KR0153944B1 - Ethernet connecting apparatus for including the ip routing function with atm switch - Google Patents

Abstract

The present invention relates to an Ethernet access device for accommodating an IP router function using an ATM switch. The present invention relates to an Ethernet access means for transmitting and receiving an IP frame through arbitration of a common bus by removing or attaching a MAC address. 10); Multi-protocol is encapsulated after receiving an IP frame from the Ethernet access means 10, and multiplexed and outputted, or demultiplexed and decapsulated after receiving encapsulated data. Multiprotocol encapsulation means for outputting an IP frame to the Ethernet access means (10) by comparing them with each other; After receiving the IP frame of the multi-protocol encapsulation means 20, add a trailer to convert the AAL 5 data, convert the output into ATM cell data by attaching a connection identifier (VPI / VCI) header value, and input the data. AAL 5 / ATM cell conversion, which removes the VPI / VCI header value from the ATM cell data and converts it into AAL 5 data, and then removes the trailer to output the encapsulated IP frame to the multiprotocol insulation means 20. Means (30); And adding an additional header, which is information for self-routing, to the cell received by the AAL 5 / ATM cell converting means 30 and outputting it to the ATM switch 3, or receiving data from the ATM switch 3 to remove the additional header. And a switch connection means 40 for outputting ATM cell data to the AAL 5 / ATM cell conversion means 30, and using a cell multicasting function of an ATM switch, that is, a copy function of a corresponding VPI / VCI cell. IP multicasting function can be provided to ATM subscribers, and Ethernet subscribers can control the multicasting data of IP frame reception buffer 25 from the bus controller / intermediator 12 to the corresponding Ethernet access circuit 11 twice. Therefore, the existing Ethernet users are left intact, and users who require new high-speed data transmission and processing are provided with ATM access functions, so that high-speed communication between them is possible by using ATM switching function. have.

Description

Ethernet connection for accommodating IP router function using ATM switch

1 is a system configuration to which the present invention is applied.

2 is a functional block diagram of an Ethernet access device (EPIM) in accordance with one embodiment of the present invention.

3 is a frame structure diagram of a multi-protocol insulation unit according to an embodiment of the present invention.

4 is a frame structure diagram of an AAL5 / ATM cell converter according to an embodiment of the present invention.

5 is a frame structure diagram of a switch connecting portion according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

10: Ethernet connection 20: Multi-protocol encapsulation

30: AAL5 / ATM cell converter 40: switch connection

The present invention relates to an Ethernet access device for accommodating an IP router function using an ATM switch, and in particular, by applying an ATM switching function to an IP routing function, an IP frame can be delivered to a destination at a higher speed than a conventional router. The Ethernet port interface module (EPIM) connected to the existing Ethernet is one of the systems that enables IP-level communication between a terminal connected to an in-Ethernet and an ATM host device having an ATM connection function. It is about.

IP routers, which are widely used at present, have a function of interpreting and routing IP frames at the network level among OSI 7 layers, and most of the routing functions rely on software processing.

However, as the number of users, such as the Internet, increases, the quality of service decreases as a bottleneck that reduces bandwidth available to a user in an existing local area network (LAN) using a shared medium.

There may be a method of applying the full ATM technology to the local area network (LAN) instead of Ethernet as a bob-up to solve the above problems, which has a problem that must completely replace the existing network elements.

Accordingly, the present invention devised to solve the above problems provides an ATM access function to a user who requires a new high-speed data transmission and processing while leaving an existing Ethernet user intact, thereby using a high-speed communication between them using an ATM switching function. The aim is to provide an Ethernet access device that accepts IP router functions using this possible ATM switch.

The present invention for achieving the above object is an Ethernet connection means connected to a plurality of Ethernet (Ethernet) to remove or paste the MAC address to send and receive IP frames through the arbitration of the common bus; Multi-protocol is encapsulated after receiving IP frame from the Ethernet access means, and then multiplexed and outputted, or demultiplexed and demultiplexed after receiving encapsulation data to compare multi-protocol. Multiprotocol encapsulation means for outputting an IP frame to the Ethernet access means; After receiving the IP frame of the multi-protocol encapsulation means, add a trailer to convert AAL 5 data, convert the VPI / VCI header value into ATM cell data, and output the converted VPI / VCI header. An AAL 5 / ATM cell converting means for removing the value and converting the AAL 5 data to the AAL 5 data, and then removing the trailer to output the encapsulated IP frame to the multi-protocol encapsulation means; And adding an additional header, which is information for self-routing, to the cell received by the AAL 5 / ATM cell converting means and outputting it to an ATM switch, or receiving data from an ATM switch to remove the additional header to remove ATM cell data from the AAL. And switch connection means for outputting to the 5 / ATM cell conversion means.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 is a system configuration diagram to which the present invention is applied, in which 1 represents an Ethernet access device, 2 represents an ATM subscriber matching device, and 3 represents an ATM switch.

