JP3314013B2 - MAC bridging server - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a MAC bridging server useful for logically forming a MAC bridge network on a wide area frame transfer network. Note that the MAC stands for Media Access C (Media Access C).
ontrol), and is a component of the data link layer of the OSI (Open System Interconnection) basic reference model. Specifically, it has a function of executing contention control based on CSMA / CD, transmitting received data to an upper layer, and sending data passed from an upper layer to a physical layer.

[0002]

2. Description of the Related Art A conventional MAC bridging server, AT
The entry registration in the transfer table is performed only when an address information registration packet is received from a MAC terminal installed on a core network, as typified by a LAN emulation server of M Forum.

In addition, M installed on a core network
Only when an address resolution request packet is received from the AC terminal, the address resolution information is transferred to the requesting MAC terminal. Note that the conventional MAC bridging server is MA
It did not have a function of transferring a MAC frame generated by the C layer.

[0004]

The conventional MAC described above
When a bridging server is used, a MAC terminal on a core network needs to explicitly notify a MAC bridging server of information of a set of a MAC address and a core address assigned to a MAC layer of the terminal. Was.

When transmitting a MAC frame, if the destination core address is unknown, it is necessary to explicitly notify the MAC bridging server of an address resolution request. At this time, it is necessary to perform transition state management in order to perform an address resolution request and a response reception process related thereto,
There was a problem that the terminal processing load became heavy.

Further, since it is necessary to multicast a MAC frame to be transmitted in the core network (broadcast in the MAC group) until address information is obtained, there is a problem that traffic in the core network abnormally increases. .

[0007] The present invention has been made in view of the above,
It is an object of the present invention to provide a MAC bridging server that can improve the use efficiency of network resources and improve the frame transfer throughput.

[0008]

In order to achieve the above object, according to the present invention, there is provided a wide area frame transfer network which performs frame transfer using a protocol system different from a MAC protocol, referred to as a core network. An installed MAC bridging server that receives a core frame transferred from a core network,
Source core address and source MAC address analysis means for extracting information of a set of a source address of the received core frame and a source MAC address of a MAC frame described in a payload portion of the core frame; Transfer table registering means for registering the address solution information extracted in the transfer table in the transfer table, MAC frame extracting means for extracting a MAC frame from the payload portion of the core frame received by the analyzing means, and MAC extracted by the MAC frame extracting means. Destination core address analysis means for resolving the core address by searching the transfer table using the destination MAC address described in the header portion of the frame as a key, and assigning the core address searched by the destination core address analysis means as a destination MAC frame The is summarized in that and a core frame encapsulation means for transmitting encapsulated in the core network.

According to the present invention, in order to eliminate the need for explicit address notification to the MAC bridging server in the MAC terminal on the core network,
The information of the pair of the source address of the received core frame and the source MAC address of the MAC frame described in the payload of the core frame is extracted, and this address resolution information is registered in the transfer table. In addition, it eliminates the need for an explicit address resolution request to the MAC bridging server when transmitting a MAC frame whose destination core address is unknown, and reduces multicast traffic in the core network (broadcast traffic in the MAC group). In order to suppress the increase, the MAC frame is extracted from the payload portion of the received core frame,
The core address is resolved by searching the transfer table using the destination MAC address described in the header portion of the C frame as a key, and the MAC frame is encapsulated in a core frame assigned with the core address as a destination and transmitted.

The present invention described in claim 2 is the same as the claim 1.
In the invention described in the above aspect, when the MAC frame is transferred, a means for notifying a source MAC terminal of a set of a destination MAC address and a destination core address on a core network is provided.

According to the present invention, the MAC
In order to reduce the traffic processing load of the bridging server itself and to improve the transfer throughput between MAC terminals on the core network and to improve the transfer throughput, when the MAC frame is transferred, the MA which becomes the transmission source on the core network
The C terminal is notified of the information of the set of the destination MAC address and the destination core address.

