JPH11252108A - Data conversion and transfer device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A plurality of MAC protocol LANs and a plurality of IPs
To connect the protocol LAN independently, LA
It is necessary to have transfer tables for the number of N connections. SOLUTION: IP protocol LAN 1a to 1c and I
The association between the set of the VCI and the destination IP address used for the communication of the P packet and the set of the VCI and the destination MAC address used for the communication of the MAC frame with the MAC protocols LAN 3a to 3c is recorded in the table 2a. The destination MAC address and the output VCI are specified by the specifying unit A2b with reference to the table 2a.
When the C frame is received, the identification unit B2d uses the table 2
, Specify the output VCI, and determine the IP packet and MAC
A data conversion and transfer device configured to convert and transfer frames.

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 technique for connecting different layers such as a network layer and a data link layer.
Multiple MAC (Media Access Control) Protocols L Using Synchronous Transfer Mode
AN (Local Area Network) and IP (Internet Protocol)
l) The present invention relates to a data conversion / transfer device suitable for efficiently connecting to a protocol LAN.

[0002]

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

[0003]

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

[0004]

To achieve the above object, a data conversion and transfer apparatus according to 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 a first communication network to a first communication network and performing a mutual conversion between an IP packet and a 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 destination M used for communication of a MAC frame with a second communication network
The association with the set of AC addresses is recorded in a table, and when an IP packet is received from the first communication network, the destination MAC address used for converting the IP packet into a MAC frame is referred to by referring to this table. VCI used for communication of the MAC frame with the second communication network,
When a MAC frame is received from the second communication network, the MAC header of the MAC frame is deleted and converted to an IP packet, and the converted IP packet is communicated with the first communication network with reference to the table. , And the communication of the IP packet and the MAC frame is performed using the specified VCI. Thus, VC
The conversion and transfer of the IP packet and the MAC frame are performed using the table indicating the correspondence for each. When converting an IP packet to a MAC frame, the corresponding entry (IP
If the address and the MAC address are not registered in the table, the MAC address is searched using ARP, and after receiving the ACK, the MAC address is registered in the table and the table is updated.

[0005]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of a configuration according to the present invention of a data conversion / transfer apparatus of the present invention. In FIG. 1, reference numerals 1a to 1c denote IP protocol LANs as a first communication network of the present invention, and 2 denotes a multi-layer connection gateway as a 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.
AN.

[0006] Between the IP protocol LANs 1a to 1c and the multilayer connection gateway 2, IP packet communication using ATM is performed, and the MAC protocols LAN 3a to 3c are transmitted.
c and the multilayer connection gateway 2 perform communication of a MAC frame using ATM.

The IP protocols LAN1a-1c and M
When establishing a connection between the AC protocol LANs 3a to 3c and the multilayer connection gateway 2,
A VC (Virtual Connection) is set for each, and thereafter, data transfer is performed using this VC.

[0008] 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.
A correspondence between a pair of a VCI and a destination IP address used for communication of a P packet and a pair of a VCI and a destination MAC address used for communication of a MAC frame with the MAC protocols LAN 3a to 3c is recorded. The details of the table 2a are shown in FIG.

When receiving an IP packet from the IP protocol LANs 1a to 1c, the specifying unit A2b refers to the table 2a and refers to the output VC corresponding to the input VCI.
I and the destination MAC address, and the conversion unit A2
c, the specified destination MAC address is
A MAC frame is generated by adding the MAC frame to the P packet and transferred to the specified output VCI.

When receiving a MAC frame from the MAC protocol LANs 3a to 3c, the identification unit B2d refers to the table 2a and refers to the output VCI (IP protocol LA) corresponding to the input VCI (MAC protocol LAN side).
(N side), the conversion unit B2e deletes the MAC header from the received MAC frame, converts it into an IP packet, and transfers it to the specified output VCI.

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 transmits a predetermined user group. (VCI #A, #B in FIG. 2)
When an address unregistered packet is received from A, an ARP is transmitted from the port #a, a MAC address and a VCI are obtained from the ACK returned corresponding to the ARP, and the destination IP address and the destination IP address of the received IP packet are obtained. 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. FIG. 2 is an explanatory diagram showing an example of a small reconfiguration of the table in FIG. 1. FIG. 3 is an explanatory diagram showing a first operation example according to the present invention of the multi-layer connection gateway in FIG. FIG. 5 is an explanatory diagram showing a second operation example according to the present invention of the multilayer connection gateway in FIG. 1, and FIG. 5 is a description showing a third operation example according to the present invention of the multilayer connection gateway in FIG. FIG.