The IP routing function is a technology that allows ATM switching technology, and then encapsulates the Ethernet IP frame primarily, and maps it to an ATM application type 5 frame.

The mapped AAL5 frame is divided into 53-byte units and added to the ATM switch 3 with the additional header of the ATM switch self-routing. The ATM switch 3 is output to the destination port by the value of the additional header.

In this case, when the ATM host is connected to the destination port, the host device reassembles the ATM cell and decapsulates the ATM cell to extract the IP frame.

However, when a host connected to the Ethernet access device (EPIM) 1 needs to be transmitted, an additional header is attached to be output to the same port of the ATM switch 3.

The ATM switch 3 distinguishes the VPI / VCI value of the cell coming into the Ethernet access device (EPIM) 1 and transmits the MAC address to the Ethernet subnetwork to which the host of the destination is connected by attaching a MAC address to the IP frame.

Therefore, the present invention encapsulates an IP frame, maps it to an AAL 5 frame, converts it into ATM cells, inputs the ATM switch 3, switches each cell, and then decomposes the input ATM again. In this case, the AAL 5 is decoded, decapsulated, and the IP frame is reproduced, and the MAC address is transmitted to the Ethernet subnetwork.

2 is a functional block diagram of an Ethernet access device according to an embodiment of the present invention, in which 10 is an Ethernet connection, 20 is a multi-protocol insulation unit, 30 is an AAL5 / ATM cell conversion unit, and 40 is a switch connection unit. Represent each.

The present invention is connected to a plurality of Ethernet (Ethernet) is connected to the Ethernet connection unit 10 to match the data / control signals on a common bus, to store the IP frame and perform the encapsulation / decapsulation (Encapsulation / Decapsulation) function A multiprotocol encapsulation unit 20, an AAL 5 / ATM cell conversion unit 30 for processing AAL 5 and VPI / VCI header values of the IP frame, and the AAL 5 / ATM cell conversion unit 30 It consists of a switch connecting portion 40 to add and remove information for self-routing to the cell received in the).

In addition, the Ethernet connection unit 10 is connected to the Ethernet to remove the MAC address or output a plurality of MAC connection or output the MAC address, MAC for storing the data for mapping the MAC / IP address and outputs Bus control / mediator 12 responsible for bus arbitration by outputting control signals to the plurality of Ethernet access circuits 11 using data from the < RTI ID = 0.0 > / IP < / RTI > lookup table 13 and the MAC / IP lookup table 13 ).

The multiprotocol encapsulation unit 20 outputs a control signal for selecting a multiprotocol when the frame is encapsulated, and stores the data for encapsulation of the frame to select the multiprotocol. A multi-protocol insulator 23 for encapsulating and outputting a multi-protocol by a control signal of the circuit 27, an IP frame transmission buffer 21 for receiving and buffering and outputting transmission data from the Ethernet connection unit 10, A multiplexer 22 and an AAL5 / ATM cell converter 30 for receiving and multiplexing the IP frame data of the IP frame transmission buffer 21 and the encapsulated data of the multiprotocol insulator 23. The demultiplexer 24 receives the output of the demultiplexer and outputs the demultiplexer 24, and demultiplexes the output of the demultiplexer 24 to compare the multi-protocol. And a multi-protocol dikep syulre data, and a comparator 26, and the IP frame reception buffer 25 for buffering and outputting the output of the demultiplexer 24.

The AAL5 / CSTM cell conversion unit 30 receives the data of the multi-protocol insulation unit 20, adds a trailer to form and output AAL 5 CPCS-PDU data, and outputs the AAL5 CPCS PDU mapper 31 for switching. Converting the output of the VPI / VCI lookup table 33 and the AAL5 CPCS PDU mapper 31 that store and output a connection identifier (VPI / VCI) into an ATM cell with reference to the data of the VPI / VCI lookup table 33 An ATM cell combiner 32 that receives the output data of the ATM cell combiner 32 and the switch connection unit 40 that outputs the received data, and outputs the AAL 5-PDU data by removing the ATM cell header with reference to the VPI / VCI lookup table. And an AAL5 CPCS PDU demapper 35 which removes the trailer receiving the output of the ATM cell decomposer 34 and outputs only the encapsulated data to the multiprotocol encapsulation unit 20.

