KR100319460B1 - High-end switched router system supporting ATM and ethernet traffic based on ATM cell switch - Google Patents

Abstract

An object of the present invention is to provide a high performance router system for Ethernet and LAN-emulated ATM traffic while simultaneously providing two or more heterogeneous access functions for Ethernet and ATM networks by one system platform.

According to the present invention, the ATM network access unit transmits LAN emulated ATM traffic and cell traffic from the ATM network to the server type layer 3 processing unit, and the OAM cell or the signal cell of the ATM cell traffic is transmitted. Performing a function of transmitting to the routing server unit when it is input; The Ethernet network access unit performs direct layer 3 processing if the incoming Ethernet traffic is user traffic and forwards it to the subscriber access unit of another segment without passing through the routing server unit, and if not, to the routing server unit. Perform a function of forwarding; The server-type layer 3 processing unit performs a function of forwarding LAN-emulated ATM traffic and cell traffic from the ATM network access unit to a subscriber access unit of another segment without passing through the routing server unit according to an LEC environment. ; The routing server unit is provided with a switched router system, characterized in that for receiving the forwarded packet data from the Ethernet network connection unit to perform the upper layer routing protocol data processing.

Description

High-performance switched router system supporting ATM and ethernet traffic based on ATM cell switch}

The present invention relates to a switched router system, and more particularly, to a high-performance switched router system that simultaneously provides an access function for an Ethernet network and an ATM network for an efficient internet data communication network for high quality Internet service.

As communication technology develops, users demand various services of high quality, and real-time services with variable bit rates and high-speed data services such as file transfer as well as continuous services such as voice service or video service. There is a need for communication networks for providing Burst services such as Real Time Moving Image Service over the same link.

AIS (Broadband ISDN) of Asynchronous Transfer Mode (Asynchronous Transfer Mode) is a representative communication method that has emerged to achieve this purpose.

On the other hand, new technologies are needed to build an economical and efficient Internet network due to the rapid increase in services and demands related to the Internet.The advantages of the high-speed local area network (LAN) based on the existing Ethernet technology or the ATM method A representative example is the implementation of a high speed local area data network based on ATM technology for application to the Internet.

Therefore, there is a situation that the existing Ethernet network and the new ATM network coexist in constructing a communication network for Internet service, and these two methods are competing with each other to develop their advantages and to compensate for their shortcomings. By developing a new technology, the company proposes an alternative to the next generation of high performance local area networks.

In addition, the rapid increase in services and demand related to the Internet is changing the situation in which the data communication volume in the same LAN area has been much larger than the communication traffic between LANs.

This change has bottlenecked the router's performance in interconnecting LAN areas in establishing a communication infrastructure for Internet services. The bottleneck of such a router is a big obstacle to the improvement of the Internet service that connects all LANs to one communication network.

In order to overcome the bottleneck of the router, technologies for the high speed processing method of the layer 3 function included in the routing function and the development of the switched router system providing the high speed switch-based routing function have been developed.

Conventional high-speed switching platforms include ATM cell switching technology and Ethernet packet switching technology, but a cell switching method having a fixed cell length can effectively achieve high speed switching performance. It is recognized in a way.

Conventional high-speed processing methods for Layer 3 functions include a method of implementing protocol processing in hardware (Wirespeed) and a new protocol such as MPOA (Multiprotocol Over ATM) or MPLS (Multi protocol Label Switching). . The former method has a disadvantage in that it is difficult to achieve continuous scale scalability due to the difficulty of implementation and the increase in hardware price as the bandwidth increases, and in the latter case, all devices must include a new protocol.

In general, Layer 3 processing of Ethernet traffic adopts the former method and the latter method for ATM traffic. In general, the former method is adopted in small LAN domains, and the latter method is used in backbone networks and large networks. In medium-sized campus or enterprise networks, the two cases often coexist.

In this case, a switched router system that includes a high-performance switching function based on an ATM cell switch as a basic platform, and which simultaneously accepts ATM traffic and Ethernet traffic while providing high-performance router function for Ethernet and LAN-emulated ATM traffic Plays a key role in the construction of Internet networks.

