KR100881659B1 - Internet protocol translation system and method. - Google Patents

Abstract

      The present invention provides an Internet protocol conversion apparatus and method for converting a packet between IPV4 / IPV6, comprising: a packet receiving unit for receiving a packet, reading, calculating, and converting a checksum for each area; and storing a data area of the received packet. An internet protocol conversion apparatus comprising a memory for generating a conversion packet by applying a checksum converted by the packet reception unit, and a packet transmission unit for transmitting a conversion packet transmitted from the memory to a destination network,

      The checksum reading, operation and conversion are performed simultaneously with the packet reception to generate a conversion checksum within the reception time of the present packet.

As a result, it is possible to perform faster packet conversion performance by calculating a desired checksum value without including the data area value when calculating the checksum in the network between IPV4 and IPV6. By incorporating the devices, computation of the checksum value to be converted simultaneously with packet reception can be configured to significantly reduce the conversion packet generation time.

Checksum, protocol, conversion

Description

INTERNET PROTOCOL TRANSLATION SYSTEM AND METHOD.

1A is a block diagram showing a TCP segment in IPV4,

1B is a diagram illustrating a TCP pseudo header in IPV4;

2 is a block diagram showing an Internet protocol conversion apparatus in the conventional IPV4 / IPV6 conversion;

3 is a flowchart illustrating an Internet protocol conversion process in the conventional IPV4 / IPV6 conversion;

4 is a block diagram showing an Internet protocol conversion apparatus in IPV4 / IPV6 conversion according to an embodiment of the present invention.

5 is a flowchart illustrating an Internet protocol conversion process in IPV4 / IPV6 conversion according to an embodiment of the present invention.

                    * Description of the symbols for the main parts of the drawings *

       5: Packet receiver 7: Compensation conversion unit

      Reference Signs List 10: first checksum processing unit 12: header separation unit 14: checksum reading unit 20: second checksum processing unit

      22: header area checksum calculator 24: pseudo header generator

      26: pseudo header area checksum calculator 30: checksum converter

      32: conversion checksum generation unit 40: memory

      50: packet transmitter

      110: reception processing unit 120: format conversion processing unit

      121: pseudo header generation unit 122: header conversion unit

      Reference numeral 123: data buffer unit 130: checksum processing unit 131: pseudo header area checksum processing unit 132: header area checksum processing unit 133: data area checksum processing unit 134: summer

      135: complementary converter 140: checksum insertion unit

      150: transmission processing unit

      201: TCP segment header area 202: TCP segment data area

      203: TCP header checksum 204: Source IPV4 address

      205: Receive IPV4 Address 206: Zero

      207: protocol 208: TCP length

      209: doctor header

The present invention relates to an apparatus and method for converting an Internet protocol, and in particular, in converting an IPV4 packet into an IPV6 packet or an IPV6 packet into an IPV4 packet, the time required for calculating the checksum value can be significantly reduced with a small amount of calculation. An apparatus and method are provided.

As the number of Internet users increased exponentially in the 1990s, the IPV4 (Internet Protocol Version 4) address, which is an address system of TCP / IP, which constitutes Internet communication, is rapidly being exhausted. To this end, the Internet Engineering Task Force (IETF) is developing and distributing a new address system, Internet Protocol Version 6 (IPV6), as a means to replace IPV4. However, many experts expect that IPV6-based networks will gradually spread over the newly introduced networks because the IPV4 address-based Internet cannot be replaced with IPV6-based networks in the morning. In addition, research is being conducted in this direction.

For this reason, the most realistic problem at present is the protocol conversion between IPV4 and IPV6-based networks. This is because communication between the IPV4-based network and the IPV6-based network can be performed smoothly only when the protocol conversion between the two different packet formats is performed quickly and accurately.

In order to communicate between an IPV4-based network and an IPV6-based network, a device that exists between the IPV4 network and the IPV6 network and converts the two network protocols appropriately is required. To this end, the IETF draws out various plans and writes them as papers and recommendations, and many companies and research institutes design and implement the actual products based on them. One of the various methods is to convert an IPV4 packet into an IPV6 packet, and then convert an IPV6 packet into an IPV4 packet and transmit the same.

