JP2001119412A - Packet exchange device and its packet exchange processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a router that can cope with communications in diversified forms by enhancing the multiplicity of communications conducted via an ATM switch so as to reduce dispersion in communication delays among multiplexed communications. SOLUTION: The router 5 is provided with the ATM switch 52, an IP control section 53 that conducts routing control, a plurality of kinds of interface sections 512-517 provided individually for a plurality of transmission lines for diversified communications, and a cell multiplexer/demultiplexer section 511, and the router 5 manages communication of cells among the sections above by identification information. The interface section 512 applies IP processing to IP packets received from an IP node 41 and assembles them into cells of a common form. Then the cell multiplexer/demultiplexer section 511 applies serial multiplexing to the cells to multiplex them with cells from other interface sections in the unit of cells and the multiplexed cells are fed to the ATM switch 52. Each interface section and the cell multiplexer/demultiplexer section 511 have a table on which correspondence relation of the identification information is registered and the table is used to set the identification information to each header part of communicated IP packets and cells with/ without conversion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an IP (Internet Protocol)
ocol) and the like, which uses an ATM (Asynchronous Transfer Mode) switch to exchange packets requiring processing of layer 3 of the packet switching method.
The present invention relates to a router device for multiplexing communication of a plurality of transmission paths for one physical port of an ATM switch.

[0002]

2. Description of the Related Art As a network that enables high-speed transfer of IP packets using ATM technology, Epsilon and
IP switching networks proposed by Networks are known. This network includes an IP switch 1 and an IP switch gateway 2 as shown in FIG. 48, and a conventional LAN / IP such as Ethernet (registered trademark) or FDDI connected to the IP switch gateway 2. It is possible to transfer and exchange IP packets communicated on a network at high speed.

In FIG. 48, a network is represented by layer 2 (lower) and layer 3 (higher), and a thick line connecting the two indicates a transition of processing between layers. LAN
The IP node 4, which is a router or the like of the IP network, first performs layer 2 LAN protocol processing such as Ethernet on the arriving packet (datagram), and then performs upper layer 3 IP protocol processing. Next, after determining a route to which the packet is to be transferred, the packet is transferred to an adjacent node by performing layer 2 processing again. Similarly, the IP switch gateway 2 of the IP switching network performs layer 2 and layer 3 processing for all packets to be transferred. The IP switch 1 also performs layer 2 and layer 3 processing, but only the layer 2 processing is performed for packets cut through in communication between the IP switch gateway 2 and the IP switch 1 or between the IP switches 1. And transfer. In FIG. 48, a thick line between layer 2 and layer 3 is indicated by a dotted line to indicate that the processing of layer 3 is cut through.

FIG. 49 shows a configuration example of an IP switch 1 and an IP switch gateway 2. The IP switch 1 includes an ATM switch 11 and an IP control unit 12, and exchanges ATM cells between an IP switch gateway 2 connected to a physical port of the ATM switch 11 and an IP node 3 that performs ATM communication. The IP switch gateway 2 includes a plurality of LAN interface units 21A and 21B individually connected to respective transmission paths of a LAN / IP network to which the IP node 4 is connected, and multiplexing / demultiplexing of IP packets communicated by the LAN interface unit. IP datagram multiplexing / demultiplexing unit 22 and IP processing unit 23
And an ATM interface unit 24 connected to the physical port of the ATM switch 11. In such a configuration, the IP control unit 12 of the IP switch 1 and the IP processing unit 23 of the IP switch gateway 2 use IFMP (Ipsilon Flow Matrix).
Communication control related to IP is performed in cooperation with a protocol called “Nagement Protocol”. Here, a flow refers to, for example, a sequence of a series of packets sent from a certain calling terminal to a called terminal. In addition, the IP control unit 12
By a protocol called MP (General Switch Management Protocol), VC (Virt
ual Channel: Controls the connection.

[0005] Communication between the IP switch gateways 2 connected via the IP switch 1 will be described with reference to FIG. IP packets A and B sent from a plurality of IP nodes 4 of the LAN / IP network to the IP switch gateway 2 are IP
The datagram multiplexing / demultiplexing unit 22 serially multiplexes the data in the order of A and B, for example. The multiplexed IP packets are sequentially
After being subjected to the IP processing by the IP processing unit 23, it is converted into an ATM cell by the ATM interface unit 24 and sent to the IP switch 1. Then, the ATM cell sent to the IP switch 1 is transferred to the destination IP switch gateway 2, and after processing by the ATM interface unit 24 and the IP processing unit 23, the IP datagram multiplexing / demultiplexing unit 22 sequentially converts the ATM cell into an IP packet. The data is synthesized and sent to the LAN interface 21 of the transfer destination. After receiving all the data of the IP packet, each LAN interface unit 21 individually sends the IP packet to the transmission path of the LAN / IP network.

[0006]

However, in the above-mentioned conventional system, since all IP packets transferred by the IP switch gateway 2 must be processed by the IP processing unit 23, the communication volume at the IP switch gateway 2 is limited. Therefore, the multiplicity of communication in the entire system cannot be increased.

[0007] In the IP switch gateway 2, the IP
To perform IP processing after serial multiplexing packets,
As shown in FIG. 50, the data amount is larger than a certain transmission path.
When the IP packet A is sent, the IP sent from another transmission path
Processing and forwarding of packet B is greatly delayed. This is a major drawback in a public network where access fairness is required.

Further, when applied to a public network, various services such as frame relay, low-speed ATM, and circuit emulation are required in addition to the IP packet service.
The IP switch gateway 2 can cope only with the service of the IP packet due to its structure, and there is a restriction on the network operation.

Accordingly, an object of the present invention is to provide a router device that improves the degree of multiplexing of communication performed via an ATM switch. It is another object of the present invention to provide a router device that reduces communication delay variation between multiplexed communications. It is another object of the present invention to provide a router device that can support various forms of communication.

[0010]

In order to achieve the above object, the present invention provides a router device for exchanging a packet accompanied by processing of a layer 3 of a packet exchange system by using an ATM switch in communication, comprising: An ATM switch that performs switching, a plurality of interface units connected to a plurality of transmission paths for transmitting the packets, a physical port of the ATM switch, and a cell demultiplexing unit connected to the plurality of interface units, A layer 3 control unit for performing and managing the layer 3 processing in the own apparatus, wherein each of the interface units converts a packet transmitted from the connected transmission path into a cell and converts the packet into a cell. Means for transmitting to the demultiplexing unit, means for converting the cell transmitted from the cell demultiplexing unit into a packet and transmitting the packet to the connected transmission path, and processing for the layer 3 For, and means for converting the information of the header portion of the cell and the packet transmitting and receiving,
The cell demultiplexing unit serially multiplexes the cells transmitted from the plurality of connected interface units and performs the AT.
Means for transmitting to the M switch, and means for separating cells sent from the ATM switch and delivering the separated cells to an interface unit connected to the transmission path of the transmission destination.
The control unit is configured for a logical port number set for each of the interface units and the physical port of the ATM switch to which the cell demultiplexing unit is not connected, and for a cell flow in the interface unit and the physical port. The communication that specifies a plurality of types of identification information for identifying the cell or packet flow, including the logical channel information and the layer 3 address information set for the packet flow in the interface unit, The present invention provides a router device that changes the contents of the packet exchange by performing the layer 3 processing in cooperation with the interface unit and the ATM switch.

