KR100317990B1 - Apparatus and Method of Supporting Multiple Entities for LAN Emulation Client - Google Patents

Abstract

Local Area Network (LAN) Emulation (LAN) is called Asynchronous Transfer Mode (ATM) without changing the existing upper application software in existing LAN environment such as Ethernet or Token Ring. A communication protocol that enables interoperability in the environment.

LAN emulation clients are used to provide a two-tier feature that emulates Medium Access Control (MAC) functionality for access to ATM from devices on endpoints or server devices that provide Internet Protocol (IP) routing. do. In particular, to provide IP routing in ATM-based Switched Router devices, a LAN emulation client function is required that is subscribed to different emulated LANs (ELANs) as many as the number of IP routing interface ports it supports. Do. The LAN emulation standard specification defines a communication protocol for one entity. Based on this, the present invention describes a structural method, operation, and interaction for providing multiple LAN emulation client entity functions in one board.

Description

LAN Apparatus and Method of Supporting Multiple Entities for LAN Emulation Client

The present invention relates to LAN emulation for interoperating in an ATM environment without modification of higher application software. More specifically, the present invention relates to an apparatus and a method for multiplexing a LAN emulation client function in one board or device.

As communication technology advances, users require various services of high quality, and high speed data routing or forwarding processing functions are required to construct a network for this purpose. As one method for this, related protocol development or standardization work has been developed to utilize the advantages of ATM system such as performance, bandwidth, and scalability in existing LAN (Local Area Network) equipment. .

Representative ATM-LAN devices using ATM technology include ATM-based switched routers and edge devices that connect existing LANs to ATM networks. At this time, ATM and LAN are protocols that operate in different networks and require a method of interworking ATM and LAN, and one of them is a LAN emulation protocol. ATM-based routers using LAN emulation protocols require multiple LAN emulation client (LEC) capabilities that are subscribed to different emulated LANs (ELANs) as many as the number of interface ports provided by the router. A method of providing is required. LAN emulation clients are used to provide Medium Access Control (MAC) -based two-layer protocol functionality in ATM host devices at endpoints or ATM-based server devices that provide three layers of IP routing.

In other words, LAN Emulation is designed to interoperate with ATM (Asynchronous Transfer Mode, ATM) environment without changing existing upper application software in existing LAN environment such as Ethernet or Token Ring. Is a communication protocol.

The LAN emulation standard defines a communication protocol for one entity, and there is a problem that multiple entity functions cannot be provided.

Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, and the multiple LAN emulation client entity in performing a LAN emulation function for operating the upper application programs running on the existing LAN without changing the ATM network. It is to provide a LAN emulation client multi-entity processing apparatus and method for efficiently supporting functions in one board.

1 is a configuration diagram of an overall system to which the present invention is applied;

2 is a functional block diagram to which the present invention is applied;

3 is a block diagram of a multi-entity processing apparatus according to the present invention;

4 is an interactive diagram of data processing according to the present invention;

5 is an interaction diagram of connection management according to the present invention;

6 is a structural diagram of a separator according to the present invention;

7 is a configuration diagram of a system call connection protocol processing according to the present invention;

8 is a protocol stack and data frame structure according to the present invention.

In order to achieve the above object, a LAN emulation client multi-entity processing apparatus according to the present invention includes: an upper layer unit for requesting transmission of user data to a lower layer and processing user information received from the lower layer; Connected to the lower layer of the upper layer unit, and processes user data from the upper layer unit for each entity to transfer to the ATM adaptation layer unit, and processes the user information from the ATM adaptation layer unit for each entity and delivers it to the upper layer unit. A multi-LAN emulation client processor; And connected to a lower portion of the multi-LAN emulation client processor, divides user data from the multi-LAN emulation client processor into ATM cells, transmits the data to a physical layer, and recombines the received ATM cells transmitted from the physical layer to generate user information. It characterized in that it comprises the ATM adaptation layer unit for transmitting to the multi-LAN emulation client processor.

