KR20010067773A - Apparatus and method for interworking the internet and asynchronous transfer mode network - Google Patents

Abstract

PURPOSE: An interlock for interlocking an ATM with an Internet protocol and an operating method thereof are provided to interlock ATM with an Internet protocol by easily detecting an ATM address corresponding to IP address and an IP address corresponding to an ATM address. CONSTITUTION: The interlock device(1) is placed between an Ethernet network(2) and an ATM network(3). The Ethernet network(2) has Ethernet hosts(21,22,23) all connected in Ethernet method. The Ethernet network has an IP DNS server(24) which has a table of IP names and their correspondent IP addresses of the Ethernet hosts(21,22,23,24) and ATM hosts(31,32). In the ATM network(3) a number of ATM hosts are connected through an ATM switch(33). An ATM DNS server(34) has a table of IP names, IP addresses and ATM addresses of the Ethernet hosts(21,22,23,24) and ATM hosts(31,32). The interlock device(1) has an Ethernet network interface card(NIC,11) and an ATM network interface card(12). The Ethernet NIC(11) and ATM NIC(12) are connected to an interlocking function block(IWF,13). The IWF(13) monitors the data between the Ethernet NIC(11) and ATM NIC(12), thereby performing bridging between the Ethernet network(2) and ATM network(3). For this, the IWF(13) has the functions of differentiating the types with respect to each Internet application for setting the connection by using a proxy signaling, an address solving process for identifying ATM address in response to the object IP, and a function of binding the IP address with AESA E.164 ATM address. The interlock device(1) can have an additional cache memory(14,15).

Description

Interworking device for interworking with internet protocol and asynchronous transmission mode and its driving method {APPARATUS AND METHOD FOR INTERWORKING THE INTERNET AND ASYNCHRONOUS TRANSFER MODE NETWORK}

The present invention relates to an apparatus for arbitrating Internet communication between an Ethernet network and an Asynchronous Transfer Mode (ATM) network, and more particularly, to an IP DNS server in an Ethernet network and an ATM Domain Name Service (DNS) server in an ATM network. The present invention relates to an interworking device for interworking with an Internet protocol and an asynchronous transmission mode for easily detecting an address of another network that a host in an Ethernet network and an ATM network wants to communicate using address information therebetween, and a driving method thereof.

The increase of Internet users, the diversification of services, and the introduction of high-speed Internet access technology have led to a rapid increase in Internet traffic. With the increase of Internet traffic, there is a need to build a new Internet backbone network that extends the current Internet to accommodate the needs of new services. The most important challenges in building next-generation Internet backbone networks can be concentrated in terms of bandwidth expansion, network scalability, and the ability to provide a variety of services.

Two methods are currently being tried to build the next generation Internet backbone network. One is to use a gigabit router with high speed packet processing capability, and the other is to deliver packets at high speed using link layer switching technology.

Currently, ATM is being promoted as an exchange transmission technology for a B-ISDN (Broadband Integrated Services Digital Network) centered on public network operators, and ATM may be a representative alternative to the Internet backbone network. Indeed, technical discussions have been conducted around the Internet Engineering Task Force (IETF) and the ATM Forum to deliver Internet Protocol (IP) packets to ATM switches.

On the other hand, the use of the Internet is exploding due to the openness of protocols and naming services, but the ATM is too long and difficult to memorize, but it does not provide the naming service provided by the Internet. There is a problem that is uncomfortable. As a solution to the naming problem in ATM networks, a method of using an ATM DNS (Domain Name Service) that can easily and simply identify and access a destination has been devised. The functional structure of ATM DNS includes two components, an ATM DNS user (ie, an ATM host) and an ATM DNS server.

The ATM DNS server maps the name and address of an ATM end system (ATM host), and connects with an adjacent ATM DNS server to exchange updated name and address information. The ATM DNS user obtains an ATM address corresponding to the name of the ATM host configured in the ATM network through the ATM DNS server and connects to the corresponding ATM host. ATM DNS users use the ATM Application Programming Interface (API) to establish these connections.

On the other hand, research is being conducted on IP over ATM which provides connectionless Internet service using ATM network, which is connected service. It can be classified according to whether there is. In the Internet centered on routers, routing is performed to determine the route to the destination host for packet delivery in Layer 3 using the IP routing protocol, whereas in the ATM network, the layer for cell delivery in Layer 2 is provided by the ATM routing protocol. Routing to the destination is taking place. From the perspective of routing, IP and ATM interworking approaches can be divided into layered routing and integrated routing.