1 is a block diagram illustrating a structure of a conventional general switched router system. The general switched router system includes a switch unit 110, a subscriber line connection unit 120, 130, and layer 3 functions. Routing unit (140), and the control management processor unit 150, and the like.

The switch unit 110 and the subscriber network connection unit 120 and 130 are connected by a switch port 160, and the control management processor unit 150 is a system control management data (System Control & Management Data). The switch port 160 may be used as a transmission / reception channel () of the communication channel) or a separate inter-processor communication channel (170) may be used. The routing unit 140 also communicates with the subscriber network access units 120 and 130 by the switch port 160 via the switch unit 110 or via the interprocessor communication channel 170. .

In general, as shown in FIG. 1, a conventional switched router system adopts a structure in which a path of user data and control data is separated. In FIG. 1, EP denotes an embedded processor, SAR denotes segmentation and reassembly, and L3 denotes a forwarding function among the layer 3 processing functions.

FIG. 2 is a block diagram of a distributed routing system architecture including a layer 3 processing function in each conventional subscriber network access unit, wherein the switched router system in the distributed architecture type includes a switch unit 210. , A subscriber network access unit (220, 230) and a routing server unit (Routing Server Unit, 240).

Each of the subscriber network access units 220 and 230 includes its own layer 3 processing function, and the routing server unit 240 that exists separately processes the upper layer routing protocol. The switch unit 210 is used as a data communication path between the routing server unit 240 and the layer 3 processing function included in each of the subscriber network access units 220 and 230, and a separate interprocessor communication channel 270 is used. You can also use

The distributed router system structure shown in FIG. 2 is superior in routing performance to the server type router system structure shown in FIG. 1 because each subscriber network access unit 220 and 230 includes a layer 3 processing function. However, there is a disadvantage in that the hardware price for the system implementation is expensive, and in addition, the ATM network access unit 220, in addition to the layer 3 processing function, cell segmentation and Because reassembly (Cell Segmentation and Reassembly) functions must be added, hardware costs are high and performance loss can occur during SAR.

In addition, since the data traffic input to each of the subscriber network access units 220 and 230 does not always require layer 3 processing, the distributed router system structure is not cost-effective overall. In addition, in case of adopting layer 3 processing technology such as MPOA to efficiently build LAN or Internet network by ATM technology in ATM network connection, the amount of traffic going through the actual layer 3 processing is significantly reduced. The same price side is huge waste. In general, in order to compensate for this problem, the ATM network access system applied to the LAN region adopts a server structure as shown in FIG.

FIG. 3 is a diagram schematically illustrating an operation operation of a switched router system structure of a server type shown in FIG. 1, which will be described in detail as follows.

In FIG. 3, LAN-emulated ATM traffic input through the ATM network access unit 320 is input to the routing server unit 340 through the ATM cell switch unit 310, and a LAN Emulation Client (LEC). Depending on the environment, it can be delivered within the same segment or via a routing function to another segment. Here, an LE server unit 370 is included for such LAN segment management and operation.

In FIG. 3, the packet traffic input through the Ethernet network access unit 330 passes through up to four SAR chips 380 to be transmitted in the same way through the routing server unit 340.

Looking at the content of the prior art described above in more detail, as follows.

A brief summary of the paper 'Implementation of an MPOA-based switched router' published by 'Jong Arm Jun' in the journal 'ICT'99 is as follows.

This paper presents the structure of a switched router that can provide MPOA based on ATM switching capability of 10 Gbps. Called SR-10, the system has three line access functions: Ethernet, Frame Relay, and ATM. SR-10 system with IP processing mechanism can provide excellent network performance in IP transport function over ATM network without causing bottlenecks or congestion related to route from router to network. .

In addition, the SR-10 system basically consists of a switch unit, a line connection unit, a routing unit and a control processor unit. The switching unit is called SRSU and provides hot standby redundancy and 10 Gbps switching capability by configuring 5 Gbps ATM cell switch elements in byte interleaving. Three line connection units include STAU with STM-1 connectivity, FRAU with frame relay connectivity, and ETAU with Ethernet connectivity.

The routing control unit, called IRCU, provides MPOA server functionality and routing protocol processing. The ATM switching platform functionality provided by the SR-10 system can also be applied to other forms of Layer 3 switching functionality such as MPLS.