Preferably, the multi-LAN emulation client processing unit, the operation command processing unit for receiving and processing operation commands, such as function initialization, entity addition and deletion, status view from the system interface, and connected to the system interface to perform a LAN emulation protocol A common connection control unit for processing a function control frame for establishing and releasing the required ATM virtual connection, a common connection table connected to the common connection connection control unit to provide overall connection information, and all information necessary for control and operation for each entity is managed. Standard using entity information tables, a management entity information table for managing unique information required for each entity to operate, a call delimiter management unit for managing call delimiters required to control multiple entities, and information classified by entity It characterized in that it comprises a LAN emulation protocol processing unit for performing a protocol according to the standard.

Preferably, multiple entities of the multi-LAN emulation client processing unit share the ATM adaptation layer unit, the multi-LAN emulation client processing unit and the ATM adaptation layer unit define a connection delimiter for ATM connection, and add the block delimiter to the AAL connection table. The data received from the ATM connection is divided in a multi-entity environment, and the AAL connection table is shared.

More preferably, the connection separator is used as an index when searching for information by using a continuous value from 1 to the maximum number of connections.

More preferably, the block separator is characterized by consisting of 1 byte for function classification and 1 byte for entity identification number assignment.

The LAN emulation client multi-entity processing method according to the present invention is a LAN emulation client multi-entity processing method for providing a 2-layer LAN emulation client multi-entity function within a single board, in an environment for providing multiple entities. Receive the data packet from the upper layer unit and process the received packet for each entity and transfer it to the ATM adaptation layer unit, and process the data flow from the ATM adaptation layer unit to the upper layer unit for each entity to process it. And a second step of processing a data packet flow, and a second step of performing control procedures such as connection management, configuration management, and state management required to control the data flow of the multiple entities.

Preferably, the multiple entities share the ATM adaptation layer, define a connection separator and a block separator that simplify the connection segment as an interface parameter to facilitate the search, and share the AAL connection table.

More preferably, the connection separator is used as an index when searching for information by using a continuous value from 1 to the maximum number of connections.

More preferably, the block separator is characterized by consisting of 1 byte for function classification and 1 byte for entity identification number assignment.

Hereinafter, a LAN emulation client multi-entity processing apparatus and method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic configuration diagram of an ATM switched router system to which the present invention is applied. This is based on the ATM switch 12, the system processor 11 which performs overall system management, network management, call processing, etc., 3 layer IP routing protocol, LAN emulation client, ATM Adaptation Layer (AAL). It consists of a router processor 13 for performing functions, line interfaces 14-16 having an STM-1 (155 Mbps) class ATM interface, a frame relay interface, and a 10/100 Mbps Ethernet interface. Each functional board is connected to each other through an internal control bus 17 for mutual communication, and a router processor 13 and various function line cards are provided at an ATM switch 12 to route and forward packets at high speed. The data bus 18 is connected to each other.

The ATM switch 12, the router processor 13, and the line interfaces 14-17 send and receive necessary data through the data bus 18. Here, the multi-lan emulation function is performed at a line interface having an Ethernet matching function serving as a router processor or an edge device interconnecting an existing LAN and an ATM network.

2 is an overall functional configuration diagram of a router processor 13 or an Ethernet matching line processor to which the present invention can be applied, and provides forwarding and routing of IP packets at high speed based on ATM. The router processor 13 is connected to an upper layer 21 that performs three or more layers of protocols including Internet routing protocols such as RIP, OSPF, and BGP, and a multiple LAN, which is a function corresponding to two layers, connected to the upper layer 21. An ATM adaptation layer (AAL5) unit 23 connected to the emulation client processing unit 22, the multi-language emulation client 22 to convert packets received from an upper layer into ATM and vice versa, and the functional units ( 21-23) is configured as a layer management unit 24 for performing management and control functions of each layer. The upper layer 21, the LAN emulation client processing unit 22, and the ATM adaptation layer unit 23 each use the layer management unit 24 to process system operation commands and interact with the call connection function in the system process. Connected through. The LAN emulation client processing unit 22 is used to provide a layer 2 protocol function in a device at an endpoint or a server device providing a routing function. In particular, to provide IP routing in ATM-based switched router devices, LAN emulation client functions are needed as many as the number of ports supported. The multi-LAN emulation client processor 22 provides a function for this, and each LAN emulation client joins a different emulated LAN (ELAN) to enable IP packet forwarding between different subnets. An edge device that connects an existing LAN to an ATM network runs on an Ethernet line interface and can be used if you want to access different emulated LANs with more than one Ethernet port. Of course, it can also be used with a single LAN emulation.

