JPH01208935A - Node equipment - Google Patents

Abstract

PURPOSE:To identify and erase a packet sent from its own station surely by adding a new header part of the packet sent in the state of acquiring the transmission right, detecting an address of an incoming packet and erasing the packet when its own station address is inserted without relaying to the next node. CONSTITUTION:A transmission section 105 receives a frame from a relay section 103 in a MAC(media access control) sub layer FDDI-MAC 102 supporting the FDDI system of a LAM 200 and sends the result to an address insertion section 106. The address insertion section 106 adds a pseudo header part H2 and inserts its own station address as a sender address SA2 to send the resulting frame to the next node 21. A reception/erasure section 104 detects whether the sender address of the header part H is coincident with its own station address or not upon the receipt of the frame sent from the node of the LAN 200 and erases the frame in case of coincidence.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is based on F D D I (['1ber Dis
The present invention relates to a node device that is applied to a token ring LAN (local area network) using a tributed data interface.

[Conventional technology]

The FDDI type token ring LAN is based on the American ANSI
/X3T9.5 Standardization is progressing at committee ii10
A LAN that assumes the use of 0MpbS optical fiber,
It has the following characteristics.

A plurality of nodes are connected in a ring shape through a transmission path through which frames, which are packetized information, are transmitted in one direction. The node that holds the token transmitted through this transmission path has the right to transmit on the transmission path. When it finishes transmitting the frame, it transmits a token and relinquishes the right to transmit. Further, if the source address of the received frame matches the address of the own node, the frame is deleted without being relayed to the next node.

[Problem to be solved by the invention]

By the way, in recent years, multiple networks are sometimes connected, and if the above method is used as is in such cases,
The following problems arise.

In other words, when a frame arriving from another network is relayed to the above-mentioned FDDI LAN, the source address of this frame is the address of a node in the above-mentioned network. Even if the frame goes around the transmission path and returns, it cannot be determined that the frame was sent by the own node. Therefore, when connecting networks, the FDDI method cannot be used as is.

Therefore, when multiple networks are combined, the present invention can accurately relay and transmit packets from one network to another, and can operate as a node of an FDDI LAN without any problems. The purpose is to provide a node device.

[Means to solve the problem]

In the node device according to the present invention, a plurality of nodes are connected in a ring shape by a transmission path through which packetized information is transmitted in one direction, and a node holding a token transmitted through the transmission path is connected to a node on the transmission path. A token-based LAN node device that has the transmission right and sends a token when the packet transmission is completed, and adds a new header to the packet to be transmitted with the transmission right, and adds a new header to this header. It detects whether or not the own station's address is inserted into the address insertion section that inserts the station's address and the new header section of the incoming packet, and if the own station's address is inserted, the packet is inserted. The present invention is characterized in that it includes a packet erasing unit that erases packets without interrupting the next node.

[Effect]

Since the node device according to the present invention is configured as described above, the control of transmission rights and the control of packet transmission are the same as in the FDDI system, and it can function as a node of the FDDI system LAN. In this case, the address of the own station is inserted into the newly added header, and if the address of the own station is inserted in the new header of the received packet, the packet is deleted. Therefore, it is possible to reliably identify and erase packets sent from the own station, and the source address of the information can be included in the other header section.
As a connecting node between other networks and the FDDI LAN, relay transmission can be performed without any trouble.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A node device according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 3 of the accompanying drawings.

FIG. 1 is a block diagram of a node device 100 according to an embodiment of the present invention, and FIG. 2 is a block diagram of a composite LAN to which the node device 100 is applied.

As shown in FIG. 2, the node device 100 has an optical fiber 1
The nodes 2.2, . Whether the LAN 300 is an FDDI type LAN or another type LAN, the node device 100 is an FDD type LAN.
Since it has the function of absorbing the difference in specifications from the I-type LAN 200, no particular problem will occur. Also, node 2 is FD
Transmission is performed using the DI method.

The node device 100 has a MAC (media access control) sublayer 1 that supports the LAN 300 method.
01 and the FDD I-MAC sublayer (hereinafter referred to as FDD I-MAC sublayer) that supports the FDD I method of LAN200.
It's called MAC. ) 102, and a relay unit 103, which is an interface that absorbs differences in methods between these sublayers. In addition to these, each LA
Corresponding to the N method, the configuration includes layers higher than the logical link control sublayer, physical layer (physical layer protocol, physical medium dependent part), interface connectors, etc. that are not shown in the figure, but these are not directly related to the present invention. , the explanation thereof will be omitted.

The FDDI-MAC 102 includes a receiving/erasing section 104, a transmitting section 105, and an address inserting section 106. When a frame is transmitted from the LAN 300 and arrives at the relay unit 103 via the MAC 101, and a data transmission request is received from the relay unit 103, the receiving/erasing unit 104 performs token capture processing. Upon capturing the token, transmitting section 105 receives the frame stored in relay section 103 and sends it to address inserting section 106 . The address insertion unit 106 duplicates the header part H of the frame,
The frame configuration is as shown in FIG. That is, since the FDDI header section H1 is added immediately before the information section (this addition is performed by the relay section 103), the pseudo header section H is added before this. The formats of the header section H1 and the pseudo header section H2 are both based on the FDDI format. Source address S of header part H1
A i becomes the address of the node in the LAN 300, and the destination address DA1 becomes the address of the node in the LAN 200. Address insertion section] 06 is pseudo header section H2
The address of the own station (own node) is inserted as the source address SA2, and the same destination address DA as the header part H1 is inserted as the destination address DA. The frame configured in this manner is transmitted from the node device 100 to a downstream node (in the information flow direction).