One of the most important processes of translating IPV6 to IPV4 is the conversion of IPV6 packet headers to IPV4 packet headers. Similarly, in the process of converting IPV4 to IPV6, it is important to convert the IPV4 packet header into an IPV6 packet header.

Therefore, converting IPV6 to IPV4 means converting an IPV6 packet header to an IPV4 packet header. Similarly, converting IPV4 to IPV6 means converting IPV4 packet headers to IPV6 packet headers. That is, a new IPV4 packet header is generated in case of IPV6-> IPV4 conversion, and a new IPV6 packet header is generated in case of IPV4-> IPV6 conversion. At this time, a checksum value of TCP / UDP or ICMPV6 (Internet Control Messaging Protocol Version 6), which is an upper layer protocol inserted into the data portion of each packet, must also be newly calculated. Because TCP / UDP checksum values are calculated for TCP / UDP pseudo headers, TCP / UDP headers, and the entire data area, each IPV4-> IPV6 or IPV6-> IPV4 conversion is performed. This is because the address and port number of the TCP / UDP area are newly designated.

The checksum calculation in the conventional IPV4-based network and the checksum calculation method in the IPV6-based network will now be described.

1A is a configuration of a TCP segment, in which the TCP segment is largely divided into a header area 201 and a data area 202. The checksum area 203 of the TCP header has a length of 16 bits, and the checksum calculation results from dividing all the information in the TCP header and data area into words of 16 bits in length, then adding the divided words by a one's complement method. It becomes thing which took 1's reward for. When the checksum value is calculated, the checksum area itself has a value of zero.

Here, when calculating the checksum value, a conceptual header called a pseudo header 209 having a format as shown in FIG. 1B is included, and the calculation is performed.

The pseudo header 209 of the TCP segment has a length of 96 bits, and its configuration includes a source IPV4 address 204, a destination IPV4 address 205, and a zero 206. ), A protocol 207, and a TCP length 208 region.

The pseudo header 209 is generated when the checksum value is calculated at the transmitting end or the checksum value is checked at the receiving end, and is not actually transmitted. The purpose of the pseudo header 209 is to protect the TCP from a badly routed segment. The pseudoheader 209 is located immediately before the TCP header and is calculated together when calculating the checksum value.

The method of calculating the checksum of a UDP datagram on an IPV4-based network is basically the same as the method of calculating the checksum of a TCP segment. In other words, the calculation of the checksum is to divide all the information in the UDP header and data area into 16-bit words, and then calculate the 1's complement of the result of adding the divided Weeds to the 1's complement method. Of course, when calculating the checksum value, the checksum area must have a value of 0, and the UDP pseudo header should also be used.

Meanwhile, the method of calculating the checksum of a TCP segment and the checksum of a UDP datagram on an IPV6-based network is the same as that of the conventional IPV4-based network, but the change is that the pseudo header is changed for IPV6.

FIG. 2 is a block diagram of an apparatus for converting a checksum in a conventional IPV4 / IPV6 converter. In FIG. A format conversion processing unit 120 for converting the data, a checksum processing unit 130 for processing the checksum for each converted region, and obtaining a checksum value of the newly updated packet header and inserting the obtained checksum value into the checksum region of the packet header. It consists of a checksum insertion unit 140 for transmitting and the transmission processing unit 150 for transmitting the converted packet to the new network.

The checksum calculation method in the conventional IPV4 / IPV6 conversion having such a configuration will be described with reference to FIGS. 2 and 3.

First, a TCP segment (or UDP datagram) of a conventional network-based (IPV4) is received through the reception processor 110 (S101).

The received TCP segment is converted by the format conversion processing unit 120 into a packet form of a new format for each region (S102).

That is, the new TCP header is converted by the header converter 122, the pseudo header of the new format is newly generated by the pseudo header generator 120, and the data is temporarily stored in the data buffer unit 123 without being converted. It is done.

The values for each region converted as described above are calculated by the checksum processor 130. The pseudo header region checksum processor 131, the header checksum processor 132, and the data region checksum processor 133 respectively calculate values of the regions. At this time, the checksum of the TCP header is reduced to zero again and calculated.