[0011] According to such a router, each interface performs layer 3 processing and cell conversion in the packet switching system, and performs cell multiplexing in the cell demultiplexing unit. It is possible to reduce the communication delay of the packet to be transmitted and improve the multiplicity of the packet flow in the own device.

[0012] In the above-mentioned router device, the means for performing serial multiplexing of the cell demultiplexing unit may include a cell transmitted from the plurality of interface units connected to the interface unit. A router device is characterized in that multiplexing is performed on a cell-by-cell basis so that variations in communication delay are reduced.

Further, the present invention relates to a router device for exchanging data blocks of communication other than regular ATM communication using an ATM switch, comprising: an ATM switch for exchanging cells; A plurality of interface units respectively connected to one or a plurality of transmission lines for individually transmitting a plurality of types of data blocks including a packet accompanied by the process 3; and one physical port of the ATM switch and the plurality of interface units. A connected cell demultiplexing unit, and a layer 3 control unit for performing and managing the layer 3 processing in the own device, wherein each of the interface units shares a data block transmitted from the transmission line. Means for converting the cell into a format cell and transmitting the cell to the cell demultiplexing unit; and transmitting the cell transmitted from the cell demultiplexing unit to the connected transmission unit. Means for converting the data into a data block corresponding to the communication in the transmission path and transmitting the data block to the transmission path, and provided when processing of the layer 3 is required. Means for converting information in a header portion, wherein the cell demultiplexing portion serially multiplexes cells transmitted from the plurality of interface portions and transmits the serially multiplexed cells to the ATM switch; and Separated cells
Means for delivering to an interface unit connected to the transmission path of the transmission destination, wherein the layer 3 control unit transmits the data to each of the interface units and a physical port of the ATM switch to which the cell demultiplexing unit is not connected. A set logical port number, and logical channel information set for a cell flow in the interface unit and the physical port,
The communication of the plurality of types of identification information for identifying the cell or packet flow, including the layer 3 address information set for the packet flow in the interface unit, allows the processing of the layer 3 to be performed. There is provided a router device characterized in that the content of the exchange of the packet is changed by performing the layer 3 processing in cooperation with the required interface unit and the ATM switch.

According to such a router device, for example, in addition to the communication of the packet requesting the processing of the layer 3 of the packet switching system, for example, the communication of the cell requesting the processing of the layer 3 or the processing of the layer 3 Multiplexing and switching can be performed for a plurality of forms of communication, such as communication that does not require communication, circuit switching communication, and the like.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings.

FIG. 1 shows an IP switch with a multiplexer (router device using an ATM switch) according to an embodiment of the present invention.
1 is a diagram illustrating an example of a network to which is applied. FIG.
48, the network is divided into layer 2 (lower) and layer 3 (higher) logical layers, as in FIG. Hereinafter, an example in which IP is used as the layer 3 protocol will be described. However, a layer 3 protocol other than IP may be used.

In the network shown in the figure, an IP switching network is constructed in which a frame relay IP network for transferring IP packets on a frame relay and an ATM / IP network for transferring IP packets on an ATM are connected. Also, the IP switching network has AT
Since M can also connect ATM / non-IP networks that transfer traffic other than IP, the Layer 2 ATM network is a network that can provide various services that are not limited to IP packet services. The IP switch 5 with a multiplexing device accommodates the transmission paths of the various types of networks described above, and exchanges ATM cells and IP packets, and performs protocol processing such as IP, IFMP, and GSMP.

FIG. 2 shows a multiplexing apparatus according to this embodiment.
4 shows a configuration example of an IP switch 5.

In FIG. 2, the IP switch 5 with a multiplexer is
Multiplexer 51 for accommodating transmission lines of a plurality of networks
, An ATM switch 52 for exchanging ATM cells, IFMP and GS
IP that performs IP processing for routing control based on MP
The control unit 53 is configured. The multiplexing device 51 is connected to one physical port of the ATM switch 52 in addition to the transmission line to be accommodated, and performs communication of the ATM cell with the physical port. ATM switch 5 to which multiplexer 51 is not connected
The other physical ports are connected to the IP control unit 53 and transmission paths such as an IP node (ATM) 3 and an adjacent node 6 for performing ATM cell communication.

The multiplexer 51 includes a plurality of interface units 512 to 517 provided corresponding to transmission lines or transmission line groups to be accommodated, and a cell multiplexing / demultiplexing unit 511.
Consists of The interface units 512 to 517 perform communication of IP packets and cells in the same form as the nodes connected thereto between the accommodated transmission path and the cell multiplexing / demultiplexing unit 5.
Communication with cells 11 is common. The cell multiplexing / separating unit 511 serially multiplexes the cells from the interface units 512 to 517 and sends them to the ATM switch 52, and separates the cells from the ATM switch 52 and sends them to the corresponding interface units 512 to 517.

Here, a plurality of multiplexing devices 51 can be arranged in the IP switch 5 with a multiplexing device. Further, the type and number of interface units to be arranged can be arbitrarily selected. For example, when a large number of multiplexing devices 51 and IP-compatible frame relay interfaces are arranged, the function of a large-capacity IP switch gateway is realized. Hereinafter, first, the configuration and operation when the multiplexing device 51 includes a plurality of IP-compatible frame relay interface units 512 will be described.
13 to 517 will be described.

Frame relay interface unit 5 for IP
Reference numeral 12 is connected to a transmission path of one or more IP nodes 41, and performs frame relay communication based on HDLC (High Level Data Link Control). Here, the IP node 41
IP (Internet Protocol)
ol) to communicate IP packets by frame relay.

FIG. 3 shows an example in which the configuration of the IP switch 5 with a multiplexer is functionally subdivided.

In FIG. 3, the ATM switch 52 includes a plurality of ATM interface units 523 provided for each physical port.
And a switch fabric unit 521 for switching a communication path for each cell, and a switch control unit 522 for controlling the switching. Here, each unit of the IP switch 5 with the multiplexing device is referred to as a switch fabric unit 5 for convenience.
It is divided into an upstream unit that processes a signal sent to the 21 side and a downstream unit that processes a signal sent from the switch fabric unit 521 side. The switch control unit 522 controls each ATM interface unit 523 by a control line indicated by a dotted line in the figure.

