JP4864461B2 - ATM converter - Google Patents

Description

  The present invention has an ATM (Asynchronous Transfer Mode) interface and an Ethernet (registered trademark) interface, converts an ATM cell from the ATM device into an Ethernet frame, transmits the Ethernet frame to the wide area Ethernet (registered trademark) network, and from the wide area Ethernet network. The present invention relates to an ATM converter that converts an Ethernet frame into an ATM cell and transmits the ATM cell to an ATM device, and more particularly to an ATM converter that enables broadband communication by connecting ATM devices between other points via a wide area Ethernet network.

  Conventional ATM systems require ATM lines such as ATM dedicated line services and cell relay services for each carrier to connect multiple ATM devices with ATM interfaces capable of broadband communication via the ATM network. Connections are also made by building expensive systems.

  FIG. 19 shows a system configuration diagram of a conventional ATM system. In FIG. 19, the ATM system 50 shows a configuration in which communication is performed between the ATM devices 51 to 53 between the three points of the bases A to C.

  The ATM device 51a at the site A is connected to an ATM line termination device 53a such as an ATM dedicated line service or a cell relay service via an ATM connection cable 52 such as a UTP (Unshielded Twisted Pair) cable or an optical fiber cable. The ATM line termination device 53a is connected to the ATM switch 54a in the ATM network 55 via the ATM connection cable 52. In the ATM network 55, the ATM switch 54a, the ATM switch 54b, and the ATM switch 54c are connected to each other. Yes. Bases B and C are connected in the same manner as base A.

  FIG. 20 shows a logical connection diagram of the ATM system of FIG. In FIG. 20, the ATM device 51a at the site A and the ATM device 51b at the site B are connected by a logical path 56a with VP = 1. The ATM device 51a at the site A and the ATM device 51c at the site C are also connected by a logical path 56b with VP = 2. Similarly, the ATM device 51b at the base B and the ATM device 51c at the base C are connected by a logical path 56c of VP = 3.

  In this way, in order to communicate between each site, the logical path must be contracted in a mesh form. Therefore, when communicating at the N site, (N-1) logical channels per site. You need to sign a pass. The ATM system 50 is an example using a “VP service” for making a contract in units of VP (Virtual Pass) among ATM leased line services and cell relay services. In this case, the VCI (Virtual Channel Identifier) value used in the logical path of each VP is transmitted without being terminated in the ATM network 55. However, VPI values 0-31 are reserved for special purposes and are not limited to this. At this time, conversion of the VPI (Virtual Pass Identifier) value is performed in the ATM network 55 by contract, but the conversion is not performed in the logical connection diagram shown in FIG.

  Next, the operation of the ATM system will be described based on FIG. 19 and FIG. Data from the base A to the base B is converted into ATM cells by the ATM device 51a. At this time, since the data is directed to the base B, VP = 1, which is a logical path to the base B, is set in the VPI of the cell header.

  VCI (Virtual Channel Identifier) is arbitrarily used in the range of 32-65535. The ATM cell toward the site B is transferred to the ATM device 51b at the site B via the ATM line terminator 53a, the ATM switch 54a, the ATM network 55, the ATM switch 54b, and the ATM line terminator 53b. Data is restored. Communication is also performed between the base A and the base C and between the base B and the base C in the same manner.

  In general, when using a VP service, data having different properties such as voice VCI and data VCI are separated by VCI for communication. Further, by applying an AAL (ATM Adaptation Layer) type corresponding to the type of traffic to each VCI data, communication with QoS (Quality of Service) can be ensured. There are 1-5 types of AAL types. Typical examples include AAL1 and AAL2 that are mainly used for real-time data, and AAL5 that is mainly used for non-real-time data and best-effort data. .

  In addition, the conventional packet switching system includes a packet switch having a flow control device and an ATM router and a gateway device, has a low processing delay related to establishment or cancellation of cut-through, and has a high packet switching capability. Reference 1 ”.

  The gateway device converts the received packet into an ATM cell, and sets the ATM cell header by setting the VPI / VCI value for transfer to the ATM router or the VPI / VCI value for cut-through within the ATM in the ATM cell header. The packet is transferred to the packet switch, and only the packet header is taken out from the packet and converted into an ATM cell. The ATM cell header is set with a VPI / VCI value for transfer to the flow control device, and the ATM cell is transferred to the packet switch. Forward to.

The flow control device cuts the VPI / VCI value for transfer to the ATM router to the gateway device when the packet number of flow packets obtained from the received ATM cell or the packet arrival frequency exceeds the threshold from below the threshold. Change to the VPI / VCI value for through, and if the threshold value falls below the threshold value, the reverse change is made.
Japanese Unexamined Patent Publication No. 2000-59397 (Summary, see FIG. 1)

  Conventional ATM systems use many ATM leased lines and cell relay services that can provide high-speed and broadband services, and many expensive services depend on the communication distance, so a network that requires multi-site communication is built. Then, there is a problem that the running cost greatly increases.

  In addition, with the practical use of transmission technologies faster than ATM, such as Gigabit Ethernet, MPLS, and even 10 Gigabit Ethernet, network services for each carrier provide services with lower bandwidths such as IP-VPN services and wide-area Ethernet services. Has been. In particular, services that use the Ethernet interface as a demarcation point are more broadband and less expensive.

  The present invention has been made to solve such a problem, and an object thereof is to connect a multi-point ATM device to an Ethernet network, and to perform broadband and inexpensive communication, an ATM interface, an Ethernet interface, and a media conversion means. It is to provide an ATM converter equipped with.

In order to solve the above problems, an ATM converter according to the present invention connects an ATM device to a multipoint via a wide-area Ethernet network, and performs communication between ATM devices to perform ATM media and Ethernet frame media conversion. a converter, a plurality of ATM interface for performing an interface ATM device and ATM cells, which effective control and a plurality of Ethernet interfaces to perform interface of the wide area Ethernet network and Ethernet frames, the media conversion of ATM cells and Ethernet frames The media conversion means includes a VPI / VCI-IP mapping unit that maps the VPI / VCI in the ATM cell header received from the ATM interface based on the configuration information and the IP address of the transfer partner, and the configuration information. VPI / VCI conversion unit that converts VPI / VCI of ATM cell to new VPI / VCI, and converted VPI / VCI An ATM-IP capsule part that encapsulates ATM cells into IP packets based on the IP address information of the transferred destination and the IP address of the device itself, and an Ethernet frame received from the Ethernet interface based on the configuration information Based on the configuration information, a capsule determination unit that determines whether the frame is an encapsulated frame, an ATM-IP decapsulation unit that restores the ATM cell to the ATM cell when the capsule determination unit determines that the ATM cell is an encapsulated frame Then, select the ATM interface to output according to the VPI / VCI of the restored ATM cell and output the ATM cell, and the ATM cell of the Ethernet frame that encapsulates the ATM cell based on the configuration information Select the Ethernet interface to input / output according to the VPI / VCI of the Ethernet, the Ethernet distribution unit to input / output the Ethernet frame, the VPI / VCI and the transfer partner I A configuration information storage unit for storing configuration information such as information for mapping P addresses and information for capsulating ATM cells into IP packets, and a configuration information change interface for changing configuration information It is characterized by.

