JP3290390B2 - MAC bridging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a MAC bridging device useful for logically forming a MAC bridge network on a wide area frame transfer network.

[0002]

2. Description of the Related Art A conventional MAC bridging device, as represented by a learning bridge, stores information on a set of a source MAC address of a MAC frame received from a MAC protocol LAN side and a port receiving the MAC frame. It learns and registers this in the forwarding table, but separately searches the forwarding table using the destination MAC address as a key and discards this MAC frame if the port to which the MAC frame should be transmitted matches the received port. Was.

[0003]

When a conventional MAC bridging device is used, the address information of a MAC terminal performing closed communication within a MAC protocol LAN is MA.
Since it is not distributed at all outside the C protocol LAN, M
If an attempt is made to transfer a MAC frame from outside the AC protocol LAN to the MAC terminal,
The output port information addressed to the MAC bridging device accommodating the terminal could not be obtained, and as a result, it was necessary to broadcast the MAC frame from all output ports. For this reason, there has been a problem that traffic between the LANs is abnormally increased in the wide area network when the connection between LANs is performed in a wide area.

An object of the present invention is to provide a MAC bridging device capable of suppressing an increase in traffic in a wide area network and improving resource use efficiency.

[0005]

According to the present invention, in order to solve the above-mentioned problems, in a learning bridge type MAC bridging device accommodating a wide area frame transfer network and a MAC protocol LAN, a MAC frame received from a MAC protocol LAN side is provided. Source MAC address and the MA
When learning the information of the pair with the port that has received the C frame and newly registering this in the forwarding table, the MAC
There is provided means for transmitting the frame to the wide area frame transfer network side regardless of the value of the destination MAC address.

According to the above configuration, the address information of the MAC terminal that has transmitted the MAC frame for the first time is learned by the MAC bridging device accommodating the MAC terminal, but the MAC bridging device transmits the MAC frame to the destination MAC address. MAC protocol LA regardless of the value of
Since the MAC address is transferred to the outside of the N, other MAC bridging devices outside the MAC protocol LAN can learn the address information of the MAC terminal.

As a result, even when a MAC frame is to be transferred from the outside of the MAC protocol LAN to the MAC terminal for the first time, the MA accommodating the MAC terminal is received.
The output port information addressed to the C bridging device can be obtained.
The MAC frame can be transferred to the destination MAC terminal without broadcasting the AC frame in the MAC group. This effect is particularly remarkable when a MAC bridging server, which is positioned as a default forwarding bridge and intensively learns terminal addresses in a MAC network, is used in combination.

The destination MAC address of the MAC frame received from the MAC protocol LAN is registered in the transfer table.
As a result of learning the information of the pair with the port that has received the AC frame, if the information is newly registered in the forwarding table, if a learning identifier is added to the MAC frame to be transmitted, the learning is performed by the MAC bridging server. By performing only address learning without transferring a MAC frame to which a service identifier is added, control traffic in the network can be reduced.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a MAC bridging device according to the present invention, FIG. 2 is an operation flowchart of an address learning table control unit of the device, FIG. 3 is a network model showing an application example of the device, and FIG. FIG. 5 shows an example of setting a communication procedure and an address table using this apparatus, and FIG. 5 shows an example of setting a communication procedure and an address table using a conventional MAC bridging apparatus.

First, the MAC bridging device shown in FIG. 1 will be described. LAN 1A and wide area network 1B
Is connected to the MAC bridging device 1C.
C frame transmission / reception unit 1D, source MAC address extraction unit 1E, destination MAC address extraction unit 1F, MAC frame filtering unit 1G, core frame encapsulation / decapsulation unit 1H, core frame transmission / reception unit 1I, and address learning table control unit 1J It is configured.

In such a configuration, the MAC frame transferred from the LAN 1A to the MAC bridging device 1C is input to the MAC frame transmitting / receiving unit 1D.
The MAC frame transmitting / receiving unit 1D converts the MAC frame input from the LAN 1A into a source MAC address extracting unit 1E.
Transfer to

The source MAC address extracting unit 1E outputs the MA
The source MAC address is extracted from the MAC frame received from the C frame transmission / reception unit 1D, is notified to the address learning table control unit 1J, and transfers the received MAC frame to the destination MAC address extraction unit 1F.