The values thus obtained are added together in the summer 134 and then converted to a complement of one in the complement converter 135 (S104).

The value thus obtained becomes a newly updated checksum value and is inserted into the checksum region of the newly converted TCP header (S105), and then transmitted to the other network (IPV6) different from the previous network (IPV4) via the transmission processing unit (S106). do.

As described above, when data is transmitted from the IPV4 network area to the IPV6 network area or vice versa, the protocol between IPV4 and IPV6 must be converted for each network.

However, simply converting the IPV4 header to the IPV6 header and vice versa does not complete the protocol conversion. When the IPV4 header changes to the IPV6 header, and when the IPV6 header changes to the IPV4 header, the checksum value of the TCP segment or UDP datagram contained in the packet must also change.

Because, initially, a pseudoheader is used when calculating the checksum value of a TCP segment or UDP datagram. When a translation is made at the IPV4 and IPV6 network interfaces, if the IP layer header changes, the pseudo header is changed according to the changed IP header. It also changes, so we need to calculate the checksum again.

In other words, when a packet is transmitted from an IPV4 network to an IPV6 network, a new IPV6-based pseudo header is created at the interface, in which values of several areas including the IP address as well as the port number of the TCP or UDP layer (source IP address, Destination IP address, length, sending port number, receiving port number) are reassigned together as necessary.

With the re-specified values, the checksum value is calculated using the same method as described above, inserted into the packet header and transmitted to the destination. (The same applies to the IPV6 network-> IPV4 network method.)

However, calculating the checksum value inserted in the packet header is calculating the value across the pseudoheader, TCP / UDP header, and data area.

In this case, the length of the pseudo header and the TCP / UDP header is fixed, so there is no problem in operation, while the longer the data area, the larger the calculation amount, and thus the data processing time increases.

The above problem is a serious bottleneck at the IPV4 / IPV6 network interface, which is a serious factor that degrades the packet conversion performance.

In order to solve the above problem, the present invention does not include the value of the data area when calculating the checksum in the network between IPV4 and IPV6, and calculates a desired checksum value to perform faster packet processing performance. To provide them.

In addition, by including the devices for the conversion of the checksum for each region in the packet receiving unit, it is possible to perform calculation on the checksum value to be converted at the same time as the packet receiving to complete the conversion checksum generation time within the packet receiving time and method and apparatus To provide.

      The object of the present invention is to apply a checksum which receives a packet, reads, computes and converts a checksum for each region, and stores the data area of the received packet and converts the checksum converted by the packet receiver according to the present invention. An internet protocol conversion device comprising a memory for generating a conversion packet and a packet transmission unit for transmitting a conversion packet transmitted from the memory to a destination network,

      The packet receiver reads a checksum value of the received packet and separates a header of the received packet; A second checksum processing unit for calculating a checksum of the header separated by the first checksum processing unit, generating a pseudo header of the header, and calculating a checksum; Including a checksum conversion unit for generating a conversion checksum by applying the checksum calculated through the first and second checksum processing unit,

      It is achieved by the Internet protocol conversion apparatus characterized by performing checksum reading, calculation and conversion simultaneously with packet reception to generate a conversion checksum within the reception time of the present packet.

     The first checksum processing unit may include a header separation unit for separating a header of the received packet and a checksum of the header, and a checksum reading unit for reading the checksum of the received packet.

     The checksum reading unit may include a complement converting unit that converts the checksum of the read packet into one's complement.

      The second checksum processing unit may further include a header region checksum calculation unit that calculates a checksum of a header separated by the header separator, a pseudo header generation unit that generates a pseudo header of the header, and a checksum of the generated pseudo header. And a pseudo header region checksum calculation unit.

      Here, the checksum conversion unit subtracts the checksum of the header calculated by the second checksum processing unit and the checksum of the pseudo header from the checksum converted by the checksum reading unit to one's complement.

       The checksum converting unit may include a complement converting unit converting the subtracted checksum into one's complement.

