KR20030018445A - Method and Apparatus for Internet Protocol Translation using NAT-PT - Google Patents

Abstract

PURPOSE: An internet protocol conversion apparatus using parallel nat-pt and internet protocol conversion method using the same are provided to realize a NAT-PT of a small-sized integrated circuit using a system on chip technology and to process NAT-PT modules in parallel. CONSTITUTION: A PHY chip(501) checks and processes a protocol of a layer 1 and an error of a packet surrounded by an electrical signal. A MAC(502) converts a protocol of a layer 2 into a protocol of a layer 3 using a signal from the PHY chip. An IP multiplexer/demultiplexer(503) distributes a packet from the MAC into an empty NAT-PT modules(505,506) and stores a packet of a standby state in an IP packet buffer(504). An SIIT(505) performs a header and address conversion operation between an IPv4 packet and an IPv6 packet using a packet from the IP multiplexer/demultiplexer. A DNS/FTP ALG(506) receives a DNS/FTP packet from a packet output from the IP multiplexer/demultiplexer and sends a DNS query packet to a DNS server in order to find an IP address and update a mapping table. A mapping table module(507) stores a pole of an IPv4 address necessary for the modules(505,506) and stores a mapping table between IPv4 and IPv6 addresses generated from the modules(505,506).

Description

Internet Protocol Translation System Using Parallel Nat-Piti and Internet Protocol Version Conversion Method Using Them {Method and Apparatus for Internet Protocol Translation using NAT-PT}

The present invention utilizes parallel Nat-PT (Network Address Translation-Protocol Translation (NAT-PT)) between Internet Protocol Version 4 (hereinafter referred to as "IPv4") and Internet Protocol Version 6 (hereinafter referred to as "IPv6"). The present invention relates to an internet protocol converter for fast packet conversion and an internet protocol version conversion method using the same.

At present, the problem of address depletion of the Internet is serious. To solve this problem, IPv6 with 128-bit address system is used.

IPv6 has the advantage of not only extending the address length but also reducing the bandwidth cost through the simplified header format and reducing the processing cost of common parts in packet processing. It also enables real-time processing of multimedia data using the flow label function. Therefore, it is possible to receive a higher level of service than the service provided in the Internet.

However, it is difficult to replace an IPv4 network with an IPv6 network at a moment because the Internet network currently being used is very widely distributed around IPv4, and services for clients must be maintained at present.

Therefore, Nat-Piti is used as a method for interworking between IPv4 and IPv6 networks.

Nat-Piti uses the Stateless IP / ICMP Translation Algorithm (SIIT) as defined in RFC2765 (RFC2765) to convert the IPv4 packet and the IPv6 packet, and converts the converted packet to Based on the network address translation algorithm specified in RFC1631), the IPv4 network and the IPv6 network are interworked using a limited IPv4 address pool.

On the other hand, the existing Nat-PT is implemented through a software method in a software-based router using a general-purpose computer (PC), a workstation, a general-purpose CPU or an MPU. .

Therefore, there were the following problems.

First, it takes up a lot of volume by being implemented using software methods on general purpose hardware rather than dedicated hardware.

Secondly, due to the nature of general-purpose hardware, a large number of integrated circuits (ICs) are required, which contributes to the price increase.

Third, power consumption is increased due to many integrated circuits (ICs).

Fourth, even if there is no expansion or expansion, there are many technical difficulties and cost increases.

Fifth, the use of general purpose hardware that is not dedicated places a lot of constraints on speed.

Sixth, distinguish all packets that can be handled at layer 4 (FTP, DNS layer) and general packets that can be processed at layer 3 (IP layer) level by integrating and processing all incoming packets in the Nat-Piti module. This can lead to performance degradation.

The present invention has been proposed to solve the above problems, and implements a conventional software Nat-PT as a small integrated circuit (IC) using a System on Chip (System on Chip) technology. Internet Protocol Translator using Parallel Nat-PT, which allows new network users to solve the problems of low cost, small volume, high speed, scalability and power consumption by parallelizing Nat-Piti modules. And an internet protocol version conversion method using the same.

In addition, the present invention, a large number of general packets that can be processed at the layer 3 (IP layer) level by separating the Nat-Piti modules, and processed in parallel in a stateless IP / ICMP Translation Algorithm (SIIT) module, layer 4 ( In case of Domain Name System (DNS) packet or FTP packet, which must be processed in FTP, DNS layer), it is separated from IP MUX / DEMUX and is used for application level gateway (ALG). It is an object of the present invention to provide an Internet protocol conversion apparatus using parallel Nat-PT (NAT-PT) which can speed up packet processing by sending a packet, and an internet protocol version conversion method using the same.

1 is an exemplary configuration diagram of a general Nat-PT module.

2A and 2B are exemplary diagrams of configurations of general IPv4 and IPv6 headers.

3 is a diagram illustrating an embodiment of a method for converting IPv4 to IPv6 according to the present invention.

4 is a diagram illustrating an embodiment of a method for converting IPv6 to IPv4 according to the present invention.

5 is a configuration diagram of an internet protocol conversion apparatus using NAT-PT according to the present invention.

FIG. 6 is a diagram illustrating an embodiment of a layer of a general 100 Base-X. FIG.