The destination MAC address extraction unit 1F extracts the destination MAC address from the MAC frame received from the transmission source MAC address extraction unit 1E, notifies the address learning table control unit 1J, and filters the received MAC frame by MAC frame filtering. Transfer to unit 1G.

If the source address does not exist in the transfer (learning) table, the address learning table control unit 1J registers the source MAC address in the transfer table,
It instructs the AC frame filtering unit 1G to transfer the MAC frame, and instructs the core frame encapsulation / decapsulation unit 1H to add a learning identifier.

The address learning table control unit 1J
If the source MAC address exists in the forwarding table, and if the destination MAC address exists in the table, MA
It instructs the MAC frame filtering unit 1G to discard the C frame, and if the destination MAC address does not exist in the table, instructs the MAC frame filtering unit 1G to transfer the MAC frame.

[0017] The MAC frame filtering unit 1G includes:
The MAC frame received from the destination MAC address extraction unit 1F is discarded according to the instruction of the address learning table control unit 1J, or transferred to the core frame encapsulation / decapsulation unit 1H.

The core frame encapsulation / decapsulation unit 1H converts the MAC frame received from the MAC frame filtering unit 1G into an address learning table control unit 1H.
A learning identifier is added according to the instruction from J or encapsulated as it is in a core frame used in a wide area network, and transferred to the core frame transmitting / receiving unit 1I. The core frame transmission / reception unit 1I performs core frame encapsulation /
The frame received from the decapsulation unit 1H is transferred to the wide area network 1B.
Transfer to

On the other hand, the frame transferred from the wide area network 1B to the MAC bridging device 1C is input to the core frame transmitting / receiving unit 1I. Core frame transceiver 1I
Transfers the core frame input from the wide area network 1B to the core frame encapsulation / decapsulation unit 1H.

The core frame encapsulation / decapsulation unit 1H decapsulates the core frame received from the core frame transmission / reception unit 1I, extracts a MAC frame, and
Transfer to the AC frame transmitting / receiving unit 1D. The MAC frame transmitting / receiving unit 1D transfers the MAC frame received from the core frame encapsulation / decapsulation unit 1H to the LAN 1A.

Next, the detailed operation of the address learning table control unit of the MAC bridging device will be described with reference to the flowchart of FIG.

The flowchart of FIG. 2 includes a step (2A) of obtaining a source MAC address from a source MAC address extraction unit, a step (2B) of analyzing whether a source MAC address exists in a learning table, and a destination (2B). Step of obtaining the destination MAC address from the MAC address extraction unit (2)
C), analyzing whether the destination MAC address exists in the learning table (2D), and instructing the MAC frame filtering unit to discard the MAC frame (2).
E), a step of writing an address to the learning table (2)
F), a step of instructing the MAC frame filtering unit to transfer the MAC frame (2G), a step of instructing the core frame encapsulation / decapsulation unit to assign a learning identifier (2H), and MA to the MAC frame filtering unit.
(2I) for instructing C frame transfer.

The address learning table controller 1J obtains the source MAC address from the source MAC address extractor 1E (2A) and analyzes whether the source MAC address exists in the learning table (2B). If the source MAC address is present in the learning table, the destination MAC address is obtained from the destination MAC address extracting unit 1F (2C), and it is analyzed whether the destination MAC address is present in the learning table (2D). ). Destination MA
If the C address is present in the learning table, it instructs the MAC frame filtering unit 1G to discard the received MAC frame (2E). If the destination MAC address does not exist in the learning table, it instructs the MAC frame filtering unit 1G to transfer the received MAC frame (2I).

On the other hand, if the source MAC address does not exist in the learning table, the source MAC address is written in the learning table (2F), and the MAC frame filtering unit 1G is instructed to transfer the received MAC frame (2G). ), And instructs the core frame encapsulation / decapsulation unit 1H to add a learning identifier (2H).

Next, the operation of such a MAC bridge device on a network will be described using the network model of FIG.