The media converter according to the present invention, you comprising the VPI / VCI-priority information mapping unit for mapping the priority information of the VPI / VCI and the IP packet of the ATM cell based on the configuration information.

Further, the media conversion means according to the present invention includes an AAL5 identifying unit that identifies a PVC transmitted by an AAL5 frame , based on VPI / VCI of an ATM cell received from an ATM interface based on configuration information , and a PVC identified as AAL5. AAL5 frame is taken out from the AAL5-IP encapsulation part that encapsulates the payload part of the AAL5 frame into an IP packet, and the payload part of the AAL5 frame restored from the frame received from the Ethernet interface is assembled into an AAL5 frame. An AAL5-IP decapsulation unit for converting into a cell is provided.

The media converter according to the present invention comprises a shaping means for shaping against Ethernet interface based on the configuration information, the priority control by the priority information included in the IP header in the frame encapsulated based on the configuration information further comprising a priority control unit for performing you characterized.

Further, the ATM interface according to the present invention, you comprising the ATM interface for connection to the ATM leased line services and cell relay services.

An ATM converter according to the present invention includes an ATM interface that executes an interface between an ATM device and an ATM cell, an Ethernet interface that executes an interface between a wide area Ethernet network and an Ethernet frame, and a medium that effectively controls media conversion between the ATM cell and the Ethernet frame. Since the conversion means is provided, the ATM cell supplied from the ATM device is converted into an Ethernet frame, the Ethernet frame is transmitted to the wide area Ethernet network, and the Ethernet frame received from the wide area Ethernet network is converted into the ATM cell to be converted into the ATM apparatus. Can be supplied to.

The media conversion means according to the present invention includes a VPI / VCI-IP mapping unit that maps a VPI / VCI in an ATM cell header received from an ATM interface based on configuration information and an IP address of a transfer partner, and a mapped IP An ATM-IP encapsulation unit that encapsulates an ATM cell into an IP packet based on the address and the IP address information of the device itself, and an Ethernet frame received from the Ethernet interface based on the configuration information is an ATM cell encapsulated frame Capsule determination unit that determines whether there is a frame, ATM-IP decapsulation unit that restores the ATM cell from the frame when the capsule determination unit determines that it is an encapsulated frame, and VPI / VCI and the IP address of the transfer partner are mapped A configuration information storage unit that stores configuration information such as information for switching the ATM cell into IP packets, and configuration information Since a configuration information change interface for changing, converts the ATM cells into Ethernet frames, it is possible to inverse transform the Ethernet frame to ATM cell.

Further, the media conversion means according to the present invention provides a VPI / VCI-priority information mapping unit that maps ATM cell VPI / VCI and IP packet priority information based on configuration information, or ATM cell VPI based on configuration information. Since either or both of the VPI / VCI converters that convert / VCI to new VPI / VCI are provided, when converting from ATM cells to Ethernet frames, data can be freely transferred based on the VPI / VCI of the ATM cells. Ru can set one or both of the priority or any data transmission destination.

Further, the media converting means according to the present invention selects an ATM interface that outputs an ATM cell based on the VPI / VCI of the restored ATM cell based on the configuration information, and distributes the ATM distribution unit to the configuration information. Equipped with an Ethernet distribution unit or ATM distribution unit that selects and distributes multiple Ethernet interfaces that input and output encapsulated Ethernet frames based on it, so bandwidth guarantee is required for real-time data etc. Select a network to transmit according to the nature of the traffic, separating it into a wide-area Ethernet network for sending and receiving secure Ethernet frames and a wide-area Ethernet network for sending and receiving non-real-time best-effort Ethernet frames it is possible to ing.

Further, the media conversion means according to the present invention includes an AAL5 identifying unit that identifies a PVC transmitted by an AAL5 frame , based on a VPI / VCI of an ATM cell received from an ATM interface based on configuration information, and a PVC identified as AAL5. Take out AAL5 frame, and further assemble AAL5-IP encapsulation unit that encapsulates AAL5 frame payload part into IP packet, and AAL5 frame payload part restored from frame received from Ethernet interface into AAL5 frame and put it into ATM cell since with the AAL5-IP decapsulation unit for converting, in the data real time is not required, and in the case of data by AAL5 is Ru can use wide area Ethernet network by higher transfer efficiency AAL5 encapsulation .

In addition, the ATM converter according to the present invention has an ATM interface for connecting to an ATM leased line service, a cell relay service, or the like, so if the data is to minimize transmission delay, the ATM cell is not converted, Ru can be transmitted using the remains ATM network of ATM cell.

Further, the media conversion means according to the present invention performs priority control by shaping means for shaping the Ethernet interface based on the configuration information and priority information included in the IP header in the frame encapsulated based on the configuration information. Since the priority control unit is provided, it is possible to prevent the Ethernet frame from being discarded in the wide area Ethernet network by shaping, and to compensate for the low delay of the Ethernet frame by priority control .

  An ATM converter according to the present invention includes an ATM interface that performs an interface between an ATM device and an ATM cell, an Ethernet interface that performs an interface between a wide area Ethernet network and an Ethernet frame, and a medium that effectively controls media conversion between the ATM cell and the Ethernet frame. Since the conversion means is provided, the ATM cell supplied from the ATM device is converted into an Ethernet frame, the Ethernet frame is transmitted to the wide area Ethernet network, and the Ethernet frame received from the wide area Ethernet network is converted into the ATM cell to be converted into the ATM apparatus. It is possible to provide wideband and inexpensive communication between the ATM devices via the Ethernet network.

The media conversion means according to the present invention includes a VPI / VCI-IP mapping unit that maps a VPI / VCI in an ATM cell header received from an ATM interface based on configuration information and an IP address of a transfer partner, and a mapped IP An ATM-IP encapsulation unit that encapsulates an ATM cell into an IP packet based on the address and the IP address information of the device itself, and an Ethernet frame received from the Ethernet interface based on the configuration information is an ATM cell encapsulated frame Capsule determination unit that determines whether there is a frame, ATM-IP decapsulation unit that restores the ATM cell from the frame when the capsule determination unit determines that it is an encapsulated frame, and VPI / VCI and the IP address of the transfer partner are mapped Configuration information storage unit for storing configuration information such as information for switching and ATM cell capsulation into IP packets, and configuration information It is possible to convert ATM cells to Ethernet frames and reversely convert Ethernet frames to ATM cells, via the ATM device and via the wide-area Ethernet network. Communication between ATM devices.

  Further, the media conversion means according to the present invention provides a VPI / VCI-priority information mapping unit that maps VPI / VCI of an ATM cell and priority information of an IP packet based on configuration information, or a VPI of an ATM cell based on configuration information. Since either or both of the VPI / VCI converters that convert / VCI to new VPI / VCI are provided, when converting from ATM cells to Ethernet frames, data can be freely transferred based on the VPI / VCI of the ATM cells. Either or both of the priority and the data transmission destination can be set arbitrarily, and the ease of use can be appealed.

