JP3468085B2 - Data conversion and transfer device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer connection technology for connecting mutually different layers such as a network layer and a data link layer.
A plurality of MAC (Media Access Control) protocols L using ynchronous Transfer Mode
AN (Local Area Network) and IP (Internet Protocol)
l) Protocol The present invention relates to a data conversion / transfer device suitable for efficient connection with a LAN.

[0002]

2. Description of the Related Art A multi-layer connection between a MAC protocol LAN and an IP protocol LAN has both functions of an IP router for processing an IP protocol at a network layer and a MAC bridging for handling a MAC protocol at a data link layer. This is possible with the multi-layer compatible data conversion and transfer device. However, in order to independently connect a plurality of MAC protocol LANs and a plurality of IP protocol LANs, it is necessary to have transfer tables for the number of LAN connections, and one device has many restrictions and is difficult to realize. there were. Regarding routers and bridges, see, for example, No. 132-141 of "Technology of Communication Protocols Easy to Understand" by Nobutaka Maruyama (1997, Ohmsha).
Pp. 157-160.

[0003]

The problem to be solved is that in the prior art, a plurality of MAC protocol LANs are used.
In order to independently connect a plurality of IP protocol LANs, it is necessary to have transfer tables for the number of LAN connections. The object of the present invention is to solve these problems of the prior art and to provide a plurality of MAC protocol LANs with a single device.
And a data conversion transfer device capable of independently connecting a plurality of IP protocol LANs.

[0004]

In order to achieve the above object, a data conversion and transfer device of the present invention comprises a first communication network for transferring IP packets by ATM and a second communication network for transferring MAC frames by ATM. A data conversion transfer device for connecting the communication network of the first communication network, performing mutual conversion between the IP packet and the MAC frame, and controlling data transfer between the first communication network and the second communication network. A set of a VCI and a destination IP address used for communication of an IP packet with a communication network, and a VCI and a destination M used for communication of a MAC frame with a second communication network
The correspondence with the set of AC addresses is recorded in a table, and when the IP packet is received from the first communication network, the table is referred to and the destination MAC address used for converting the IP packet into the MAC frame and the conversion Specify the VCI used for communication of the MAC frame with the second communication network,
Further, when receiving a MAC frame from the second communication network, the MAC header of the MAC frame is deleted and converted into an IP packet, and the table is referred to to communicate the converted IP packet with the first communication network. The VCIs used for are specified, and the IP packets and the MAC frames are communicated using the specified VCIs. In this way, VC
Conversion and transfer of the IP packet and the MAC frame are performed using a table showing the correspondence for each. When converting an IP packet to a MAC frame, the corresponding entry (IP
If the (address, MAC address) is not registered in the table, the MAC address is searched using ARP, and after the ACK is received, the MAC address is registered in the table and the table is updated.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the configuration of the data conversion transfer device of the present invention according to the present invention. In FIG. 1, 1a to 1c are the IP protocol LAN as the first communication network of the present invention, and 2 is the multi-layer connection gateway as the data conversion transfer device of the present invention (in the figure, described as "multi-layer connection GW"). ) 3a-3
c is the MAC protocol L as the second communication network of the present invention.
It is AN.

Between the IP protocols LAN1a to 1c and the multi-layer connection gateway 2, IP packet communication using ATM is performed, and the MAC protocols LAN3a to 3c.
The MAC frame communication using ATM is performed between the c and the multi-layer connection gateway 2.

IP protocols LAN 1a-1c and M
When establishing a connection between the AC protocol LANs 3a to 3c and the multi-layer connection gateway 2,
A VC (Virtual Connection) is set for each, and thereafter, data transfer is performed using this VC.

The multi-layer connection gateway 2 includes a table 2a, a specifying unit A2b, a converting unit A2c and a specifying unit B2.
d, a conversion unit B2e, and an update unit 2f, and the table 2a includes I with the IP protocols LAN1a to 1c.
Correspondence is recorded between a set of VCI and destination IP address used for P packet communication and a set of VCI and destination MAC address used for MAC frame communication with the MAC protocols LAN 3a to 3c. Details of the table 2a are shown in FIG.