       Preferably, the checksum converter comprises a transform checksum generator for generating a transform checksum using the checksum converted to the one's complement.

        On the other hand, the above object is, according to the present invention, a first step of calculating the read checksum value of the received packet, and separating the header of the received packet; Calculating a checksum value of the separated header, generating a pseudo header of the separated header, and calculating a checksum value of the generated pseudo header; And a third step of generating a conversion checksum value using the checksum calculated in the first step and the second step.

      Here, the first step converts the checksum value of the read packet into one's complement.

      In the third step, the checksum value converted into the one's complement by the first step is subtracted by the checksum value of the pseudo header and the checksum value of the header calculated in the second step.

      Further, the third step converts the subtracted checksum value to one's complement and generates a converted checksum value using the checksum value converted to one's complement.

       Hereinafter, the present invention will be described in more detail with reference to specific examples. Prior to the description, these examples are merely to illustrate the present invention, and it is noted that the protection scope of the present invention is not limited by these examples.

       In addition, the Internet protocol conversion apparatus according to the present invention can be applied to protocol conversion between IPV4 / IPV6, but in order to avoid duplication of explanation, the following description will only be described in the case of conversion from IPV4 to IPV6.

        Further, the packet in the description is strictly a TCP segment or a UDP datagram, but is described in packets for simplicity of explanation.

       4 is a block diagram of an Internet protocol conversion apparatus according to an embodiment of the present invention.

        4, the Internet protocol conversion apparatus according to the present invention,

       A packet receiver 5 for receiving packets (TCP segments or UDP datagrams), a memory 40 for storing the data area of the received packets, and a packet transmitter 50 for transmitting the converted packets.

      The packet receiver 5 includes a first checksum processing unit 10, a second checksum processing unit 20, and a checksum conversion unit 30 for performing a checksum conversion operation of a received packet therein.

       In addition, the first checksum processing unit 10 includes a header separator 12 for separating the header of the received packet and a checksum read unit 14 for reading the checksum of the packet.

       Here, the header separator 12 transmits the data area except for the separated header area to the memory 40, and the checksum read unit 14 compensates for converting the read checksum value to 1's complement. And a conversion unit 7.

      In addition, the second checksum processor 20 may include a header inverse checksum calculator 22 for calculating a checksum value of a header area of a packet separated by the header separator 12 and a pseudo header generator for generating a pseudo header. (24) and a pseudo header region checksum calculating section 26 for calculating a checksum value of the pseudo header region generated by the pseudo header generating section 24.

      Here, the checksum conversion unit 30 converts the checksum values calculated by the first and second checksum processing units so that they can be applied to the destination network (IPV4-> IPV6 or IPV6-> IPV4). It includes.

      In addition, the conversion checksum generation unit 32 includes a complement conversion unit 7 for converting the calculated checksum value into one's complement.

      In this case, the checksum converter 30 may include a checksum value calculated by the header region checksum calculator 22 and a pseudo header region checksum calculator 26 based on a checksum value of a packet converted into a one's complement by the checksum reader. Subtract the computed checksum value.

       The subtracted checksum value is generated as a conversion checksum value applicable to the target network by the conversion checksum generation unit 32 included in the checksum conversion unit 30 and transmitted to the memory 40.

       The memory 40 temporarily stores a data area portion of a packet transmitted from the header separator 12, and when a transform checksum value passed through the transform checksum generator 32 is transmitted, a header to which the transform checksum value is applied. And the stored data are added together and transmitted to the packet transmitter 50.

        Finally, the packet transmitter 50 transmits the converted packet transmitted from the memory 40 to the destination network.

      As described above, the packet receiver 5 includes devices for converting the checksum value in the packet receiver 5 so as to be applicable to the target network. Therefore, the checksum calculation and conversion are performed simultaneously with packet reception. There is a significant speed difference in packet conversion performance over the technology.

      5 is a flowchart illustrating an internet protocol conversion process according to an embodiment of the present invention.