  Further, the media converting means according to the present invention selects an ATM interface that outputs an ATM cell based on the VPI / VCI of the restored ATM cell based on the configuration information, and distributes the ATM distribution unit to the configuration information. Equipped with an Ethernet distribution unit or ATM distribution unit that selects and distributes multiple Ethernet interfaces that input and output encapsulated Ethernet frames based on it, so bandwidth guarantee is required for real-time data etc. Select a network to transmit according to the nature of the traffic, separating it into a wide-area Ethernet network for sending and receiving secure Ethernet frames and a wide-area Ethernet network for sending and receiving non-real-time best-effort Ethernet frames And a more flexible system can be constructed.

  Further, the media conversion means according to the present invention includes an AAL5 identifying unit for identifying a PVC transmitted by an AAL5 frame based on VPI / VCI of an ATM cell received from an ATM interface based on configuration information, and a PVC identified as AAL5. The AAL5 frame is taken out from the AAL5 frame, and the AAL5-IP encapsulation unit that encapsulates the payload part of the AAL5 frame into an IP packet, and the payload part of the AAL5 frame restored from the frame received from the Ethernet interface is assembled into an AAL5 frame, and the ATM cell The AAL5-IP decapsulation unit that converts to AAL5 enables the use of a wide-area Ethernet network by AAL5 encapsulation with higher transfer efficiency when real-time data is not required and data is AAL5. The communication cost can be reduced.

  In addition, the ATM converter according to the present invention has an ATM interface for connecting to an ATM leased line service, a cell relay service, or the like, so if the data is to minimize transmission delay, the ATM cell is not converted, The ATM cell can be transmitted using the ATM network, and a more flexible network can be constructed according to the type of traffic.

  Further, the media conversion means according to the present invention performs priority control by shaping means for shaping the Ethernet interface based on the configuration information and priority information included in the IP header in the frame encapsulated based on the configuration information. Since the priority control unit is provided, shaping prevents the Ethernet frame from being discarded within the wide area Ethernet network, and the priority control can compensate for the low delay of the Ethernet frame, thus improving the reliability of the Ethernet frame. Can be secured.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In the present invention, in order to communicate between existing ATM devices via a broadband, low-cost broadband Ethernet network, an interface with the ATM device, an interface with the broadband Ethernet network, an ATM cell and an Ethernet frame are provided. The present invention provides an ATM converter including media conversion means for performing the conversion of the above.

  FIG. 1 is a system configuration diagram of a first embodiment of an ATM system to which an ATM converter according to the present invention is applied. In FIG. 1, an ATM system 1A will be described as a system that performs communication using ATM Ethernet 2 between ATM devices 2A, 2B, and 2C between three sites A to C.

  The ATM device 2A is connected to the ATM converter 4A via an ATM connection cable 3 such as a UTP (Unshielded Twisted Pair) cable or an optical fiber cable. Here, various interfaces such as an ATM25M interface using a UTP cable, an ATM155M interface using an optical fiber cable, an ATM622M interface, and a 1.5M Tl / El interface are used as an interface between the ATM device 2A and the ATM converter 4A. The same applies to all subsequent ATM interfaces.

  The ATM converter 4A is connected to the line connection device 6A via an Ethernet connection cable 5 such as a UTP cable or an optical fiber cable. Here, as the Ethernet interface between the ATM converter 4A and the line connection device 6A, there are various speed interfaces such as 10M / 100M / 1G / 10G, and the same applies to all subsequent Ethernet interfaces.

  The line connection device 6A is connected to the wide area Ethernet network 8 via the access line 7A. Here, the line connection device 6A is a line termination device for the access line 7A for connection to the wide area Ethernet network 8, and differs depending on the type of the access line 7A.

  The access line 7A includes various types of lines such as a high-speed digital leased line service, an economy leased line, Ethernet access using dark fiber, and the same applies to all subsequent access lines. In this embodiment, the wide-area Ethernet network 8 is used, but various network services such as IP / VPN and Internet VPN (Virtual Private Network), an intranet constructed by a company, etc. are used. Various networks that can transfer IP packets can be used. The base B and the base C are also connected to the wide area Ethernet network 8 similarly to the base A.

  FIG. 2 is a basic block diagram of an embodiment of an ATM converter according to the present invention. In FIG. 2, an ATM converter 4 (for example, an ATM converter 4A) is composed of a software program based on a microprocessor, an ATM interface 11 for executing an interface between the ATM device 2A and an ATM cell, a wide area Ethernet network 8 and an Ethernet. An Ethernet interface 12 for executing a frame interface and media conversion means 13 for effectively controlling the media conversion of ATM cells and Ethernet frames are provided.

  The media conversion means 13 media converts the ATM cell of the ATM device 2A supplied from the ATM interface 11 into an Ethernet frame, transmits the converted Ethernet frame to the wide area Ethernet network 8 via the Ethernet interface 12, and the Ethernet interface 12 The Ethernet frame of the wide-area Ethernet network 8 supplied from is media-converted into ATM cells, and the converted ATM cells are supplied to the ATM device 2A via the ATM interface 11.

  Thereby, the ATM converter 4 can execute communication between ATM apparatuses (for example, ATM apparatuses 2A, 2B, 2C) installed between multiple points shown in FIG.

  FIG. 3 is a block diagram of the main part of the first embodiment of the media converting means according to the present invention. In FIG. 3, the media conversion means 13a includes a VPI / VCI-IP mapping unit 14, an ATM-IP encapsulation unit 15, a configuration information storage unit 16, a capsule determination unit 17, and an ATM-IP decapsulation unit 18. A configuration information changing interface 19 is provided.

VPI / VCI-IP mapping unit 14 maps the VPI (Virtual Pass Identifier) / VCI IP address (Virtual Channel Identifier) and transfer destination in ATM cell header received from the ATM interface 11 based on the configuration information.

  The ATM-IP encapsulation unit 15 encapsulates the ATM cell into an IP packet based on the mapped IP address and the IP address information of the device itself.

  The configuration information storage unit 16 stores configuration information such as information for mapping the VPI / VCI and the IP address of the transfer partner and information for encapsulating ATM cells into IP packets, for example, as a data table.

  The capsule determination unit 17 determines whether the Ethernet frame received from the Ethernet interface 12 is an ATM cell or an encapsulated frame based on the configuration information.

  When the capsule determination unit 17 determines that the frame is an encapsulated frame, the ATM-IP decapsulation unit 18 restores the ATM cell from the frame.

  The configuration information change interface 19 receives change configuration information for changing the configuration information from an input device such as an external personal computer, and supplies it to the configuration information storage unit 16.

  FIG. 5 is an image view of ATM-IP encapsulation according to an embodiment of the ATM-IP encapsulation unit according to the present invention. In FIG. 5, the ATM-IP encapsulation unit 15 first extracts necessary information from the ATM cell. The extracted data is in the range from 48 bytes which is the payload of the ATM cell to 53 bytes which is the whole including the ATM cell header, and the data range to be extracted is different depending on the needs of the system.

  Next, an IP header is added to the extracted data. Although the IP header differs depending on the version, the source IP address and the destination IP address are common. Here, the IP address set in the own device is set as the source IP address, and the IP address of the communication partner associated with the VPI / VCI of the ATM cell is set as the destination IP address.