On the other hand, the invention proposed in the above paper has the effect of providing an effective and cost-effective system foundation for the construction of high-quality medium-to-large campus network or enterprise network where ATM network and Ethernet network coexist. Since the functions and the routing control functions form a single server, there is a problem that it is difficult to expect effective processing and high performance for the layer 3 processing.

The present invention has been made to solve the above problems of the prior art, while simultaneously providing two or more heterogeneous access functions for the Ethernet network and the ATM network by one system platform, and for the Ethernet and LAN-emulated ATM traffic The purpose is to provide a high performance router system.

1 is a configuration diagram showing the structure of a conventional general switched router system,

2 is a configuration diagram of a switched router system in a distributed structure including layer 3 processing functions in each conventional subscriber network access unit;

FIG. 3 is a diagram schematically illustrating an operation of a switched router system structure of a server type shown in FIG. 1;

4 is a block diagram showing a structure of a switched router system according to an embodiment of the present invention,

5 is a view schematically showing an operation operation for user traffic of a switched router system according to an embodiment of the present invention;

FIG. 6 is a diagram schematically illustrating an operation operation for traffic when it is not user traffic in a switched router system according to an embodiment of the present invention;

7 is a block diagram showing a structure according to the function of the ATM network access unit shown in FIG.

8 is a block diagram showing a structure according to the function of the Ethernet network connection unit shown in FIG.

FIG. 9 is a diagram illustrating a structure according to a function of a layer 3 processing unit for ATM traffic shown in FIG. 4;

FIG. 10 is a block diagram illustrating a structure according to a function of a processor unit including the routing server unit and the control management processor unit shown in FIG. 4.

According to the present invention for achieving the above object, the present invention includes an ATM network access unit, an Ethernet network access unit, a high speed ATM cell switch unit, a server type layer 3 processing unit, and a processor unit; The ATM network connection unit, the Ethernet network connection unit and the server type Layer 3 processing unit are interconnected by being connected to the high speed ATM cell switch unit by a switch port; The ATM network access unit transmits LAN emulated ATM traffic and cell traffic from the ATM network to the server type layer 3 processing unit, and the OAM (Operations And Maintenance) cell or signaling cell of ATM cell traffic is transmitted. Transmits to the processor unit if input; The Ethernet network access unit performs direct layer 3 processing if the incoming Ethernet traffic is user traffic, and forwards it to another segment of the subscriber access unit without passing through the processor unit. Perform a function of forwarding to a unit; The server-type layer 3 processing unit forwards LAN emulated ATM traffic and cell traffic from the ATM network access unit to another segment of a subscriber access unit without passing through the processor unit by a LAN Emulation Client (LEC) environment. Perform a function; The processor unit is provided with a switched router system, characterized in that to initialize and monitor each unit of the system, and to provide access to the ATM network and Ethernet network at the same time by performing the processing of the forwarded packet data.

More specifically, the processor unit includes a control management processor that performs initialization and monitoring functions for each unit of the system; A routing server unit which receives the forwarded packet data from the Ethernet network access unit and performs upper layer routing protocol data processing; And connecting means for connecting the control management processor and the routing server unit to the high speed ATM cell switch unit, respectively, through two separate channels therein.

In more detail, the control management processor is provided with a switched router system, characterized in that for transmitting and receiving data necessary to perform the initialization and monitoring function for each unit of the system through a separate system monitoring channel.

In more detail, the Ethernet network access unit performs a layer 3 processing function on user traffic input from an Ethernet network, thereby decentralized layer for forwarding to a subscriber access unit of another segment without passing through the processor unit. Provided is a switched router system comprising three processing units.

In more detail, the Ethernet router, the processor unit, and the server-type Layer 3 processing unit are provided with a switched router system, characterized in that it comprises a SAR unit for performing ATM cell segmentation and reassembly (SAR) function. .

In more detail, the server-type layer 3 processing unit and the distributed layer 3 processing unit are provided by the switched router system, characterized in that the forwarding information is updated in the switching path through the SAR unit and the high-speed ATM cell switch unit. do.

In the following, with reference to the accompanying drawings, a preferred embodiment according to the present invention will be described in detail.