FIG. 4 is a diagram showing another example of realizing the IP switch 5 with a multiplexer.

The IP switch 5 with a multiplexer shown in FIG.
The M switch and the multiplexing device are integrated, and the same function as the device of FIG. Hereinafter, description will be made based on the configuration shown in FIG.

In FIG. 4, the switch fabric unit 5
21 has a total of 12 physical ports sequentially numbered 1 to 12 physical port numbers, and ATM interface units 523A to 523H are connected to the 1st to 8th physical ports, respectively. Each port has a cell multiplex /
The separation units 511A to 511D are connected. Each of the cell multiplexing / demultiplexing units 511 is connected to 16 interface units. For example, 16 IP-compatible frame relay interface units 512A to 512P are connected to the cell multiplexing / demultiplexing unit 511A connected to the ninth physical port.

FIG. 5 shows an example of a correspondence relationship between identification information (address information) of various ports used in the IP switch 5 with a multiplexer.

In FIG. 5, the switch port number is AT
It is a serial number set for each of the various interface units such as the M interface unit and the IP-compatible frame relay interface unit, and the same value as the physical port number is set for the ATM interface unit in this example. This switch port number is used by the IP control unit 53 to recognize the port.

The multiplex port number is stored in the cell multiplexing / demultiplexing unit 51.
This is a serial number set for the interface unit connected to 1 and takes a value of 1 to 16 for each cell multiplexing / demultiplexing unit 511 in this example. This multiplex port number is used by each cell multiplexing / demultiplexing unit 511 to recognize the port of the interface unit.

Next, a description will be given of various connection identifiers for a default VC fixedly set in advance by a PVC (Parmanent VC) and a redirect VC dynamically set by IFMP and GSMP processing.

The local identifier is stored in the cell multiplexing / demultiplexing unit 51
This is an identifier for uniquely identifying a connection used for communication between the communication interface 1 and each interface unit connected thereto.

The connection within the cell multiplexing / demultiplexing unit 511 can be uniquely identified by the local identifier and the multiplex port number. In this example, 128 connections are assumed for each IP-compatible frame relay interface unit, and the default VC is number 1 and the redirect VC is number 2 to 1.
No. 28 is assigned respectively.

The internal connection identifier uniquely identifies a connection used for communication between the cell multiplexing / demultiplexing units 511, between the ATM interface units, or between them, in the cell multiplexing unit 511 or the ATM interface unit 523. This is an identifier for identifying. The connection within the switch fabric unit 521, that is, the connection within the IP switch 5 with a multiplexer can be uniquely identified by the internal connection identifier and the physical port number. In this example, 4095 connections are assumed for each ATM interface unit, and the internal connection identifiers for the externally connected ATM interface units 523B to 523H are such that the default VC is 1 and the redirect VC is 2 to 4095. Is assigned. Since the default VCs of all the other interface units are concentrated on the ATM interface unit 523A connected to the IP control unit, an internal connection identifier that sets the default VC to the 16th to 86th and the redirect VC to the 128th to the 4095th Is assigned. here,
The remaining number 15 is used for a connection for GSMP to be connected to the switch control unit, and the other numbers are left as missing numbers or used for other purposes. On the other hand, as shown in FIG. 5, the connection of each cell multiplexing / demultiplexing unit 511 is assigned an internal connection identifier of No. 1 to 2048 in ascending order of the multiplex port number.

VPI / VCI is an identifier of a connection that is used not only inside the device but also as a standard. For example, this VPI / VCI is used for communication with the outside of the ATM interface unit.

In this example, the VPIs are all set to 0, and the VCI has the same value as the internal connection identifier.

However, the default VC is uniformly VPI = 0, VC
I = 15 (hereinafter referred to as (0,15)) is assigned. Also, the redirect VC of the cell multiplexing / demultiplexing unit 511
Has the value of the local identifier plus 14 as an example
Assign an I value.

The information indicating the correspondence between the various port numbers and the various identification information described above is partially registered in tables provided in the various interface units and the cell multiplexing / demultiplexing unit. Various interface units and cell multiplexing / demultiplexing units identify header information (address information) for communicating IP packets and cells according to the registered contents of the table.
Is converted.

The details of each part of the IP switch 5 with a multiplexer will be described below.

FIG. 6 shows the configuration of the IP-compatible frame relay interface unit 512.

As shown in the figure, the IP-compatible frame relay interface unit 512 includes an up unit 5121 and a down unit 5.
122 and an IP flow management unit 5123 that performs IFMP processing. Each of the ascending part 5121 and the descending part 5122,
Frame processing unit for IP packet communication by frame relay, IP processing unit, ALL5 processing unit for processing in accordance with ALL type 5 protocol, ATM processing unit for cell communication, header identification of cell and IP packet It is composed of a table used for information conversion. In FIG. 6, one transmission line is connected to the frame processing unit, but a plurality of transmission lines may be connected.

In such a configuration, an IP packet sent from the network to the upstream unit 5121 is subjected to reception processing by the frame processing unit 51211 and then processed by the IP processing unit 5112.
At 212, IP processing such as detection of address information is performed. Then, the data is divided into SAR-PDU frames by the ALL5 processing unit 51213, converted into cells in which identification information (local identifier) determined by the registered contents of the table 51215 is set by the ATM processing unit 51214, and transmitted to the cell multiplexing / demultiplexing unit 511. Can be

On the other hand, the cells transmitted from the cell multiplexing / demultiplexing section 511 to the downstream section 5122 are subjected to reception processing by the ATM processing section 51224, and then subjected to the SAR-PDU by the ALL5 processing section 51223.
Combined into frame. Then, IP processing such as setting of address information is performed by the IP processing unit 51222 according to the registered contents of the table 51225, and the packet is transmitted from the frame processing unit 51221 to the transmission path as an IP packet. Here, the registration content of each table is stored in the IF that communicates with the IP control unit 53.
The IP flow management unit 5123 updates the message according to the message of the MP.

FIG. 7 shows the configuration of the ATM interface unit 523.

As shown, the ATM interface unit 5
Each of the ascending part 5231 and the descending part 5232 of the 23 comprises an ATM processing unit for performing conversion of identification information of a header part of a cell to be transferred and a table used for conversion of identification information. Here, the registered contents of each table are updated according to the control information sent from the switch control unit 522 via the control line 5233.

FIG. 8 shows the configuration of the cell multiplexing / demultiplexing unit 511.

As shown, the cell multiplexing / demultiplexing unit 511
Each of the upstream unit 5111 and the downstream unit 5112 includes a time division bus used for multiplexing / demultiplexing cells, a time division bus arbitration unit that arbitrates transmission timing of cells on the time division bus, and a cell division of the time division bus. AT for converting header identification information
It is composed of an M processing unit and a table used for conversion of identification information. Here, the registered content of each table is updated by control information sent from the switch control unit 522 via the control line 5113.