3 is an internal configuration diagram of a multiple LAN emulation processing unit according to an embodiment of the present invention. The packet received from the upper layer 31 is transferred to the multiple LAN emulation protocol processor 33 through the LAN Emulation Client (LEC) service interface 32. The multi-language emulation protocol processor 33 performs a protocol according to a standard specification using information distinguished for each entity, and converts the data packet to an ATM cell via an ATM adaptation layer (AAL) service interface 35.

In addition, the cell received from the ATM as the reverse process is recombined into AAL 5 frames via the ATM Adaptation Layer (AAL) service interface 35. The recombined frame is distinguished whether it is user information or control information through the AAL 5 frame routing control unit 34. If the user information is used, the block identifier (BID :) removed from the LAN emulation header and provided by the AAL service interface 35 is used. Block ID) is transmitted to the upper layer 31 using the LAN emulation client entity port number as a parameter. The upper layer 31 distinguishes the router interface from the entity's port number. On the other hand, in the case of control information, it is transmitted to the multiple LAN emulation protocol processor 33 for processing.

In order to provide a multi-LAN emulation client function, the system interface 314, the operation command processor 310, the common connection connection control unit 311, the common connection table 312, the call separator management unit 36, and the entity information table 38 are provided. ) Must be included.

The operation command processor 310 receives and processes operation commands, such as function initialization, entity addition and deletion, and status view, from the system interface 314. The common connection connection control unit 311 is connected to the system interface 314 to process a function control frame for establishing and releasing the ATM virtual connection required to perform the LAN emulation protocol. The common connection table 312 is a common connection connection control unit ( 311) to provide overall connection information. The entity information tables 38 manage all information necessary for control and operation for each entity. The call delimiter manager 36 manages call delimiters necessary to control multiple entities, such as requiring multiple entities to establish a connection at short time intervals. The entity information tables 38 are created and used when the entity is added and removed when the entity is deleted. The timer 313 is used to send control information and the like to a counterpart entity that wishes to communicate and wait for a response or to age various states.

4 is a data processing operation diagram of the multi-LAN emulation client processing unit shown in FIG. The upper layer unit 41 transmits user data to the multi-language emulation client processor 42. When the data transmission request is requested, the upper layer unit 41 inputs the start address of the buffer in which the user information is stored, the data size to be transmitted, and the entity port number to be transmitted. (44). The user data transmitted to the multi-LAN emulation client processor 42 retrieves a protocol and an ATM virtual connection to be transmitted using entity information about the corresponding entity port, and sends the data to the ATM adaptation layer unit 43. The ATM adaptation layer section 43 sends data divided into packets of a certain size called an ATM cell.

In the reverse process, ATM cells received from the ATM adaptation layer unit 43 are reassembled and stored in the packet buffer, and the start address, size, connection identifier, and block identifier of the stored packets are extracted to multi-lan emulation through parameters. The client processor 42 notifies that data has been received (47). The multi-LAN emulation client processor 42 distinguishes whether it is control information or user information from the LAN emulation header value of this information and identifies the corresponding entity by using port information included in the block identifier. In the case of user information, the upper layer unit 41 is notified of the reception using the start address of the buffer in which the user information is stored, the data size to be transmitted, and the received entity port number as parameters (46).

5 is an interaction diagram of connection management required to perform multiple entity functions. When the multi-LAN emulation client processor 51 receives the packet data requesting delivery from the upper layer to the ATM network, first obtains a destination MAC (Medium Access Control) address from the Ethernet header of the received packet, and retrieves the LAN emulation cache table. Find the ATM address for the MAC address. If there is an ATM address, the LAN emulation connection table 510 is searched if there is an ATM virtual channel connection (VCC) set to the ATM address, and if a valid connection exists, packet data is transmitted to the found ATM connection.

