KR100388969B1 - Apparatus and method for interface between ATM and ETHERNET LAN for transparent LAN services - Google Patents

Abstract

The present invention provides an ATM and an Ethernet LAN matching device and a method for transparent LAN service, comprising: a LAN on one side to provide a short-range communication function; A router connected to one LAN and connecting a network layer between one LAN and an ATM switch; A plurality of ATM switches connected to a router and configured to perform an ATM switching function; A passive optical network unit connected to one of the plurality of ATM switches, connecting the ATM switch and the plurality of ATM fabrics by passive optical elements, and forming a network line by using a broadcasting TDM scheme downstream; An ATM fabric connected to the passive optical network unit and configured to transmit / receive ATM cells by CPCS-PDU; An Ethernet fabric connected to the ATM fabric and configured to perform data transmission / reception between the ATM network and the LAN; By configuring the LAN on the other side connected to the Ethernet fabric or the passive optical network part, it implements the transparent LAN service between different networks by using the UTOPIA level and the ATM-PON network to efficiently manage traffic and The other network can be used as one network.

Description

ATM and Ethernet LAN matching device and method for transparent LAN service {Apparatus and method for interface between ATM and ETHERNET LAN for transparent LAN services}

The present invention relates to an Asynchronous Transfer Mode (ATM) and an Ethernet (ETHERNET) LAN matching device and a method thereof for a local area network (LAN) service, and more particularly, to AAL5 (ATM Adaptation Layer 5, ATM matching layer 5). Universal Test and Operations Physical Interface for ATM (UTOPIA) level and Passive Optical Network (ATM-PON) in applying Ethernet frame to ATM cell using segmentation and reassembly (SAR) of ATM By using a network, it is possible to efficiently implement transparent LAN service between different networks, which is more efficient in terms of traffic management than conventional point-to-point transmission. It relates to an ATM and an Ethernet LAN matching device and a method for a transparent LAN service which is suitable to be made available as such.

In general, a LAN is a collection of PCs, mainframes, and workstations connected over 300m of communication lines. A LAN is a high-speed communications network that connects computers and computers in an institution's building to the most efficient distance at which currents or radio signals can be transmitted between computers.

Ethernet is the most widely installed LAN technology. This is defined as a standard in IEEE 802.3. Ethernet LANs generally use coaxial cables or special graded unshielded twisted pairs.

The most commonly installed Ethernet system is called 10BASE-T and provides a transmission rate of 10Mbps. All devices are connected by cable and competitively accessed using the Carrier Sense Multiple Access with Collision Detection (CSMA / CD) protocol. Fast Ethernet and 100BASE-T provide up to 100 Mbps and are commonly used as the backbone of local area networks to support workstations with 10BASE-T cards. Gigabit Ethernet is around 1,000 Mbps, supporting higher levels of backbone speed.

ATM is a dedicated-connection switching technology that divides digital data into 53 bytes of cells or packets and transmits them through a medium using digital signal technology. One cell is individually processed asynchronously with respect to the other cells and placed in a queue for multiplexing for circuit sharing. Because ATM is designed to be easier to implement in hardware than software, it is possible to speed up processing. Along with SONET (Synchronous Optical Network), ATM is used in broadband ISDN (BISDN).

And since LAN is a computer network, it is the basis for data transmission. As the multi-media multi-access system continues to develop rapidly, the amount of information and LAN traffic will continue to increase.

New technologies are required to transmit and exchange such vast information, which can be solved to some extent by the combination of ATM networks and LANs that perform high-speed switching functions.

1 is a block diagram showing a structure of a conventional ATM and a LAN network, and shows a conventional ATM network and various types of LAN configurations.

Here, reference number 1 is Ethernet, 2 is TOKEN RING, 3 is DTE (Data Terminal Equipment), and 4 is a router. Also, reference numeral 5 is an ATM digital service unit (DSU), 6 is an ATM switch, and 7 is a hub.

Thus, there are Ethernet (1) based on IEEE802.3 and Token Ring (2) based on IEEE802.5. These local networks are combined with ATM switches (6) through ATM-DSU (5).

