KR100261291B1 - Global address resolution method for ipoa(internet protocol and address resolution protocol over atm) - Google Patents

Abstract

PURPOSE: A global address resolution method for IPOA(IP AND ARP OVER ATM) is provided to enable direct connection between any IP entities on an ATM network by providing a mechanism supporting global address resolution in the IPOA. CONSTITUTION: A global address resolution method for IPOA includes the following steps. A client registers their subnet information in each ARP server in the first step. If a certain client wants IP communication, he or she requests an ATM address by using IP of a destination client to be linked to the first ARP server in which himself or herself is registered in the second step. If the ATM address information of the destination client who is requested to be linked is not registered in the first ARP server and the first ARP server does not manage the subnet of the corresponding destination client, another ARP server constituting the first ARP server and network is requested to send the address information of the destination client in the third step. The corresponding address information is transmitted to the first ARP server from the second ARP server managing the subnet information of the destination client in the fourth step.

Description

Global Address Resolution Method for I.P.O.A

The present invention relates to a global address resolution method for IP and ARP over ATM (IPOA), and in particular, in the IPOA method for supporting IP (Internet Protocol) services on an ATM network. A method for global address resolution for IPOA, which provides address resolution for IP stations throughout the ATM network, supporting direct connections between any IP stations in the ATM network, away from Logical IP Subnet (LIS) -based address resolution. will be.

Recently, the acceptance of IP services in ATM networks is considered to be a very important task due to the rapid increase in the demand for IP services represented by Internet services. As a method for accommodating IP in the ATM network, various types of research such as IPOA (IP and ARP over ATM), NHRP (Next Hop Resolution Protocol), ATM-LANE (ATM LAN Emulation), and MPOA (Multi-Protocol over ATM) As many of these methods have advantages and disadvantages, we cannot easily determine which one is efficient.

However, dual IPOA adopts the ARP (Address Resolution Protocol) mechanism in the existing LAN as it is, it is relatively easy and simple to accept the IP network compared to other methods. In other words, it is designed to accommodate the so-called IP service represented by Internet service in ATM network, which is a high-speed communication network, and adopts ATM Address Resolution Protocol (ATMARP) similar to ARP (Address Resolution Protocol), which is an address resolution protocol in the existing LAN environment. As a method of supporting IP services on an ATM network relatively simply and reliably, it has been in the spotlight.

1 is a process diagram for address resolution of a conventional IPOA. Referring to FIG. 1, a conventional IPOA is connected to an IP station, that is, clients 10 and 30, to an ARP server 20 located in an ATM network. It is.

At this time, the address resolution procedure using the ARP server 20 and the client (10, 30) is as follows.

First, the client A 10 located in the ATM network attempts an ATM connection with its ARP server 20 during the initialization process, and when the corresponding connection is generated (s101), the ARP server 20 uses an InATMARP_Request / Reply packet. Register the station in its own cache. That is, when the connection is made (s101), the ARP server 20 sends an InATMARP_Request packet to the client A 10 to request the client's IP information (s102), and the client A 10 carries its own IP information. The InATMARP_Reply packet is sent to the ARP server 20 to register itself with the ARP server 20 (s103). In addition, client B 30, which is another client included in the subnet of the ARP server 20, also passes its own IP information through the same procedure (s104, s105, s106) as that of the client A 10. Register).

Then, if the client A 10 wants to communicate with another IP station in the same subnet, that is, the client B 30, the client A 10 to the ARP server 20 via ATMARP_Request to the corresponding IP station The client requests an address resolution for the client B 30 (s106). Then, the ARP server 20 analyzes the address and transmits the ATMARP_Reply packet carrying the ATM address of the client B 30 to the client A 10 (s107). At this time, if the address information of the client B 30 is not valid, ATMARP_NAK is transmitted to the client A 10. When the address resolution is successful as described above, the client A 10 establishes an ATM connection to the ATM address of the client B 30 (s108), and then performs IP communication through the corresponding connection (s109).

This is similar to the method of attempting to communicate with a corresponding station after obtaining a medium access control (MAC) address of an opposite station by ARP on Ethernet, which is a typical representative LAN, and the ARP packet format is almost similar. However, in contrast to the conventional ARP in the LAN, the IPOA uses ATM ARP_NAK, in addition to ATMARP_Request and ATMARP_Reply, which performs address resolution request and response functions to support registration and address resolution through the ARP server. The difference is that InATMARP_Request and InATMARP_Reply are added.

In the conventional IPOA having the above procedure, ARP is available only within the same subnet by using a conventional routing method in an IP network, and has a structure that passes through an IP router when communicating with another subnet. Therefore, the conventional IPOA has a merit that it is very easy and simple to map the IP network to the ATM network by supporting the existing subnet-based network structure and the address resolution protocol without any significant change. An intermediate IP router is required, and since a low speed IP protocol exists in a higher layer in a high speed ATM network, it has an inefficiency in performance that must pass through the IP layer for each IP endpoint in the ATM network.