4 is a block diagram illustrating a structure of a switched router system according to an embodiment of the present invention, wherein the structure of the switched router system includes a high performance ATM cell-based switch unit (410) and an ATM network access unit (420). ), An Ethernet network access unit 430 including a Layer 3 processing unit 431 for Ethernet traffic, a processor unit 440 including a routing server unit 442 and a control management processor unit 441 and ATM traffic. For the Layer 3 processing unit 450.

The switch unit 410, each subscriber network access unit 420, 430, the processor unit 440, and the layer 3 processing unit 450 for ATM traffic are connected by a switch port 460, and the control management processor System initialization and transmission and reception of system monitoring data of the unit 441 are configured to be performed by a separate initialized and system monitoring channel 490.

Meanwhile, the SAR-4 function units 432, 443, and 452 provide high performance ATM cell SAR functions to the Ethernet network access unit 430, the processor unit 440, and the layer 3 processing unit 450 for ATM traffic. Is included. The SAR-4 functional units 432, 443, and 452 may provide SAR processing performance for the maximum bandwidth that one Ethernet network access unit may provide. In this embodiment, one Ethernet network access unit is designed to accommodate up to four ports of Fast Ethernet traffic, and thus, the unit SAR-4 function unit is designed to provide SAR function processing capability of such traffic.

FIG. 5 is a diagram schematically illustrating an operation operation for user traffic of a switched router system according to an embodiment of the present invention.

In FIG. 5, LAN-emulated ATM traffic input through the ATM network access unit 520 is input to the layer 3 processing unit 540 for the ATM cell through the ATM cell switch unit 510 (①), By doing so, forwarding is performed directly to the subscriber access unit of another segment without passing through the routing server unit 580 (③, ④).

In FIG. 5, the packet traffic input through the Ethernet network access unit 530 is forwarded by the layer 3 processing unit 531 for the Ethernet traffic included in the Ethernet network access unit 530 to pass through the routing server unit 580. Instead, it is forwarded to the subscriber access unit of another segment (⑤). Here, the LE server unit 570 is included for such LAN segment management and operation.

FIG. 6 is a view schematically illustrating an operation operation for traffic when not user traffic in a switched router system according to an embodiment of the present invention.

In FIG. 6, data to be processed in a higher layer routing protocol among cell or packet traffic input through the ATM network access unit 620 or the Ethernet network access unit 630 is layer 3 processing for an ATM cell in case of ATM cell traffic. Unit 640 (6), and in the case of Ethernet packet traffic, is forwarded to the routing server unit 680 by the layer 3 processing unit 631 for the Ethernet traffic included in the Ethernet network access unit 630 and routed. It is processed by the server processor 681 (7).

In this forwarding transfer process, the SAR-4 functional units 632, 642, and 683 of each unit are transformed or segmented into a cell form required by the ATM cell switch unit 610.

In addition, in FIG. 6, the forwarding information of each layer 3 processing unit 631 and 641 is provided by the routing server processor 681, and such forwarding information update is performed by the SAR-4 functional units 632 and 683. And a switching path through the ATM cell switch unit 610 (8).

On the other hand, the OAM (Operations And Maintenance) cell or the signaling cell of the ATM cell traffic input through the ATM network access unit 620, as shown in Figure 6 the control management processor included in the routing server unit 680 The data is transmitted to and processed by the control management processor 682 by the control management processor 682 by the initialization and system monitoring channel 690.

FIG. 7 is a block diagram illustrating a structure according to the function of the ATM network access unit illustrated in FIG. 4. The ATM network access unit 720 generally includes a physical medium interface 710 and a physical layer processor. Layer Processor 722, ATM Layer Processor 721, and Initialization & System Monitoring Channel Interface 740.

The physical layer processing unit 722 is basically designed to accommodate 4 ports of STM-1 traffic or 1 port of STM-4 traffic. Therefore, the ATM network access unit 720 of the present embodiment is designed to have 16 STM-1 ports or 4 STM-4 port capacities, but the number of ports may be changed according to the implementation situation.