However, if the connection does not exist, the connection establishment procedure for the destination ATM address must be performed. To this end, first, the connection establishment request frame is sent to the call connection function processing unit 53 of the system processor, and the call connection function processing unit 53 performs a call processing protocol, and as a result, connects hardware to the ATM adaptation layer unit 52. A control frame is sent 55 to set up a lookup table. When the AAL adaptation layer 52 receives the hardware connection establishment request, the AAL adaptation layer 52 adds the AAL connection table 510 to the call processing function processor 53 and adds the result of the process to the call processing function processor 53. The call processing function processing unit 53 receives the response to the connection establishment 58 to the multi-LAN emulation client processing unit 51, and the multi-LAN emulation client processing unit 51 is necessary for management from the ATM adaptation layer unit 52. Get the connection separator (57, 58) In addition, a block delimiter is added to the AAL connection table 511 to distinguish data received from the connection in a multi-entity environment. Block delimiters include functional blocks and entity identifiers. The ATM connection between the multi-LAN emulation client processor 51 and the ATM adaptation layer 52 defines and uses a connection identifier (CID).

A block identifier (BID) is used for the block and entity routing in the AAL connection table 511 to simplify the processing and to operate efficiently. ATM connection division between the multi-language emulation client processing unit 51 and the call processing function processing unit 53 defines and uses a call connection identifier (CCID). The Call Delimiter (CCID) is used independently in the system without duplication, and the Connection Delimiter (CID) and Block Delimiter (BID) are used independently in the function board.

6 is a configuration diagram of each delimiter defined in performing a multi-entity function. First, the connection identifier (CID) 61 is used to distinguish between ATM connections between the ATM adaptation layer unit and the LAN emulation entity, and uses consecutive values from 1 to the maximum number of connections. Since continuous values are used, the information can be easily used as an index when searching for information using the connection separator 61. The block delimiter (BID) 62 is composed of 2 bytes, and the upper 1 byte is used to distinguish the upper function, and the lower 1 byte is assigned an entity distinguishing number. Entity numbers are assigned sequentially from 1 The upper block delimiter is used in the ATM adaptation layer to facilitate the distinction because there is only one function block on the board and at least one functional block exists. The call connection identifier (CCID) 63 is generated and managed by the call connection function processing unit and used to distinguish the call connection between the LAN emulation entity and the call connection processing unit. As such, the simple and implied type of delimiter is used at the service access point, thereby reducing the processing time for data and call processing, thereby enabling efficient processing. The AAL connection table 64 managed by the ATM adaptation layer includes a connection identifier (CID) 61, a block identifier (BID) 62, a virtual path identifier (VPI) / virtual channel identifier (VCI). Channel Identifier) and a structure containing information necessary for management.

FIG. 7 is a diagram illustrating an internal configuration of the call connection function processor shown in FIG. 5. Because ATM uses Virtual Channel Connection (VCC), LAN emulation entities that work with all ATMs must implement signaling protocols. In the system, a number of line interfaces are connected to ATM switches, and in order to send and receive ATM cells through the switch, user network signaling protocol (UNI Signaling) must be used to establish ATM connection. However, if all entities have their own signaling protocols on board, the complexity of the protocol processing can be complicated to perform LAN emulation functions in a complex structure, resulting in poor data transfer performance and complex connectivity in the system. To solve this problem, each line interface board (73, 74, 75) does not process the signal protocol directly, but the slave connection function of the proxy signal connection unit 76 through the call connection protocol processing unit of the upper system processor and the centralized type. This simplifies the processing structure and reduces the system configuration cost. The upper processor performs the proxy master 71 function to control the call connection function from multiple slaves.

8 illustrates a protocol stack and a data frame structure according to the present invention. First, looking at the protocol stack, there are various types of upper layer 81 such as a bridge, an IP layer, and a multi-protocol over ATM (MPOA). Next, the upper layer service interface 82 connected to the upper layer 81 of various types performs an adjustment function for connecting the upper layer 81 to the LAN emulation client (LEC) 83. Next, the LAN emulation client unit (LEC) 83 is connected to the upper layer service interface 82 to perform an interworking function with ATM. Next, the ATM adaptation layer 84 connected to the lower layer of the LAN emulation client (LEC) 83 splits the data packet into ATM cells for forwarding the LAN emulation data packet to the ATM layer 85, or vice versa. Assemble the ATM cell into packets. The ATM layer unit 85 is connected to the lower part of the ATM adaptation layer 84.

The upper layer data is configured in the form of an Ethernet frame 86 in the upper layer service interface unit 82, and the LAN emulation client unit 83 adds a 2-byte LEC header before the Ethernet frame, and the LAN emulation data frame 87 Is stored in the AAL5 payload portion and an AAL5 header is added at the beginning (88). The AAL frame is divided in units of ATM cells (89), and the ATM layer 85 transfers the ATM cells received from the ATM adaptation layer to the physical layer in units of cells using the ATM header connection information. The reverse is different except that the headers of each layer are removed.

