication processing unit 320, the control signal unit 340 analyzes the CID of the packet to determine the destination of the packet. If the destination is any terminal in the header compression operation network, the packet is transmitted to the terminal through the packet transceiver 340.

On the other hand, the control signal unit 340 determines whether to use the decompression server 500 when the destination of the packet is a terminal in an area other than the header compression operation network and performs the operation control accordingly.

That is, the control signal unit 340 generates the decompression server discovery request message and transmits the decompression server 500 to the decompression server 500 through the packet transceiver 360. If there is a response message from the decompression server 500, the control signal unit 340 interprets the response message to determine whether the decompression server 500 operates normally.

If it is determined that the decompression server 500 operates normally, the control signal unit 340 drives the header compression expansion unit 330 to relay the IP header compression packet received from the terminal to the decompression server 500.

Accordingly, the header compression extension unit 330 adds the router identifier to the IP header compression packet received from the terminal to transmit the decompression server 500 through the packet transceiver 360.

Meanwhile, when it is determined that the decompression server 500 does not operate normally, the control signal unit 340 drives the header decompression unit 350 to perform the decompressor mode.

Accordingly, the header decompressor 350 decompresses the compressed header with reference to the CID from the IP header compressed packet received from the terminal and restores the compressed header into an uncompressed packet.

The control signal unit 340 transmits the packet through the packet transceiver 360 to the corresponding terminal when the IP header is decompressed by the header decompressor 350.

14 is a block diagram illustrating a decompression server according to an embodiment of the present invention.

Referring to FIG. 14, the decompression server 500 may include an authentication processor 510, a router identifier manager 520, a control signal unit 530, a header decompressor 540, and a packet transceiver 550. It is made, including.

When the packet is received from the first terminal 100, the authentication processor 510 determines whether to provide a routing service to the first terminal 100 by authenticating the first terminal 100 that has transmitted the packet. do.

The router identifier managing unit 520 issues and manages router identifiers to the routers 300 and 400.

The control signal unit 530 performs an overall control for releasing the IP header compressed packet received from the routers 300 and 400 and transmitting the packet to the destination terminal of the packet.

That is, when the control signal unit 530 receives the decompression server discovery request message transmitted from the routers 300 and 400, the control signal unit 530 transmits a response message for informing the normal operation of the decompression server 500 to the corresponding router. .

In addition, the control may be performed to decompress the IP header compression packet received from the routers 300 and 400 to perform a decompressor mode for transmission to the corresponding terminal.

The header decompressor 540 decompresses the compressed header by referring to the CID from the IP header compressed packets received from the routers 300 and 400 when the control signal unit 530 performs the decompressor mode. Restore to a packet.

The packet transceiver 550 transmits a packet received from the routers 300 and 400 under the control of the control signal unit 520 to the corresponding terminal according to the operation of the header decompressor 540.

The IP header compression packet transmission operation of the decompression server 500 configured as described above will be described.

When the decompression server discovery request message is received from the routers 300 and 400 through the packet transmitter / receiver 550, the control signal unit 530 receives the CID, operation information, authentication type, authentication data, and router from the decompression server discovery request message. The IP address is extracted and transmitted to the authentication processing unit 510. The authentication processor 510 refers to the information and performs authentication on the corresponding packet. Authentication is successfully performed in the authentication processing unit 510.

When authentication is completed in the authentication processing unit 510, the control signal unit 530 generates a response message (success) informing that the decompression server 500 is in a normal operation state and transmits it to the corresponding routers 300 and 400. Meanwhile, when the decompression server 500 does not operate normally, the control signal unit 530 generates a response message (failure) for notifying that the decompression server 500 is not in a normal operating state and transmits it to the corresponding routers 300 and 400.

In this state, the control signal unit 530 drives the header decompressor 540 to decompress the IP compressed packet.

Accordingly, the header decompressor 540 decompresses the compressed header with reference to the CID from the IP header compressed packet received from the router and restores the compressed header into an uncompressed packet.

The control signal unit 530 transmits the decompressed packet through the packet transceiver 340 to the corresponding terminal when the IP header is decompressed by the header decompressor 540.

According to the present invention, by decompressing the IP header compressed packet through the decompression server, the cost of performing the decompression on the IP header compressed packet in the router can be effectively reduced, thereby reducing the cost. Can implement the router, and improve the performance of the router.

Claims (18)

A first device configured to relay a compressed packet received from a terminal by performing a decompression extension mode, or perform a decompressor mode to decompress the compressed packet and transmit the decompressed packet to a corresponding destination; And a second device relaying through the first device to decompress the received compressed packet and transmit the decompressed packet to a destination of the packet. The method of claim 1, wherein the first device, If the destination of the compressed packet is a terminal capable of decompressing the compressed packet, the compressed packet transmission system for transmitting the received compressed packet to the terminal. 2. The compressed packet transmission system of claim 1, wherein the first device performs the decompression extension mode when the second device is operable by querying the second device connected on a network. The compressed packet transmission system of claim 1, wherein the first device queries the second device connected on a network and performs the decompressor mode when the second device cannot operate. The system of claim 1, wherein the first apparatus is a router or a base station. The compressed packet transmission system according to claim 1, wherein the compressed packet is an IP header compressed packet. The compressed packet transmission system of claim 1, wherein the first device transmits a first message to the second device to determine an operating state of the second device connected on a network. The system of claim 7, wherein the first message includes at least one of a CID, an action, an authentication type, authentication information, and a first device address. 8. The compressed packet transmission system according to claim 7, wherein the second device transmits a second message to the first device indicating the operating state of the second device corresponding to the first message. The system of claim 9, wherein the second message comprises at least one of a CID, an action, a length of a first device identifier, and a first device identifier. Relaying the compressed packet received by the first device from the terminal to the second device by performing a decompression extension mode; And decompressing the compressed packet received relayed from the first device in the second device to transmit the decompressed packet to a corresponding destination. The method of claim 11, And transmitting the compressed packet to a corresponding destination terminal when the destination of the compressed packet received from the terminal to the first device is a terminal capable of decompressing the compressed packet. The compressed packet transmission method according to claim 11, wherein the compressed packet is an IP header compressed packet. The method of claim 11, And the first device further comprises transmitting a first message to the second device to determine an operation state of the second device connected on a network. The method of claim 14, And the first message comprises at least one of a CID, an action, an authentication type, authentication information, and a first device address. The method of claim 14, And transmitting, by the second device to the first device, a second message indicating an operation state of the second device corresponding to the first message. 17. The method of claim 16, wherein the second message comprises at least one of a CID, an action, a length of a first device identifier, and a first device identifier. The method of claim 16, If it is determined that the second device cannot perform the decompression operation according to the second message, the first device performs a decompressor mode to decompress the header compressed packet received from the terminal. A compressed packet transmission method of a compressed packet transmission system further comprising.

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