[0012]

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

FIG. 1 shows a MAC according to an embodiment of the present invention.
FIG. 3 is a block diagram illustrating a configuration of a bridging server. The MAC bridging server 3 shown in FIG. 1 is connected to the core network 1, receives a core frame transferred from the core network 1, and stores a source address of the received core frame and a payload portion of the core frame. Source core address and source M for extracting information of a set of source MAC addresses of the described MAC frame
An AC address analysis unit 5, a transfer table registration unit 43 for registering the address solution information extracted by the analysis unit 5 in a transfer table 45, and a MAC frame extraction for extracting a MAC frame from a payload portion of a core frame received by the analysis unit 5 Unit 7, the MA extracted by the MAC frame extraction unit 7
A destination core address analysis unit 9 for resolving a core address by searching the transfer table 45 using the destination MAC address described in the header portion of the C frame as a key,
The transfer table search unit 47 searches the transfer table 45 in response to the search request from the destination core address analysis unit 9 and returns the destination core address to the destination core address analysis unit 9. A core frame encapsulation unit 11 that encapsulates a MAC frame in a core frame to which the searched core address is assigned as a destination and transmits the core frame to the core network 1, and a transmission source notified from the transmission source core address and transmission source MAC address analysis unit 5 An address information notification processing unit 49 transfers the core address and the destination MAC address notified from the core address and destination core address analysis unit 9 to the core frame encapsulation unit 11.

The core network 1 is a connectionless frame transfer network for transferring data using a protocol different from the user protocol.
I. For example, there is a CLSF network defined by H.364.

In the MAC bridging server 3 configured as described above, the core frame transferred from the core network 1 includes the source core address and the source M
It is received by the AC address analysis unit 5. The transmission source core address and transmission source MAC address analysis unit 5 extracts the transmission source MAC address and the transmission source core address from the received frame, and notifies the transfer table registration unit 43 and the address information notification processing unit 49 of the extracted information. The frame is transferred to the MAC frame extraction unit 7. The transfer table registration unit 43 that has received the address information of the source MAC address and the source core address registers the address information in the transfer table 45.

The MAC frame extractor 7 extracts a MAC frame from the received core frame and transfers it to the destination core address analyzer 9. The destination core address analysis unit 9 uses M
When a MAC frame is received from the AC frame extraction unit 7, a search request is issued to the transfer table search unit 47. The transfer table search unit 47 having received the search request searches the transfer table and returns the destination core address to the destination core address analysis unit 9. The destination core address analysis unit 9 to which the destination core address is input notifies the core frame encapsulation unit 11 of the destination core address and the address information notification processing unit 4
9 is also notified. The core frame encapsulation unit 11 creates a core frame from the notified destination core address information and transfers it to the core network 1.

On the other hand, the address information notification processing unit 49 for performing the redirection notification includes the transmission source core address notified by the transmission source MAC address analysis unit 5 and the destination notified by the destination core address analysis unit 9. A redirection frame is created using the core address and the destination MAC address, and transferred to the core frame encapsulation unit 11. The core frame encapsulation unit 11 encapsulates the received redirection frame in the core and transfers the frame to the core network 1.

Next, a MAC bridge network 13 using the above-described MAC bridging server 3 will be described with reference to FIG. The MAC bridge network 13 shown in FIG. 2 is a core network (C conforming to ITU-TI.364).
LS network) 1. The communication devices on the MAC bridge network 13 include a MAC bridging server 3, a broadcast server 4, a MAC terminal accommodating device E15, and a MAC terminal accommodating device F17. , MAC terminal C19, and MAC terminal D21
It is composed of A MAC terminal is a terminal that enables mutual communication by transmitting and receiving a MAC frame.
The AC terminal accommodating device is a device accommodating a plurality of MAC terminals, and the broadcast server 4 is a LAN-Emula.
This is a device that has a function corresponding to the BUS of the tor. The core network 1 has a MAC bridging server 3, a broadcast server 4, a MAC terminal accommodation device E15, M
The AC terminal accommodation device F17 is connected, the MAC terminal accommodation device E15 is connected to the MAC terminal C19, and the MAC terminal accommodation device F17 is connected to the MAC terminal D21.

Addresses MAC1 and MAC2 are assigned to the MAC terminals C19 and D21, which are communication devices on the MAC bridge network 13, respectively. The core network 1 is, for example, an ITU-T as described above.
I. A 364 compliant CLSF network,
The MAC terminal accommodating device E15, the MAC terminal accommodating device F17, the MAC bridging server 3, and the broadcast server 4, which are communication devices on the core network 1, each have an address CORE. 1.1, CORE. 1.2, C
ORE. 2.1, CORE. 2.2 has been allocated.