Another local network has a form in which information transmitted from a terminal is combined with an ATM switch 6 through a hub 7 and a router 4.

For this combination, an ATM interface block must be embedded in the router 4 or implemented as an ATM-DSU 5 between the router 5 and the ATM switch 6.

2 is a diagram illustrating a connection protocol layer between a conventional ATM switch and Ethernet.

Therefore, in order to transmit the packet data transmitted from the PC to the ATM switch 6, a segmentation process is performed, and a reassembly process is performed in the opposite transmission path.

LAN emulation is also required in this process. LAN emulation is located at the ATM (4) ATM-to-LAN converter, Router (4) or ATM-DSU (5), and ATM host.The ATM data is compared with the Ethernet MAC address and converted to the correct destination. Help to find

If the DTE increases, an Add Drop Mux (ADM) (which is not shown in the drawing) must be additionally installed between the ATM switch 6 and the ATM-DSU 5.

In addition, routers need to perform protocols and address routing when connecting multiple DTEs.

However, this conventional technology has a problem in that an add-drop multiplexer must be additionally installed between the ATM switch and the ATM-DSU as the DTE increases.

In addition, performing a protocol at the router and performing an address routing in a plurality of DTE connections cause a delay in data transmission time, and thus, a transmission rate is degraded in a plurality of DTE connections.

Accordingly, the present invention has been proposed to solve the above-mentioned conventional problems, and an object of the present invention is to apply an Ethernet frame to an ATM cell using an AAL5 SAR, and to apply it to a transmission section in a UTOPIA level and an ATM-PON network. It is possible to efficiently implement transparent LAN service between different networks by using a transparent LAN service that is more efficient in terms of traffic management than conventional point-to-point transmission and can use different networks in a long distance as one network. To provide an ATM and Ethernet LAN matching device and method thereof.

ATM and Ethernet LAN matching device for transparent LAN service according to an embodiment of the present invention to achieve the above object,

A LAN on one side that provides a short-range communication function; A router connected to the LAN of one side and connecting a network layer between the LAN of one side and an ATM switch; A plurality of ATM switches connected to the router and configured to perform an ATM switching function; A passive optical network unit connected to one of the plurality of ATM switches, connecting the ATM switch and the plurality of ATM fabrics by passive optical elements, and forming a network line by using a broadcasting TDM scheme downstream; An ATM fabric connected to the passive optical network unit and configured to transmit / receive ATM cells by CPCS-PDU; An Ethernet fabric connected to the ATM fabric and configured to perform data transmission / reception between an ATM network and a LAN; The technical configuration is characterized by including the LAN of the other side connected to the Ethernet fabric or the passive optical network portion.

ATM and Ethernet LAN matching method for transparent LAN service according to an embodiment of the present invention to achieve the above object,

In case of transmitting ATM signal, it analyzes VCI and checks whether the corresponding channel is currently active. If the corresponding channel is currently active, CRC and CPCS-SDU payload length information is obtained from memory, and CRC check is performed. Determining whether to perform; Performing HEC on an ATM signal if the HEC is to be performed; If the HEC or the HEC is not to be performed, padding the CPCS-PDU with zero as necessary; Inserting a CPCS-PDU trailer after the padding, generating a 5-byte cell header, performing segmentation, and combining an ATM-PDU cell header and an ATM-SDU to construct an ATM-PDU; And performing the step of transmitting the configured ATM-PDU cell to UTOPIA level 2 is characterized by its technical configuration.

ATM and Ethernet LAN matching method for transparent LAN service according to an embodiment of the present invention to achieve the above object,

When receiving the ATM signal, the VCI is analyzed to determine whether the corresponding channel is currently active. If the corresponding channel is currently active, the CRC and CPCS-SDU payload length information is obtained from the memory, and the CRC check is performed. Determining whether to perform; Performing HEC on an ATM signal if the HEC is to be performed; Removing the zero-padded zeros from the CPCS-PDU by performing a 48-byte modulo if the HEC or the HEC is not to be performed; Removing the padding, removing the CPCS-PDU trailer and recovering the 48 byte SAR-PDU; And transmitting the SAR-PDU payload from the recovered SAR-PDU to the output FIFO and storing the state of the CPCS-SDU.