The MAC bridge network 3D in FIG. 3 is logically constructed on a core network (for example, a CLSF network conforming to ITU-TI.364) 3A. As a communication device on the MAC bridge network 3D, MA
There are C bridging devices 3E, 3F, MAC bridging server 3G, and MAC terminals 3H, 3I, 3J.

The function of each device will be described. MAC terminal: a terminal that enables mutual communication by transmitting and receiving MAC frames. MAC bridging device: a proposed MAC bridging device. MAC bridging server: an address resolution server that resolves the destination of the destination MAC address. It is assumed that a MAC address is allocated to a communication device on the MAC bridge network 3D as follows. MAC terminal 3H: MAC. 1 MAC terminal 3I: MAC. 2 MAC terminal 3J: MAC. 3. Further, it is assumed that the communication device on the core network 3A is assigned a core address as follows. MAC bridging server 3G: CORE. 2.1 MAC bridging device 3E: CORE. 1.1 MAC bridging device 3F: CORE. 1.2 Here, the connection relation of the devices will be described. The MAC bridging server 3G, MA
The C bridging devices 3E and 3F are connected, the MAC terminals 3H and 3I are connected beyond the MAC bridging device 3E, and the MAC terminals 3J are connected beyond the MAC bridging device 3F.
Is connected.

The proposed MA on this MAC bridge network 3D
A communication procedure using the C bridging device will be described with reference to FIG.

The communication procedure shown in FIG. 4A includes the transmission of a MAC frame by the MAC terminal 3H (4A) and the transmission of a MAC frame by the MAC terminal 3I.
Frame reception (4B), MAC frame transfer of MAC bridging device 3E (4C), MAC frame broadcast transfer of MAC bridging server 3G (4D), MAC frame transfer of MAC bridging device 3F (4E), MA
MAC frame transfer of C bridging device 3E (4
F), discarding the MAC frame of the MAC terminal 3J (4G),
MAC frame reception (4H) of MAC terminal 3I, MAC
Discard MAC frame of terminal 3H (4I), MAC terminal 3
MAC frame transmission of I (4J), M of MAC terminal 3H
AC frame reception (4K), MAC bridging device 3
E MAC frame transfer (4L), MAC frame discarding of MAC bridging server 3G (4M), MAC frame transmission of MAC terminal 3J (4N), MAC frame transfer of MAC bridging device 3F (4O), MAC bridging server 3G MAC frame transfer (4P), M
MAC frame transfer of AC bridging device 3E (4
Q), MAC frame reception of MAC terminal 3I (4R),
MAC frame discard (4S) of the MAC terminal 3H.

FIGS. 4B, 4C, and 4D show address tables in the MAC bridging server 3G. The address table (address table 4T) in the operation sequence 4D and the address table in the operation sequence 4M respectively. Address information (address table 4U), address information in operation sequence 4P (address table 4U)
V).

Here, the MAC terminal 3H and the MAC terminal 3I
When the terminal communicates with the MAC terminal 3H, the MAC terminal 3H transmits the MAC frame to the MAC terminal 3I and the MAC bridging device 3E (4A).

[0032] The MAC terminal 3I receives the MAC frame (4B). Upon receiving the MAC frame, the MAC bridging device 3E transmits the source MAC address MAC. 1 is registered on the transfer table, and the MAC frame is transferred to the MAC bridging server 3G (4C). M
MAC bridging server 3G that has received the AC frame
Is the source MAC address MAC. 1 and the source core address CORE. 1.1 is registered on the transfer table, and the MAC frame is broadcast to the MAC bridging devices 3E and 3F (4D).

The MAC bridging device 3F that has received the MAC frame transfers the MAC frame to the MAC terminal 3J (4E). Upon receiving the MAC frame, the MAC bridging device 3E stores the MAC frame in the MAC terminal 3
Transfer to I, 3H (4F). At this time, the MAC terminal 3
H and 3J discard the MAC frame (4G) (4I)
However, the MAC terminal 3I receives the MAC frame (4
H).

After performing the above operation, the MAC terminals 3I and M
When communicating with the AC terminal 3H, the MAC terminal 3I
The AC frame is transmitted to the MAC terminal 3H and the MAC bridging device 3E (4J).