Layer routing is typically associated with an overlay model, where the IP routers act as peers between IP routers and the ATM switches act as peers between switches. In this way, IP routers and ATM switches are not recognized as peers. In the overlay model by layer routing, routing is performed independently in IP and ATM. That is, in the third layer, the route to the destination host is set by IP routing by IP address, and in the second layer, the route for cell delivery is independently determined by the routing of ATM. The most typical method is to use IP routing protocols such as Open Shortest Path First (OSPF) or Routing Information Protocol (RIP) at the upper layer, that is, Layer 2, and ATM routing protocols such as Private Network to Network Interface (PNNI). It is to use. Therefore, in an overlay model with a hierarchical model, an ATM endpoint (ATM host) must have an ATM address and an IP address, and all IP packets are transmitted through the ATM network using the ATM routing function. Therefore, there must exist ATM Address Resolution Protocol (ATM ARP) which translates IP destination address in IP packet into corresponding ATM address.

Unified routing is usually related to the peer model, which refers to the model in which IP routers and ATM switches act as peers. In integrated routing, the ATM and IP layers use a single routing protocol. The main advantage of this method is that it avoids the complexity and inefficiency of the interaction between the two routing protocols. In this method, IP layer routing protocols such as OSPF or RIP are used to transmit IP packets over ATM networks, and non-standardized ATM signaling protocols such as LDP (Label Distribution Protocol) may be used for connection establishment. . Integrated routing does not require a separate ATM ARP because it uses a single routing protocol, but there is a problem that the complexity of the ATM switch increases because the ATM switch must perform the same function as the multiprotocol router. MPLS (Multiprotocol Label Switching), which is being standardized by the IETF, is a representative example of integrated routing.

On the other hand, in the overlay model described above, the destination is identified by DNS and ATM ARP. In other words, IP DNS is used to identify the IP address from the destination name, and ATM ARP is used to derive the ATM address from the identified IP address. This procedure is inefficient because it can access the terminal only through two processes of identifying an IP address and ARP.

An object of the present invention is to solve the problem of the present invention, and the Internet protocol and asynchronous transmission that can easily detect the ATM address corresponding to the IP address and the IP address corresponding to the ATM address to facilitate communication between them. The present invention provides an interworking device for mode interworking.

Another object of the present invention is a method of driving an interworking device for interworking with an Internet protocol and an asynchronous transmission mode that can easily detect an ATM address corresponding to an IP address and an IP address corresponding to an ATM address, thereby facilitating communication between them. To provide.

In order to achieve the above object, the present invention provides an apparatus for arbitrating communication between an Ethernet network and an Asynchronous Transfer Mode (ATM) network, the IP name and address of an Ethernet host configured in the Ethernet network and An IP DNS server having an IP name and an IP address of an ATM host in the ATM network; It is configured in the ATM network and has an IP name, an IP address, and an ATM address of an ATM host in an ATM network, and has an IP name and an IP address of an Ethernet host of the Ethernet network, but is preset in the Ethernet hosts in the Ethernet network. An ATM DNS server to which an ATM address for the companion device is assigned; An interworking device configured between the Ethernet network and the ATM network, wherein the interworking device is assigned an ATM address for the interworking device, and corresponds to an ATM address of the ATM host corresponding to a destination IP address of a packet provided from the Ethernet host. Reads from the ATM DNS server to form a virtual channel with a corresponding ATM host, converts a packet of the Ethernet host into an ATM cell, and provides the virtual channel with the virtual channel; The companion device changes the ATM cell provided from the ATM host into an Ethernet packet, and the MAC address detects a MAC address corresponding to the IP address of the ATM cell through an ARP process through the Ethernet network. Configure it to serve the appropriate Ethernet host.

The present invention also provides a cache memory for an asynchronous transfer mode (ATM) network, and provides a method for operating a companion device for providing a packet from an Ethernet host in an Ethernet network to a predetermined ATM host in an ATM network, wherein the ARP request is provided from the Ethernet host. Determining whether an IP address in the ARP request message and its corresponding ATM address are stored in the ATM memory cache if the IP address in the message is not the address of the companion device; If the IP address corresponding to the IP address of the ARP request message and its corresponding ATM address are not stored in the cache memory for the ATM network, the IP address corresponding to the IP address of the ARP request message from the ATM DNS server in the ATM network and the corresponding ATM. A second step of reading corresponding ATM address information when there is an address and storing the corresponding ATM address in the cache memory for the ATM network; The IP address corresponding to the IP address of the ARP request message and the corresponding ATM address are stored in the ATM network cache memory, or the ARP request message is stored after storing an ATM address from the ATM DNS servo corresponding to the IP address. Providing a MAC address of the companion device to the Ethernet host provided with the second host and forming a virtual channel corresponding to the ATM address; When the packet of the Ethernet host receiving the MAC address of the companion device as the MAC address of the destination is received, it is determined whether the IP address of the packet is stored in the cache memory of the ATM network. A fourth step; If the IP address in the packet of the Ethernet host is stored in the cache memory for the ATM network, it is determined whether a virtual channel and an ATM host having an ATM address corresponding to the IP address are set. Establishing a channel; Converting a packet of the Ethernet host to an ATM cell after performing the fourth and fifth steps, and transmitting the converted ATM cell through the virtual channel.