On the other hand, the receiver 13/erase unit 104 detects the header part H of the frame received from the node of the LAN 200, and when it detects that the source address SA is the address of its own station, the receiver 13/erase unit 104 deletes the received (B) frame. The frame is erased without being relayed to the next node.Furthermore, when the source address of the header section H is an address other than the own address, the frame is sent to the frame section 105.The transmitting section 105
The frame sent from the receiving/erasing section 104 is sent out without going through the address inserting section 106 (symbol a in FIG.
(according to the route shown). Note that even if the transmitting unit 105 receives a frame sent from the receiving/erasing unit 104, if the frame is being transmitted, the transmitting unit 105
Ignore frames sent from .

Since the relay of frames from the LAN 200 to the LAN 300 is not directly related to the present invention, it is shown by a broken line in FIG. 1 and its explanation will be omitted. Further, it is assumed that this node device 100 only performs relaying between the LAN 300 and the LAN 200, and does not receive any data transmission requests from its own node.

Next, the operation of the above embodiment will be explained.

The node device 100 configured in this manner operates as follows. When frames transmitted from the LAN 300 are accumulated in the relay unit] 03 (at this stage - C frames or hM is configured to match the FDDI method), a data transmission request is sent to the FDDI -MAC102
I can help you. As a result, the receiving/erasing unit 104 starts receiving usable tokens, and when a usable token is received, it captures and holds it, and
200 to obtain the right to send ID.

Next, in the FDDI-MAC 102, the transmitting unit] 05 receives the frame from the relay unit 10', and the address insertion unit 1
Send to 06. As explained with reference to FIG. 3, the address insertion section 106 adds a pseudo header section H2, inserts its own address as the source address S A 2, and sends out the frame. The frame in which the header part H is duplicated in this manner is transmitted to the next node 21.

At the same time, the receiving/erasing unit 104 of the FDDI-MAC 102 is receiving a frame transmitted from a node of the LAN 200, and when the frame is received, the source address in the header H of the frame is the own station. It is detected if it matches the address, and if it matches, /'r'r is increased for this frame.

Each node 2 is transmitted from the node device 100.

Since the header part H of the frame that has gone around and returned via 22 and . . Also, each node'2, ,...
・For the frame sent from -1'''2, check whether the header part H is duplicated, or if the header part H is at the beginning of the frame, detect the source address SA in the same way as above. , relay transmission processing can be performed.

On the other hand, other nodes 2, 22°, etc. of the LAN 200 are
When a frame is received, whether it is relayed to the next node (
(including when copying), the deletion is determined based on the header section H at the beginning of the frame, so even if the header section H is duplicated as shown in Fig. 3, normal FDDI Even if the frame includes a header section (one) of the system, it can be processed without any problem. Furthermore, when a duplicated frame is copied, each node 2.
2, . . ., the above determination is made in the pseudo header section H2, and the address of the node of the LAN 300 (the real source address) can be detected from the address of the source address SAl in the header section H1.

The transmitter 105 of the FDDI-MAC 102 transmits a token when there are no more frames to transmit, and
The C 102 begins to relay the frame within the LAN 200. In this way, frames transmitted from the LAN 300 are accurately transmitted within the FDDI LAN 200.

The present invention is not limited to the above embodiments, and various modifications are possible.

For example, the frames transmitted by the node device may include not only those transmitted from other LANs, but also frames obtained from a terminal that generates a data transmission request provided at the node device. In this case, the header part of the information sent from the terminal does not need to be duplicated. Further, although there is no restriction on the position of the header section added in the present invention, it is most convenient to place it at the beginning of the frame as in the embodiment from the viewpoint of relationships with other nodes of the FDDI system.

Furthermore, when relaying through two or more LAN stages, the header section may be triplexed.

〔Effect of the invention〕

As explained in detail above, in the present invention, a new header section is added to the packet, the address of the own station is inserted into this new header section, and the erasure of the packet is performed by adding the address of the own station in the new header section. Since it is performed when detected, it is possible to accurately erase packets sent from the own station, and when multiple networks are combined, it is possible to accurately transmit packets from one network to the other network (FDDI method). It has the effect of being able to operate as a FDDI LAN node without any problems. Moreover, by appropriately setting the position of the added header section, there is an effect that there is no need to make any changes to the deletion algorithm of packets related to transmission from the local station in the FDDI I system, including other nodes and the local node.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a node device according to an embodiment of the present invention;
FIG. 2 is a configuration diagram of a composite LAN to which a node device according to an embodiment of the present invention is applied, and FIG. 3 is a diagram showing the format of a frame transmitted from a node device according to an embodiment of the present invention. 1... Optical fiber, 2.22... Node, 100 ■... Node device, 101... MAC sublayer, 1
02...MAC sublayer of FDDI system, 103.
... Relay section, 104... Receiving/erasing section, 105...
Transmission section, 106...address insertion section, 200...F
DDI type LAN, 300...LAN0 patent applicant Sumitomo Electric Industries, Ltd.

Claims (1)

[Claims] A plurality of nodes are connected in a ring shape by a transmission path through which packetized information is transmitted in one direction, and a node holding a token transmitted through the transmission path has the right to transmit on the transmission path. In a token-based LAN node device that has the following functions and sends a token when the packet transmission is completed, a new header section is added to the packet to be sent after obtaining the transmission right, and the address of the own station is added to this header section. Detects whether or not the address of the own station is inserted into the address insertion section to be inserted and the new header section of the incoming packet, and if the address of the own station is inserted, interrupts the packet to the next node. A node device comprising: a packet erasing unit that erases packets without deleting them.