In this configuration, each interface unit 5
The cells transmitted from 12 to 517 to the upstream unit 5111 are transmitted to the time division bus 51111 at a predetermined timing by the time division bus arbitration unit 51112 and serialized.
Cells on the serialized time division bus 51111 are AT
The M processing section 51113 converts the identification information of the header section into A
It is sent to the physical port of the TM switch 52.

On the other hand, the downstream unit 511
After the identification information is converted by the ATM processing unit 51123, the cell transmitted to the transmission unit 2 is sent out onto the time division bus 51121 by the time division bus arbitration unit 51122, and is taken into the interface units 512 to 517 of the transmission destination. In the above configuration, the transmission and arbitration of the upstream cell and the downstream cell may be performed collectively by sharing the time division bus. The cells may be multiplexed / separated by a method other than the time division bus.

Further, of the interface units 512 to 517, the interface unit connected to a plurality of transmission lines
For example, a parallel / serial conversion unit is arranged at a connection portion with the transmission path, and serializes packets and the like sent from a plurality of transmission paths and inputs the packets. Conversely, the exchanged packets and the like are transmitted to the corresponding transmission paths. I do.

Next, an operation example of the IP switch 5 with the multiplexing device will be described with reference to an example in which the IP node 41 communicates with the adjacent node 6.

For communication in the IP switch 5 with the multiplexing device, as shown in FIG.
There is a mode in which communication is performed via the control unit 53, and a mode (cut-through) in which communication is performed without using the IP control unit 53 by the redirect VC as shown in FIG. Normally, at the start, communication by the default VC is performed, and thereafter, the communication shifts to communication by the redirect VC. The setting of the redirect VC is performed by IFMP and GSMP protocol processing.

Here, the registered contents of the table relating to the above operation will be described.

As shown in FIG. 11, the IP flow identifier and the local identifier of the IP packet of the redirect VC are registered in the table in the upstream unit 5121A of the IP-compatible frame relay interface unit. All IP packets for which no IP flow identifier is registered are all default VCs, that is, 1
Number corresponding to the local identifier. The IP flow identifier includes a source IP address xxxx and a destination IP address yyyy. As the IP flow identifier, a combination of these IP addresses and a port number in a header of a higher-level protocol such as TCP or UDP, a network address for identifying a network, or the like may be used.

As shown in FIG. 12, an output physical port number and an internal connection identifier are registered in the table in the upstream section 5111A of the cell multiplexing / demultiplexing section, corresponding to the multiplex port number and the value of the local identifier. I have. These registrations are divided into a fixedly registered default VC and a renewed redirect VC.

As shown in FIG. 13, VPI / VCI is registered in the table 52322A in the downstream section 5232A of the ATM interface section connected to the IP control section 53, corresponding to the value of the internal connection identifier. Similarly, the downstream unit 523 of the ATM interface unit connected to the adjacent node
As shown in FIG. 14, VPI / VCI is also registered in the table 52322B in 2B corresponding to the value of the internal connection identifier.

As shown in FIG. 15, an output physical port number and an internal connection identifier are registered in the table 5212A of the upstream section 5231A of the ATM interface section connected to the IP control section, in correspondence with the VPI / VCI values. ing.

The communication by the default VC performed according to the registered contents of the above table will be described with reference to FIGS.

In FIG. 16, an IP bucket sent from an IP node 41 and set with a calling side IP address xxxx and a called side IP address yyyy is first sent to the corresponding section 5121A of the IP corresponding frame relay interface section. Since the flow identifier (xxxx, yyyy) is not registered in the table, it is converted into a cell (FIG. 17 (a)) in which the first multiplex port number and the local identifier are set in the header, and the cell multiplexing / demultiplexing unit It is sent to the ascending unit 5111A.
After multiplexing the transmitted cells, the uplink unit 5111A replaces the identification information of the header part with the first output physical port number and the 23rd internal connection identifier based on the registered contents of the table (FIG. 17B). ), And sends the cell to the switch fabric unit 521. This cell is transferred to the downstream section 5232A of the ATM interface section according to the output physical port number of the header section. In the downlink unit 5232A, the VPI of (0, 23) is determined based on the internal connection identifier in the header of the transmitted cell.
An ATM header including / VCI is generated, and the transmitted cell is converted into an ATM cell in a standard format (FIG. 17C) and transmitted to the IP control unit 53. In the IP control unit 53, the received ATM cell
The P packet is reproduced, a new output physical port and the corresponding default VC VPI / VCI are determined by IP processing based on the value of the IP flow identifier of the IP packet, and the VPI / VCI is set to (0, 1).
The ATM cell (FIG. 18 (a)) converted to 6) is sent to the upstream unit 5231A of the ATM interface unit. In the uplink section 5231A, the second output physical port number and the first internal connection identifier are set in the header of the sent ATM cell, and the
The packet is sent to the ATM cell switch fabric unit 521. This ATM
The cell is transferred to the downstream section 5232B of the ATM interface section according to the output physical port number, where (0,15)
VPI / VCI is set and sent to the adjacent node 6.

Next, the processing for cut-through is shown in FIG.
This will be described with reference to FIGS.

In FIG. 19, the IP control unit 53, which has received the cell of the IP data from the IP-compatible frame relay interface unit 512A, determines that the IP data can be communicated by the redirect VC, and if the IP control unit 53 and the IP node 4
For setting up a redirect VC connection between one
The GSMP add branch message (FIG. 20A) is output. This message is sent to the ATM interface unit 523.
A is sent to the switch control unit 522 via A and the switch fabric unit 521. The switch control unit 522 generates two pieces of control information (FIGS. 20 (b) and (c)) for connection setting based on the transmitted message, and sends the control information to the cell multiplexing / demultiplexing unit 511 and the ATM interface unit 523, respectively. send. Thereby, the upstream section 5111A of the cell multiplexing / demultiplexing section
The registration for the redirect VC is added to each table of the downstream section 5232A of the ATM interface unit. And
The switch control unit 522 returns an add branch response message notifying that the processing has been completed to the IP control unit 53.

The IP that received the add branch response message
The control unit 53 transmits an IFMP redirect message (FIG. 20) to instruct the IP-compatible frame relay interface unit 512A to switch the communication to the redirect VC.
(d)) is generated and transmitted. The transmitted message is transmitted to the switch fabric unit 521 and the cell multiplexing / demultiplexing unit 511.
Frame relay interface unit 51 for IP via A
It is sent to the IP flow management unit 5123 in 2A. The IP flow management unit 5123 registers the content (FIG. 20 (e)) for changing the local identifier of the communication of the IP packet to No. 2 in the upstream table 51215A based on the transmitted message.