While the invention has been described above based on the preferred embodiments thereof, these embodiments are intended to illustrate rather than limit the invention. It will be apparent to those skilled in the art that various changes, modifications, or adjustments to the above embodiments can be made without departing from the spirit of the invention. Therefore, the protection scope of the present invention will be limited only by the appended claims, and should be construed as including all such changes, modifications or adjustments.

As described above, according to the present invention, multiple LAN emulation client entity functions can be provided in a board using one software. This allows efficient middle layer protocols to be implemented in similar system architectures that require multiple layers of multiple entities simultaneously, such as in ATM-based switched routers. In addition, in performing the user manganese protocol in the system, by processing the centralized call connection protocol between the system processor and the line interface, it is possible to simplify the processing structure and reduce the configuration cost in the system.

Claims (9)

A LAN emulation client multi-entity processing apparatus for providing a 2-layer LAN emulation client multi-entity function, An upper layer unit for requesting transmission of user data to a lower layer and processing user information received from the lower layer; Connected to the lower layer of the upper layer unit, and processes user data from the upper layer unit for each entity to transfer to the ATM adaptation layer unit, and processes the user information from the ATM adaptation layer unit for each entity and delivers it to the upper layer unit. A multi-LAN emulation client processor; And Connected to a lower part of the multi-LAN emulation client processing unit, divides user data from the multi-LAN emulation client processing unit into ATM cells, transmits the data to the physical layer, and recombines the receiving ATM cells transmitted from the physical layer to generate user information; LAN emulation client multi-entity processing apparatus comprising the ATM adaptation layer to pass to the multi-language emulation client processor. The method of claim 1, wherein the multiple LAN emulation client processor, An operation command processor that receives and processes operation commands such as function initialization, entity addition and deletion, and status view from a system interface; A common connection access controller connected to the system interface to process a function control frame for establishing and releasing an ATM virtual connection necessary to perform a LAN emulation protocol; A common connection table connected to the common connection connection control unit and providing overall connection information; Entity information tables in which all information required for control and operation is managed for each entity; A management entity information table for managing unique information required for each of the entities to operate; A call delimiter manager that manages call delimiters necessary to control multiple entities, and LAN emulation client multi-entity processing apparatus comprising a LAN emulation protocol processing unit for performing a protocol according to the standard by using information separated by entity. The method according to claim 1, wherein the multiple entities of the multi-LAN emulation client processing unit share the ATM adaptation layer unit, the multi-LAN emulation client processing unit and the ATM adaptation layer unit define a connection delimiter for ATM connection, and the block delimiter to the AAL connection table. In addition, the LAN emulation client multi-entity processing apparatus for distinguishing data received from the ATM connection in a multi-entity environment, and sharing the AAL connection table. 4. The LAN emulation client multiple entity processing apparatus according to claim 3, wherein the connection separator is used as an index when retrieving information by using consecutive values from 1 to the maximum number of connections. 4. The LAN emulation client multiple entity processing apparatus according to claim 3, wherein the block delimiter comprises 1 byte for function classification and 1 byte for entity identification number assignment. In the LAN emulation client multi-entity processing method for providing a 2-layer LAN emulation client multi-entity within a single board, In a multi-entity environment, data packets from an upper layer unit are received, the received packets are processed for each entity, and delivered to the ATM adaptation layer unit. The data flow from the ATM adaptation layer unit to the upper layer unit is divided by entities. To process the data packet flow of multiple entities, And a second step of performing control procedures such as connection management, configuration management, and state management required to control the data flow of the multiple entities. The method according to claim 6, wherein the multiple entities share the ATM adaptation layer, define a connection separator and a block separator that simplify the connection classification as an interface parameter so as to facilitate searching, and share the AAL connection table. How to handle LAN emulation client multiple entities. 8. The method of claim 7, wherein the connection separator uses a continuous value from 1 to the maximum number of connections as an index when searching for information. 8. The method of claim 7, wherein the block delimiter comprises 1 byte for function classification and 1 byte for entity identification number assignment.