1 is a block diagram showing the structure of a conventional ATM and LAN network,

2 is a diagram illustrating a connection protocol layer between a conventional ATM switch and Ethernet.

3 is a block diagram of an ATM and an Ethernet LAN matching device for transparent LAN service according to an embodiment of the present invention.

4 is a flowchart illustrating an ATM and Ethernet LAN matching method for transparent LAN service during transmission according to an embodiment of the present invention.

5 is a flowchart illustrating an ATM and Ethernet LAN matching method for transparent LAN service upon reception according to an embodiment of the present invention;

6 is a diagram showing the structure of an ATM-PDU used in the present invention.

Explanation of symbols on the main parts of the drawings

10: LAN 20: Router

30: ATM switch 40: passive optical network unit

41: optical line terminal 42: passive light distribution

43: optical network section 50: ATM fabric

60: Ethernet fabric

Hereinafter, an embodiment of the present invention configured as described above, an ATM and an Ethernet LAN matching device for a transparent LAN service, and a method thereof will be described in detail with reference to the accompanying drawings.

3 is a block diagram of an ATM and an Ethernet LAN matching device for transparent LAN service according to an embodiment of the present invention.

As shown therein, a LAN 10a on one side that provides a short-range communication function; A router 20 connected to the LAN 10a of the one side and connecting a network layer between the LAN 10a of the one side and the ATM switch 30; A plurality of ATM switches (30) connected to the router (20) and performing ATM switching functions; It is connected to one of the plurality of ATM switches 30, and connects the ATM switch 30 and the plurality of ATM fabrics (50) by passive optical elements, broadcasting (Time Division Multiplexing) TDM (Broadcasting) A passive optical network (PON) 40 for forming a network line by using a downstream method of the present invention; An ATM fabric 50 connected to the passive optical network unit 40 to perform transmission / reception of ATM cells by a Common Part Convergence Sublayer-Protocol Data Unit (CPCS-PDU); An Ethernet fabric (60) connected to the ATM fabric (50) and configured to perform data transmission / reception between the ATM network and the LAN; It is configured to include a LAN (10b) (10c) of the other side connected to the Ethernet fabric 60 or the passive optical network portion 40.

The passive optical network unit 40 includes: an optical line terminal (OLT) 41 connected to one of the plurality of ATM switches 30 to form an optical line; The ATM signal transmitted through the optical line terminal 41 is distributed and transmitted to the plurality of optical network units (ONU) 43, and the ATM signals received from the plurality of optical network units 43 are transmitted. A passive optical splitter (POS) 42 which is synthesized and transmitted to the optical line terminal 41; The ATM signals distributed by the passive light distribution unit 42 are respectively transmitted to the plurality of ATM fabrics 50, and the ATM signals respectively transmitted from the plurality of ATM fabrics 50 are transmitted to the passive light distribution unit 42. It comprises a plurality of optical network section 43 for transmitting.

4 is a flowchart illustrating an ATM and Ethernet LAN matching method for transparent LAN service during transmission according to an embodiment of the present invention.

As shown in FIG. 2, when the ATM signal is transmitted, a virtual channel identifier (VCI) is analyzed to determine whether the corresponding channel is currently active. If the corresponding channel is currently active, a cyclic redundancy check is performed from the memory. Obtaining the CPCS-SDU (Common Part Convergence Sublayer-Service Data Unit) payload length information, performing a CRC check, and then determining whether to perform HEC (Header Error Correction) (ST11 to ST13); Performing HEC on an ATM signal if the HEC is to be performed (ST14); If the HEC or the HEC is not to be performed, padding 0 as necessary in the CPCS-PDU (ST15); Inserting a CPCS-PDU trailer after the padding, generating a 5-byte cell header, performing segmentation, and then configuring an ATM-PDU by combining an ATM-PDU cell header and an ATM-SDU (ST16 to ST18); ; And transmitting the configured ATM-PDU cell to UTOPIA level 2 (ST19).