When the registration is completed, the IP data from the IP node 41 is sent to the IP control unit 53 by the redirect VC as shown in FIG. That is, IP
The data is first converted by the IP-compatible frame relay interface unit 512A into a cell (FIG. 22A) in which the second local identifier is set. Then, the 128th internal connection identifier is set by the cell multiplexing / demultiplexing unit 511A (FIG. 22B), and the ATM interface unit 523A sets it.
ATM cell with VPI / VCI of (0,128) (FIG. 22)
(c)) is sent to the IP control unit 53. Then, the packet is sent from the IP control unit 53 to the adjacent node 6 by the default VC as in FIG.

In FIG. 23, when the adjacent node 6 that has received the IP data from the IP node 41 determines that the IP data can be communicated by the redirect VC, the communication is redirected.
An IFMP redirect message (FIG. 24 (a)) designating switching to VC is generated and sent to the IP control unit 53. The IP control unit 53 generates a GSMP move branch message (FIG. 24 (b)) for setting a redirect VC connection between the adjacent node 6 and the switch fabric unit 521 in response to this message, and sends the message to the switch control unit 522. send. The switch control unit 522 responds to this message with two pieces of control information (FIG. 24) for setting a connection.
(c) and (d)) and generate the ATM interface unit 523, respectively.
B and the cell multiplexing / demultiplexing unit 511A. This allows the AT
The registered contents of the respective tables of the downlink section 5232B of the M interface section and the uplink section 5111A of the cell multiplexing / demultiplexing section are updated, and the IP control section 53 between the IP node 41 and the adjacent node 6 is updated.
Cut-through that connects with the redirect VC without going through is established. Thereafter, the switch control unit 522 sends control information (FIG. 24 (e)) for releasing the connection to the downstream unit 5232A of the ATM interface unit, and releases the connection of the redirect VC before switching. Finally, the move branch response message notifying the completion of the processing is sent to the IP
It is returned to the control unit 53.

Next, the communication after the cut-through is established is shown in FIG.
This will be described with reference to FIG.

When the cut-through is established, the communication from the IP node 41 to the adjacent node 6 is all performed by the redirect VC without going through the IP control unit, as shown in FIG.

That is, the IP packet from the IP node 41 is converted into a cell (FIG. 26A) by the IP-compatible frame relay interface unit 512A, and the cell multiplexing / demultiplexing unit 51
Sent to 1. This cell is set with the second physical port number by the cell multiplexing / demultiplexing unit 511 (FIG. 26B), and is sent to the downstream unit 5232B of the ATM interface unit via the switch fabric unit. Then, it is converted into an ATM cell (FIG. 26 (c)) in which the VPI / VCI of (0, 16) is set by the downstream unit 5232B of the ATM interface unit and transmitted to the adjacent node 6.

In the above, the operation example of the IP switch 5 with the multiplexing device when the communication is performed from the IP node 41 to the adjacent node 6 has been described.

Next, an example of the operation when the adjacent node 6 communicates with the IP node 41 will be described.

In this communication, the same operation as described above is performed. The communication state also shifts from communication performed by the default VC via the IP control unit 53 as shown in FIG. 27 to communication performed without the IP control unit 53 by the redirect VC as shown in FIG.

Here, the registered contents of the table relating to the above operation will be described.

As shown in FIG. 29, the local identifier of the IP packet of the redirect VC and the IP address of the redirect VC are stored in the table in the downstream unit 5122A of the frame relay interface unit for IP.
The flow identifier is registered in association with the flow identifier.

As shown in FIG. 30, a multiplex port number and a local identifier are registered in advance in a table in the downstream unit 5112A of the cell multiplexing / demultiplexing unit, corresponding to the value of the internal connection identifier. These registrations are divided into those for default VCs that are fixedly registered and those for redirect VCs that are updated.

Up section 5231A of ATM interface section
And each table in the ascending section 5231B has a
As shown in FIG. 1 and FIG. 32, an output physical port number and an internal connection identifier are registered corresponding to the value of VPI / VCI.

The communication based on the default VC performed according to the registered contents of the above table will be described with reference to FIGS.

The ATM cell transmitted from the adjacent node 6 (FIG. 3)
4 (a)), the first output port number and the 16th internal connection identifier are set in the upstream section 5231B of the ATM interface section (FIG. 34 (b)), and the ATM interface section 523A is transmitted via the switch fabric section 521. Sent to The ATM interface unit 523A adds
The VPI / VCI of (0,16) is set (FIG. 34 (c)) and its ATM is set.
Send the cell to the IP controller. The IP control unit performs IP processing and performs VPI /
An ATM cell (FIG. 35 (a)) obtained by converting the VCI to (0, 23) is output. In the output cell, the ninth output port number and the first internal connection identifier are set in the upstream section 5231A of the ATM interface section (FIG. 35 (b)), and the cell multiplexing / demultiplexing section is switched via the switch fabric section 521. 511A
Sent to

The cell multiplexing / demultiplexing unit 511A sets the first multiplex port number and the local identifier corresponding to the internal connection identifier of the transmitted cell (FIG. 35 (c)).
Output a cell. Then, this cell is taken into the IP-compatible frame relay interface unit 512A, converted into an IP packet, and sent to the IP node 41.

Next, the processing for cut-through will be described with reference to FIG.
This will be described with reference to FIGS.

In FIG. 36, the ATM from the adjacent node 6
Upon determining that the cell can be communicated by the redirect VC, the IP control unit 53 that has received the cell generates an GSMP add branch message (FIG. 37A) and sends it to the switch control unit 522. The switch control unit 522 performs control information (FIG. 3) for setting a connection based on the transmitted message.
7 (b), (c)) and sends them to the downstream section 5232A and the upstream section 5231B of the ATM interface section, respectively. With this control information, registration for the redirect VC is made in each table of the downstream section 5232A and the upstream section 5231B of the ATM interface section.

After this registration, the switch control unit 52
2 in response to the add branch response message sent from
The IP control unit 53 transmits the IFMP redirect message (FIG. 3)
7 (d)) and sends it to the adjacent node 6. After receiving this message, the adjacent node 6 sets the (0, 17) VPI / VCI specified by the message in the ATM cell and transmits the ATM cell.

The AT transmitted by the adjacent node 6 by the above processing
As shown in FIG. 38, the M cell
This is sent to the P control unit 53. Here, the ATM cell is sent to the IP control unit 53 while the identification information of the header part is sequentially converted as shown in FIGS. 39 (a), (b) and (c). And
The default VC is sent from the IP control unit 53 to the IP-compatible frame relay interface unit 512A as in FIG.