  Further, in order to transfer the Ethernet frame from the Ethernet interface 12, a MAC header is added. The MAC header consists of a total of 14 bytes, 6 bytes for the destination MAC address, 6 bytes for the source MAC address, and 2 bytes for the Type / Length field, and 4 bytes for the frame check sequence (FCS) are added to the end of the Ethernet frame. .

  Next, the operation of the ATM system 1A shown in FIG. 1 will be described. Data transfer from the base A to the base B will be described as an example. An ATM cell with VPI = 2 is sent from the ATM device 2A at the site A to the ATM converter 4A. The ATM converter 4A selects the IP address B of the ATM converter 4B at the base B from the received ATM cell VPI = 2 information, performs the encapsulation shown in FIG. 5, and directs the Ethernet frame toward the wide area Ethernet network 8 side. Send it out.

  The sent Ethernet frame is transferred to the wide area Ethernet network 8 via the line terminating device 6A and the access line 7A. In the wide-area Ethernet network 8, a switching operation is performed in the network based on the destination MAC address of the Ethernet frame, in this case, the MAC address of the ATM converter 4B in the base B, and finally the data is transferred to the base B.

  The transferred Ethernet frame reaches the ATM converter 4B via the access line 7B and the line terminating device 6B at the base B. The ATM converter 4B confirms that the received Ethernet frame is an encapsulated Ethernet frame, decapsulates it in the reverse process of the encapsulation shown in FIG. 5, and restores the ATM cell. The restored ATM cell is transferred to the ATM device 2B at the base B, and the data transfer is completed. The same operation is performed for communication between other bases.

  In the present embodiment, the destination IP address is determined only by the VPI, but the destination may be determined by combining VPI / VCI.

Thus, media conversion means 13a according to the present invention, the VPI / VCI-IP mapping unit 14 for mapping the IP address of the VPI / VCI and the transfer destination in the ATM cell header received from the ATM interface 11 based on the configuration information An ATM-IP encapsulation unit 15 that encapsulates an ATM cell into an IP packet based on the mapped IP address and the IP address information of the device itself, and whether the Ethernet frame received from the Ethernet interface based on the configuration information is an ATM cell. A capsule determination unit 17 that determines whether the frame is an encapsulated frame, an ATM-IP decapsulation unit 18 that restores a frame to an ATM cell when the capsule determination unit 17 determines an encapsulated frame, and a VPI / Configuration information such as information for mapping the VCI and the IP address of the transfer partner, and information for encapsulating ATM cells into IP packets The configuration information storage unit 16 for storing the configuration information and the configuration information change interface 19 for changing the configuration information are provided, so that the ATM cell can be converted into the Ethernet frame and the Ethernet frame can be converted back into the ATM cell. It is possible to perform communication between ATM devices via a wide area Ethernet network via an ATM device.

  FIG. 4 is a block diagram of the main part of the second embodiment of the media converting means according to the present invention. In FIG. 4, the media conversion means 13b of the ATM converter 4b includes a VPI / VCI-IP mapping unit 14, an ATM-IP encapsulation unit 15, a configuration information storage unit 16, a capsule determination unit 17, and an ATM-IP decapsulation. , A configuration information changing interface 19, a VPI / VCI-priority information mapping unit 20, and a VPI / VCI conversion unit 21.

  The media conversion unit 13b shown in FIG. 4 has a configuration in which a VPI / VCI-priority information mapping unit 20 and a VPI / VCI conversion unit 21 are added to the media conversion unit 13a shown in FIG.

  The VPI / VCI-priority information mapping unit 20 can map the VPI / VCI of the ATM cell and the priority information of the IP packet based on the configuration information, and can freely set the priority of the IP packet.

  The VPI / VCI converter 21 converts the ATM cell VPI / VCI into a new VPI / VCI based on the configuration information, and can arbitrarily set a data transmission destination.

  FIG. 6 is a mapping image diagram of ATM cell VPI / VCI and IP packet priority information according to an embodiment of the VPI / VCI-priority information mapping unit according to the present invention. This image diagram specifically shows the service type field used in IP version 4.

  In IP version 4, priority and traffic class are set using 6 bits out of 8 bits in the service type field. Bits 0-2 in the figure are fields for priority and take values from 0-7. Bit string “111” 7 has the highest priority, and bit string “000” 0 has the lowest priority.

  In the service type field, a “low delay” bit set for data that requires low delay, a “high throughput” bit set for data that requires high throughput, and data that requires higher reliability. There is a “high reliability” bit set to.

  Further, the service type field may be redefined and used as 6-bit priority information called a DS field. In this case, priority can be assigned to any combination of 6-bit DS fields. In addition, even when using IP version 6 or the like, mapping is performed to fields related to the same priority and QoS (Quality of Service).

  FIG. 7 is a mapping image diagram of VPI / VCI-priority information mapping unit according to another embodiment of the present invention in which ATM cell VPI / VCI and IP packet priority information are mapped. This image diagram shows in particular the mapping to priority in the service type field used in IP version 4.

  Mapping information is set in the ATM converter according to the present invention, and mapping is performed based on this information. In this embodiment, priority 0, 1, 3, 5, and 7 are set to be mapped to ATM cells with VPI / VCI = 1 / 32-37 based on the VCI. When the ATM cell received from the ATM interface is encapsulated as shown in FIG. 5, the mapping information is used to set the priority in the IP header. In this embodiment, the priority for mapping is determined by VCI, but the priority for mapping may be determined by a combination of VPI / VCI.

  FIG. 8 is a VPI / VCI conversion image diagram of an ATM cell according to an embodiment of the VPI / VCI conversion unit according to the present invention. This image diagram particularly shows the case of converting VPI. Conversion information is set in the ATM converter of the present invention, and VPI conversion is performed based on this information. In this embodiment, VPI = 1-6 is set to be converted into 11, 12, 13, 21, 22, and 23, respectively. When the encapsulation shown in FIG. 5 is performed, the ATM cell is set by converting the VPl / VCI value of the cell information to be encapsulated using this conversion information. In the present embodiment, only VPI is converted, but conversion may be performed by combining VPI / VCI.

  As described above, the media converting means 13b according to the present invention is based on the VPI / VCI-priority information mapping unit 20 that maps the VPI / VCI of the ATM cell and the priority information of the IP packet based on the configuration information, or on the basis of the configuration information. Since one or both of the VPI / VCI conversion unit 21 for converting the VPI / VCI of the ATM cell into the new VPI / VCI is provided, when converting from the ATM cell to the Ethernet frame, the VPI / VCI of the ATM cell is based on the VPI / VCI of the ATM cell. Thus, it is possible to freely set either one or both of the data priority and the data transmission destination, and appeal the ease of use.

  FIG. 9 is a system configuration diagram of the second embodiment of the ATM system to which the ATM converter according to the present invention is applied. In FIG. 9, an ATM system 1B includes a wide-area Ethernet network 8A for transmitting real-time Ethernet frames between ATM devices 2A, 2B, and 2C between three sites A to C, and non-real-time and best A system for performing communication using the wide area Ethernet network 8B for transmitting the Ethernet frame for effort will be described. Note that the Ethernet frame for best effort includes an AAL (ATM Adaptation Layer) -5 frame.