The switch connection unit 40 receives ATM cell data from the additional header lookup table 42 and the AAL5 / ATM cell converter 30 that stores and outputs an additional header, and adds an additional header of the additional header lookup table to the ATM. The switch header header extractor 43 for outputting the switch header header generator 41 and the ATM switch 3 outputted to the switch 3 and removing the header header and outputting the header header to the AAL5 / ATM cell converter 30 Equipped.

Referring to FIGS. 3 to 5, the operation of the present invention configured as described above will be described first, and the operation of the Ethernet switch 10 toward the ATM switch 3 from the Ethernet side may include a plurality of Ethernet connection circuits ( 11) After receiving the Ethernet frame to remove the 6-byte MAC address from the Ethernet frame, and outputs to the IP frame transmission buffer 21 of the multi-protocol insulation unit 20.

Here, the bus control / mediator arbitrates the bus usage rights in order to prevent data input from multiple Ethernet ports from being mixed in the IP frame transmission buffer 21.

The multiprotocol encapsulation unit 20 generates and outputs a frame having a form as shown in FIG. 3 in an IP payload data unit (IP PDU) stored in the IP frame transmission buffer 21.

As shown in FIG. 3, the 8-byte data is stored in the multiprotocol insulator 23 to encapsulate the frame by the control signal of the multiprotocol selector 27. In other words, multi-protocol control signals are stored in advance when encapsulation data of various protocols such as 802.3, 4, 5, 6 and FDDI, that is, multi-protocol communication, is stored in advance. The protocol is outputted by multiplexing the data stored in the IP frame transmission buffer 21 with the multiplexer 22.

For example, for the most widely used Ethernet, the LLC value is OxAA-AA-03, the Ethertype is 0x00-00-00, and the last two bytes are 0x08-00-00 indicating the IP protocol. This IP PDU is multiplexed to generate and output a frame as shown in FIG.

The AAL5 CPCS PDU mapper 31 of the AAL5 / ATM cell converter 30 receives data from the multiplexer 22 of the multi-protocol encapsulation unit 20, adds a trailer, and adds a trailer. Create and print

In the trailer, CPCS-UU, Length and CRC-32 are calculated. The ATM cell combiner 32 assigns a unique VPI / VCI value to the IP address of the output of the AAL5 CPCS PDU mapper 31 by referring to the data of the VPI / VCI lookup table 33 and stores the AAL 5 CPCS-PDU by 53 bytes. Units are converted into ATM cells and output to the switch connection unit 40.

The switch connection 40 refers to the VPI / VCI value of the 53-byte cell received from the ATM cell combiner 32 to provide information on which port to which the cell should be routed. Insert the cell into the ATM switch 3 and insert the cell into the ATM switch 3.

For example, when the Ethernet access device (EPIM) is connected to port 1 of the ATM switch 3, when the Ethernet frame is transmitted from the second Ethernet connection circuit # 1 to # N-1, Cells that have undergone various processes mentioned above are inputted to switch 1 port and outputted to switch 1 port.

Next, referring to the transmission process from the ATM switch 3 to the Ethernet, the switch header header extractor 43 of the switch connection unit 40 receives the cells with the additional header from the ATM switch 3 and adds the header. After removing the in-switch self-routing information, 53-byte ATM cell data is output to the ATM cell decomposer 34 of the AAL 5 / ATM cell converter 30.

The ATM cell resolver 34 of the AAL 5 / ATM cell converter 30 reassembles 53-byte cells into an AAL 5 CPCS PDU as shown in FIG. 4 using the VPI / VCI value of the cell. Output to 350.

The AAL 5 CPCS PDU demapper 35 receives the output data of the ATM cell decomposer 34 and checks whether an error of the CRC-32 of the trailer is detected. Discard it.

If no error occurs, the trailer is removed and only the encapsulated data is output to the demultiplexer 24 of the multiprotocol insulation unit 20.

The demultiplexer 24 of the multiprotocol encapsulation unit 20 demultiplexes the 8-byte encapsulated data of the AAL 5 CPCS PDU demapper 35 to demultiplex the multiprotocol desulator and the comparator. When the output is compared with the multi-protocol, only this part is removed and stored in the IP frame receiving buffer 25 when it matches the protocol.

However, if the protocol does not match, the frame is discarded. In this case, the IP frame corresponding to the VIP / VCI 1: 1 may be stored in the IP frame receiving buffer 25 by using a queue management method and output to the Ethernet connection unit 10.

The bus control / arbitration unit 12 of the Ethernet connection unit 10 intercepts the state of use of the bus and arbitrates the output from the IP frame reception buffer 25 to the corresponding port of the Ethernet connection circuit 11.