The present invention also provides a method for operating an interlocking device having a cache memory for an Ethernet network and providing a packet from an ATM host in an asynchronous transmission mode (ATM) network to a predetermined Ethernet host in an Ethernet network. Converting into an Ethernet packet; A second step of determining whether the corresponding IP address and its corresponding MAC address are stored in the cache memory of the Ethernet network if the IP address in the converted Ethernet packet is not the address of the companion device; If the IP address corresponding to the IP address of the Ethernet packet and the corresponding MAC address are not stored in the cache memory for the Ethernet network, an ARP process is performed on the Ethernet network to detect the MAC address corresponding to the IP address of the Ethernet packet. A third step of storing in a cache memory for an Ethernet network corresponding to the IP address; The IP address of the Ethernet packet and its corresponding MAC address are stored in the cache memory for the Ethernet network, or the MAC address obtained through the ARP process is stored in the cache memory for the Ethernet network after corresponding to the IP address. And a fourth step of transmitting the MAC address as a destination address.

1 is a conceptual diagram of a companion device for interworking with the Internet protocol and the asynchronous transmission mode according to the present invention;

2 is a table state diagram in a DNS server configured in an Ethernet network and an asynchronous transmission mode network according to the present invention;

3 is a detailed block diagram of a companion device according to the present invention;

4 is a diagram illustrating a process of transferring information from an Ethernet network to an arbitrary host in an asynchronous transmission mode;

5 is a table state diagram of a cache memory configured in the companion device of the present invention;

6 is a diagram illustrating a process of transferring information to an arbitrary host in an Ethernet network from an asynchronous transmission mode.

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

1: linkage device 2: Ethernet network

3: asynchronous transmission mode network 11: Ethernet NIC

12: Asynchronous Transfer Mode NIC 13: IWF

14,15: cache memory 21-23: Ethernet host

24: IP DNS server 31, 32: asynchronous transfer mode host

33: Asynchronous Transfer Mode Switch 34: Asynchronous Transfer Mode DNS Server

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of an interlock device according to the invention. As shown, the interworking device 1 of the present invention is configured between the Ethernet network 2 and the ATM network 3, and the Ethernet hosts 21, 22, and 23 in the Ethernet network 2 are connected in an Ethernet manner. . There is one IP DNS server 24 in the Ethernet network 2, and the IP DNS server 24 is an Ethernet host 21 in the Ethernet network 2 and the ATM network 3 as shown in FIG. 2A. -24) and a table with the IP names of the ATM hosts 31 and 32 and their corresponding IP address information.

In the ATM network 3, as shown, a plurality of ATM hosts 31 and 32 are connected through the ATM switch 33, and the ATM DNS server 34 is connected to the IP network 2 as shown in FIG. 2B. And IP tables, IP addresses and ATM addresses of Ethernet hosts 21-23 and ATM hosts 31 and 32 in ATM network 3, respectively. Here, the ATM addresses for the Ethernet hosts 21, 22, and 23 configured in the IP network 2 are not assigned ATM addresses for the Ethernet hosts 21, 22, and 23, as described below. The address A4 for (1) is given.

3 shows a schematic block diagram of an interlock device 1 according to the invention. As shown, the interworking apparatus 1 of the present invention includes an Ethernet network interface card (hereinafter referred to as NIC) 11 and an ATM NIC 12. The Ethernet NIC 11 and the ATM NIC 12 are connected to an interworking function block (IWF) 13, and the IWF 13 monitors data between the Ethernet NIC 11 and the ATM NIC 12 to monitor the Ethernet network 2. ) And bridging between the ATM network 3. To this end, within the IWF 13, type identification for each Internet application for establishing a connection using proxy signaling, an address resolution procedure for determining an ATM address corresponding to a destination IP, an IP address and an AESA E.164 ATM address, Binding function and the like. In addition, separate cache memories 14 and 15 may be configured in the companion device 1, and information stored in the cache memories 14 and 15 will be described in detail later.