Accordingly, the present invention provides an IPOA which provides a mechanism for supporting global address resolution in the IPOA to provide a direct connection between any IP entities on an ATM network. To provide a global address resolution method.

The method provided by the present invention consists of an address resolution protocol (ARP) server that manages subnet information and a plurality of ARP clients that perform mutual data communication after registering their protocol information in the ARP server to perform IP communication in an ATM network. In the receiving IPOA, a plurality of ARP servers in an ATM network are configured to share the addresses of clients managed by each ARP server, and to each ARP server. Steps of registering their own address information, and a second step of requesting an ATM address using the IP of a destination client to which the client wants to connect to the registered first ARP server if any one client wants IP communication. And the ATM address information of the destination client for which connection is requested in the second step is not registered in the first ARP server. A third step of requesting ATM address information of a destination client from any other ARP server constituting a network with the first ARP server if the ARP server does not manage the subnet of the corresponding destination client; and the first ARP server A fourth step of transmitting the corresponding address information from the second ARP server managing the subnet information to which the destination client belongs among any other ARP server configuring the network to the first ARP server; and in the fourth step A fifth step in which the first ARP server receiving the address information of the destination client transmits the subnet information of the destination client to any one client that has requested IP communication in the second step; and receiving the address information of the destination client. A sixth step in which any one client establishes a virtual channel as a destination client, and using the virtual channel And a seventh step of performing data communication between the any one client and the destination client.

1 is a procedure for address analysis of a conventional IPOA,

2 is a process diagram for global address resolution for IPOA according to an embodiment of the present invention;

3 is a block diagram of an ARP server in the form of a mesh according to an embodiment of the present invention;

4 is a block diagram of an ARP server in a hierarchical form according to an embodiment of the present invention;

5 is a configuration diagram of a hybrid ARP server according to an embodiment of the present invention.

<Explanation of symbols for main parts of drawing>

10: Client A 20: ARP Server

30: Client B 40: Station A

50: first ARP server 60: second ARP server

70: station B 100: ATM network

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

2 is a flowchart illustrating global address resolution for IPOA according to an embodiment of the present invention, FIG. 3 is a block diagram of an ARP server in mesh form according to an embodiment of the present invention, and FIG. 4 is an embodiment of the present invention. ARP server configuration in a hierarchical form according to an embodiment, Figure 5 is a hybrid ARP server configuration according to an embodiment of the present invention.

The present invention configures a network between the plurality of ARP servers in the ATM network to support global address resolution so that each ARP server shares the addresses of clients managed.

In other words, this global address resolution is performed on all IP entities in the entire ATM network without being dependent on the IP subnet. Therefore, for this purpose, ARP server needs to have information about other subnets in the whole ATM network other than the subnet managed by itself, or interoperate between ARP servers that should be able to request other ARP servers. Accordingly, in the present invention, the ARP server also uses one ATM entity, and interconnects them in a logical connection, that is, a Permanent Virtual Channel (PVC) or Switched Virtual Channel (SVC), thereby collecting or exchanging mutual information using the ATMARP protocol. To support global address resolution.

The network configuration of ARP server for global address resolution can be approached from the perspective of ARP client and server. For ARP client, IP subnet masking information by the existing IP routing mechanism is no longer needed. You can always communicate with your desired destination station by requesting address resolution without being subnet dependent. Since it is not necessary to use only subnet masking information without modifying network configuration considerations in the conventional IPOA, using global address resolution does not require modification or addition of the IPOA function of the existing client. For example, if you configure subnet masking in the existing IPOA client as 0.0.0.0, the client will follow the global address resolution procedure.

On the other hand, ARP server is interconnected by a logical connection to collect or exchange information between each other in order to provide an address analysis function for the entire ATM network, in the present invention for this purpose mesh configuration, hierarchical configuration and mixed configuration, etc. Three ways of constructing are presented. In the case of mesh configuration, all ARP servers are interconnected 1: 1 by PVC or SVC. In the case of hierarchical configuration, the ARP server is hierarchically formed by having its own ARP server hierarchically again. In the mixed configuration, the ATM network is partitioned into several IP networks and the corresponding partition network is partitioned. ARP server in the) is configured in a mesh form, and one or more representative servers in each partition have a hierarchical structure in which a mesh form is formed again.

FIG. 2 is a process diagram for global address resolution for IPOA according to an embodiment of the present invention. Referring to FIG. 2, the IPOA for the present invention includes a first ARP server 50 and a second ARP server connected through a network. 60, a station A 40 registered in the first ARP server 50, and a station B 70 registered in the second ARP server 60.