* Explanation of symbols for the main parts of the drawings

501, 511 PHY Chip 502, 510 MAC

503, 508: IP Multiplexer / Demultiplexer (IP MUX / DEMUX)

504, 509 IP packet buffer 505 SIIT

506 DNS / FTP ALG507 mapping table module

The apparatus of the present invention for achieving the above object is, in the Internet protocol conversion apparatus using a parallel Nat-Piti, to check the error of the protocol and packet of the layer (Layer) wrapped with electrical signals input through the network Physical layer interfacing means for signal processing; Protocol conversion means for converting a protocol of Layer 2 into a protocol of Layer 3 among the signals output from the physical layer interfacing means; Multiplexing and demultiplexing for distributing the packet output from the protocol conversion means to the empty IP version converting means, storing the packet waiting to be stored in the IP packet storing means, and demultiplexing the packet converted by the IP version converting means. Way; The IP version converting means for converting packets output from the multiplexing and demultiplexing means into different IP versions and separating and converting packets of different layers; And a mapping table storage means for storing an IP address required by the IP version converting means and storing a mapping table between IP addresses of different versions.

On the other hand, the method of the present invention, in the Internet protocol version conversion method using the Internet protocol conversion apparatus, a domain name system (DNS) query asking the address of the system using the version 6 Internet protocol from the version 4 domain name system (DNS) Receiving a first step of sending a domain name system query to a version 6 domain name system; Receiving an address of a system using a version 6 internet protocol from a version 6 domain name system in response to the domain name system query; A third step of mapping an address of a system using the version 6 internet protocol to a version 4 internet protocol address; A fourth step of sending the mapped version 4 internet protocol address in response to the first step; And the system using the version 4 internet protocol receives a packet sent to the system using the version 6 internet protocol, examines an address mapping table, and converts the address mapping table into a version 6 internet protocol address instead of the mapped version 4 internet protocol address. And a fifth step of transmitting the packet to an Internet protocol address.

In addition, another method of the present invention, in the Internet protocol version conversion method using the Internet protocol conversion apparatus, receiving a domain name system query for knowing the address of the system using the version 4 Internet protocol in the version 6 domain name system Stage 1; Converting the domain name system query into a version 4 Internet protocol address and transmitting to a version 4 domain name system; A third step of receiving an address of a system using the version 4 internet protocol from a version 4 domain name system, converting the address to a version 6 internet protocol, and transmitting the address to the version 6 domain name system; And receiving a packet to be delivered to an address of a system using the received version 4 Internet protocol, inspecting a mapping table, and delivering the packet.

Meanwhile, the present invention receives a domain name system (DNS) query from the version 4 domain name system (DNS) for an address of a system using the version 6 internet protocol, and receives a version 6 domain name from the version 4 domain name system (DNS). A first function of sending the domain name system query to a system; A second function of receiving an address of a system using a version 6 internet protocol from a version 6 domain name system in response to the domain name system query; A third function of mapping an address of a system using the version 6 internet protocol to a version 4 internet protocol address; A fourth function of sending the mapped version 4 internet protocol address in response to the first step; And the system using the version 4 internet protocol receives a packet sent to the system using the version 6 internet protocol, examines an address mapping table, and converts the address mapping table into a version 6 internet protocol address instead of the mapped version 4 internet protocol address. A computer readable recording medium having recorded thereon a program for realizing a fifth function of transmitting a packet to an Internet protocol address is provided.

The present invention also provides an Internet protocol conversion apparatus having a processor, comprising: a first function of receiving a domain name system query for knowing an address of a system using a version 4 internet protocol in a version 6 domain name system; A second function of translating the domain name system query into a version 4 internet protocol address and transmitting it to a version 4 domain name system; A third function of receiving an address of a system using the version 4 internet protocol from a version 4 domain name system and converting the address of the system using the version 4 internet protocol to a version 6 internet protocol; And receiving a packet to be delivered to an address of a system using the received version 4 Internet protocol, inspecting a mapping table, and recording a computer readable recording medium having recorded a program for realizing a fourth function of delivering the packet. to provide.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary configuration diagram of a general Nat-PT module.

In the figure, "100" represents a NAT-PT module, "120" represents an IPv6 network, and "130" represents an IPv4 network, respectively.

In addition, the NAT-PT module 100 includes an application level gateway (ALG) 101, an application level gateway (ALG) 102, and a transmission control protocol. TCP / UDP (103), Network Address Translation (NAT) (104), Protocol Translation (PT) (105), IPv6 / IPv4 mapping table (106), Address Pool (IPr4) (107), Packet Capture Filter (108), IPv6 (109), NIC (Network Interface Card) 110, IPv4 (111), and Nick (NIC: Network Interface Card) 112.

The NAT-PT converts an IPv4 packet and an IPv6 packet by the SIIT (Stateless IP / ICMP Translation) 105 specified in RFC 2765 (RFC2765: Request for Comments 2765). Interworking the IPv4 network 130 and the IPv6 network 120 using the limited IPv4 address pool 107 based on the Network Address Translation algorithm specified in RFC1631. It plays a role.

On the other hand, the PT 105 includes SIIT.

2A and 2B are exemplary diagrams of configurations of general IPv4 and IPv6 headers.

FIG. 2A shows an IPv4 header, and FIG. 2B shows an IPv6 header.

2A and 2B, a stateless IP (Internet Protocol) / ICMP (Internet Control Message Protocol Translation) algorithm is described as follows.

First, the method for converting from an IPv4 header to an IPv6 header sets the 4-bit version 220 to "6".