In FIG. 4A, the entire process of transmitting the ATM host 32 packet according to the request of the Ethernet host (eg, 21) by the companion device 1 having the above-described configuration is shown. In FIG. 4B, the companion device ( The flowchart performed by 1) is shown.

First, the process of FIG. 4A will be described. The portion shown by the dotted line in Figure 4a is not necessarily performed portion, it will be easily understood by the description below to be performed selectively as needed.

When an Ethernet host (for example 21) in the Ethernet network 2 wants to send a packet to an ATM host (for example 32) in the ATM network 3, the Ethernet host 21 first starts the IP name of the ATM host 32 (in this example). The IP DNS server 24 queries the IP address I32 corresponding to 32). The IP DNS server 24 has an IP address corresponding to the IP names of the hosts 21-23, 31, and 32, as shown in FIG. 2A. Provide the corresponding IP address (I32)

The Ethernet host 21 that receives the IP address I32 of the ATM host 32 from the IP DNS server 24 determines whether the MAC address corresponding to the IP address I32 is already stored in the internal cache memory. As a result of the determination, when the corresponding MAC address is stored in the internal cache memory, the process proceeds to the Ethernet packet transmission process described later without performing the ARP process described later. That is, if there is no MAC address, the Ethernet host 21 performs an ARP process to obtain a MAC address.

The ARP process for obtaining a MAC address is as follows.

The Ethernet host 21 provides an ARP request message having an IP address I32 to the Ethernet network 2, whereby all hosts 21, 22, 23 in the Ethernet network 2 and the interworking device of the present invention ( 1) receives an ARP request message from the Ethernet host 21. The Ethernet hosts 21, 22, and 23 in the Ethernet network 2 function to provide their MAC addresses to the Ethernet host 21 when the IP address in the ARP request message corresponds to the host device. 1) Also, it is determined whether the IP address in the received ARP request message corresponds to its own address, and if it corresponds to itself, it performs its function of providing its MAC address as an ARP response message to the Ethernet host 21.

If the IP address in the ARP request message is the IP address of the companion device 1, the Ethernet host 21 attempts to transmit a packet to the companion device 1, that is, the Ethernet between the Ethernet host 21 and the companion device 1 In this case, since the communication is performed and the Ethernet host 21 and the companion device 1 are the same as in the conventional case of communicating through a general Ethernet network, detailed illustration and description are omitted herein.

However, if the IP address in the ARP request message does not correspond to its own IP address, the companion device 1 of the present invention further performs the following process. That is, in this case, since the IP address in the ARP request message may be for the ATM host 31 or 32 in the ATM network 3, the interworking device 1 may have an internal ATM cache memory 15 and an ATM DNS server. (34) is performed to confirm this. First, whether the IP address in the ARP request message relates to the ATM host 31 or 32 in the ATM network 3 can be easily obtained by querying the ATM DNS server 34 whether there is an ATM host 31 or 32 having this IP address. Can be performed. In this case, the ATM DNS server 34 searches whether the IP address corresponding to the IP address from the interlocking device 1 and the corresponding ATM address are stored through the table of FIG. 2B, and the corresponding ATM host (32 in this example) is found. When the address is found, the ATM address A32 information of the ATM host 32 is provided to the companion device 1 of the present invention.

On the other hand, it is unreasonable in terms of retrieval speed and communication load to perform the above process, that is, querying the ATM DNS server 34 whether there is an ATM host corresponding to the IP address in the ARP request message every time the ARP request message is received. In order to solve this problem, the inventor has constructed a cash memory 15 for ATM in the companion device 1. That is, in the cache memory 15, as shown in FIG. 5A, the IP address (e.g., I32) that queries the ATM DNS server 34 and the ATM address provided by the ATM DNS server 34 in response to the IP address ( A32) are stored in correspondence with each other. In this state, when an ARP request message not corresponding to the IP address of the companion device 1 is received, the IP address is first stored in the cache memory 15 by searching for one of the IP addresses stored in the cache memory 15. If not, the ATM DNS server 34 requests ATM address information corresponding to the IP address.

As described above, the process in the solid line in FIG. 4A illustrates an example in which there is no IP address in the ARP request message in the cache memory 15. As shown, when the ATM address corresponding to the IP address is provided from the ATM DNS server 34, the interworking device 1 of the present invention corresponds the IP address and the ATM address to the internal cache memory 15 as described above. Save it.