The MAC bridge network 1 thus configured
3 will be described with reference to an operation sequence diagram shown in FIG. Here, the MAC terminal C1
A communication operation between the MAC terminal 9 and the MAC terminal D21 will be considered. Also, the MAC terminal C19 is the MA of the MAC terminal D21.
C address is acquired, and the MAC terminal D21 receives the MAC terminal C
It is assumed that 19 MAC addresses have been acquired. In the following description, the MAC terminal accommodation device E15
And the MAC terminal accommodation device F17 are abbreviated as the MAC accommodation terminal E15 and the MAC accommodation terminal F17, respectively. At each operating point in the sequence shown in FIG.
Accommodating terminal E15, MAC bridging server 3, MAC
FIG. 4 shows the address information registered in the accommodation terminal F17.

When the MAC terminal C19 transmits a frame to the MAC terminal D21, the MAC terminal C19
The C frame is transmitted to the MAC accommodation terminal E15 (process 3A). The MAC accommodation terminal E15 that has received the MAC frame registers the source MAC address (MAC.1) of the received frame in the transfer table,
The MAC frame is transferred to the MAC bridging server 3 (process 3B).

Upon receiving the MAC frame, the MAC bridging server 3 transmits the MAC frame to the source MA.
C address (MAC.1) and source core address (CO
RE. 1.1) on the transfer table and M
The AC frame is transferred to the broadcast server 4 (process 3C). Upon receiving the MAC frame, the broadcast server 4 broadcasts the MAC frame to the MAC accommodation terminal E15 and the MAC accommodation terminal F17 on the MAC bridge network 13 (process 3D). MAC that received the broadcast frame
The accommodation terminal F17 transmits the MAC frame to the MAC terminal D21.
To the MAC terminal E15, and the MAC terminal C15
(Steps 3E and 3F).

After performing the above operation, the MAC terminal D2
1 transmits a MAC frame to the MAC terminal C19, the MAC terminal D21 transmits the MAC frame to the MAC accommodation terminal F17.
The C frame is transmitted (process 3I).

The MAC accommodation terminal F17 receiving the MAC frame registers the source MAC address (MAC.2) of the received frame on the transfer table,
The MAC frame is transferred to the MAC bridging server 3 (process 3J).

The MAC bridging server 3 that has received the MAC frame transmits the source MAC address (MAC.2) and the source core address (CORE.
1.2) is registered on the transfer table, and the destination core address (CORE. 1.1) and the destination MAC address (M) resolved to the MAC accommodation terminal F17.
AC. The set of 1) is notified, and the MAC frame is transferred to the MAC accommodation terminal E15 (processing 3K). The MAC accommodation terminal E15 that has received the MAC frame converts the MAC frame into M
It transmits to AC terminal C19 (process 3L).

After performing the above operation, MAC terminal C
When a frame is transmitted from 19 to the MAC terminal D21, a MAC frame is transmitted from the MAC terminal C19 to the MAC accommodation terminal E15 (Process 30). The MAC accommodation terminal E15 that has received the MAC frame
A set of address information of the source MAC address (MAC.1) and the source core address (CORE.1.1) of the AC frame is registered in the transfer table, and the MAC frame is transferred to the MAC bridging server 3 (processing). 3
P).

The MAC bridging server 3 that has received the MAC frame transmits the destination core address (CORE. 1..
2), and the MAC frame is stored in the MAC accommodation terminal F17.
And the resolved address information is notified to the MAC accommodation terminal E15 (process 3Q). The MAC accommodation terminal F17 that has received the MAC frame converts the MAC frame into M
Transfer to AC terminal D21 (Process 3R).

After performing the above operation, the MAC terminal D
When transmitting the MAC frame from the MAC terminal 21 to the MAC terminal C19, the MAC terminal D21 transmits the M
The AC frame is transferred (process 3U). The MAC accommodation terminal F17 that has received the MAC frame resolves the destination core address (CORE. 1.1) and resolves the MAC accommodation terminal E15.
(Step 3V). The MAC accommodation terminal E15 that has received the MAC frame transfers the MAC frame to the MAC terminal C19 (process 3W).

After performing the above operation, MAC terminal C
When transmitting a frame from 19 to the MAC terminal D21,
The MAC terminal C19 transmits a MAC frame to the MAC accommodation terminal E15 (Process 3Y). MAC accommodation terminal E15
Resolves the destination core address (CORE.1.2) and transfers the MAC frame to the MAC accommodating terminal F17 (Process 3Z). The MAC accommodation terminal F17 that has received the MAC frame transfers the MAC frame to the MAC terminal D21, and the MAC terminal D21 receives the MAC frame (processing 3AA, 3AB).