The 8-bit service type value 203 of the IPv4 header is then obtained to the 8-bit traffic class 221. At this time, the 8-bit traffic class 221 can be set to "0" unconditionally.

Next, the flow control 222 is all set to the "0" bit.

The payload length 223 sets the 16 bit full length 204 value of the IPv4 header. Here, the 16 bit full length 204 is the sum of the size of the header and the length of the option 213.

Next header 224 retrieves the 8-bit protocol 209 value of the IPv4 header.

The hop limit 225 takes the 8 bit Time to Live 208 value of the IPv4 header.

The lower 32 bits of the source address 226 take the 32 bit source IP address 211 of the IPv4 header as it is, and fill the 96 bits with "0 :: ffff".

The lower 32 bits of the destination address 227 take the 32 bits destination IP address 212 of the IPv4 header as it is, and fill the 96 bits with "0 :: ffff: 0".

In contrast, the conversion from the IPv6 header to the IPv4 header is as follows.

The 4-bit version 201 is set to four.

The 4-bit header length 202 is set to five.

The 8 bit service type 203 gets the 8 bit traffic class 221 value of the IPv6 header. At this time, the 8-bit service type 203 can be set to "0" unconditionally.

The 16 bit full length 204 is equal to the sum of the payload length 223 value of the IPv6 header and the IPv4 header size.

The 16 bit identifier 205 is in mode "0".

The 3-bit flag 206 is set to "0" if the fragment is greater than or equal to "1" if the fragment cannot be fragmented.

The 13-bit fragment options 207 are all set to "0".

The 8-bit time-to-leave 208 gets the hop limit 225 value of the IPv6 header.

The 8 bit protocol 209 gets the next header 224 value of the IPv6 header.

The 32 bit source IP address 211 gets the lower 32 bits of the source address 226 of the IPv6 header.

The 32 bit destination IP address 212 gets the lower 32 bits of the destination address 227 of the IPv6 header.

By the above method, the IPv4 header may be converted into an IPv6 header or an IPv6 header may be converted into an IPv4 header.

3 is a diagram illustrating an embodiment of a method for converting IPv4 to IPv6 according to the present invention.

First, some assumptions will be made to explain one embodiment of a method for converting IPv4 to IPv6 according to the present invention.

First, the URL of the operator using the IPv4 (URL) is "v4.etri.re.kr", the IP (IP) is called "129.254.165.141", and the operator's URL using the IPv6 "v6. huneed.com ", IP is called" fec0 :: 2a0: c9ff: fec8: 1 ".

In addition, the IP of the version 4 domain name system 302 is "129.254.15.15", the domain is "etri.re.kr", and the name server is "132.146.134.184".

The IP of version 6 domain name system 304 is "fec0: f1 :: 2a0: c9ff: fec8: eaab", the domain is "huneed.com", and the name server is "aaaa :: ffff :: 129.254. .15.15 ".

First, a domain name system (DNS) query is sent from the "v4.etri.re.kr" (301) to the version 4 domain name system (DNS) 302 to send the packet to "v6.huneed.com" (305). Send and ask for the address of "v6.huneed.com" (305).

Next, version 4 domain name system (DNS) 302 sends a domain name system (DNS) query for "v6.huneed.com" 305 back to Nat-PT (303).

At this time, the source address (SA) of the packet is "129.254.15.15" which is the address of the version 4 domain name system (DNS) 302, and the destination address (DA) is the NAT-PT (303). IPv4 address "132.146.134.184".

Next, NAT-PT 303 again throws a query for "v6.huneed.com" 305 to version 6 domain name system (DNS) 304. At this time, the source address (SA) of the query packet is "aaaa: ffff: 129.254.15.15", which is the IPv6 address of the NAT-PT (303), and the destination address (DA) is a version 6 domain name system ( DNS address 304 is " fec0: f1 :: 2a0: c9ff: fec8: eaab ".

Next, version 6 domain name system (DNS) 304 responds to the query packet thrown by NAT-PT, in response to the "feo0: f1 ::" address of "v6.huneed.com" (305). 2a0: o9ff: fec9: 1 "to Nat-PT 303.

Next, the received NAT-PT 303 performs address mapping.

The address mapping operation selects and maps 132.146.134.180, an address not being used in the IPv4 address pool 306, instead of “fec0: f1 :: 2a0: c9ff: fec8: 1”. .

Next, the NAT-PT 303 responds to a Domain Name System (DNS) query of the Version 4 Domain Name System (DNS) 302 using the mapped address "132.146.134.180".

Next, "v4.etri.re.kr" 301 regards the address of "v6.huneed.com" 305 as "132.146.134.180", and the source address is its own address "129.254.165.141". The packet is sent to "v6.huneed.com" 305 with "132.146.134.180" in the destination address.

Next, the NAT-PT 303 receives this packet, examines the address mapping table, and then replaces "fec0: f1 :: 2a0: c9ff: fec9:" with the packet's destination address instead of "132.146.134.180". Enter 1 "and convert it to an IPv6 address by prefixing the source address" 129.254.165.141 "with" aaaa :: ffff ".

Next, an IPv6 converted packet is sent to "v6.huneed.com" 305.

4 is a diagram illustrating an embodiment of a method for converting IPv6 to IPv4 according to the present invention.

First, some assumptions will be made to explain one embodiment of a method for converting IPv6 to IPv4 according to the present invention.