  The four ATM interfaces of the ATM device 2A installed at the site A are connected to the ATM converter 4A via a plurality of ATM connection cables 3 such as UTP cables and optical fiber cables. The ATM converter 4A is connected to two line terminators 6A1 and 6A2 via an Ethernet connection cable 5 such as a UTP cable or an optical fiber cable. The line termination device 6A1 is connected to the wide area Ethernet network 8A via the access line network 7A1, and the line termination apparatus 6A2 is connected to the wide area Ethernet network 8B via the access line 7B2.

  Here, the line termination devices 6A1 and 6A2 are access line line termination devices for connecting to the wide area Ethernet networks 8A and 8B, and differ depending on the type of the access line. In this embodiment, the wide-area Ethernet networks 8A and 8B are used. In addition, various network services such as IP-VPN and Internet VPN, and an intranet constructed by a company are used. Various networks that can transfer IP packets are available.

  The bases B and C have the same connection form as the base A, except that the ATM devices 2B and 2C and the ATM converters 4B and 4C are connected by a single ATM connection cable 3, respectively.

  Next, the operation in the system configuration of FIG. 9 will be described. First, data transfer from the base A to the base B will be described. An ATM cell from the ATM device 4A at the site A is transmitted from any one of the four ATM interfaces. In the ATM converter 4A, the destination IP address is selected from the received VPI / VCI information of the ATM cell and the encapsulation shown in FIG. 5 is performed. Among the two Ethernet interfaces based on the VPI / VCI information of the ATM cell, The Ethernet frame is sent out by determining which interface should be sent out.

  The correspondence between the VPI / VCI and the Ethernet interface to be transmitted is preset in the ATM converter 4A. The sent Ethernet frame is transferred to the wide area Ethernet network 8A or 8B via the line terminator 6A1 or 6A2 and the access line 7A1 or 7A2. In the wide area Ethernet network 8A or 8B, the switching operation is performed in the network based on the destination MAC address of the Ethernet frame, in this case, the MAC address of one of the two Ethernet interfaces of the ATM converter 4B in the base B. To base B.

  The transferred Ethernet frame reaches the ATM converter 4B via the access line 7B1 or 7B2 and the line termination device 6B1 or 6B2 at the site B. The ATM converter 4B confirms that the received Ethernet frame is an encapsulated Ethernet frame, decapsulates it in the reverse process of the encapsulation shown in FIG. 5, and restores the ATM cell. The restored ATM cell is transferred to the ATM device 2B at the base B, and the data transfer is completed. In the case of data transfer from the base B to the base A, the data is sent from the ATM device 2B at the base B to the ATM converter 4B. An ATM interface that should be output from the VPI / VCI of the ATM cell when the ATM cell passes through the only ATM interface and when the ATM cell from the base B reaches the ATM converter 4A at the base A and transfers it to the ATM device 2A. The operation is the same except that is selected. Communication between other bases also operates as described above.

  The point of the configuration of this system is the best for non-real-time network and network for transmitting data that requires bandwidth guarantee with real-time data etc. using two network services of wide-area Ethernet network 8A and wide-area Ethernet network 8B. The network for transmitting effort-type data is separated. By doing so, it becomes possible to select a network for transmission according to the nature of the traffic, and it is possible to construct a more flexible system.

  FIG. 10 is a block diagram showing the principal part of a third embodiment of the media converting means according to the present invention. In FIG. 10, the ATM converter 4c to which the media converting means 13c belongs includes four ATM interfaces 11A, 11B, 11C, and 11D. The media conversion means 13c includes a VPI / VCI-IP mapping unit 14, an ATM-IP encapsulation unit 15, a configuration information storage unit 16, a capsule determination unit 17, an ATM-IP decapsulation unit 18, and a configuration. An information change interface 19, a VPI / VCI-priority information mapping unit 20, a VPI / VCI conversion unit 21, and an ATM distribution unit 22 are provided.

  The media conversion unit 13c in FIG. 10 has the same configuration as the media conversion unit 13b shown in FIG. 4 except that an ATM distribution unit 22 is added.

  Based on the configuration information, the ATM distribution unit 22 selects and distributes a plurality of ATM interfaces 11A, 11B, 11C, and 11D that output ATM cells based on the restored ATM cell VPI / VCI.

  FIG. 11 is a block diagram showing the principal part of the media converting means according to the fourth embodiment of the present invention. In FIG. 11, the ATM converter 4d to which the media conversion unit 13d belongs includes two Ethernet interfaces 12A and 12B. The media conversion means 13d includes a VPI / VCI-IP mapping unit 14, an ATM-IP encapsulation unit 15, a configuration information storage unit 16, a capsule determination unit 17, an ATM-IP decapsulation unit 18, and a configuration. An information change interface 19, a VPI / VCI-priority information mapping unit 20, a VPI / VCI conversion unit 21, and an Ethernet distribution unit 23 are provided.

  The media conversion unit 13d shown in FIG. 11 has the same configuration as the media conversion unit 13b shown in FIG. 4 except that an Ethernet distribution unit 23 is added.

  The Ethernet distribution unit 23 selects and distributes a plurality of Ethernet interfaces 12A and 12B that input and output the encapsulated Ethernet frame based on the configuration information.

  The Ethernet interface 12A outputs an Ethernet frame that requires bandwidth guarantee, such as real-time data, via the wide-area Ethernet network 8, and the non-real-time, best-effort Ethernet frame is output from the Ethernet interface 12B via the wide-area Ethernet network 8B. By doing so, it becomes possible to select a network for transmission according to the nature of the traffic.

  FIG. 12 is a block diagram showing the main part of the fifth embodiment of the media converting means according to the present invention. In FIG. 12, the ATM converter 4e to which the media conversion means 13e belongs includes four ATM interfaces 11A, 11B, 11C, and 11D and two Ethernet interfaces 12A and 12B. The media conversion means 13e includes a VPI / VCI-IP mapping unit 14, an ATM-IP encapsulation unit 15, a configuration information storage unit 16, a capsule determination unit 17, an ATM-IP decapsulation unit 18, and a configuration. An information change interface 19, a VPI / VCI-priority information mapping unit 20, a VPI / VCI conversion unit 21, an ATM distribution unit 22, and an Ethernet distribution unit 23 are provided.

  The media conversion means 13e in FIG. 12 is a combination of the media conversion means 13c shown in FIG. 10 and the media conversion means 13d shown in FIG.

  As described above, the media conversion means 13c, 13d, and 13e according to the present invention can output a plurality of ATM interfaces 11A, 11B, 11C, which output ATM cells based on the VPI / VCI of the restored ATM cells based on the configuration information. An ATM distribution unit 22 that selects and distributes 11D, an Ethernet distribution unit 23 that selects and distributes a plurality of Ethernet interfaces 12A and 12B that input and output an encapsulated Ethernet frame based on configuration information, or an ATM distribution unit 22 And the Ethernet distribution unit 23, a wide-area Ethernet network 8A for transmitting and receiving Ethernet frames requiring bandwidth guarantee for real-time data and the like and a wide-area for transmitting and receiving best-effort Ethernet frames in a non-real-time system Select a network to be used separately according to the nature of the traffic, separated into the Ethernet network 8B. And a more flexible system can be constructed.