Next, in order to show the effectiveness of the network operation when the MAC bridging server 3 of the present embodiment is used,
A communication sequence when a conventional MAC bridging server is used instead of the MAC bridging server 3 in the MAC bridge network 13 of FIG. 2 will be described with reference to FIG.

In this description, the communication operation between the MAC terminal C19 and the MAC terminal D21 will be similarly considered. Also, it is assumed that the MAC terminal C19 has acquired the MAC address of the MAC terminal D21, and the MAC terminal D21 has acquired the MAC address of the MAC terminal C19.

When the MAC terminal C19 transmits a frame to the MAC terminal D21, the MAC terminal C19
An AC frame is transmitted to the MAC accommodation terminal E15 (Process 4A). The MAC accommodation terminal E15 that has received the MAC frame transmits an address resolution request for the destination core address to the MAC bridging server, and also transmits the source core address (CORE.1.1) and the source MAC address (MAC.1). The notification and registration are performed, and the MAC frame is transferred to the broadcast server 4 (process 4B). MA
Upon receiving the C frame, the broadcast server 4
The MAC frame is broadcast to the AC accommodation terminal E15 and the MAC accommodation terminal F17 (process 4E). Upon receiving the MAC frame, the MAC accommodation terminal F17 sends the M
The AC accommodation terminal E15 transfers the MAC frame to the MAC terminal C19 (Process 4H).

After performing the above operation, the MAC terminal D
When transmitting the MAC frame from the MAC terminal 21 to the MAC terminal C19, the MAC terminal D21 transmits the MAC frame to the MAC accommodation terminal F17 (processing 4L). The MAC accommodation terminal F17 that has received the MAC frame transmits an address resolution request for the destination core address to the MAC bridging server (processing 4S), and furthermore, the transmission source core address (CORE. 1.1) and the transmission source MAC address (MA).
C. 1) is notified and registered (processing 4U, 4V), and the MAC frame is transferred to the broadcast server 4 (processing 4U).
M).

The broadcast server 4 having received the MAC frame broadcasts the MAC frame to the MAC accommodating terminal F17 and the MAC accommodating terminal E15 (process 4N). MA
The MAC accommodating terminal E15 and the MAC accommodating terminal F17 that have received the C frame transfer the MAC frame to the MAC terminal C19 and the MAC terminal D21, respectively (processing 40, 4).
P).

Here, after receiving the solution response from the MAC bridging server (process 4X), the MAC accommodation terminal E15 sends the MA from the MAC terminal D21 to the MAC terminal C19.
When transmitting the C frame, the MAC terminal C19
The C frame is transmitted to the MAC accommodation terminal E15 (Process 4AA). MAC accommodating terminal E that has received the frame
15 transfers the MAC frame to the MAC accommodating terminal F17 based on the address information resolved by the MAC bridging server (process 4AB). Received MAC accommodation terminal F1
7 transfers the MAC frame to the MAC terminal D21 (Process 4AC).

Here, when the MAC accommodation terminal E15 receives the solution response from the MAC bridging server (process 4Z) and transmits a frame from the MAC terminal C19 to the MAC terminal D21, the MAC terminal D21 transmits the MAC frame To the MAC accommodation terminal F17 (Process 4
AE). MAC accommodation terminal F1 that has received the MAC frame
7 transfers the MAC frame to the MAC accommodating terminal E15 based on the address information resolved by the MAC bridging server (process 4AF). MA that received the MAC frame
The C accommodation terminal E15 transmits the MAC frame to the MAC terminal C1.
9 (process 4AG).

As described above, the operation sequence using the MAC bridging server 3 of the present invention and the conventional M
Comparing the operation sequence in the case of using the AC bridging server, the broadcast server is frequently used in the communication procedure using the conventional MAC bridging server. This means that the traffic load in the network increases, which is not preferable. However, the broadcast frequency can be reduced by using the MAC bridging server of the present invention.

In the communication procedure using the conventional apparatus, in addition to the transfer of the user data, the address registration to the server and the request for address resolution to the server are executed in parallel.
The communication processing load becomes heavy.

Further, since these processes require state management control, the processing mechanism of the MAC terminal accommodating device becomes complicated, and the cost of the device increases. However, by using the device of the present invention, these processes become unnecessary, the MAC terminal accommodating device can be easily mounted, and the device cost can be reduced.