Meanwhile, the ATM layer processor 721 is connected to the physical layer processor 722 in a UTOPIA I or II manner. In the receiving direction, header information of an ATM cell received from the physical layer processor 722 is received. ) And payload are separated, the header information is distributed to the switch controller, and the payload portion is distributed to the switch memory buffer and transmitted to the switch controller in the transmission direction. After viewing the header information of the transmitting cell, the payload information is read from the switch memory buffer, and the transmitting cell is created and sent to the physical layer processor 720.

The initialization and system monitoring channel interface unit 740 provides an interface function of the initialization and system monitoring channel managed by the control management processor unit 441 included in the processor unit 440 of FIG. 4. The control management processor unit 441 of FIG. 4 accesses and initializes the physical layer processing unit 722 and the ATM layer processing unit 721 of FIG. 7 through the initialization and system monitoring channel interface unit 740, and monitors as necessary. It can get information or send control command data. In addition, each ATM layer processing unit 721 provides an external interface for OAM cell collection for providing an ABR processing function or a separate management function.

FIG. 8 is a diagram illustrating a structure according to the function of the Ethernet network access unit illustrated in FIG. 4. The Ethernet network access unit 810 generally includes a physical medium connection unit 850, a physical layer processing unit 830, and an Ethernet processing unit. 820, the layer 3 processor 840, and the initialization and system watch channel interface 860.

The physical layer processor 830 is basically designed to accommodate 4 ports of Fast Ethernet traffic or 1 port of Gigabit Ethernet traffic. Therefore, the Ethernet network access unit 810 of the present embodiment is designed to have 16 Fast Ethernet ports or 4 Gigabit Ethernet port capacity, but the number of ports may be changed according to the implementation situation.

Meanwhile, the Ethernet processing unit 820 is connected to the physical layer processing unit 830 in an MII manner, and extracts header information of the Ethernet packet received from the physical layer processing unit 830 in the egress direction. 3 is sent to the processing unit 840 to obtain the forwarding destination information, the obtained destination information in the form of a cell header and delivered to the switch control unit, and the packet data is divided into a series of cell unit payloads into a switch memory buffer. Distribute and deliver On the other hand, in the ingress direction, the header information of the transmission cell sent to the switch controller is read, and a series of corresponding payload information is read from the switch memory buffer, and a transmission packet is generated and sent to the physical layer processor 830.

The layer 3 processor 840 receives header information of the received packet from the Ethernet processor 820 and provides forwarding destination information for a given packet through a table lookup.

The initialization and system monitoring channel interface unit 860 provides an interface function of the initialization and system monitoring channel managed by the control management processor unit 441 included in the processor unit 440 illustrated in FIG. 4. The control management processor unit 441 illustrated in FIG. 4 accesses and initializes the physical layer processing unit 830 and the Ethernet processing unit 820 of FIG. 8 through the initialization and system monitoring channel interface unit 860. The monitoring information can be obtained or control command data can be sent.

FIG. 9 is a block diagram illustrating a structure according to a function of a layer 3 processing unit for ATM traffic shown in FIG. 4, and the layer 3 processing unit 910 for the ATM traffic is basically connected to the Ethernet network shown in FIG. 8. Except for the physical medium connection unit 850 and the physical layer processing unit 830, the Ethernet processing unit 820 has a functional structure for operating in a loopback mode.

The cell requiring layer 3 processing among the ATM cell traffic input through the ATM network access unit illustrated in FIG. 7 is transferred to the layer 3 processing unit 910 for ATM traffic through the switch unit 410.

The layer 3 processing unit 910 for ATM traffic shown in FIG. 9 looks at the header information of the transmitting cell sent to the switch control section, reads a series of corresponding payload information from the switch memory buffer, creates a packet, and sends the packet to the transmission direction. Is input to the receiving side again. The receiving side extracts the header information of the input packet and sends it to the layer 3 processing unit 930 to obtain forwarding destination information. The obtained destination information is formed in the form of a cell header and transmitted to the switch control unit. After dividing by, it is distributed and transferred to the switch memory buffer.

The layer 3 processor 930 receives the header information of the packet from the Ethernet processor 920 by receiving the header information of the packet, which is received in a loopback manner, and provides forwarding destination information for a given packet through a table lookup.

FIG. 10 is a block diagram illustrating a structure according to a function of a processor unit including the routing server unit and the control management processor unit illustrated in FIG. 4, wherein the processor unit 1010 basically includes two processing environments and one SAR and Path interface controller 1030. Two processing environments are used as routing server unit 1020 and control management processor unit 1040, respectively.