In the cache memory 15 of FIG. 5A, an IP address and an ATM address are stored in correspondence with each other. The IP address and ATM address newly received from the ATM DNS server 34 are located at the top of the table. In addition, the cache memory 15 may further store time information in which an IP address and an ATM address are stored, and this time information may be updated each time an IP address is searched by the companion device 1. When the capacity of the cache memory 15 is exceeded, the cache memory 15 may be deleted in the order of the oldest address information at the bottom, and only information that has elapsed for a predetermined time or more may be deleted using the time information.

When the ATM address corresponding to the IP address in the ARP request message is detected by the internal cache memory 15 or the ATM DNS server 34, the companion device 1 sends its MAC address as an ARP response message to the ARP request message. Is provided to the Ethernet host 21, and it is determined whether the virtual channel between the ATM NIC 12 and the ATM host 32 having the corresponding ATM address is set. If the virtual channel is not set, the ATM NIC 12 is used. By providing the ATM address to the ATM switch 33, a virtual channel (VCC), that is, a call path with the ATM host 32 is established.

Through the above-described process, the Ethernet host 21 receives the MAC address of the companion device 1 as the MAC address corresponding to the IP address, and designates the received MAC address as the MAC address of the packet to be provided to the ATM host 32. Send it. Therefore, the packet of the Ethernet host 21 is received by the companion device 1 of the present invention. The IWF 13 in the companion device 1 transfers the received packet of the Ethernet host 21 to ATM cells, but the address of the ATM cell corresponds to the ATM address stored in the cache memory 15 corresponding to the IP address in the packet. It is set and transmitted to the ATM switch 33 in the ATM network 3. However, when the information of the cache memory 15, that is, the ATM address information corresponding to the IP address in the packet is lost or as described above, the Ethernet host 21 already knows the MAC address of the companion device 1 and thus performs the ARP process. There may be a case where the MAC address of the packet is set to the MAC address of the companion device 1 and transmitted without performing the operation. Therefore, the companion device 1 determines whether the IP address and the ATM address corresponding to the packet from the Ethernet host 21 are stored in the cache memory 15, and if it is not stored, perform the following process.

The process in the dotted line is the same as the process in the dotted line described above. That is, the companion device 1 inquires the ATM DNS server 34 of the ATM address corresponding to the IP address, receives the ATM address information provided from the ATM DNS server 34, and stores it in the internal cache memory 15. After that, it is determined whether the virtual channel between the ATM NIC 12 and the ATM host 32 having the corresponding ATM address is set. If the virtual channel is not set, the ATM switch 33 uses the ATM NIC 12 to transfer the corresponding ATM address. By providing to the virtual channel (VCC), that is, the call path with the ATM host 32 is established.

When the virtual channel of the ATM host 32 is set or set as described above, the companion device 1 changes the Ethernet packet provided from the Ethernet host 21 into an ATM cell (the ATM address of the ATM cell is cache memory as described above). (15) or the corresponding ATM address of the ATM DNS server 34.) Provided to the corresponding ATM host 32 through the virtual channel.

4B shows an operation flowchart of the interlocking device 1 that receives an ARP request message from the Ethernet host 21 and establishes a call path with an ATM host 32 having an IP address in the ARP request message.

As shown, when the ARP request message is received from the Ethernet host 21 (S11), the companion device 1 determines whether the IP address in the received ARP request message is its own IP address (S13). As a result of the determination in step S13, if the IP address is its own address, it provides its MAC address to the Ethernet host 21 (S15) and makes a call with the corresponding Ethernet host (S17).

However, if the IP address in the ARP request message is not its own address, the companion device 1 proceeds to step S19 to check whether the corresponding IP address and the corresponding ATM address exist in the internal cache memory 15. As a result of the search, if the corresponding ATM address exists in the cache memory 15 (S21), the companion device 1 proceeds to step S29 and provides its MAC address to the corresponding Ethernet host 21, but the cache memory 15 If the corresponding IP address does not exist in step c), the process proceeds to step S23.

In step S23, the companion device 1 queries the ATM DNS server 34 for an ATM address corresponding to the IP address, and determines whether ATM address information is provided from the ATM DNS server 34 (S25). As a result of the determination in step S25, if the ATM address information is not provided from the ATM DNS server 34, all processes are terminated. If the ATM address information is provided, the companion device 1 proceeds to step S27 and receives the received ATM. The address and the corresponding IP address are stored in correspondence with the internal cache memory 15.