In order for the IPOA having the above configuration to perform communication by address resolution, the first and second ARP servers 50 and 60 first go through an initialization process (s201). It refers to the process of collecting or exchanging subnet information when a connection is established between each other according to the network configuration.

This ARP server exchanges information using IPATA's InATMARP_Request / Reply. In other words, when an arbitrary connection is established, the ARP server attempts to register the other party by executing an InATMARP_Request to the other party.Also, when establishing a connection between ARP servers, the ARP server exchanges InATMARP_Request and Reply with each other by performing the same mechanism, and the subnet packet is assigned to the reply packet. By sending the subnet domain and subnet masking information, it informs the IP area that it manages.

This is slightly different depending on the network configuration. In the case of the mesh type, all act as servers to exchange information. In the hierarchical form, the lower server acts as a client so that only the upper server requests InATMARP_Request. As the lower server responds to this, only the upper server manages the subnet information of the lower ARP servers. In the case of the hybrid configuration, the method in the mesh form is hierarchical.

After the server-to-server initialization process as described above, each station (40, 70) attempts to establish a connection to its ARP server (50, 60) for IP communication, if the connection is established (s202, s205) 50 and 60 transmits to each station 40 and 70 an InATMARP_Request packet requesting IP information of each station (s203 and s206), and each of the stations 40 and 70 receiving the information includes its own IP information. The station is registered with the server by sending InATMARP_Reply to the ARP server 50, 60 (s204, s207).

If the station A 40 wants IP communication with the station B 70 after the station is registered with each server as described above, the station A 40 transmits the station B to the first ARP server 50 to which the station A 40 belongs. The ATMARP_Request packet requesting the IP information of 70 is transmitted (s208). Then, the first ARP server 50 determines the following matters according to the location of the destination station. First, if the corresponding destination is located in the same subnet, the first ARP server 50 registers the destination with itself. If the information is valid, ATMARP_Reply is transmitted. Otherwise, ATMARP_NAK is transmitted (s209). Second, if the corresponding destination is located outside the ATM network, that is, no other server manages the subnet, the server forwards the ATM address of the router connected to the outside through ATMARP_Reply (s210). On the other hand, if not the two cases the server relays the packet to the server that manages the subnet (s211). The counterpart server depends on the network configuration. That is, in the case of the mesh form, the server manages the corresponding subnet, and in the case of the hierarchical configuration, the server is the upper layer server.

The relayed ATMARP_Request packet is analyzed by the corresponding server 60 managing the station B 70 to generate ATMARP_Reply or ATMARP_NAK, which is relayed to the station A 40 via the corresponding server 50 (s212). s213), the global address resolution procedure ends. Through this procedure, when the address of the station B 70, which is the destination station, is analyzed, the station A 40 uses the station B 70 and the ATM signaling function to establish a direct connection (s214) regardless of the IP subnet. In this case, direct communication is performed through the direct connection between them (S215).

On the other hand, in order to achieve the configuration and operation as described above is shown in Figures 3 to 5 to configure the network of the ARP server.

3 is a block diagram of an ARP server in the form of a mesh according to an embodiment of the present invention.

Referring to FIG. 3, in the mesh type ARP server, there are a plurality of subnets (LIS: Logical IP Subnets) 101, 102, 103 in the ATM network 100, and all ARP servers 105, 106, 107) are connected one-to-one with each other, and when the connection is established, the ARP server exchanges subnet information with each other using an InATMARP packet. This subnet information is composed of the IP address of the server and the subnet masking flag (Subnet Masking Flag or Netmask Flag). However, since the InATMARP packet has only an IP address field and does not include information on the subnet masking flag in the conventional IPOA, an additional field for the subnet masking flag is required only for the InATMARP packet. In addition, the ARP server managing multiple subnets informs the counterpart ARP server of its own information by sending as many response packets. When the connection is established between all servers, the IP subnet information in the entire ATM network You will know. Therefore, the ARP server receiving the address resolution request to the other subnet can refer to the subnet information of the other ARP server and relay the request to the corresponding ARP server, thereby enabling global address resolution.

4 is a block diagram of an ARP server in a hierarchical form according to an embodiment of the present invention.

Referring to FIG. 4, in the hierarchical ARP server, a higher level ARP server 104 exists in an ATM network 100 including a plurality of LISs 101, 102, and 103, and an existing ARP server 105 is present. 106 and 107 operate as lower-level ARP servers and act as ARP clients for higher-level ARP servers 104. That is, the lower level ARP server attempts to establish a connection to its higher level server like the ARP client during initialization, and the higher level server recognizes the lower level server as a client using the InATMARP packet to perform the registration procedure. In this case, the lower level server transmits an InATMARP response packet including its IP address and subnet masking flag to the upper level server as in the mesh form. Therefore, the upper level server manages the subnet information for the plurality of lower level servers connected to it.