5 is a flowchart illustrating an ATM and Ethernet LAN matching method for transparent LAN service upon reception according to an embodiment of the present invention.

As shown in the figure, when receiving an ATM signal, the VCI is analyzed to determine whether the corresponding channel is currently active. If the corresponding channel is currently active, CRC and CPCS-SDU payload length information is obtained from the memory, and the CRC check is performed. Determining whether to perform the HEC after the operation (ST21 to ST23); Performing HEC on an ATM signal if the HEC is to be performed (ST24); Removing the zero-padded zeros from the CPCS-PDU by performing a 48-byte modulo if the HEC or the HEC is not to be performed (ST25); Removing the padding, removing the CPCS-PDU trailer and restoring the 48-byte SAR-PDU (ST26) (ST27); And transmitting the SAR-PDU payload from the recovered SAR-PDU to the output FIFO and storing the state of the CPCS-SDU (ST28) (ST29).

Operation of the ATM and the Ethernet LAN matching device and the method for the transparent LAN service according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

First, in the present invention, the passive optical network unit 40 is located between the portion corresponding to the ATM-DSU composed of the Ethernet fabric 60 and the ATM fabric 50 and the ATM switch 30, thereby matching the conventional point-to-point transmission. Unlike the point-to-multipoint form, an efficient local area network and the ATM switch 30 can be combined.

Here, the router 20 connected to the LAN 10a of one side of the local network is a device for connecting separate networks using the same transmission protocol and connects network layers to each other. In addition to the functionality of the bridge, such a router 20 determines a node in another network or its own network according to a routing table. It selects the most efficient route among the various routes and sends the packet. The router 30 performs flow control, configures various subnetwork within the internetwork, and performs various network management functions.

In addition, unlike the conventional network construction scheme, the passive optical network unit 40 does not use an active device such as an existing Ad-Drop Multiplexer (ADM) to end subscriber terminal equipment, but the passive optical distribution unit 42, which is a passive optical device, is used. By using, the low cost of construction can be realized. In addition, the multiplexing time can be shortened when performing data transmission to multipoint using the broadcasting TDM downstream.

For the interface between the passive optical network unit 40 and the ATM fabric 50, a backplane is connected to UTOPIA level 2 of a 16-bit stream.

6 is a diagram showing the structure of an ATM-PDU used in the present invention.

So, when you want to transmit the ATM signal in the ATM fabric 50 is performed as follows.

That is, the VCI is analyzed to determine whether the corresponding channel is currently active.

Therefore, if the current channel is active, the CRC and CPCS-SDU payload length information is obtained from the memory, and the CRC check is performed.

Perform HEC if necessary.

The modulo pads the CPCS-PDU with zeros as necessary to decompose it into 48 bytes.

Insert a CPCS-PDU trailer.

A 5-byte cell header is generated for the ATM-PDU configuration.

The segmentation is performed by inserting the CPCS-DPU in the 48-byte SAR-P space.

ATM-PDU cell header and ATM-SDU are combined to complete 53 bytes of ATM-PDU.

Send the completed ATM-PDU cell to UTOPIA level 2.

When receiving the ATM signal in the lower ATM fabric 50 is performed as follows.

First, the VCI is analyzed to see if the channel is currently active.

Therefore, if the current channel is active, the CRC and CPCS-SDU payload length information is obtained from the memory, and the CRC check is performed.

Perform HEC if necessary.

A 48-byte modulo is performed to remove zero-padded zeros from the CPCS-PDU.

Once the padding has been removed, remove the CPCS-PDU trailer.

And recover the 48-byte SAR-PDU.

The recovered SAR-PDU sends the SAR-PDU payload to the output FIFO and stores the state of the CPCS-SDU again.

Meanwhile, aspects of transparent LAN service are as follows.

That is, the TLS (Transparent LAN Service) according to the present invention forms an interconnection of each LAN through a high speed optical transmission. Each LAN subscriber can send and receive data in the same network concept as a remote LAN without knowing or knowing that their data traverses a backbone network such as the Metropolitan Network.