First, the URL of the operator using the IPv4 (URL) "v4.etri.re.kr", the IP (IP) is called "129.254.165.142", and the operator's URL using the IPv6 "v6. huneed.com ", IP is called" fec0 :: 2a0: c9ff: fec8: 2 ".

In addition, the IP of the version 4 domain name system 302 is "129.254.15.15", the domain is "etri.re.kr", and the name server is "132.146.134.184".

The IP of version 6 domain name system 304 is "fec0: f1 :: 2a0: c9ff: fec8: eaab", the domain is "huneed.com", and the name server is "aaaa :: ffff :: 129.254. .15.15 ".

First, "v6.huneed.com" (405) tells the version 4 domain name system (DNS) 402 the domain name system (DNS) to determine the IP address of "v4.etri.re.kr" (401). Send a query.

Next, version 6 domain name system (DNS) 404 again sends a domain name system (DNS) query to version 4 domain name system (DNS) 402. At this time, the source address (SA) of the query packet becomes "fec0: f1 :: 2a0: c9ff: fec8: eaab", which is the address of the version 6 domain name system (DNS) 404, and the destination address (DA) is version 4 The address "aaaa :: ffff: 129.254.15.15" converted from the domain name system (DNS) 402 address "129.254.15.15" into IPv6 format.

Next, the NAT-PT 403 receives the packet "aaaa :: ffff: 129.254.15.15" and removes "prefix (aaaa: ffff)" of the destination address DA, thereby deciding a destination address. (DA) to "129.254.15.15" and the version 6 domain name system (DNS) 404 source address (SA) to find the mapping table and change to "132.146.134.184".

Next, the converted packet is sent to the version 4 domain name system (DNS) 402. The version 4 domain name system (DNS) 402 then responds to the version 6 domain name system (DNS) 404 with the address of " v4.etri.re.kr "

Next, the NAT-PT 403 receives the response packet, adds a prefix, finds a mapping table, and converts the destination address “132.146.134.184” into a version 6 domain name system (DNS) ( 404) to the version 6 domain name system (DNS) 404. " fec0: f1 :: 2a0: c9ff: fec8: eaab "

In addition, a prefix is added to the address of the resource data "v4.etri.re.kr" (401) to make "aaaa: ffff: 129.254.165.142".

Next, "v6.huneed.com" 405 knows the address of "v4.etri.re.kr" 401 from the version 6 domain name system (DNS) 404, and thus the destination address (DA). Send the packet by entering "aaaa: ffff: 129.254.165.142" in the source address (SA), "fec0: f1 :: 2a0: o9ff: fec8: 2".

Next, the NAT-PT 403 receives the packet, searches the mapping table, finds the IPv4 address of "v6.huneed.com" 405, and selects the source address (SA). 132.146.134.180 ", remove the prefix" aaaa: ffff "from the destination address (DA), and send the packet to" v4.etri.re.kr "(401).

5 is a configuration diagram of an internet protocol conversion apparatus using NAT-PT according to the present invention.

As shown in FIG. 5, the Internet protocol conversion apparatus according to the present invention includes a PHY chip 501 and 511 for inspecting and processing an error of a packet wrapped with a layer 1 protocol and an electrical signal. MAC (502, 510) for sending a layer 2 protocol to a layer 3 protocol (IPv4 and IPv6) from the signal output from the PHY Chip (PHY Chip: 501, 511). In order to distribute packets output from the MACs 502 and 510 to the empty Nat-Piti modules 505 and 506, and to store packets waiting to be processed in the IP packet buffers 504 and 509, Header and address conversion between IPv4 packet and IPv6 packet in the packet output from the Firearm / Demultiplexer (IP MUX / DEMUX) (503, 508) and the IP Multiplexer / Demultiplexer (IP MUX / DEMUX) (503, 507). The SIIT (505), the IP multiplexer / demultiplexer (IP MUX / DEMUX) (503, 50 Receives only DS / FTP packet from the packet output from 7), sends DS query packet to DS server, finds IP address, updates the mapping table, and opens the RF packet to send the RF command. DNS / FTP ALG 506 for translating host addresses between IPv4 / IPv6, and a pool of IPv4 addresses required by the NAT-PT module 505, 506, and NAT- PT) module 505, 506 includes a mapping table module 507 for storing a mapping table between IPv4 and IPv6 addresses.

The components of the Internet protocol conversion apparatus according to the present invention will be described in more detail as follows.

First, PHY chips 501 and 511 are chips that are responsible for Layer 1, and may be configured to generate packets (for example, Ethernet, Sonnet, Asynchronous Transfer Mode (ATM), etc.). Responsible for electrical signal processing of packets).

The MACs 502 and 510 are chips that are responsible for Layer 2, encapsulating / decapsulating a complete IPv4 / IPv6 packet for Layer 1.

IP MUX / DEMUX (503, 508) is an empty Nat-PT (NAT-PT) module 505, the IP (IP) packets generated in the MAC (502, 510) 506, and the packet waiting to be processed is stored in the IP Packet Buffer 504,509.

The IP Packet Buffers 504 and 509 are storage devices for storing packets that are waiting to be processed by the IP MUX / DEMUX 503 and 508.

The nat-feet modules 505 and 506 are composed of an SIIT 505 and a DNS / FTP ALG 506.