Thereafter, the companion device 1 sets its MAC address as a response message to the ARP request message and provides it to the Ethernet host 21 (S29). The ATM host 32 having the ATM NIC 12 and the corresponding ATM address is provided. It is determined whether the virtual channel is established between the network controllers (S31). If the virtual channel is established, the communication between the corresponding Ethernet host 21 and the ATM host 32 is mediated (S33). By providing the corresponding ATM address to the ATM switch 33, the virtual channel (VCC) with the corresponding ATM host 32 is established, and a communication path is established (S35).

FIG. 4C illustrates an operation flowchart of the companion device 1 that transmits a packet provided from the Ethernet host 21 that has received the MAC address of the companion device 1 to the corresponding ATM host 32 by the process of FIG. 4B. have.

As shown, the companion device receives the MAC packet from the Ethernet host 21 (S41) and detects the IP address in the received MAC packet to determine whether it is its own IP address (S43, S45). As a result of the determination in step S45, if the IP address is the address of the interlocking device 1 itself, the received MAC packet information is received in a higher layer (where the MAC packet is received in the Ethernet NIC 12, and the higher layer is referred to as the corresponding Ethernet host). It refers to a layer that can communicate with.) And initiates a call between the corresponding Ethernet host 21 and the companion device 1 of the present invention.

However, if the IP address in the MAC packet is not its own address, then the companion device 1 proceeds to steps S49 and S51 to determine whether the corresponding IP address exists in the internal cache memory 15. As a result of the search, if the corresponding IP address exists in the cache memory 15, the companion device 1 proceeds to step S53. In step S53, the companion device 1 determines whether a virtual channel is formed between the internal ATM NIC 12 and the corresponding ATM host 32, and if the virtual channel is not formed, the corresponding address in step S55. By providing an ATM address corresponding to the ATM switch, a virtual channel is formed with the corresponding ATM host 32.

However, if the virtual channel is already established with the corresponding ATM host 32 (or after performing step S55), the companion device 1 may ATM-cell the received packet, The address is configured to have an ATM address corresponding to the IP address of the packet in the cache memory 15 and transmitted to the ATM switch 33. That is, in steps S57 and S59, the packet from the Ethernet host 21 is converted into an ATM cell and provided to the corresponding ATM host 32.

On the other hand, if the corresponding IP address does not exist in the cache memory 15 as a result of the determination in step S51, the companion device 1 proceeds to step S61 and transmits the ATM address corresponding to the IP address to the ATM DNS server 34. It inquires and determines whether ATM address information is provided from the ATM DNS server 34 (S63). As a result of the determination in step S63, if the ATM address information is not provided from the ATM DNS server 34, it is provided to the user, that is, the corresponding Ethernet host 21, that the transmission of the packet is impossible, and all processes are terminated (S65). When the ATM address information is provided, the companion device 1 proceeds to step S67 and stores the received ATM address and the corresponding IP address in correspondence with the internal cache memory 15.

Thereafter, the companion device 1 determines whether a virtual channel between the ATM NIC 12 and the ATM host 32 having the corresponding ATM address is set (S69), and if the virtual channel is not set, forms a virtual channel (S71). ). Thereafter (or when the virtual channel is already set as a result of the determination in step S69), the companion device 1 ATMizes the Ethernet packet, but the ATM address corresponds to the IP address of the packet in the cache memory 15. It is configured to have an ATM address to transmit to the ATM switch 33 (S73, S75). That is, in steps S73 and S75, the packet from the Ethernet host 21 is converted into an ATM cell and provided to the corresponding ATM host 32.

In FIG. 6A, the entire process of transmitting the ATM cell to the Ethernet host 21 according to the request of the ATM host 32 is illustrated by the companion device 1 having the above-described configuration.

First, the process of FIG. 6A will be described. The portion shown by the dotted line in Figure 6a is not necessarily performed portion, it will be readily understood that the description will be described later to be performed selectively as needed.

When an ATM host (for example 32) in the ATM network 3 wants to send a packet to an Ethernet host (for example 21) in the Ethernet network 2, the ATM host 32 first attaches to the IP name 21 of the Ethernet host 21. The ATM DNS server 34 is queried for the corresponding IP address. The ATM DNS server 34 stores IP addresses and ATM addresses corresponding to IP names of the hosts 21-23, 31, and 32 as shown in FIG. 2B, and the Ethernet host 21 in the Ethernet network 2. The ATM addresses of -23) are set to the ATM address A4 of the companion device 1. The ATM DNS server 34 thus provides the IP address I21 of the Ethernet host 21 requested from the ATM host 32.

Upon receiving the IP address I21 of the Ethernet host 21 from the ATM DNS server 34, the ATM host 32 requests the ATM DNS server 34 again from the ATM DNS server 34 for an ATM address corresponding to the Ethernet host 21. DNS server 34 provides ATM address A4 of interworking device 1 to ATM host 32.