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

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

The example of FIG. 4 shows an operation of updating the table 2a, that is, an operation when a corresponding entry is not registered in the table 2a at the time of receiving an IP packet from the IP protocol LAN. Is received from the VC whose VCI is "#A", the multi-layer connection gateway 2 refers to the table 2a by the specifying unit A2b.

However, since the corresponding entry is not registered in the table 2a, the VC 2 is updated by the updating unit 2f.
I outputs (transmits) the 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 table 2a in association with the input VCI “#A”.
Register with. Then, the converting unit B2e uses the updating unit 2f.
Generates a MAC header consisting of the MAC address “# β” obtained in step 2, adds the MAC header to the received IP packet, and updates the
It is transmitted from the VCI “#a” obtained at f.

The example of FIG. 5 shows the operation when receiving a MAC frame from the MAC protocol LAN.
MAC frame (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 specifies the corresponding output VCI “#B” with reference to the table 2a by the specifying unit B2d, and Generates the IP packet having the destination IP address of “# 3” by deleting the MAC header of the MAC frame, and specifies the output VCI “#
B ”.

As described above with reference to FIGS. 1 to 5, the data conversion and transfer apparatus of the present embodiment uses the table 2a indicating the correspondence for each VC and
Performs conversion and transfer of C frames. As described above, using the table 2a indicating the correspondence for each VC, the IP packet and the M
Since the conversion and transfer of the AC frame are performed, the connection between a plurality of MAC protocol LANs and the plurality of IP protocol LANs can be performed independently without having a transfer table for the number of LAN connections. It can be performed with one device.

When a corresponding entry (IP address, MAC address) is not registered in the table 2a at the time of converting an IP packet to a MAC frame, the
Since the MAC address is searched using the P, the ACK is received, the ACK is registered in the table, and the table is updated, so that it is possible to dynamically cope with a change or movement of a terminal on each LAN.

The present invention is not limited to the embodiment described with reference to FIGS. 1 to 5, and can be variously modified without departing from the gist thereof. For example, in FIG. 2 of the present example, a VCI of a network using a MAC address and a VC of a network using an IP address
I was a network configuration provided independently, but MA
The present invention can also be applied to a network configuration in which VCI of a network using a C address = VCI of a network using an 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, there is no need to have a transfer table for the number of LAN connections, and one data conversion / transfer device Thus, a plurality of MAC protocol LANs and a plurality of IP protocol LANs can be independently connected, and a plurality of MAs using ATM can be connected.
The connection between the C protocol LAN and the IP protocol LAN can be efficiently performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a configuration according to the present invention of a data conversion / transfer apparatus of the present invention.

FIG. 2 is an explanatory diagram showing an example of a small reconfiguration of a table in FIG. 1;

FIG. 3 is an explanatory diagram showing a first operation example of the multilayer 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 multilayer connection gateway in FIG. 1;

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

[Explanation of symbols]

1a to 1c: IP protocol LAN, 2: Multilayer connection gateway, 2a: Table, 2b: Identifying unit A,
2c: conversion unit A, 2d: identification unit B, 2e: conversion unit B, 2
f: Update unit, 3a to 3c: MAC protocol LAN.

Claims (2)

[Claims] 1. A first method for transferring an IP packet by an ATM.
Communication network and transfer of MAC frame by ATM
A data conversion / transfer apparatus for connecting the communication network of the first communication network and the MAC packet to each other, and performing data transfer control between the first communication network and the second communication network. A set of a VCI and a destination IP address used for IP packet communication with the first communication network;
Means for recording a correspondence between a VCI used for communication of a MAC frame with a communication network of the same and a set of a destination MAC address;
With reference to the recorded association, a destination MAC address used for converting an IP packet from the first communication network into the MAC frame, and a converted MAC frame used for communication with the second communication network. Means for specifying a VCI, and means for specifying 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 and 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 association based on the ACK returned in response to the ARP.