The SIIT 505 converts an IPv4 packet into an IPv6 packet and an IPv6 packet into an IPv4 packet by referring to the mapping table module 507 by the SIIT algorithm.

The DNS / FTP ALG 506 receives only the DNS / FTP packet from the IP multiplexer / demultiplexer 503 and 508, sends a DNS query packet to the DNS server to find the IP address, updates the mapping table module 507, and FTP. Open the packet to convert the host address in the FTP command between IPv4 / IPv6.

The mapping table module 506 is a module for storing and updating the IPv4 and IPv6 address mapping table and the IPv4 address pool generated in each NAT-PT module 505. .

That is, according to the present invention, a large amount of general packets that can separate the Nat-Piti modules 505 and 506 to be processed at the layer 3 (IP layer) level are parallel in the stateless IP / ICMP Translation Algorithm (SIIT) module 505. IP MUX / DEMUX (503, 508) for domain name system (DNS) packets or FTP packets that must be processed at layer 4 (FTP, DNS layer). This can be speeded up by processing the packet by sending it to the Application Level Gateway (ALG).

On the other hand, Ethernet 100Mbps-Tx (TX) (IEEE 802.3) widely used as the physical layer 1, 2 (Layer 1, 2) in order to use the Internet protocol conversion apparatus using a parallel Nat-Piti according to the present invention An example of implementing the present invention using the standard will be described.

First, the structure of the Ethernet frame or MAC frame is shown in Table 1 below.

Preamble Sfd Destination address Source address Length Information pad FCS

Here, the preamble (Preamble: 7 or 8 bytes) is defined as a 7-byte bit string in which 1 and 0 are repeated in IEEE802.3, and 7 bytes in which 1 and 0 are repeated in Dix 2.0 Ethernet. The entire bit string defined as " 10101011 " after the bit string is called preamble. The preamble is a bit string in which 1 and 0 are repeated so that the bit can be synchronized by extracting the reception clock from the received bit string of the receiver in the Physical Coding Sublayer (PCS) layer of the receiving data terminal equipment (DTE). It consists of. That is, the biggest purpose of the preamble is to match the bit synchronization to match the transmission / reception speeds between the transmitting side and the receiving side.

Starting Frame Delimiter (SFD: 1 byte: 10101011) is a receiver that plays a reception clock using a preamble, and then the bytes are combined in units of 8 bits after the SFD bit string. It is to announce that there is. In other words, the meaning of SFD is a bit string for frame synchronization indicating that byte synchronization for identifying a byte unit in the bit string and that the byte string after this area is the start of a valid frame.

There are two main types of destination addresses (DA: 6 bytes).

First, the individual address (Indivisual address) is the address of the least significant bit (LSB) value of 0, the address of each destination ethernet card. In the configuration of the destination address, which is a total of 6 bytes, the first 3 bytes are designated by a code that identifies a card manufacturer called a block ID or an organizationally unique identifier (OUI). The remaining three bytes (24 bits) identify the individual destinations.

The multicast address is the least significant bit (LSB) value of 1. An example of using this is the Internet Multicast protocol specified in RFC-1112. And an address with all bits of 1 is a broadcast address for broadcasting to all communication stations. This broadcast address is used by ARP (Address Resolution Protocol) and RRP (Reverse ARP).

The source address (SA: 6 bytes) is the sending MAC address. In general, a LAN card records its Ethernet address in a ROM. When the MAC controller initializes itself, it reads an address from this ROM and stores it in an internal register. When the frame is transmitted, the MAC controller reads the contents of the register and transmits the frame. Automatic insertion into source address (SA) field.

The length identifier (called the length identifier or the EtherType area) is a 2-byte area after the source address (SA), and is used as an area indicating the length of the information area of the MAC frame in the IEEE 802.3 standard. However, in the Dix 2.0 standard, this area is used as the Ethertype field, which indicates the type of higher-layer protocol contained in the data portion of the MAC frame. In order to coexist with these two meanings, the value of EtherType has a value of "0x0600" or more. For reference, the Ethertype code of IP is "0x0800".

Information is data and the maximum length is 1500 bytes.

The pad is an area filled with " 0 " when the data length is too short to satisfy the MAC frame minimum length rule (64 bytes). The length of this area is calculated as "max (0, minFrameSize)-(DA + SA + LengthField + data + FCS))".

For example, when one byte of data is transmitted, the length of the padding is "max (0, 64)-(6 + 6 + 2 + 1 + 4) = 64-19 = 45 bytes".

FCS (4 bytes) is used to check for errors in the bit strings of valid MAC frames, except for the Preamble and SFD parts.

In calculation of FCS, "X ^ 32 + X ^ 26 + X ^ 23 + X ^ 16 + X ^ 12 + X ^ 11 + X ^ 10 + X ^ 8 + X ^ 7 + X ^ 5 + X ^ 4 + X ^ 2 + X ^ 1 + 1 "polynomials are used.

The MAC controller transmits the frame bit stream and simultaneously calculates the transmission FCS. When the information area transmission is completed, the MAC controller immediately adds the FCS that has been calculated. Upon reception, the MAC controller accepts the received bit string and simultaneously calculates the FCS to check whether the transmitted / received FCS matches, and invalidates the reception of this frame.

Meanwhile, the hierarchical structure of 100 Base-X will be described in more detail with reference to FIG. 6.

FIG. 6 is a diagram for explaining an embodiment of a general layer of 100 Base-X.