When the lower level server having the higher level server receives the address resolution request, the lower level server relays the address to the higher level server if it is not its own subnet, so that the address resolution occurs at the upper level, and the higher level server is configured to target the target subnet of the request. It finds and relays it back to the downlevel server that manages the subnet, producing the results for that request.

5 is a configuration diagram of a hybrid ARP server according to an embodiment of the present invention.

Referring to FIG. 5, a mesh type ARP server is hierarchically configured.

Hybrid configuration is a method of hierarchically reconfiguring ATM networks by splitting ATM networks because it may be difficult to connect all ARP servers in a mesh form in a relatively large ATM network. That is, as shown in the figure, one ATM network 100 is divided into a plurality of divided networks 111, 112, and 113, and the mesh-type network composed of only representative servers 114, 115, and 116 in the divided network is restarted. It can be configured to exchange information in the entire ATM network.

At this time, the ARP server in each divided network (111, 112, 113) can only know the IP subnet information in the divided network to which it belongs, the representative server (114, 115, 116) of each divided network belongs to Not only the information in the network but also information about other segmented networks can be obtained. Therefore, when an address resolution request, each ARP server relays it to a representative server when the subnet cannot be resolved, the corresponding request can be analyzed.

Using the global address resolution method of the present invention as described above, IPOA enables direct connection for IP communication by supporting global address resolution for all IP entities in the ATM network without dependency of the IP subnet. This reduces the cost of additional devices such as routers to support existing IP routing by allowing direct connection over ATM, and improves ATM performance by performing direct communication without going through the IP layer for each IP endpoint in the ATM network, which is a high-speed communication network. It is available enough. In addition, the allowance of the direct connection can guarantee the end-to-end quality of service, and thus, there is an advantage of supporting traffic characteristics depending on the service rather than the network situation.

Claims (6)

It is composed of address resolution protocol (ARP) server that manages subnet information and a plurality of ARP clients that register their protocol information in the ARP server and perform mutual data communication to accommodate IP communication in ATM network. In IPOA, I.P.A. (A.P.A.) Which supports global address resolution by forming a network through a logical connection between the plurality of ARP servers in an ATM network and sharing the addresses of clients managed by each ARP server. Global address resolution method for IPOA). The method of claim 1, The global address resolution method for IPOA is A first step in which clients register their subnet information with each ARP server, A second step of requesting an ATM address using an IP of a destination client to which the client wants to connect to the registered first ARP server if any client wants IP communication; If the ATM address information of the destination client that is requested to connect in the second step is not registered in the first ARP server, and the first ARP server does not manage the subnet of the destination client, the network is connected to the first ARP server. A third step of requesting address information of a destination client from any other ARP server constituting A fourth step of transmitting the corresponding address information to the first ARP server from a second ARP server managing subnet information to which the destination client belongs among any other ARP servers constituting the network with the first ARP server; A fifth step in which the first ARP server receiving the address information of the destination client in the fourth step transmits the address information of the destination client to any one client requesting IP communication in the second step; A sixth step in which any one client that has received the address information of the destination client establishes a virtual channel as a destination client, And a seventh step of performing data communication between the any one client and the destination client using the virtual channel. The method of claim 1, Many ARP servers All ARPs are connected one-to-one with each other, and when the connection is established, a mesh-type ARP server configuration is used to exchange subnet information between ARP servers. ARP server of a higher level and an ARP server of a lower level exist so that the ARP server of a higher level has a hierarchical ARP server configuration for managing subnet information on the ARP server of the lower level, A global address analysis method for IPOA, characterized in that it is composed of any one of the mesh ARP server configuration and a hybrid ARP server configuration of a hierarchical ARP server configuration. The method of claim 3, wherein The hierarchical ARP server When the lower level server having the higher level server receives the address resolution request, if the destination is not its own subnet, the lower level server relays the address resolution request to the higher level server, Receiving this, the higher level server finds the subnet of the silent destination for which address resolution is requested, and relays the IP address to the lower level server managing the subnet. Global address resolution method. The method of claim 3, wherein The mixed ARP server The ARP server in the divided network connects one-to-one with each other like the ARP server in the mesh type, and sets one representative server in each divided network to connect the representative servers in mesh form again. When any ARP server receives an address resolution request, if the destination is not its own subnet, the representative server relays it to perform the address resolution on the representative server for IPOA. Global address resolution method. The method of claim 5, The representative server A method for resolving global addresses for IPOA, characterized by simultaneously including subnet information of a subnetwork to which it belongs and subnet information of another subnetwork.

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