Then, the specification unit A2b refers to the table 2a when receiving the IP packet from the IP protocol LANs 1a to 1c, and outputs the output VC corresponding to the input VCI.
I and the destination MAC address are specified, and the conversion unit A2
c receives the specified destination MAC address from the received I
A MAC frame is generated by adding it to a P packet and transferred to the specified output VCI.

Further, the specification unit B2d refers to the table 2a when receiving the MAC frame from the MAC protocols LAN3a to 3c, and refers to the output VCI (IP protocol LA) corresponding to the input VCI (MAC protocol LAN side).
The N-side) is specified, the conversion unit B2e deletes the MAC header from the received MAC frame, converts the IP header into an IP packet, and transfers the IP packet to the specified output VCI.

Further, when receiving the IP packet from the IP protocol LANs 1a to 1c, if the corresponding entry (IP address, MAC address) is not registered in the table 2a, the updating unit 2f determines whether a predetermined user group has been registered. For each (VCI #A, #B in FIG. 2), for example, #
When an address unregistered packet is received from A, ARP is transmitted from the port #a, the MAC address and VCI are acquired from the ACK returned corresponding to this ARP, and the destination IP address of the received IP packet is set. Input V
It is registered in the table 2a in association with the CI.

Hereinafter, such an operation will be described with reference to FIGS. 2 is an explanatory diagram showing a small reconfiguration example of the table in FIG. 1, and FIG. 3 is an explanatory diagram showing a first operation example according to the present invention of the multi-layer connection gateway in FIG. 5 is an explanatory diagram showing a second operation example according to the present invention of the multi-layer connection gateway in FIG. 1, and FIG. 5 is an explanation diagram showing a third operation example according to the present invention of the multi-layer connection gateway in FIG. It is a figure.

In FIG. 2, a table 2a includes a set of VCI and IP address on the IP protocol LAN side, and M.
The MAC address and the VCI set on the AC protocol LAN side are recorded in association with each other. For example, the VCI “#A” and the IP address “# 1” on the IP protocol LAN side are recorded.
Is associated with the MAC address “# α” and the VCI “#a” on the MAC protocol LAN side.

The example of FIG. 3 shows the operation at the time of receiving an IP packet from the IP protocol LAN. When the IP packet having the destination IP address "# 1" is received from the VC having the VCI "#A". The multi-layer connection gateway 2 refers to the table 2a by the identifying unit A2b, and outputs the corresponding output VCI “#a” and the destination M.
The AC address “# α” is specified, and the conversion unit A2c
Generates a MAC header composed of the destination MAC address “# α” specified by the specifying unit A2b, and receives the received IP
A MAC frame is added to the packet to generate a MAC frame, and the MAC frame is transferred from the specified output VCI “#a”.

The example of FIG. 4 shows the updating operation of the table 2a, that is, the operation when the corresponding entry is not registered in the table 2a when the IP packet is received from the IP protocol LAN. When the IP packet of "# 2" is received from the VC of which VCI is "#A", the multilayer connection gateway 2 refers to the table 2a by the identifying unit A2b.

However, since the corresponding entry is not registered in the table 2a, the updating unit 2f causes the VC
I outputs (transmits) ARP to the VC of “#a”, and this A
The MAC address “# β” and the VCI “#a” are acquired from the ACK (MAC frame) returned corresponding to the RP, and the destination IP address “#” of the received IP packet is acquired.
2 "and the input VCI"#A"in association with each other in the table 2a.
Register with. Then, the conversion unit B2e causes the update unit 2f
A MAC header composed of the MAC address “# β” acquired in step 3 is generated and added to the received IP packet.
It is transmitted from the VCI “#a” acquired in f.