As shown in FIG. 6, the layer of 100 Base-X includes MAC (601), Reconciliation (602), MII (603), PCS (PCS). (604), PMA (605), Fiber PMD (606), Fiber MDI (607), TP PMD (608), TPM TP MDI) 609, and Media 610.

The role of the PHY chip in 100Base-TX Ethernet is to process a signal input through the MII 603 to convert it to the media 610 or to convert a signal input through the media 610. MII (603) serves to change the transmission to match.

On the other hand, MII (Media Independent Interface) 603 is a connection portion for connecting the MAC (601) and the physical device (Physical device (eg PLS / PCS, PMA, etc.)). In the MII 603, a transmit / receive stream is transmitted in nibble units, and is transmitted from the PLS layer to the Reconciliation 602 layer through the MII 603. FIG. The 25 MHz transmit / receive clocks (TXCLK and RXCLK) are used to adjust the transmission speed of nibbles. In addition to the signal transmitted to the MI (MII) 603, the collision detection signal reported to the MAC (601) (this is called "COL") and the carrier detection signal (CRS) and when the transmission / reception error report There is a traffic light.

The reconciliation layer 602 combines the frames requested by the MAC layer 601 in a 4-bit nibble form (TXD <3: 0>), which is a TTL level. Via (MII) 603 to the PCS layer 604. The opposite is true when receiving. The transmission and reception of such a nibble uses a 25 MHz clock for transmission and reception provided by the PCS layer 604. Since the 802.3 MAC frame is transmitted first from the least significant bit (LSB) of each bit, the nibble delivered to the MI (MII) 603 is first transmitted from the least significant bit (LSB), and then 4 bits are transmitted first. The remaining four bits are passed.

Meanwhile, the PCS (Physical Coding Sublayer) 604 will be described in more detail as follows.

The function of the PCS layer 604 encodes a 4-bit nibble transmitted from the MII 603 into a 5-bit code group, or performs the reverse function. In addition, a carrier sense and a collision detection signal are delivered.

Also, code-groups are listed for delivery to PMA.

In addition, a transmit, receive, carrier sense, and collision detection signal is mapped between the MII 603 and the PMA.

Looking at the function of the PC (PCS) in more detail as follows.

First, the transmitter continues to transmit "/ I / code group" during an idle period in which there is no bit string to transmit.

When the bit string TXD <3: 0> of the 4-bit unit is received from the MI (MII) 603, it is converted into a 5-bit code group bit by the "4B5B" coding scheme specified by 100Base-X, and transmitted. Thus, the "tx_code_bit" delivered from the PCS layer 604 to the PMA is 125 Mbps.

At this time, the MAC frame requested to be transmitted from the MAC 601 converts the first byte of the preamble of the frame into a SSD (Start of Stream Delimiter) composed of a JK code group and transmits the same. . All subsequent frame bit strings are regarded as data code groups and transmitted.

When transmission is completed up to FCS, End of Stream Delimiter (ESD) consisting of a T-R code group is continuously transmitted, and transmission is completed.

When the transmission is completed, the IDLE code group is transmitted. Upon reception of the IDLE code group and receiving the SDD code group, the SDD is restored to "10101010" which is the first byte part of the CSMA / CD preamble. Next, restore the subsequent data code group.

If a collision is detected during transmission, the MAC layer 601 is notified with a COL signal.

In addition, if a command of "TX_ER = TRUE" is transmitted to the Reconciliation layer 602 during transmission, the HALT code group continues to be transmitted, and if "TX_EN" becomes FALSE, then the ID ( ESD) and terminate the transmission process.

The receiver performs channel activity detection, code group adjustment, 4B / 5B decoding, and the like.

When the other party's receiver of 100Base-X is in an idle state, it transmits an idle code group "11111", and the receiver receives two non-contiguous "0" s among the received 10 code bits (code_bit). If this is the case, it is determined that there is channel activity.

The result of the channel activity is reported to the MAC layer 601 as a CRS signal and transmitted to the collision detection function of the PCS transmitter.

Once there is a channel activity, the receiver combines the received code bits into a code group and adjusts the code group to enable 4B / 5B coding. If the part of the two code groups that constitutes the SD that marks the start of a frame is correctly found in the "rx_shift" register, the parts of the SD which are "/ J /" and " / K / "codes are respectively transferred to the 4B5B decoder and restored back to the 8-bit preamble used in Ethernet, and transmitted to the MAC layer 601 by 4 bits.

The "RX_DV" signal reported to the MII 603 becomes TRUE after detecting the SSD in the "rx_shift" register.

However, if the received code group is not a prescribed code group, it reports "RX_ER = ON".

Subsequently, when the ESD indicating the end of the frame is received, the ESD is decoded into an IDLE code “11111 11111”. This is because the original ESD is added after the FCS, which is the end of the original MAC PDU on the transmitting side, and thus, the ID is recovered. If a "link_status = FAIL" signal is reported from the PMA during transmission and reception, a problem such as a failure of the receiver of the PMA layer or a disconnection of the cable has occurred. Therefore, the transmission / reception is stopped immediately. do.

The carrier detector is for providing a CRS signal to the MAC layer 601. In order to emulate this, "(logical OR) CRS = ON" when the transmitter is currently operating or the carrier state reported by the channel activity unit of the receiver is on.

The collision detection unit is for reporting the COL signal to the MAC layer 601. For this purpose, " (logical AND) COL = ON " when both the transmitter and receiver operate.