In FIG. 40, an IP-compatible frame relay interface unit 51 receiving a cell from an adjacent node 6
When determining that the cell can be communicated with the redirect VC, 2A performs registration (FIG. 41 (a)) for receiving the cell with the redirect VC in the table of the downlink unit 5122, and
An IFMP redirect message (FIG. 41B) for designating switching of the communication to the redirect VC is generated and sent to the IP control unit 53. The IP control unit 53 responds to this message
A GSMP move branch message (FIG. 41C) for setting a redirect VC connection between the IP-compatible frame relay interface unit 512A and the switch fabric unit 521 is generated and sent to the switch control unit 522. The switch control unit 522 responds to this message with control information for connection setting (FIG. 41 (d),
(e)) is generated and sent to the cell multiplexing / demultiplexing unit 511 and the upstream unit 5231B of the ATM interface unit, respectively. As a result, the data is redirected to each table of the downstream section of the cell multiplexing / demultiplexing section 511 and the upstream section 5231B of the ATM interface section.
Registration for the VC is performed, and cut-through is established in which the IP node 41 and the adjacent node 6 are connected by the redirect VC without passing through the IP control unit. After that, the switch control unit 522
The control information (FIG. 41 (f)) for releasing the connection is transmitted to the ATM.
The downstream section 5232A of the interface section cancels the connection setting of the redirect VC before the switching, and notifies the IP control section 53 of the completion of the processing by a move branch response message.
Notify to

Next, the communication after the cut-through is established is shown in FIG.
This will be described with reference to FIG.

When cut-through is established, the adjacent node 6
As shown in FIG. 42, the communication from
All will be performed by the redirect VC without going through the control unit. First, the cell from the adjacent node 6 (FIG. 43 (a))
Is set in the header section by the ATM interface section 523B (FIG. 43 (b)), and the cell multiplexing / demultiplexing section 511
Sent to The transmitted cell is transmitted to the cell multiplexing / demultiplexing unit 511.
Cell where the first multiplex port number was set in (Fig. 43 (C))
And the frame relay interface 512 corresponding to the IP.
Sent to A. Then, the packet is converted into an IP packet by the IP-compatible frame relay interface unit 512A and an IP address is set, and then sent to the IP node 41.

The operation example when communication is performed from the adjacent node 6 to the IP node 41 has been described above.

Next, an example of communication between the cell multiplexing / demultiplexing units 511 connected via the switch fabric unit 521 will be described with reference to FIG.

In FIG. 44, the same cell multiplexing / demultiplexing unit 5
IP packets A and B transmitted from the two IP nodes connected to the network interface 11 are interface units 512A and 512A, respectively.
After being subjected to IP processing in B and converted into cells, the cells are serially multiplexed in cell units by a cell multiplexing / demultiplexing unit 511. As shown in the figure, even if the IP data A and B in the form of cells are output from the interface units 512A and 512B at the same timing, they are alternately multiplexed for each cell at a predetermined time interval. Then, the cell train is sent to the cell multiplexing / demultiplexing unit 511 of the transmission destination via the switch fabric unit 521. The cell sequence is divided into cell units by the destination cell multiplexing / demultiplexing unit 511, and the destination interface unit 512
A ′ and B ′ are taken in. And IP packets A and B
And transmitted to the transmission path.

As can be seen from the comparison with FIG. 50, in the IP switch 5 with the multiplexing device, since the IP data is multiplexed as described above, the IP packet B multiplexed together with the IP packet A having a large data amount is also required. Communication can be performed with a small delay time. This characteristic is very useful for a public network or the like where fairness of access is important.

Although the delay time caused by the IP processing is not shown in FIGS. 44 and 50, in the IP switch 5 with the multiplexing device, the interface provided for each transmission path to be multiplexed or each transmission path group is provided. Since each of the units has a function of performing the IP processing, compared to the method of FIG.
The communication delay caused by the processing can be reduced, whereby the multiplicity of traffic in the entire system can be increased.

Further, in the IP switch 5 with a multiplexing device, the correspondence of various identification information such as physical ports and switch ports is determined as shown in FIG. 5, and the identification information is converted by various interface units to transfer cells. Therefore, the transfer of control information for the transfer control can be reduced. Also, the IP control unit 53 can perform IP processing according to general IFMP or GSMP by recognizing a port based on a switch port number.

As described with reference to FIG. 2, the IP switch 5 with the multiplexing device can also multiplex and exchange the communication of the node and the transmission line which perform the communication different from the IP node 41. Hereinafter, the interface units 513 to 517 of FIG.
Will be described in detail.

FIG. 45 shows the configuration of the IP-compatible low-speed ATM interface unit 513 shown in FIG.

This IP-compatible low-speed ATM interface unit 51
3 is an IP node that has IP as a network layer protocol and communicates information of IP packets at a low speed through ATM cells.
(ATM) 42 is connected to the transmission line. As shown in the figure, the interface unit 513 is different from the IP-compatible frame relay interface unit 512 in FIG. 6 in that the frame processing units 51211 and 51221 are replaced by an ATM / ALL processing unit 51311.
The configuration is replaced with 51321. In this configuration, the ATM / ALL processing unit 51311 of the uplink unit 5131
Performs reception processing on ATM cells transmitted at a low speed from the transmission path, reproduces IP packets from the ATM cells,
Send to 1312. The subsequent processes of the IP processing unit, the ALL5 processing unit, and the ATM processing unit are the same as those of the interface unit 512 in FIG. Similarly, in the downstream unit 5132, the same processing as that of the interface unit 512 in FIG. 6 is performed in the IP processing unit, the ALL5 processing unit, and the ATM processing unit, and an IP packet processed by the IP processing unit 51322 is generated. The ATM / ALL processing unit 51321 converts the IP packet into an ATM cell and sends it out to the transmission line at a low speed. In the IP switch 5 with the multiplexing device, the cells communicated via the
The same IP processing and exchange as those of the cells communicated by the IP-compatible frame relay interface unit 512 are performed.

FIG. 46 shows the configuration of the non-IP-compatible frame relay interface unit 514.

The non-IP compatible frame relay interface unit 514 is connected to the transmission path of the non-IP node 43 that does not have an IP and performs frame relay communication. The interface unit 514 does not need to perform IP-related processing, and thus has a configuration in which the IP processing unit and the IP flow management unit are removed from the IP-compatible frame relay interface unit 512 in FIG. In this configuration, the frame processing unit and the ATM processing unit perform conversion processing of the identification information of the packet and the ATM cell according to the registered contents of the table. The cells communicated by the interface unit 514 are directly exchanged and transferred without passing through the IP control unit 53.

Low-speed ATM interface unit 515 not supporting IP
Is a non-IP node (ATM) 4 that does not have IP and performs ATM cell communication
4 transmission lines. This interface unit 515
Is composed of a circuit (not shown) for converting the communication speed of the ATM cell between the non-IP node (ATM) 44 and the cell multiplexing / demultiplexing unit 511. The cells communicated by the interface unit 515 are also directly exchanged and transferred without passing through the IP control unit 53.