The control management processor unit 1040 includes a control management processor 1041, memory and input / output devices for various purposes, and an initialization and system monitoring channel controller 1042.

On the other hand, the routing server unit 1020 is composed of a routing server processor 1021, memory and input / output devices for various purposes. These two processing environments are each connected with a switch unit through two channels separated within the one SAR and path interface controller 1030. The SAR and path interface controller 1030 is connected to the switch memory buffer and the switch controller in the same manner as the ATM layer processor 721 and the Ethernet processor 820 and 920 shown in FIGS. The method is the same.

Meanwhile, the initialization and system monitoring channel controller 1042 forms and manages the initialization and system monitoring channel 1050 for initialization of hardware elements of each system and transmission and reception of system monitoring and monitoring data for system management purposes. .

The present invention as described above is recorded on a computer-readable recording medium, and can be processed by a computer.

As described in detail above, the present invention is based on a high-speed ATM cell switch, provides a server-type layer 3 processing function that can be flexibly configured according to the amount of ATM traffic requiring layer 3 processing, and at the same time, ATM By accommodating server layer 3 processing structure of traffic and distributed layer 3 processing structure of Ethernet traffic at the same time and presenting high performance router structure that can effectively interwork ATM and Ethernet traffic, ATM network and Ethernet network coexist It is effective to lay the foundation for an effective and cost-effective system for constructing high-quality medium-sized campus or enterprise network.

The technical spirit of the present invention has been described above with reference to the accompanying drawings, but this is by way of example only and not by way of limitation to the present invention. In addition, it is obvious that any person skilled in the art may make various modifications and imitations without departing from the scope of the technical idea of the present invention.

Claims (6)

An ATM network connection unit, an Ethernet network connection unit, a high speed ATM cell switch unit, a server type Layer 3 processing unit and a processor unit; The ATM network connection unit, the Ethernet network connection unit and the server type Layer 3 processing unit are interconnected by being connected to the high speed ATM cell switch unit by a switch port; The ATM network access unit transmits LAN emulated ATM traffic and cell traffic from the ATM network to the server type layer 3 processing unit, and the OAM (Operations And Maintenance) cell or signaling cell of ATM cell traffic is transmitted. Transmits to the processor unit if input; The Ethernet network access unit performs direct layer 3 processing if the incoming Ethernet traffic is user traffic and forwards it to the subscriber access unit of another segment without passing through the processor unit. Perform a function of forwarding to a unit; The server-type layer 3 processing unit forwards LAN emulated ATM traffic and cell traffic from the ATM network access unit to another segment of a subscriber access unit without passing through the processor unit by a LAN Emulation Client (LEC) environment. Perform a function; The processor unit is connected to the high-speed ATM cell switch unit to initialize and monitor each unit of the system and to process forwarded packet data, thereby simultaneously providing an access function to an ATM network and an Ethernet network. High-performance switched router system based on high-speed AT cell switch that can effectively handle ATM and Ethernet traffic. The method of claim 1, The processor unit, A control management processor that performs initialization and monitoring functions for each unit of the system; A routing server unit which receives the forwarded packet data from the Ethernet network access unit and performs upper layer routing protocol data processing; And And connecting means for connecting the control management processor and the routing server unit to the high speed ATM cell switch unit through two separate channels therein. The method of claim 2, The control management processor, Switched router system, characterized in that for transmitting and receiving data necessary to perform the initialization and monitoring function for each unit of the system through a separate system monitoring channel. The method of claim 1, The Ethernet network connection unit, And a distributed layer 3 processor configured to perform a layer 3 processing function on user traffic input from an Ethernet network and forward the same to a subscriber access unit of another segment without passing through the processor unit. The method according to any one of claims 1, 2 or 4, The Ethernet network connection unit, processor unit and server layer 3 processing unit, Switched router system comprising a SAR unit for performing the ATM cell Segmentation And Reassembly (SAR) function. The method of claim 5, And the server-type layer 3 processing unit and the distributed layer 3 processing unit update forwarding information through a switching path through the SAR unit and the fast ATM cell switch unit.