Meanwhile, the functions of the physical medium attachment layer (PMA) layer 605 are as follows.

The PMA component for 100Base-X consists of a transmit / receive unit, a link monitor function, and a wave and fault unit consisting of a non-return to zero inverter (NRZI) encoder / decoder (NRZI) encoder / decoder. far end fault) A detector / generator.

Transmitter is an NRZI encoder and transfers the "tx_code_bit" string of 125 Mbps NRLJET (NRZ: Non-Return to Zero) code requested from PCS. Convert to The receiver decodes a 125 Mbps NRZI bit string received from PMD to NRZ and transmits the decoded NRZI bit to a PCS and a "pma_carrier" detector. The " pma_carrier " detect function performed at the PMA layer 605 collects 10 NRZI bit strings received from the PMD and, if received, receives 10 RNZI bits. If there are two or more non-contiguous " 0s " among the NRZI bits, a signal " pma_carrier_sense = ON " However, this signal is not passed to the PCS (PCS) layer 604 and it is not specified how to use this signal.

The link monitor function determines whether the reception channel is intact (for example, disconnection of the link, etc.) and reports "link_status = (FAIL, OK, READY)" to the PCS layer 604. do.

The receiving unit of the PMD receives a signal "signal_status = OFF" when the idle (actually 1111) signal is not received from the counterpart, and the link monitor and the far end fault generator. Are all passed).

The link monitor unit immediately considers that the reception channel connected to the counterpart communication station is disconnected for this signal and reports to the PCS layer as "link_status = FAIL". Here, "Link_status = OK" is a signal reported when "signal_status = ON" that there is no abnormality in the receiving unit.

"Link_status = READY" is valid only when the auto-negotiation function is used, which means that the data bit cannot be received because it is currently in the auto-negotiation process.

If there is no auto-negotiation function, only link_status value is reported as OK or FAIL.

Far end fault signaling and detection can be used in the absence of auto-negotiation.

A far end fault generator transmits a far end fault indication signal to a counterpart communication station with respect to the " Signal_status = OFF " signal reported by the PMD. The far end fault detector receives such a far end fault indication signal consisting of a combination of three or more bits consisting of 84 consecutive 1s and one 0. Inform the link monitor of this fact. In response to this, the link monitor unit reports a "link_status = FAIL" signal to the PCS layer so that the user knows this.

Physical Medium Dependent (PMD) converts NRZI bits received from PMA into a signal according to a specific medium.

So far, the functions of the PHY stage have been examined.

Next, it receives the MII signal from the PHY stage and sends the IP packet stored and stored in the buffer to the IP multiplexer / demultiplexer (IP MUX / DEMUX). IP packet from firearm / demultiplexer (IP MUX / DEMUX) is encapsulated for Ethernet frame and converted into MII signal to MAC layer that plays a role of sending to PHY stage. Let's look at it.

The MAC layer consists of a buffer memory interface and a buffer descriptors (BD) structure, a Tx Ethernet MAC (transmit function), and a Rx Ethernet MAC ( receive function), and the MAC Control Module.

First, the Buffer Memory Interface and Buffer Descriptor (BD) structure (BD) are pointers to data when data packets are written to external memory.

The Tx Ethernet MAC receives a byte stream from an external memory and turns it into an MII nibble data stream. In addition, a backoff algorithm considering IPG (Inter Packet Gap) is performed. In addition, the error check (FCS) is calculated, and the physical media is monitored using a carrier sense and a collision signal.

The Rx Ethernet MAC receives a nibble stream from MI and converts it into a byte stream and transfers it to external memory. Then, the SFD (Start frame delimiter) is found at the start of the packet, and the FCS is checked to find an error.

The MAC Control Module detects the control frame and either discards it or passes it to memory. When the PAUSE control frame is detected, transmission of the transmission MAC TxMAC is stopped from a specific time point. In addition, the MAC Control Module is connected between the memory interface and the Tx MAC module.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

As described above, the present invention solves the problems of volume, speed, scalability and power consumption of the existing software Nat-PT using System on Chip technology. It is possible to solve the speed and scalability problem simultaneously by parallelizing Nat-PT modules using multiplexer / demultiplexer.

Claims (17)