       Referring to Figure 5, the process of the Internet protocol conversion apparatus according to the present invention,

      When the packet is received by the packet receiver 5 (S11), the checksum of the received packet is read (S13), and the header area separation and pseudo header generation (S17) of the received packet are performed. When the checksum of the packet is read (S13), the checksum value is converted into a one's complement by the maintenance converting unit 7 included in the checksum read unit 14 (S15).

        When the header area of the packet is separated and a pseudo header is generated (S17), the checksum value is calculated for each area by the header area checksum calculating unit 22 and the pseudo header area checksum calculating unit 26.

        The checksum values passed through steps S15 and S19 are subtracted by the checksum converter 30 (packet checksum value-pseudo header region checksum value-header region checksum value) (S21).

       The checksum value subtracted through the step S21 is transmitted to the conversion checksum generation unit 32 included in the checksum conversion unit 30 to calculate a conversion checksum value (S23).

       The calculated transform checksum value is converted into a complement of 1 by the complement conversion unit 7 included in the transform checksum generator 32, and finally a checksum value to be converted (applicable to the destination network). It is generated (S27).

       The converted checksum value generated as described above is transmitted to the memory 40 to generate a converted packet in which the data portion stored at the first reception of the packet and the header portion applying the converted checksum value for each region are generated (S29).

      The generated converted packet is transmitted to the packet transmitter 50, and is transmitted (S31) by the packet transmitter 50 to the destination network (to IPV6 at IPV4 conversion and to IPV4 at IPV6 conversion).

As described above, the Internet protocol conversion apparatus according to the present invention,

When calculating the checksum in the network between IPV4 and IPV6, faster packet conversion performance can be performed by calculating a desired checksum value without including the data area value.

In addition, by including devices for area-specific checksum conversion within the packet receiving unit, the packet check unit can be configured to perform calculation on the checksum value to be converted at the same time as the packet reception, thereby completing the conversion checksum generation time within the packet reception time.

Claims (11)

      A packet receiving unit for receiving a packet, reading, calculating, and converting a checksum for each region, a memory for storing a data region of the received packet, and applying a checksum converted by the packet receiving unit to generate a converted packet; An internet protocol conversion device comprising a packet transmission unit for transmitting a conversion packet transmitted from a memory to a target network,       The packet receiver reads a checksum value of the received packet and separates a header of the received packet; A second checksum processing unit for calculating a checksum of the header separated by the first checksum processing unit, generating a pseudo header of the header, and calculating a checksum; A checksum converter configured to generate a transform checksum by applying checksums calculated through the first and second checksum processors; The first checksum processing unit includes a header separation unit for separating the header of the received packet and the checksum of the header, and a checksum reading unit for reading the checksum of the received packet.  The checksum reading unit includes a complementary converting unit for converting the checksum of the read packet into one's complement, The second checksum processing unit includes a header region checksum calculation unit that calculates a checksum of the header separated by the header separator, a pseudo header generation unit that generates a pseudo header of the header, and a pseudooperation that calculates the checksum of the generated pseudo header. Includes header area checksum operation, The checksum converting unit subtracts the checksum of the header and the checksum of the pseudo header calculated by the second checksum processing unit from the checksum converted to 1's complement by the checksum reading unit, And a checksum reading, arithmetic, and transforming at the same time as the packet is received to generate a conversion checksum within the reception time of the packet. delete delete delete delete         The method of claim 1,        And the checksum converting unit includes a complement converting unit converting the subtracted checksum into one's complement.         The method of claim 6,         And the checksum conversion unit comprises a conversion checksum generation unit generating a conversion checksum using the checksum converted into the one's complement. In the Internet protocol conversion method between IPV4 and IPV6 network, Calculating a read checksum value of the received packet and separating a header of the received packet; Calculating a checksum value of the separated header, generating a pseudo header of the separated header, and calculating a checksum value of the generated pseudo header; And a third step of generating a conversion checksum value using the checksum calculated in the first and second steps. The first step converts the checksum value of the read packet into one's complement, And the third step subtracts the checksum value converted into the one's complement by the first step to the checksum value of the pseudo header and the checksum value of the header calculated in the second step. delete delete         The method of claim 8,        And the third step converts the subtracted checksum value into one's complement and generates a converted checksum value using the checksum converted to one's complement.

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