It retains the connectionless characteristic of the LAN and enables point-to-multipoint virtual connection. This is possible because the data is transmitted to the backbone network through the matching of the passive optical network (PON) and LAN proposed in the present invention and data encapsulation through AAL5 SAR.

As such, the present invention efficiently implements a transparent LAN service between different networks using a UTOPIA level and an ATM-PON network, efficiently performing traffic management aspects, and uses different networks in a long distance as a single network. will be.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

As described above, an ATM and an Ethernet LAN matching device and a method for transparent LAN service according to the present invention are UTOPIA level and ATM- in applying an ATM frame to an ATM cell using an AAL5 SAR. By using PON network, it is possible to efficiently implement transparent LAN service between different networks, so it is more efficient in traffic management than conventional point-to-point transmission and can use different networks in long distance as one network. do.

In addition, the present invention can provide a more transparent LAN service through an efficient network configuration can be implemented between different local area networks, as if all the terminals are configured in the same area or building by tying the networks separated in the distance under the same sub-network. It can also be used and further improves performance by minimizing delay in the overall data transfer and by optimally implementing point-multipoint.

Claims (4)

A local area network (LAN) providing near field communication function; A router connected to the LAN of one side and connecting a network layer between the LAN of one side and an ATM switch; A plurality of ATM switches connected to the router and configured to perform an ATM switching function; A passive optical network unit connected to one of the plurality of ATM switches, connecting the ATM switch and the plurality of ATM fabrics by passive optical elements, and forming a network line by using a broadcasting TDM scheme downstream; An ATM fabric connected to the passive optical network unit and configured to transmit / receive ATM cells by CPCS-PDU; An Ethernet fabric connected to the ATM fabric and configured to perform data transmission / reception between an ATM network and a LAN; ATM and Ethernet LAN matching device for a transparent LAN service, characterized in that it comprises a LAN of the other side connected to the Ethernet fabric or passive optical network portion. The method of claim 1, wherein the passive optical network unit, An optical line terminal connected to one of the plurality of ATM switches to form an optical line; A passive optical distribution unit for distributing ATM signals transmitted through the optical line terminals and transmitting them to a plurality of optical network units, and synthesizing the ATM signals received from the plurality of optical network units and transmitting the synthesized ATM signals to the optical line terminals; And a plurality of optical network units for transmitting the ATM signals respectively distributed by the passive optical distribution unit to the plurality of ATM fabrics, and transmitting the ATM signals respectively transmitted from the plurality of ATM fabrics to the passive optical distribution unit. ATM and Ethernet LAN matching device for transparent LAN service. In case of transmitting ATM signal, it analyzes VCI and checks whether the corresponding channel is currently active. If the corresponding channel is currently active, CRC and CPCS-SDU payload length information is obtained from memory, and CRC check is performed. Determining whether to perform; Performing HEC on an ATM signal if the HEC is to be performed; If the HEC or the HEC is not to be performed, padding the CPCS-PDU with zero as necessary; Inserting a CPCS-PDU trailer after the padding, generating a 5-byte cell header, performing segmentation, and combining an ATM-PDU cell header and an ATM-SDU to construct an ATM-PDU; Transmitting the configured ATM-PDU cell to UTOPIA level 2; and the ATM and Ethernet LAN matching method for transparent LAN service. When receiving the ATM signal, the VCI is analyzed to determine whether the corresponding channel is currently active. If the corresponding channel is currently active, the CRC and CPCS-SDU payload length information is obtained from the memory, and the CRC check is performed. Determining whether to perform; Performing HEC on an ATM signal if the HEC is to be performed; Removing the zero-padded zeros from the CPCS-PDU by performing a 48-byte modulo if the HEC or the HEC is not to be performed; Removing the padding, removing the CPCS-PDU trailer and recovering the 48 byte SAR-PDU; And transmitting the SAR-PDU payload from the recovered SAR-PDU to an output FIFO and storing a state of a CPCS-SDU.