The non-IP-compatible low-speed ATM interface unit 516 in FIG. 2 is connected to the transmission line of the IP node (ATM) 45 that has IP and performs low-speed ATM cell communication. The interface unit 516 is composed of a circuit (not shown) for converting the communication speed of the ATM cell and the message of the IMFP between the IP node (ATM) 45 and the cell multiplexing / demultiplexing unit 511. The IP processing is performed in the IP node (ATM) 45. In FIG. 2, the IP node (ATM) 3 connected to the physical port of the ATM switch 52 also performs IP processing within the own node and performs normal ATM communication.

FIG. 47 shows the configuration of the circuit emulation interface unit 517.

The circuit emulation interface unit 517 is connected to the circuit transmission line of the circuit switching node 46. As shown, the uplink section 5171 and the downlink section 5172 of the interface section 517 are respectively a line processing section and an AL section.
It is composed of an L1 processing unit, an ATM processing unit, and a table. In the uplink section 5171, the signal sent from the line transmission line is subjected to reception processing and address conversion processing in the line processing section 51711, and is converted to ATM cells by the ALL1 processing section 51712 by the ALL type 1 protocol processing. . Then, the converted ATM cell is sent to the cell multiplexing / demultiplexing unit 511 after the identification information is added by the ATM processing unit. On the other hand, the descending section 517
In 2, the ATM cell sent from the cell multiplexing / demultiplexing unit 511 is subjected to reception processing by the ATM processing unit 51723,
The signal is converted into a signal on the line transmission line by the processing unit 51722, and is subjected to address conversion processing by the line processing unit before being sent out to the line transmission line. The address conversion processing in the line processing unit and the ATM processing unit is performed according to the registered contents of the table.

As described above, the IP switch 5 with a multiplexing device can cope with various services such as frame relay, low-speed ATM, and circuit emulation in addition to IP packet services, and can perform flexible network operation. In addition, each of the interface units 513 to 51 enabling these services
7 and the multiplexing device 51 take the same format as the cells communicated by the IP-compatible frame relay interface unit 512. For this reason, the cell multiplexing / demultiplexing unit 511 does not need to be aware of the type of the connected interface unit, and only has to transfer the ATM cell and convert the identification information according to the identification information. Similarly, the IP processing unit 53 also
It is not necessary to be aware of the number of 1s and the type of interface unit connected to it. It recognizes the target node of IP processing by the switch port number and uses general IP based on IFMP and GSMP.
Processing may be performed. With these features, the IP switch 5 with the multiplexing device can easily cope with a change or expansion of the configuration.

[0101]

As described above, according to the present invention, it is possible to provide a router device that improves the multiplicity of communication performed via an ATM switch. Further, it is possible to provide a router device that reduces a variation in communication delay between multiplexed communications. Further, it is possible to provide a router device that can support various forms of communication.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a network to which an IP switch with a multiplexer according to the present invention is applied.

FIG. 2 is a diagram illustrating a configuration example of an IP switch with a multiplexer.

FIG. 3 is a diagram illustrating a more detailed configuration example of an IP switch with a multiplexer.

FIG. 4 is a diagram showing another configuration example of an IP switch with a multiplexer.

FIG. 5 is a diagram illustrating an example of a correspondence relationship between various types of identification information used in an IP switch with a multiplexer.

FIG. 6 is a diagram illustrating a configuration example of an IP-compatible frame relay interface unit.

FIG. 7 is a diagram illustrating a configuration example of an ATM interface unit.

FIG. 8 is a diagram illustrating a configuration example of a cell multiplexing / demultiplexing unit.

FIG. 9 is a diagram illustrating an example of communication using a default VC in an uplink flow.

FIG. 10 is a diagram illustrating an example of communication by a redirect VC of an uplink flow.

FIG. 11 is a diagram showing an example of a table of an IP-compatible frame relay interface unit upstream unit A;

FIG. 12 is a diagram illustrating an example of an upstream table of a cell multiplexing / demultiplexing unit.

FIG. 13 is a diagram illustrating an example of a table of a downstream unit A of the ATM interface unit.

FIG. 14 is a diagram illustrating an example of a table of a downstream unit B of the ATM interface unit.

FIG. 15 is a diagram illustrating an example of a table of an upstream unit A of the ATM interface unit.

FIG. 16 is a diagram showing an example (part 1) of a processing sequence in an uplink flow.

FIG. 17 is a diagram illustrating an example (part 1) of a cell format in an uplink flow.

FIG. 18 is a diagram illustrating an example (part 2) of a cell format in an uplink flow.

FIG. 19 is a diagram illustrating an example (part 2) of a processing sequence in an uplink flow.

FIG. 20 is a diagram illustrating an example (part 1) of a control message for an uplink flow.

FIG. 21 illustrates an example of an uplink flow processing sequence (part 3);
FIG.

FIG. 22 is a diagram illustrating an example (part 3) of a cell format in an uplink flow.

FIG. 23 is a diagram illustrating an example (part 4) of a processing sequence in the uplink flow.

FIG. 24 is a diagram illustrating an example (part 2) of a control message for an uplink flow.

FIG. 25 illustrates an example of an uplink flow processing sequence (part 5);
FIG.

FIG. 26 is a diagram illustrating an example (part 4) of a cell format in an uplink flow.

FIG. 27 is a diagram illustrating an example of communication using a default VC of a downlink flow.

FIG. 28 is a diagram showing an example of communication by a redirect flow redirect VC.

FIG. 29 is a diagram illustrating an example of a table of an IP-compatible frame relay interface unit downstream unit A;

FIG. 30 is a diagram illustrating an example of a table of a downlink section of the cell multiplexing / demultiplexing section.

FIG. 31 is a diagram illustrating an example of a table of an ATM interface unit upstream unit A;

FIG. 32 is a diagram showing an example of a table of an ATM interface section up section B.

FIG. 33 is a diagram showing an example (part 1) of a processing sequence in a downlink flow.

FIG. 34 is a diagram illustrating an example (part 1) of a cell format in a downlink flow.

FIG. 35 is a diagram illustrating an example (part 2) of a cell format in a downlink flow.

FIG. 36 is a diagram illustrating an example (part 2) of a processing sequence in a downlink flow.

FIG. 37 is a diagram illustrating an example (part 1) of a control message for a downlink flow.

FIG. 38 is a diagram illustrating an example (part 3) of a processing sequence in a downlink flow.

FIG. 39 is a diagram illustrating an example (part 3) of a cell format in a downlink flow.

FIG. 40 is a diagram illustrating an example (part 4) of the processing sequence in the downlink flow.