In the internet protocol conversion apparatus using a parallel nat-pitty, Physical layer interfacing means for inspecting an error of a protocol and a packet of Layer 1 wrapped with an electrical signal input through a network and performing electrical signal processing; Protocol conversion means for converting a protocol of Layer 2 into a protocol of Layer 3 among the signals output from the physical layer interfacing means; Multiplexing and demultiplexing for distributing the packet output from the protocol conversion means to the empty IP version converting means, storing the packet waiting to be stored in the IP packet storing means, and demultiplexing the packet converted by the IP version converting means. Way; The IP version converting means for converting packets output from the multiplexing and demultiplexing means into different IP versions and separating and converting packets of different layers; And Mapping table storage means for storing an IP address required by the IP version converting means and storing a mapping table between IP versions of different versions Internet protocol converter comprising a. The method of claim 1, The physical layer interfacing means, An Internet protocol converter, which is responsible for packet data layer 1 such as Ethernet, Sonnet, and Asynchronous Transfer Mode (ATM). The method of claim 1, The protocol conversion means, An internet protocol converter, which encapsulates or decapsulates a complete IP version 4 (IPv4) or IP version 6 (IPv6) packet according to the layer 1. The method of claim 1, The IP version converting means, Practically, algorithms described in RFC 2766 (RFC2765: Request for Comments 2766) convert IP version 4 packets to IP version 6 packets, or IP version 6 packets to IP version 4 packets, at the layer 3 level. A large amount of general packets that can be processed are processed in parallel by the SIIT module, and Domain Name System (DNS) packets or FTP packets that are processed by Layer 4 are DNS / FTTP ALS. Internet protocol converter characterized in that the processing in parallel (DNS / FTP ALG). The method of claim 1, The mapping table storage means, And an IP version 4 and an IP version 6 address mapping table and an IP version 4 address pool generated by the IP version converting means. In the Internet protocol version conversion method using the Internet protocol converter, Receiving a Domain Name System (DNS) query from the Version 4 Domain Name System (DNS) for the address of a system using the Version 6 Internet Protocol and sending the Domain Name System query to the Version 6 domain name system; Receiving an address of a system using a version 6 internet protocol from a version 6 domain name system in response to the domain name system query; A third step of mapping an address of a system using the version 6 internet protocol to a version 4 internet protocol address; A fourth step of sending the mapped version 4 internet protocol address in response to the first step; And The system using the version 4 internet protocol receives the packet sent to the system using the version 6 internet protocol, examines the address mapping table, converts it to the version 6 internet protocol address instead of the mapped version 4 internet protocol address, and converts the converted version 6 The fifth step of sending a packet to an internet protocol address Internet protocol version conversion method comprising a. The method of claim 6, The first step is, And a source address is an address of a version 4 domain name system, and a destination address is a version 4 internet protocol address of NAT-PT. The method of claim 6, The second step, Nat-Piti sends a query to a version 6 domain name system using a version 6 Internet protocol, where the source address for the query becomes the version 6 Internet protocol address of Nat-Piti, and the destination address is a version 6 domain. Internet protocol version conversion method, characterized in that the address of the name system. The method of claim 6, The third step, An internet protocol version conversion method, wherein an address not used in a version 4 Internet protocol address pool is selected and mapped instead of an address of a system using a version 6 internet protocol. The method of claim 6, The method using the version 4 internet protocol of the fifth step sends a packet to the system using the version 6 internet protocol. A system using a version 4 internet protocol considers the address of a system using a version 6 internet protocol as the mapped address and uses the version 6 internet protocol by putting its address in a source address and the mapped address in a destination address. Internet protocol version conversion method comprising sending a packet to the system. The method of claim 6, The method of converting to the version 6 internet protocol address of the fifth step, In Nat-Piti, converting a destination address to a version 6 Internet Protocol address by inserting the address of the system using the existing version 6 Internet protocol instead of the mapped address and prefixing the source address with the prefix of Nat-Piti. Internet protocol version conversion method characterized by. In the Internet protocol version conversion method using the Internet protocol converter, A first step of receiving a domain name system query for knowing an address of a system using a version 4 Internet protocol in a version 6 domain name system; Converting the domain name system query into a version 4 Internet protocol address and transmitting to a version 4 domain name system; A third step of receiving an address of a system using the version 4 internet protocol from a version 4 domain name system, converting the address to a version 6 internet protocol, and transmitting the address to the version 6 domain name system; And A fourth step of receiving a packet to be delivered to an address of a system using the received version 4 Internet protocol, inspecting a mapping table, and delivering the packet Internet protocol version conversion method comprising a. The method of claim 12, The first step is, Wherein the source address is an address of a version 6 domain name system and the destination address is an address of a version 4 domain name system. The method of claim 12, The second step, Removing a prefix of the destination address and converting the destination address into a destination address conforming to a version 4 internet protocol, and converting a source address in the mapping table using the source address. The method of claim 12, The conversion to the version 6 Internet protocol of the third step, And a prefix is added to the received address, and a version 6 internet protocol address is found and converted in a mapping table. In the Internet protocol converter equipped with a processor, A first function receiving a Domain Name System (DNS) query from a Version 4 Domain Name System (DNS) for the address of a system using a Version 6 Internet Protocol and sending the Domain Name System query to a Version 6 domain name system; A second function of receiving an address of a system using a version 6 internet protocol from a version 6 domain name system in response to the domain name system query; A third function of mapping an address of a system using the version 6 internet protocol to a version 4 internet protocol address; A fourth function of sending the mapped version 4 internet protocol address in response to the first step; And The system using the version 4 internet protocol receives the packet sent to the system using the version 6 internet protocol, examines the address mapping table, converts it to the version 6 internet protocol address instead of the mapped version 4 internet protocol address, and converts the converted version 6 Fifth function for sending packets to Internet protocol addresses A computer-readable recording medium having recorded thereon a program for realizing this. In the Internet protocol converter equipped with a processor, A first function of receiving a domain name system query for knowing an address of a system using a version 4 Internet protocol in a version 6 domain name system; A second function of translating the domain name system query into a version 4 internet protocol address and transmitting it to a version 4 domain name system; A third function of receiving an address of a system using the version 4 internet protocol from a version 4 domain name system and converting the address of the system using the version 4 internet protocol to a version 6 internet protocol; And A fourth function of receiving a packet to be delivered to an address of a system using the received version 4 Internet protocol, inspecting a mapping table, and delivering the packet A computer-readable recording medium having recorded thereon a program for realizing this.