  FIG. 13 is an image of IP packet encapsulation from an AAL5 frame according to an embodiment of the AAL5-IP encapsulation unit according to the present invention. In FIG. 13, first, an AAL5 frame is restored from a plurality of ATM cells. An 8-byte trailer is added to the AAL5 frame, and padding data is added so as to be an integral multiple of 48 bytes of the ATM cell payload length.

  Next, a payload part other than trailer and padding data is extracted from the received AAL5 frame. An IP header is added to the extracted payload. As in the case where the ATM cell shown in FIG. 5 is encapsulated in an IP packet, the IP header differs depending on the version, but the source IP address and the destination IP address exist in common.

  In the present embodiment, the IP address set in the own device (for example, the ATM converter 4A) is set as the source IP address, and the communication partner associated with the VPI / VCI of the ATM cell (the destination IP address) For example, the IP address of the ATM converter 4B) is set. In addition, a MAC header is added to transfer frames from the Ethernet interface. The MAC header is composed of a total of 14 bytes including a destination MAC address of 6 bytes, a source MAC address of 6 bytes, and a Type / Length field of 2 bytes. At the end of the frame, 4 bytes of the frame check sequence (FCS) are added. . At this time, the MAC address obtained by the MAC address resolution by the destination IP address is used as the destination MAC address in the MAC header. As a means for MAC address resolution, ARP (Address Resolution Protocol) is generally used, but static setting is also possible. Although FIG. 13 shows an example of an Ethernet frame to which no VLAN (Virtual LAN) tag is added, there may be a case where an IEEE 802.1Q VLAN tag is added to the Ethernet frame.

  FIG. 14 is a block diagram showing the main part of a sixth embodiment of the media converting means according to the present invention. The ATM converter 4f to which the media conversion unit 13f belongs includes two Ethernet interfaces 12A and 12B.

  The media conversion unit 13f includes a VPI / VCI-IP mapping unit 14A, an ATM-IP encapsulation unit 15, a capsule determination unit 17A, and an ATM-IP decapsulation that constitute a system for inputting / outputting an Ethernet frame to / from the Ethernet interface 12A. Unit 18, VPI / VCI-priority information mapping unit 20A, VPI / VCI conversion unit 21A, VPI / VCI-IP mapping unit 14B constituting a system for inputting / outputting Ethernet frames to / from Ethernet interface 12B, capsule A determination unit 17B, a VPI / VCI-priority information mapping unit 20B, a VPI / VCI conversion unit 21B, an AAL5-IP encapsulation unit 25, and an AAL5-IP decapsulation unit 26 are provided.

  In addition, a configuration information storage unit 16, a configuration information change interface 19 and an AAL5 identification unit 24 common to both systems are provided.

  The AAL5 identifying unit 24 identifies the PVC transmitted by the AAL5 frame based on the VPI / VCI of the ATM cell received from the ATM interface 11 based on the configuration information.

  As described with reference to FIG. 13, the AAL5-IP encapsulation unit 25 extracts an AAL5 frame from a PVC (Permanent Virtual Circuit) identified as AAL5, and further encapsulates the payload portion of the AAL5 frame into an IP packet.

  The AAL5-IP decapsulation unit 26 assembles the restored payload portion of the AAL5 frame into an AAL5 frame in the reverse order described with reference to FIG. 13 from the frame received from the Ethernet interface, and converts it into an ATM cell.

  As described above, the media converting means 13f according to the present invention includes the AAL5 identifying unit 24 for identifying the PVC transmitted by the AAL5 frame based on the VPI / VCI of the ATM cell received from the ATM interface based on the configuration information, An AAL5 frame is extracted from the identified PVC, and further, an AAL5-IP encapsulation unit 25 that encapsulates the payload portion of the AAL5 frame into an IP packet, and the payload portion of the AAL5 frame restored from the frame received from the Ethernet interface 12B is AAL5 Since the AAL5-IP decapsulation unit 26 that assembles the frame and converts it into ATM cells is provided, if it is data that does not require real-time property and is data based on AAL5, AAL5 encapsulation with higher transfer efficiency enables wide area Ethernet A network can be used, and communication costs can be reduced.

  FIG. 15 is a system configuration diagram of the third embodiment of an ATM system to which the ATM converter according to the present invention is applied. In FIG. 15, the ATM system 1C identifies the AAL5 PVC, and both a method of encapsulating the payload of the AAL5 frame and a method of sending ATM cells not identified as AAL5 from the dedicated ATM interface. In particular, the system configuration is shown in the case of communication between three bases equipped with one Ethernet interface, one ATM service connection interface, and an interface accommodating one ATM device.

  The ATM device 2A installed at the site A is connected to the ATM converter 4A via an ATM connection cable 3 such as a UTP cable or an optical fiber cable. The ATM converter 4A is equipped with an interface for connecting to the ATM network 10 and an Ethernet interface, and is connected to the ATM line terminator 9A via the ATM connection cable 3 such as a UTP cable or an optical fiber cable. It is connected to the line terminator 6A via an Ethernet connection cable 5 such as a fiber cable.

  The ATM line terminator 9A is a line terminator for the ATM network 10 and is connected to the ATM network 10. The line termination device 6A is connected to the wide area Ethernet network 8 via the access line network 7A. Here, the line termination device 6A is a line termination device for an access line for connection to the wide area Ethernet network 8, and differs depending on the type of the access line. In addition, the configuration of this system uses a wide-area Ethernet network, but in addition to this, various network services such as IP-VPN and Internet VPN, IP networks such as using an intranet built by a company, etc. It is possible to use various networks that can transfer data. The base B and the base C are also connected in the same manner as the base A.

  Next, the operation in the system configuration of FIG. 15 will be described. Data transfer from the base A to the base B will be described as an example. Data from the ATM device 2A at the site A to the ATM device 2B at the site B is sent to the ATM converter 4A. In the ATM converter 4A, based on the set mapping information, it is determined whether or not it is AAL5 from the received VPI / VCI information of the ATM cell.

  First, a case where it is determined that it is not AAL5 will be described. If it is determined that it is not AAL5, the received ATM cell is sent as it is to the ATM line terminating device 9A and transmitted to the ATM network 10.

  In the ATM network 10, switching is performed based on the contents of the contract, and the result is sent to the ATM line terminating device 9B at the base B. Further, an ATM cell is sent from the ATM line terminator 9B to the ATM converter 4B. Since the ATM cell is an ATM cell received from the interface connected to the ATM network 10, the ATM cell 4B sends it to the ATM device 2B, and sends it to the ATM cell. Transfer is complete.

  Next, a case where it is determined that the ATM cell transmitted from the ATM device 2A at the site A to the ATM converter 4A is an AAL5 frame will be described. If the ATM converter 4A determines that it is AAL5, the ATM cell is buffered, and the VPI / VCI ATM cell is buffered until the AAL5 frame is completed.

  When the reception of all ATM cells constituting one AAL5 frame is completed and the extraction of the AAL5 frame is completed, the destination IP address is selected and the cab cell is converted as shown in FIG. Send it out.