FIG. 41 is a diagram illustrating an example (part 2) of a control message for a downlink flow.

FIG. 42 is a diagram illustrating an example (part 5) of a processing sequence in a downlink flow.

FIG. 43 is a diagram illustrating an example (part 4) of a cell format in a downlink flow.

FIG. 44 is a diagram illustrating an example of packet delay in an IP switch with a multiplexer.

FIG. 45 is a diagram illustrating a configuration example of an IP-compatible low-speed ATM interface unit.

FIG. 46 is a diagram illustrating a configuration example of a non-IP-compatible frame relay interface unit.

FIG. 47 is a diagram illustrating a configuration example of a circuit emulation interface unit.

FIG. 48 is a diagram illustrating an example of a conventional IP switching network.

FIG. 49 is a diagram showing a conventional example of an IP switch and an IP switch gateway.

FIG. 50 is a diagram illustrating an example of packet delay in a conventional example.

[Explanation of symbols]

5 ... IP switch with multiplexer, 51 ... multiplexer,
52: ATM switch; 53: IP control unit; 511: Cell multiplexing / demultiplexing unit; 512: IP-compatible frame relay interface unit; 513: IP-compatible low-speed ATM interface unit.

[Procedure amendment]

[Submission date] September 20, 2000 (2009.2)
0)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

Patent application title: Packet switching apparatus and packet switching processing method

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihiko Takase 216 Totsukacho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Hitachi, Ltd.Information Communication Division (72) Inventor Masaru Murakami 216 Totsukacho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Hitachi, Ltd.Information and Communication Division (72) Koji Wakayama, Inventor, 1-280 Higashi-Koigakubo, Kokubunji-shi, Tokyo Tokyo, Japan Inside (72) Inventor 1-280, Tetsuro Yoshi ▼ Tetsuro Higashi-Koigakubo, Kokubunji, Tokyo, Japan Address: Central Research Laboratory, Hitachi, Ltd.

Claims (7)

[Claims] 1. Layer 3 of packet switching system in communication
A router device for exchanging a packet accompanied by the above processing using an ATM switch, comprising: an ATM switch for exchanging cells; a plurality of interface units connected to a plurality of transmission paths for transmitting the packet; A cell demultiplexing unit connected to one physical port of the switch and the plurality of interface units; and a layer 3 control unit for performing and managing the layer 3 processing in the own device. Means for converting a packet transmitted from the connected transmission line into cells and transmitting the cells to the cell demultiplexing unit, and converting the cells transmitted from the cell demultiplexing unit into packets and connecting the cells. Means for transmitting to a transmission path, and means for converting information of a header part of a cell and a packet to be transmitted and received for processing of the layer 3, wherein the cell demultiplexing unit comprises: Continued been said plurality of interface units than the transmitted cell by serial multiplexed the AT
Means for transmitting to the M switch, and means for separating cells sent from the ATM switch and delivering the separated cells to an interface unit connected to the transmission path of the transmission destination, wherein the layer 3 control unit includes: An interface unit, a logical port number set for a physical port of the ATM switch to which the cell demultiplexing unit is not connected, and logical channel information set for a cell flow in the interface unit and the physical port, The interface unit and the ATM switch are provided by communication that specifies a plurality of types of identification information for identifying the cell or packet flow, including the layer 3 address information set for the packet flow in the interface unit. The content of the packet exchange is changed by performing the processing of the layer 3 in cooperation with Router device. 2. The router device according to claim 1, wherein the means for performing serial multiplexing of the cell demultiplexing unit converts cells sent from the plurality of connected interface units between the interface units. A router for multiplexing in a unit of cell so as to reduce a variation in communication delay. 3. The router device according to claim 1, wherein each of the physical ports of the ATM switch is provided with an ATM interface unit having means for converting information of a header portion of a cell to be transmitted and received. In the communication between the interface unit and the ATM interface unit connected to the cell demultiplexing unit and the communication between the ATM interface units, a plurality of types of identification information for identifying the flow of the cell or the packet are individually identified. In each of the interface unit and the ATM interface unit, the correspondence between the identification information is registered, and,
A router device having a memory used for conversion of means for converting the information of the header portion, wherein registered contents of each memory are updated based on identification information specified by the layer 3 control portion. . 4. A router device for exchanging data blocks for communications other than regular ATM communications using an ATM switch, comprising: an ATM switch for exchanging cells; and a packet exchange layer 3 process in communications. A plurality of interface units respectively connected to one or a plurality of transmission paths for individually transmitting a plurality of types of data blocks including accompanying packets, and a cell connected to one physical port of the ATM switch and the plurality of interface units A demultiplexing unit; and a layer 3 control unit for performing and managing the layer 3 processing in the own device. Each of the interface units converts a data block transmitted from the transmission line into a cell of a common format. Means for converting and transmitting to the cell demultiplexing unit, and supporting communication on the connected transmission path for cells transmitted from the cell demultiplexing unit. Means for sending to said transmission line is converted into that data block, provided when the processing of the layer 3 is required,
Means for converting information of a header part of a cell and a data block to be transmitted and received for the processing of the layer 3, wherein the cell demultiplexing unit serially multiplexes the cells sent from the plurality of interface units. Means for transmitting to the ATM switch, and means for separating cells sent from the ATM switch, and delivering the cells to an interface unit connected to the transmission path of the transmission destination, the layer 3 control unit, A logical port number set for each interface unit and a physical port of the ATM switch to which the cell demultiplexing unit is not connected, and logical channel information set for a cell flow in the interface unit and the physical port. The cell or the packet, including layer 3 address information set for the flow of the packet in the interface unit. The packet exchange is performed by performing the layer 3 processing in cooperation with the ATM switch and the interface unit requiring the layer 3 processing by communication specifying a plurality of types of identification information for identifying the flow. A router device characterized by changing the content of a router. 5. The router device according to claim 4, wherein the means for performing serial multiplexing of the cell demultiplexing unit converts cells sent from the plurality of connected interface units between the interface units. A router for multiplexing in a unit of cell so as to reduce a variation in communication delay. 6. The router device according to claim 4, wherein each of the physical ports of the ATM switch is provided with an ATM interface unit having means for converting information of a header portion of a cell to be transmitted and received. In the communication between the interface unit and the ATM interface unit connected to the cell demultiplexing unit and the communication between the ATM interface units, a plurality of types of identification information for identifying the flow of the cell or the packet are individually identified. In each of the interface unit and the ATM interface unit, the correspondence between the identification information is registered, and,
A router device having a memory used for conversion of means for converting the information of the header portion, wherein registered contents of each memory are updated based on identification information specified by the layer 3 control portion. . 7. The router device according to claim 1, wherein a plurality of sets of the cell demultiplexing unit and a plurality of interface units connected to the cell demultiplexing unit are provided. Router device to do.