The ATM host 32 that receives the ATM address by the above-described process determines whether a virtual channel corresponding to the received address is set. If the virtual channel is not established, the ATM host 33 determines the received ATM address. In this case, the ATM host 32 forms an virtual channel with the companion device 1 because the ATM address provided by the ATM DNS server 34 is the ATM address of the companion device 1.

Thereafter, the ATM host 32 transmits the ATM cell through the established virtual channel so that the ATM cell of the ATM host 32 is provided to the companion device 1 through the virtual channel. At this time, the ATM cells provided by the ATM host 32 should include an IP address indicating a destination.

The interworking device 1, when provided with an ATM cell, combines the ATM cells to perform operations according to IP addresses by the ATM cells. This operation process is described with reference to FIG. 6B.

As shown, when the ATM cell is received (S101), the companion device 1 reconfigures the ATM cells into IP packets (S103). The address of the reconstructed IP packet is examined to determine whether the companion device 1 owns an IP address (S105 and S107). As a result of the determination in step S107, the case where the address of the IP packet is the address of the companion device 1 and the ATM host 32 wants to transmit a packet to the companion device 1, that is, the ATM host 32 and the companion device This is the case where IP communication between (1) is performed. In this case, since the ATM host 32 and the companion device 1 communicate with each other through the ATM network (S109), detailed illustration and description are omitted herein.

On the other hand, if the IP address of the IP packet is not the IP address of the companion device 1 as a result of the determination in step S107, the companion device 1 of the present invention proceeds to step S111 and the cache memory 14 and the IP for the Ethernet network therein. The process of confirming this is performed using the DNS server 24 (deletion). Here, the cache memory 14 for the Ethernet network performs a function similar to the cache memory for the ATM network described above, and as shown in FIG. 5B, the IP addresses (IP21-IP23) and the IP addresses of the Ethernet hosts 21-23 in the Ethernet network 2 are shown. MAC (M21-M23) address information is stored, and this information is acquired and stored through the ARP process performed in the Ethernet network 2. That is, the companion device 1 determines whether the IP address and the corresponding MAC address of the packet by the ATM cell are stored in the cache memory 14 for the Ethernet network in step S113. As a result of the determination in step S113, if the corresponding IP address and the corresponding MAC address are stored, the companion device 1 reads the MAC address corresponding to the corresponding IP address and adds the MAC address to the corresponding packet to transmit to the Ethernet network ( S115) The Ethernet host 21 having the MAC address receives the packet.

However, if the determination result of step S113 indicates that there is no IP address of the packet by the ATM cell in the cache memory 114 for the Ethernet network, the companion device 1 proceeds to step S117 to send an ARP request message to all Ethernet hosts in the Ethernet network. To (21-23). The ARP request message contains the IP address of the packet by the ATM cell (I21 in this example). Among the Ethernet hosts 21-24 that have received the ARP request message, the Ethernet host 21 having the IP address included in the ARP request message provides its MAC address to the companion device 1. If the ARP response from the corresponding Ethernet host 21, that is, MAC address information is provided (S119), the companion device 1 stores the MAC information in the cache memory 114 for the Ethernet network in correspondence with the IP address in the Ethernet packet. The flow advances to step S115 (S121).

However, if the MAC address information is not provided as a result of performing step S119, the companion device 1 proceeds to step S123 to notify the ATM host 32 that provided the ATM cell that the IP address is wrong and to perform all processes. Quit.

As described above, the IP address and the MAC address are stored in the cache memory 14 for the Ethernet network. At this time, the cache memory 14 for the Ethernet network may have the IP address and the corresponding MAC address of the Ethernet packet most recently requested from the ATM network 3 on the top. In addition, the cache memory 14 may further store time information in which an IP address and a MAC address are stored, and this time information may be updated whenever an IP address is searched by the companion device 1. When the capacity of the cache memory 14 is exceeded, the cache memory 14 may be deleted in the order of the oldest address information at the bottom, and only information that has elapsed for a predetermined time or more may be deleted using the time information.

As described above, the present invention enables bridging the Ethernet network and the ATM network as a simple interworking device by utilizing the present invention, and has an effect that the address problem between them can be simplified and simply processed.

In addition, in the present invention, the cache memory is configured in the companion device, thereby reducing the unnecessary address request procedure and improving the speed.