The example of FIG. 5 shows the operation at the time of receiving a MAC frame from the MAC protocol LAN,
MAC frame (addressed to the multi-layer connection gateway 2 and its destination MAC address is “# β”)
Is received from the VC whose VCI is “#b”, the multilayer connection gateway 2 identifies the corresponding output VCI “#B” by referring to the table 2a by the identifying unit B2d, and then the converting unit B2E. By deleting the MAC header of the MAC frame, an IP packet having a destination IP address of "# 3" is generated, and the specified output VCI "#
B ".

As described above with reference to FIGS. 1 to 5, in the data conversion and transfer apparatus of this embodiment, the IP packet and the MA are used by using the table 2a showing the correspondence for each VC.
Converts and transfers C frame. In this way, using the table 2a indicating the correspondence for each VC, the IP packet and the M
Since AC frames are converted and transferred, it is possible to independently connect a plurality of MAC protocol LANs and a plurality of IP protocol LANs without having a transfer table for the number of LAN connections, and control the connection of them. It can be done with one device.

When the corresponding entry (IP address, MAC address) is not registered in the table 2a when converting the IP packet into the MAC frame, the AR
Since the P is used to search for the MAC address, and after receiving the ACK, it is registered in the table and the table is updated, it is possible to dynamically respond to the change or movement of the terminal on each LAN.

The present invention is not limited to the embodiment described with reference to FIGS. 1 to 5, and various modifications can be made without departing from the scope of the invention. For example, in FIG. 2 of this example, the VCI of the network using the MAC address and the VC of the network using the IP address
Although the network configuration is provided independently of I,
The present invention can also be applied to a network configuration in which the VCI of the network using the C address = the VCI of the network using the IP address.

[0021]

According to the present invention, since a plurality of MAC protocol LANs and a plurality of IP protocol LANs are independently connected, it is not necessary to have a transfer table for the number of LAN connections, and one data conversion transfer device is provided. In this way, multiple MAC protocol LANs and multiple IP protocol LANs can be connected independently, and multiple MAs using ATM can be connected.
It is possible to efficiently connect the C protocol LAN and the IP protocol LAN.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a configuration according to the present invention of a data conversion transfer device of the present invention.

FIG. 2 is an explanatory diagram showing an example of small reconfiguration of the table in FIG.

FIG. 3 is an explanatory diagram showing a first operation example of the multi-layer connection gateway in FIG. 1 according to the present invention.

FIG. 4 is an explanatory diagram showing a second operation example according to the present invention of the multi-layer connection gateway in FIG. 1.

5 is an explanatory diagram showing a third operation example of the multi-layer connection gateway in FIG. 1 according to the present invention.

[Explanation of symbols]

1a to 1c: IP protocol LAN, 2: multi-layer connection gateway, 2a: table, 2b: specifying unit A,
2c: conversion unit A, 2d: specification unit B, 2e: conversion unit B, 2
f: update unit, 3a to 3c: MAC protocol LAN.

Continuation of front page (56) References JP-A-6-85817 (JP, A) JP-A-6-46063 (JP, A) JP-A-10-56474 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) H04L 12/28 H04L 12/46 H04Q 3/00

Claims (2)

(57) [Claims] 1. A first IP packet transfer using ATM
Second communication network and ATM frame transfer by ATM
A data conversion transfer device for connecting the communication network of No. 1 to each other, performing mutual conversion between the IP packet and the MAC frame, and controlling data transfer between the first communication network and the second communication network. , A set of VCI and destination IP address used for communication of the IP packet with the first communication network, and the second
Means for recording the association between the VCI used in the communication of the MAC frame with the communication network and the destination MAC address,
Referring to the recorded association, the destination MAC address used for converting the IP packet from the first communication network into the MAC frame, and the communication of the converted MAC frame with the second communication network are used. Means for identifying a VCI, and means for identifying a VCI used for communication with the first communication network of an IP packet obtained by converting a MAC frame from the second communication network with reference to the recorded association A data conversion / transfer device comprising: 2. The data conversion transfer device according to claim 1, wherein when the IP packet in which the association is not recorded is received from a first communication network, an ARP is output to the second communication network, A data conversion / transfer device comprising means for generating and recording the above correspondence based on the ACK returned in response to the ARP.