Further, in the present embodiment, when a MAC terminal on the core network transmits a MAC frame whose destination core address cannot be resolved, this MAC frame is encapsulated in a core frame and transferred to the MAC bridging server. The MAC bridging server can automatically learn the information of the pair of the source MAC address and the source core address from the received core frame. Therefore,
The MAC terminal on the core network does not need to notify the MAC bridging server of an explicit address.

Further, since the MAC bridging server can relay the MAC frame to an appropriate destination based on the automatically learned address information, the MAC terminal on the core network specifies the MAC frame to the MAC bridging server. It is not necessary to make an address resolution request. As a result, since all the address information of the terminal that transmitted the MAC frame is stored in the MAC bridging server, it is also possible to suppress the multicast (broadcast in the MAC group) in the core network.

Further, the MAC bridging server which has transferred the MAC frame notifies the MAC terminal serving as the transmission source on the core network of the information of the set of the destination MAC address and the destination core address.
When transmitting a MAC frame continuously to the same destination, the C terminal can directly transfer the MAC frame to the destination MAC terminal on the core network without going through the MAC bridging server. As a result, the frame transfer throughput is improved.

[0043]

As described above, according to the present invention,
Since the MAC bridging server can automatically collect the address information on the MAC terminal on the core address and can suppress the multicast in the core network (broadcast in the MAC group), the use efficiency of the network resources is reduced. Improved, resulting in reduced frame transfer costs. Also, the address processing load other than the frame transfer processing of the MAC terminal on the core network is reduced, and the transmission throughput is improved.

Further, according to the present invention, it is possible to reduce the traffic processing load of the MAC bridging server itself, and to dramatically increase the frame transfer throughput when continuously transmitting MAC frames to the same destination. Can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a MAC bridging server according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a MAC bridge network using the MAC bridging server of the embodiment shown in FIG.

FIG. 3 is a diagram showing an operation sequence of the MAC bridge network shown in FIG. 2;

4 is a diagram showing address information registered in each unit in the operation sequence shown in FIG.

FIG. 5 shows a MA using a conventional MAC bridging server.
It is a figure showing the operation sequence of a C bridge network.

[Explanation of symbols]

Reference Signs List 1 core network 3 MAC bridging server 4 broadcast server 5 source core address and source MAC address analysis unit 7 MAC frame extraction unit 9 destination core address analysis unit 11 core frame encapsulation unit 13 MAC bridge network 15 MAC terminal accommodation device E 17 MAC terminal accommodating device F 19 MAC terminal C 21 MAC terminal D 43 Transfer table registration unit 45 Transfer table 47 Transfer table search unit 49 Address information notification processing unit

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Hara 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References 1997 IEICE Communications Society Conference B- 7-23, August 13, 1997 IEICE Technical Report IN 97-117, October 17, 1997 IEICE Technical Report IN 97-65, July 18, 1997 Junichi Murayama et al. "Designing a Core Network for Building a Large-Scale Internet", NTT R & D, The Telecommunications Association, March 10, 1997, Vol. 46, No. 3, pp. 222-232. Research Report CS 97-27, June 23, 1997 Shigeaki Tanimoto et al., "Logical Office Services", NTT R & D, Telecommunications Association, 1 October 10, 996, Vol. 45, No. 10, pp. 987-996 (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/56 H04L 12/66 H04L 12/46

Claims (2)

(57) [Claims] 1. An MA installed in a wide area frame transfer network that performs frame transfer using a protocol system different from the MAC protocol, referred to as a core network.
A C-bridging server that receives a core frame transferred from a core network, and sets a source address of the received core frame and a source MAC address of a MAC frame described in a payload portion of the core frame. Source address and source MAC address analysis means for extracting the information of the address, transfer table registration means for registering the address resolution information extracted by the analysis means in a transfer table, and a payload portion of the core frame received by the analysis means Frame extracting means for extracting a MAC frame from a MAC address, and a destination for resolving a core address by searching the forwarding table using a destination MAC address described in a header portion of the MAC frame extracted by the MAC frame extracting means as a key. Core address analysis means; MAC bridging server, characterized in that the core address retrieved in the core address analyzing unit encapsulates MAC frames into the core frame assigned as a destination and a core frame encapsulation means for transmitting to the core network. 2. When the MAC frame is transferred,
Destination M to the source MAC terminal on the core network
2. The MAC bridging server according to claim 1, further comprising means for notifying information of a set of an AC address and a destination core address.