Claims (4)

Device that mediates communication between Ethernet and Asynchronous Transfer Mode (ATM) networks, An IP DNS server configured in the Ethernet network and having an IP name and address of an Ethernet host in the Ethernet network and an IP name and IP address of an ATM host in the ATM network; It is configured in the ATM network and has an IP name, an IP address, and an ATM address of an ATM host in an ATM network, and has an IP name and an IP address of an Ethernet host of the Ethernet network, but is preset in the Ethernet hosts in the Ethernet network. An ATM DNS server to which an ATM address for the companion device is assigned; An interworking device configured between the Ethernet network and the ATM network: The companion device is assigned an ATM address for the companion device, reads an ATM address of the ATM host corresponding to a destination IP address of a packet provided from the Ethernet host, from the ATM DNS server, and establishes a virtual channel with the corresponding ATM host. Form a packet of the Ethernet host to an ATM cell to provide to the virtual channel; The companion device changes the ATM cell provided from the ATM host into an Ethernet packet, and the MAC address detects a MAC address corresponding to the IP address of the ATM cell through an ARP process through the Ethernet network. Interworking device for interworking with the asynchronous transfer mode with the Internet protocol configured to provide its Ethernet host. The method of claim 1, In the companion device, a cache memory for ATM network and a cache memory for Ethernet network are provided. The destination IP address and ATM address read from the ATM DNS server are stored in the cache memory for the ATM network. The companion device is configured to first read an ATM address corresponding to an IP address in a packet from an Ethernet host in the ATM network cache memory and to use the ATM DNS server when there is no corresponding information in the ATM network cache memory. The destination IP address and the MAC address read from the IP DNS server are stored in the cache memory for the Ethernet network, and the companion device primarily caches the MAC address corresponding to the IP address of the ATM cell provided from the ATM host. A companion device for interworking with an Internet protocol and an asynchronous transmission mode configured to read from a memory and use the IP DNS server when there is no corresponding information in the cache memory for the Ethernet network. A method of driving an interworking device having a cache memory for an asynchronous transmission mode (ATM) network and providing a packet from an Ethernet host in an Ethernet network to a predetermined ATM host in an ATM network. A first step of determining whether an IP address in the ARP request message and its corresponding ATM address are stored in the ATM memory cache memory if the IP address in the ARP request message provided from the Ethernet host is not the address of the companion device; If the IP address corresponding to the IP address of the ARP request message and its corresponding ATM address are not stored in the cache memory for the ATM network, the IP address corresponding to the IP address of the ARP request message from the ATM DNS server in the ATM network and the corresponding ATM. A second step of reading corresponding ATM address information when there is an address and storing the corresponding ATM address in the cache memory for the ATM network; The IP address corresponding to the IP address of the ARP request message and the corresponding ATM address are stored in the ATM network cache memory, or the ARP request message is stored after storing an ATM address from the ATM DNS servo corresponding to the IP address. Providing a MAC address of the companion device to the Ethernet host provided with the second host and forming a virtual channel corresponding to the ATM address; When the packet of the Ethernet host receiving the MAC address of the companion device as the MAC address of the destination is received, it is determined whether the IP address of the packet is stored in the cache memory of the ATM network. A fourth step; If the IP address in the packet of the Ethernet host is stored in the cache memory for the ATM network, it is determined whether a virtual channel and an ATM host having an ATM address corresponding to the IP address are set. Establishing a channel; Interworking for interworking with an internet protocol and an asynchronous transmission mode comprising converting a packet of the Ethernet host to an ATM cell after performing the fourth step and the fifth step, and transmitting the converted ATM cell through the virtual channel. Method of driving the device. An operating method of a companion device having a cache memory for an Ethernet network and providing a packet from an ATM host in an asynchronous transmission mode (ATM) network to a predetermined Ethernet host in an Ethernet network, Converting an ATM cell from the ATM host into an Ethernet packet; A second step of determining whether the corresponding IP address and its corresponding MAC address are stored in the cache memory of the Ethernet network if the IP address in the converted Ethernet packet is not the address of the companion device; If the IP address corresponding to the IP address of the Ethernet packet and the corresponding MAC address are not stored in the cache memory for the Ethernet network, an ARP process is performed on the Ethernet network to detect the MAC address corresponding to the IP address of the Ethernet packet. A third step of storing in a cache memory for an Ethernet network corresponding to the IP address; The IP address of the Ethernet packet and its corresponding MAC address are stored in the cache memory for the Ethernet network, or the MAC address obtained through the ARP process is stored in the cache memory for the Ethernet network after corresponding to the IP address. And a fourth step of transmitting the MAC address as a destination address and transmitting the Internet protocol.