At this time, the MAC / IP lookup table 13 is used to obtain information on which Ethernet connection circuit 11 is output. Finally, the Ethernet connection circuit 11 attaches the MAC address of the destination to the IP frame and transmits it to the terminal side.

The present invention configured as described above can provide IP multicasting function to a plurality of ATM subscribers by using a cell multicasting function of an ATM switch, that is, a copy function of a corresponding VPI / VCI cell, and an IP frame receiving buffer ( 25) Multicasting data from the bus controller / mediator 12 to the corresponding Ethernet connection circuit 11 is output twice so that the existing Ethernet user is left as it is and the user requests new high speed data transmission and processing. Gives the ATM access function has the effect of high-speed communication between them using the ATM switching function.

Claims (5)

Ethernet connection means (10) connected to a plurality of Ethernet (Ethernet) to remove or paste the MAC address to send and receive IP frames through the arbitration of the common bus; Multi-protocol is encapsulated after receiving an IP frame from the Ethernet access means 10 and then multiplexed and output, or decapsulated after receiving the encapsulated data and demultiplexed. Multiprotocol encapsulation means for outputting an IP frame to the inner access means 10 by comparing protocols; After receiving the IP frame of the multi-protocol encapsulation means 20, add a trailer to convert the AAL 5 data, convert it to ATM cell data by attaching a connection identifier (VPI / VCI) header value, and output the result. AAL 5 / ATM cell conversion means for removing the VPI / VCI header value from ATM cell data to AAL 5 data and then removing the trailer to output the encapsulated IP frame to the multiprotocol insulation means 20. 30; And adding an additional header, which is information for self-routing, to the cell received by the AAL 5 / ATM cell converting means 30 and outputting the added header to the ATM switch 3, or receiving data from the ATM switch 3 to remove the additional header. Switch connection means (40) for outputting ATM cell data to the AAL 5 / ATM cell conversion means (30). 2. The apparatus of claim 1, wherein the Ethernet connection means (10) comprises: a plurality of Ethernet connection circuits (11) connected to the Ethernet to remove and output the MAC address or to output the MAC address; A MAC / IP lookup table 13 for storing and outputting data for mapping MAC / IP addresses; And a bus control / mediator 12 for bus arbitration by outputting control signals to the plurality of Ethernet connection circuits 11 using the data of the MAC / IP lookup table 13. Ethernet access device to accept IP router function using ATM switch. The multiprotocol encapsulation means (20) according to claim 1, further comprising: a multiprotocol selection circuit (27) for outputting a control signal for selecting a multiprotocol upon encapsulation of a frame; A multiprotocol insulator (23) for storing data for encapsulation of a frame and insulating and outputting the multiprotocol by a control signal of the multiprotocol selection circuit (27); An IP frame transmission buffer 21 for receiving, buffering and outputting transmission data from the Ethernet connection means 10; A multiplexer (22) which receives the IP frame data of the IP frame transmission buffer (21) and the encapsulated data of the multi-protocol insulator (23), and multiplexes and outputs the received data; A demultiplexer 24 which receives the output of the AAL5 / ATM cell converting means 30 and demultiplexes the output; A multi-protocol demultiplexer and comparator (26) which receives the output of the demultiplexer (24) and de-insulates and compares the multi-protocol; And an IP frame receiving buffer (25) for buffering and outputting the output of the demultiplexer (24). The AAL5 CPCS PDU according to claim 1, wherein the AAL5 / ATM cell converting means (30) receives the data of the multiprotocol encapsulation means (20) and adds a trailer to form and output AAL 5 CPCS-PDU data. Mapper 31; A VPI / VCI lookup table 33 for storing and outputting a connection identifier (VPI / VCI) for switching; An ATM cell combiner (32) for converting the output of the AAL5 CPCS PDU mapper (31) into an ATM cell by referring to the data of the VPI / VCI lookup table (33); An ATM cell decomposer 34 which receives the output data of the switch connection means 40 and outputs AAL 5-PDU data by removing the ATM cell header with reference to the VPI / VCI lookup table; And an AAL5 CPCS PDU demapper 35 which receives the output of the ATM cell decomposer 34 and removes the trailer and outputs only the encapsulated data to the multiprotocol encapsulation means 20. Ethernet access device to accept IP router function using ATM switch. The switch connection means (40) according to claim 1, further comprising: an additional header lookup table (42) for storing and outputting additional headers; A switch addition header generator 41 which receives ATM cell data from the AAL5 / ATM cell conversion means 30, adds an additional header of the additional header lookup table 42, and outputs the added header to the ATM switch 3; And an additional header extractor 43 for receiving the output of the ATM switch 3 and removing the additional header and outputting the additional header to the AAL5 / ATM cell converting means 30. Ethernet connection for