The MAC terminal 3H receives the MAC frame (4K). Upon receiving the MAC terminal frame, the MAC bridging device 3E transmits the source MAC address MAC.
2 is registered on the transfer table, a learning identifier is assigned, and the MAC frame is transferred to the MAC bridging server 3G (4L). M that has received the MAC frame
The AC bridging server 3G transmits the source MAC address MAC. 2 and the source core address CORE. 1.1 is registered in the transfer table, and the MAC frame is discarded (4M).

After performing the above operation, the MAC terminals 3J and M
When communicating with the AC terminal 3I, the MAC terminal 3J
The AC frame is transmitted to the MAC bridging device 3F (4N).

Upon receiving the MAC frame, the MAC bridging device 3F transmits the MAC address MAC. 3 and register the MA in the MAC bridging server 3G.
The C frame is transferred (4O). Upon receiving the MAC frame, the MAC bridging server 3G transmits the source MAC address MAC. 3 and the source core address CORE. 1.
2 is registered on the transfer table, the destination core address is resolved, and the MAC frame is transferred to the MAC bridging device 3E (4P).

Upon receiving the MAC frame, the MAC bridging device 3E converts the MAC frame into MAC terminals 3I and 3I.
H (4Q). At this time, the MAC terminal 3I
Upon receiving the C frame (4R), the MAC terminal 3H
The frame is discarded (4S).

Next, on the MAC bridge network 3D, the conventional M
A communication procedure using the AC bridging device will be described with reference to FIG.

The communication procedure shown in FIG. 5A includes the transmission of the MAC frame of the MAC terminal 3H (5A) and the transmission of the MAC frame of the MAC terminal 3I.
Frame reception (5B), MAC frame transfer of MAC bridging device 3E (5C), MAC frame broadcast transfer of MAC bridging server 3G (5D), MAC frame transfer of MAC bridging device 3F (5E), MA
MAC frame transfer of the C bridging device 3E (5
F), MAC frame discard of the MAC terminal 3J (5G),
MAC terminal 3I MAC frame reception (5H), MAC
MAC frame discard of terminal 3H (5I), MAC terminal 3
MAC frame transmission of I (5J), M of MAC terminal 3H
AC frame reception (5K), MAC bridging device 3
E MAC frame discard (5L), M of MAC terminal 3J
AC frame transmission (5M), MAC bridging device 3
F MAC frame transfer (5N), MAC bridging server 3G MAC frame broadcast transfer (5O), MAC
MAC frame transfer (5P) of the bridging device 3F,
MAC frame transfer of the MAC bridging device 3E (5
Q), MAC frame discard of the MAC terminal 3J (5R),
MAC terminal 3I receives MAC frame (5S), MAC
MAC frame discard (5T) of the terminal 3H.

FIGS. 5B and 5C show the address tables in the MAC bridging server 3G. The address information in the operation sequence 5D (address table 5U) and the address information in the operation sequence 50 (address information) are respectively shown. Table 5V).

Here, the MAC terminal 3H and the MAC terminal 3I
When the MAC terminal 3H communicates with the MAC terminal 3H, the MAC terminal 3H transmits the MAC frame to the MAC terminal 3I and the MAC bridging device 3E (5A).

The MAC terminal 3I receives the MAC frame (5B). Upon receiving the MAC frame, the MAC bridging device 3E transmits the source MAC address MAC. 1 and the source core address CORE. 1.1 is registered on the transfer table, and the MAC frame is transferred to the MAC bridging server 3G (5C). Upon receiving the MAC frame, the MAC bridging server 3G transmits the MAC
C address MAC. 1 and the source core address CORE.
1.1 is registered on the transfer table, and the MAC frame is broadcast to the MAC bridging devices 3E and 3F (5D).

The MAC bridging device 3F that has received the MAC frame transfers the MAC frame to the MAC terminal 3J (5E). Upon receiving the MAC frame, the MAC bridging device 3E stores the MAC frame in the MAC terminal 3
Transfer to I, 3H (5F). At this time, the MAC terminal 3
H and 3J discard the MAC frame (5G) (5I)
However, the MAC terminal 3I receives the MAC frame (5
H).