  The sent Ethernet frame is transmitted to the wide area Ethernet network 8 via the line terminating device 6A and the access line 7A. In the wide area Ethernet network 8, a switching operation is performed in the network based on the destination MAC address of the Ethernet frame, in this case, the MAC address of the ATM converter 4B in the base B, and is finally transferred to the base B. The transferred Ethernet frame reaches the ATM converter 4B via the access line 7B and the line terminating device 6B at the base B.

  The ATM converter 4B confirms that the received Ethernet frame is an AAL5-encapsulated Ethernet frame, decapsulates it in the reverse process of encapsulation shown in FIG. 13, and restores a plurality of ATM cells. The restored ATM cell is transferred to the ATM device 2B at the base B, and the data transfer is completed. Other inter-base communication is the same operation.

  The point of the configuration of this system is that it is used by being distributed between the ATM network 10 and the wide area Ethernet network 8 depending on the nature of data transferred on the ATM. As a result, when the ATM cell is data that does not require real-time property and is based on AAL5, the ATM cell wants to minimize transmission delay by using the wide area Ethernet network 8 by AAL5 encapsulation with higher transfer efficiency. In the case of data, by using the ATM network 10, it is possible to construct a more flexible network according to the type of traffic.

  FIG. 16 is a block diagram showing the principal part of the seventh embodiment of the media converting means according to the present invention. In FIG. 16, the ATM converter 4g to which the media converting means 13g belongs includes the four ATM interfaces 11A, 11B, 11C, and 11D connected to the ATM device 2A, the ATM interface 27 connected to the ATM line terminating device 9A, and the Ethernet interface. 12 is provided. The media conversion means 13g includes an AAL5 identification unit 24, a VPI / VCI-IP mapping unit 14, a VPI / VCI-priority information mapping unit 20, a VPI / VCI conversion unit 21, and an AAL5-IP encapsulation unit 25. A configuration information storage unit 16, a capsule determination unit 17, an AAL5-IP decapsulation unit 26, an ATM distribution unit 22, and a configuration information change interface 19.

  The AAL5 identifying unit 24 identifies whether or not the ATM cell supplied from the ATM interfaces 11A, 11B, 11C, and 11D is AAL5. If the ATM cell is not AAL5, the AAL5 identifying unit 24 transmits the ATM cell to the ATM interface 27.

  If the AAL5 identifying unit 24 identifies the AAL5, the AAL5 identifying unit 24 provides the ATM cell to the VPI / VCI-IP mapping unit 14, and the VPI / VCI-IP mapping unit 14, the VPI / VCI-priority information mapping unit. 20, the VPI / VCI conversion unit 21 and the AAL5-IP encapsulation unit 25 are converted into Ethernet frames by the method shown in FIG. 13, and the Ethernet frame is converted to an Ethernet wide area for best effort shown in FIG. It is transmitted to the Ethernet network 8.

  The ATM interface 27 constitutes an interface for connecting an ATM cell whose transmission delay is to be minimized to the ATM network 10 such as an ATM leased line service or a cell relay service.

  As described above, the ATM converter 4g according to the present invention includes the ATM interface 27 for connecting to an ATM leased line service, a cell relay service, or the like. Therefore, in the case of data (ATM cell) for which transmission delay is desired to be minimized. The ATM cell is not converted and can be transmitted as it is using the ATM network 10, and a more flexible network can be constructed according to the type of traffic.

  FIG. 17 is a configuration comparison diagram of whether or not the shaping unit according to the present invention is applied. In FIG. 17, the upper configuration is a case where the ATM converter 4 does not have a shaping function, and the lower configuration is a case where the ATM converter 4 has a shaping function.

  In the upper configuration, the ATM device 2 is connected to the ATM converter 4 via an ATM connection cable 3 such as a UTP cable or an optical fiber cable. The ATM converter 4 is connected to a shaping device 30 via an Ethernet connection cable 5 such as a UTP cable or an optical fiber cable, and the shaping device 30 is also a medium via an Ethernet connection cable 5 such as a UTP cable or an optical fiber cable. Connected to the converter 31. The media converter 31 is connected to the wide area Ethernet network 8 via the Ethernet access line 7. Here, the media converter 31 is a line terminating device for the Ethernet access line 7. The contract conditions for the Ethernet access line 7 are that the interface is 10BASE-T and the contract speed is 5 Mbit / S. In the lower configuration, the shaping device 30 is removed from the upper configuration, and the ATM converter 4 has a built-in shaping function.

  Next, the operation in the system shown in FIG. 17 will be described. First, the upper configuration will be described. An ATM cell is sent from the ATM device 2 to the ATM converter 4. The ATM converter 4 selects the IP address of the ATM converter as the destination from the received VPI / VCI information of the ATM cell, converts it into a cab cell shown in FIG. 5, and sends it to the shaping device 30. The shaping device 30 sends an Ethernet frame to the wide area Ethernet network 8 while shaping the 5 Mbit / S band, which is a wide area Ethernet contract band.

  At this time, the shaping device 30 transfers Ethernet frames requiring low delay while performing priority control based on the priority information mapped in the IP header in the frame. The Ethernet frame transmitted from the shaping device 30 is transferred to the wide area Ethernet network 8 via the media converter 31 and the Ethernet access line 7.

  The reason why the shaping device 30 is necessary in this system configuration is that when the Ethernet access line 7 is used, if shaping is not performed on the contracted band, data may be discarded in the wide area Ethernet network 8. It is.

  Next, the configuration of the lower stage will be described. An ATM cell is sent from the ATM device 2 to the ATM converter 4. The ATM converter 4 selects the IP address of the ATM converter as the destination from the received VPI / VCI information of the ATM cell and performs the encapsulation shown in FIG. Further, the ATM converter 4 transmits the encapsulated Ethernet frame while shaping it into a 5 Mbit / S band, which is a wideband Ethernet contract band.

  At this time, the ATM converter 4 transfers a frame requiring low delay while performing priority control based on the priority information mapped in the IP header within the frame. The sent Ethernet frame is transferred to the wide area Ethernet network 8 via the media converter 31 and the Ethernet access line 7.

  The point of this system is that, when the ATM converter 4 of the present invention is used, the shaping device 30 in the upper configuration shown in FIG. Since the ATM converter 4 has the function of the shoeing device 30, the initial cost of the system can be reduced.

  FIG. 18 is a block diagram showing the principal part of the eighth embodiment of the media converting means according to the present invention. In FIG. 18, the ATM converter 4 h to which the media conversion unit 13 h belongs includes an ATM interface 11 and an Ethernet interface 12. The media conversion means 13h includes a VPI / VCI-IP mapping unit 14, a VPI / VCI-priority information mapping unit 20, a VPI / VCI conversion unit 21, an ATM-IP encapsulation unit 15, and a priority control unit 28. A shaping unit 29, a configuration information storage unit 16, a capsule determination unit 17, an ATM-IP decapsulation unit 18, and a configuration information change interface 19.

  The priority control unit 28 performs priority control based on priority information included in an IP header in a frame encapsulated based on configuration information.

  The shaping unit 29 shapes (limits the bandwidth) the Ethernet interface 12 based on the configuration information.

  The media conversion means 13h according to the present invention performs priority control by shaping means 29 for shaping the Ethernet interface based on the configuration information and priority information included in the IP header in the frame encapsulated based on the configuration information. Since the priority control unit 28 is provided, it is possible to prevent the Ethernet frame from being discarded in the wide-area Ethernet network by shaping, and to compensate for the low delay of the Ethernet frame by the priority control. Sex can be secured.