After performing the above operation, the MAC terminals 3I and M
When communicating with the AC terminal 3H, the MAC terminal 3I
The AC frame is transmitted to the MAC terminal 3H and the MAC bridging device 3E (5J).

The MAC terminal 3H receives the MAC frame (5K). The MAC bridging device 3E discards the received MAC frame (5L).

After performing the above operation, the MAC terminals 3J and M
When communicating with the AC terminal 3I, the MAC terminal 3J
The AC frame is transmitted to the MAC bridging device 3F (5M).

[0048] Upon receiving the MAC frame, the MAC bridging device 3F sends the MAC bridging device 3G to the MAC bridging server 3G.
The C frame is transferred (5N). Upon receiving the MAC frame, the MAC bridging server 3G transmits the source MAC address MAC. 3 and the source core address CORE. 1.
2 is registered in the forwarding table, and since there is no destination MAC address in the forwarding table, the MAC frame is broadcast to the MAC bridging devices 3E and 3F (5
O).

[0049] Upon receiving the MAC frame, the MAC bridging device 3F transfers the MAC frame to the MAC terminal 3J (5P). The MAC bridging device 3E that has received the MAC frame transfers the MAC frame to the MAC terminals 3H and 3I (5Q). At this time, the MAC terminal 3J,
3H discards the MAC frame (5R) (5T), MA
The C terminal 3I receives the MAC frame (5S).

As described above, when a conventional MAC bridging device is used, a broadcast server (MAC bridging server) is frequently used. This means an increase in traffic in the network, which is undesirable. However, by using the apparatus of the present invention, the frequency of this broadcast can be reduced. Therefore, it can be said that the device of the present invention is more effective than the conventional device.

[0051]

As described above, according to the present invention,
When providing the MAC bridging service, it is possible to suppress broadcast in the wide area network, so that the resource use efficiency in the wide area network is improved and the cost of providing the MAC bridging service can be reduced. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a MAC bridging device of the present invention.

FIG. 2 is an operation flowchart of an address learning table control unit in FIG. 1;

FIG. 3 is a diagram showing a network model using the present apparatus.

FIG. 4 is a diagram showing a communication procedure using the present apparatus and an example of setting an address table.

FIG. 5 is a diagram showing a communication procedure and a setting example of an address table using a conventional MAC bridging device.

[Explanation of symbols]

1A: LAN, 1B: Wide area network, 1C: MAC bridging device, 1D: MAC frame transmitting / receiving unit, 1E: Source MAC address extracting unit, 1F: Destination MAC address extracting unit, 1G: MAC frame filtering unit, 1H: Core Frame encapsulation / decapsulation unit, 1I: core frame transmission / reception unit, 1J: address learning table control unit,
3A: core network, 3B, 3C: Ethernet,
3D: MAC bridge network, 3E, 3F: MAC bridging device, 3G: MAC bridging server, 3H, 3
I, 3J: MAC terminal.

Continuation of front page (72) Inventor Hiroyuki Hara 3-19-2 Nishi Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References JP-A-11-122286 (JP, A) JP-A-6 -62013 (JP, A) IEICE Technical Report, IN 97-117, October 17, 1997 IEICE Communications Society Conference B-7-23, August 13, 1997 (58) Field surveyed (Int. Cl. ⁷ , DB name) H04L 12/46 H04L 12/56 H04L 12/66

Claims (2)

(57) [Claims] 1. A learning bridge type MAC bridging device accommodating a wide area frame transfer network and a MAC protocol LAN, comprising: a source MAC address of a MAC frame received from a MAC protocol LAN side and a port receiving the MAC frame. When learning the information of a pair and newly registering it in the forwarding table, the received MAC frame is
A MAC bridging device comprising means for transmitting data to a wide area frame transfer network regardless of an address value. 2. A destination MAC address of a MAC frame received from a MAC protocol LAN is registered in a transfer table.
2. The MAC bridging according to claim 1, wherein a learning identifier is added to a MAC frame to be transmitted when information of a pair with a port that received the frame is newly registered in a forwarding table as a result of learning. apparatus.