  In addition, in this Embodiment, although demonstrated by applying to three bases of the base A-base C, it is also applicable to four or more bases. Further, the ATM converter 4 and the media conversion means 13 of the present invention can be configured by combining the configuration requirements of the ATM converters 4A to 4C and the media conversion means 13a to 13h as required.

  As described above, the ATM converter 4 according to the present invention includes the ATM interface 11 that executes the interface between the ATM device and the ATM cell, the Ethernet interface 12 that executes the interface between the wide area Ethernet network 8 and the Ethernet frame, and the ATM cell. Since the media conversion means 13 for effectively controlling the media conversion of the Ethernet frame is provided, the ATM cell supplied from the ATM device is converted into an Ethernet frame, and the Ethernet frame is transmitted to the wide area Ethernet network 8. The received Ethernet frame can be converted into an ATM cell and supplied to the ATM device, and broadband and inexpensive communication can be realized between the ATM devices via the Ethernet network.

  An ATM converter according to the present invention comprises an ATM interface, an Ethernet interface, and media conversion means for connecting a multi-point ATM device to an Ethernet network and enabling broadband and inexpensive communication. It can be applied to any system that connects to an Ethernet network and communicates between ATM devices.

First Embodiment System Configuration Diagram of an ATM System to which an ATM Converter According to the Invention is Applied Basic block configuration diagram of an ATM converter according to an embodiment of the present invention Block diagram of main part of the first embodiment of the media converting means according to the present invention Block diagram of main part of second embodiment of media converting means according to the present invention One embodiment of ATM-IP encapsulation unit according to the present invention Image diagram of ATM-IP encapsulation Embodiment of VPI / VCI-priority information mapping unit according to the present invention Mapping of VPI / VCI of ATM cell and priority information of IP packet Another embodiment of VPI / VCI-priority information mapping unit according to the present invention Mapping image of VPI / VCI of ATM cell and priority information of IP packet Embodiment of VPI / VCI converter according to the present invention VPI / VCI conversion image diagram of ATM cell Second Embodiment System Configuration Diagram of an ATM System to which an ATM Converter According to the Invention is Applied Block diagram of essential parts of a third embodiment of media converting means according to the present invention Block diagram of essential parts of a media converting means according to a fourth embodiment of the present invention Block diagram of essential parts of fifth embodiment of media converting means according to the present invention An embodiment of an AAL5-IP encapsulation unit according to the present invention An AAL5 frame to IP packet encapsulation image diagram Block diagram of essential parts of sixth embodiment of media converting means according to the present invention. System configuration diagram of a third embodiment of an ATM system to which the ATM converter according to the present invention is applied Block diagram of essential parts of seventh embodiment of media converting means according to the present invention Comparison diagram of presence / absence of application of shaping unit according to the present invention Block diagram of essential parts of eighth embodiment of media converting means according to the present invention. System diagram of conventional ATM system Logical connection diagram of ATM system in FIG.

Explanation of symbols

1A, 1B, 1C ATM system 2A, 2B, 2C ATM equipment 3 ATM connection cable 4, 4A, 4B, 4C ATM converter 5 Ethernet connection cable 6A, 6B, 6C Line connection equipment 7A, 7B, 7C Access line 8, 8A, 8B Wide area Ethernet network 9A, 9B, 9C ATM line terminator 10 ATM network 11, 11A, 11B, 11C, 11D ATM interface 11
12, 12A, 12B Ethernet interface 13, 13a to 13h Media conversion means 14, 14A, 14B VPI / VCI-IP mapping unit 15 ATM-IP encapsulation unit 16 Configuration information storage unit 17, 17A, 17B Capsule determination unit 18 ATM- IP decapsulation unit 19 Configuration information change interface 20, 20A, 20B VPI / VCI-priority information mapping unit 21, 21A, 21B VPI / VCI conversion unit 22 ATM distribution unit 23 Ethernet distribution unit 24 AAL5 identification unit 25 AAL5-IP capsule 26 AAL5-IP decapsulation unit 27 ATM interface 28 Priority control unit 29 Shaping unit 30 Shaping device 31 Media converter

Claims (5)

It is an ATM converter that performs media conversion between ATM cells and Ethernet frames in order to connect ATM devices to multiple points via a wide-area Ethernet network and perform communication between ATM devices.
A plurality of ATM interface for performing an interface of the ATM device and the ATM cell, the wide area Ethernet network and a plurality of Ethernet interfaces to perform interface Ethernet frame, media conversion means for effective control media conversion of ATM cells and Ethernet frames With
The media conversion means includes a VPI / VCI-IP mapping unit that maps a VPI / VCI in an ATM cell header received from the ATM interface based on configuration information and an IP address of a transfer partner;
A VPI / VCI converter that converts ATM cell VPI / VCI to a new VPI / VCI based on the configuration information;
An ATM-IP capsule unit that encapsulates an ATM cell into an IP packet based on the IP address information of the transfer partner and the IP address of the device itself mapped to the converted VPI / VCI;
A capsule determination unit that determines whether an Ethernet frame received from the Ethernet interface is a frame obtained by encapsulating an ATM cell based on configuration information;
When the capsule determination unit determines that the ATM cell is encapsulated frame, an ATM-IP decapsulation unit that restores the ATM cell from the frame;
Based on the configuration information, select the ATM interface to output according to the VPI / VCI of the restored ATM cell, ATM distribution unit to output the ATM cell,
Based on the configuration information, select the Ethernet interface that inputs and outputs according to the VPI / VCI of the ATM cell of the Ethernet frame that encapsulates the ATM cell, and an Ethernet distribution unit that inputs and outputs the Ethernet frame;
A configuration information storage unit for storing configuration information such as information for mapping the VPI / VCI and the IP address of the transfer partner and information for encapsulating ATM cells into IP packets;
An interface for changing configuration information for changing configuration information;
An ATM converter characterized by comprising: Prior Symbol media conversion means, ATM converter according to claim 1, comprising the VPI / VCI-priority information mapping unit for mapping the priority information of the VPI / VCI and the IP packet of the ATM cell based on the configuration information . The media conversion means includes an AAL5 identifying unit for identifying a PVC transmitted by an AAL5 frame based on VPI / VCI of an ATM cell received from the ATM interface based on configuration information, and an AAL5 frame from the PVC identified as AAL5. The AAL5-IP encapsulation unit that takes out and further encapsulates the payload part of the AAL5 frame into an IP packet, and the payload part of the AAL5 frame restored from the frame received from the Ethernet interface is assembled into an AAL5 frame and converted into an ATM cell 3. The ATM converter according to claim 1, further comprising an AAL5-IP decapsulation unit. The media conversion means includes: shaping means for shaping the Ethernet interface based on the configuration information; and priority control for performing priority control based on priority information included in an IP header in a frame encapsulated based on the configuration information claim 1 or claim 2 ATM converter according to comprising the parts. 3. The ATM converter according to claim 1 , wherein the ATM interface includes an ATM interface for connecting to an ATM leased line service, a cell relay service, or the like.

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