JPH02137541A - Node device with token control function - Google Patents

Abstract

PURPOSE:To attain the improvement of the communication effect and the multiple address and to prevent crosstalk even if p-p communication and multiple address are applied to a node simultaneously by setting lots of tokens corresponding to number of nodes in a communication group. CONSTITUTION:A data conversion between a slotted ring type LAN transmission line 10 and a communication equipment 40 is implemented by a node equipment 11 and a transmission line synchronizing detection section 21 detects the synchronization or a transmission frame on the transmission line 10 to extract a transmission clock and to generate various kinds of timings and they are distributed to each block in the node. Moreover, the content of a packet header is analyzed by a packet branch section 22 to branch the packet from the slot of the LAN to apply reception notice to a packet conversion control section 25. Then a packet is inserted to the transmission line 10 according to the packet branch, communication frame reception control to a packet reception buffer section 26 and a request from a packet transmission control section 32.

Description

[Detailed Description of the Invention] [Summary of the Invention] Regarding a node device with a token control function that accommodates communication devices in a slotted ring type LAN, it is possible to set a large number of tokens to increase communication efficiency, and to improve communication efficiency between each node. The purpose is to enable communication and broadcast communication within a group, and the communication devices that are installed in a large number on the transmission path of a slotted ring type LAN and divided into communication groups are connected to the LAN.
The node device with a token control function accommodated in N analyzes the content of the communication frame data received from the communication device, and generates inter-node communication tokens or individual communication tokens for each node according to the destination node and communication form. An analysis selection unit that selects a token for intra-group broadcast communication that is common to nodes, and an analysis and selection unit that selects a token for intra-group broadcast communication that is common to nodes, and an analysis and selection unit that determines whether the packet is inter-node communication data or intra-group broadcast communication data when assembling and transmitting a packet from a communication frame. a packet assembling and disassembling unit that selects a reception buffer to store a communication frame reconstructed from the packet based on the attributes set in the attribute setting part in the packet header and that analyzes the packet header of the received packet; p-p as a buffer
It is configured to include a communication reception buffer section and an intra-group broadcast communication reception buffer section.

[Industrial application field]

The present invention relates to a node device with a token control function that accommodates communication devices in a slotted ring type LAN.

Slotted Ring type L
In AN (Local Area Network),
The assigned ID number slot is used as a token.
There is a method in which transmission right arbitration is performed by using it as n). In other words, a node that has captured an empty slot with the assigned ID number assumes that it has obtained the right to transmit, inserts the transmission data into that slot and the following empty slots, and when the transmission is completed, the node that has captured the slot with the ID number that has been circulating Return it from being used to free and transfer the transmission right to another node.

A plurality of nodes are provided on the transmission path of the LAN, and a communication device is connected to each node to perform transmission and reception. Communication is performed between one node and one node using p −p (p
In addition to point-to-point (point-to-point) communication, there is also broadcast communication performed between one node and multiple nodes.

A large number of nodes provided on a LAN transmission path may be divided into a plurality of communication groups, and a token may be assigned to each group. The present invention relates to a node with a token control function in such a system.

[Conventional technology]

A slotted ring type LAN is a LAN that transmits all data based on fixed-length mini-packets, and since the transmission frame length within the ring is always kept constant, there is always a constant number of slots on the ring. . Each slot is assigned an ID number. For example, if one slot is always used for communication, the I
A constant band can be obtained regardless of the D number.

Between multiple (three or more) communication devices housed in a slotted ring type LAN, data generated from multiple communication devices is simultaneously sent to one communication device, causing interference. In order to avoid this, and to achieve communication in which only one device can transmit at the same time, it is necessary to perform transmission right arbitration. The communication device that has acquired the transmission right transmits one communication frame (data processing unit) in one acquisition of the transmission right, and then delegates the transmission right to the next communication device.

Although transmission right arbitration control can be realized in the upper layer of the communication protocol between communication devices, in order to obtain high communication efficiency, it is necessary to implement control between each node in the lower layer as a function of the slotted ring type LAN. It is necessary to realize high-speed processing.

Such transmission right arbitration is realized by the procedure described above. In other words, only one slot, called a token, indicating the right to transmit is reserved in a slotted ring type LAN, and a node that captures the token in an empty slot recognizes that it has acquired the right to transmit, and uses the token. and then start sending. When the node finishes transmitting, it returns the token to an empty slot, and the right to transmit is transferred to a downstream node.

When a node that has obtained the transmission right is ready to transmit a packet, it acquires an empty slot and transmits it, but there is a delay due to blocking of communication frames (delay due to packetization, etc.)
For example, it is not always possible to transmit packets to all available slots that can be captured. If the communication frame length is long, even if a token that is in use comes around,
There may still be some data that is not ready to be sent. In such a case, dummy data is inserted into the token slot in order to make the circulating token in use again so that the node can continue transmitting data.

In this transmission right arbitration method, nodes that communicate with each other are grouped into communication groups, and a unique token is assigned to each communication group, thereby making it possible to improve the communication efficiency of the entire system.

In FIG. 5, nodes 11 to 13 provided on the transmission line 10 of the slotted ring type LAN are divided into communication group 8, and nodes 15 to 17 are divided into communication group B. In communication group A, token A is used to Communication group B uses token B for communication. By using this token, transmission rights arbitration between different communication groups can be controlled without interfering with each other.

In the method shown in Fig. 5, one token is allocated to each communication group, but in this token allocation method, as the number of nodes composing the communication group increases, the delay time (Round Trip De
ray) increases, the communication efficiency within the communication group is suppressed, and the communication efficiency per node decreases.

Therefore, we have changed the meaning of tokens not only to acquire the right to transmit within a communication group, but also to acquire the right to transmit within a communication group, and to acquire the right to use the receiving buffer of the destination node. If used, tokens for the number of nodes can be reserved for use within a communication group, thereby improving communication efficiency within the communication group. 7th
The figure shows this example, and tokens are provided corresponding to nodes. That is, communication group A is allocated tokens All to A14, and communication group B is allocated tokens B15 to B1B. The meaning of these tokens is, for example, token A12.
indicates that it may be transmitted to the node 12, and token A14 indicates that it may be transmitted to the node 14, and the following applies accordingly.

FIG. 7 shows that in communication group A, node 11 acquires token A12 and sends pp communication to node 12.
Also, node 13 acquires token A14 and node 14
This shows that pp communication is being performed simultaneously for both. Although not shown in the diagram, in communication group A, it is also possible to simultaneously perform p-p communication from node 12 to node 11 using token A11, and from node 14 to node 13 using token A13. (The same applies to communication group B).

Increasing the number of tokens in this way increases communication opportunities for each node, allowing prompt transmission. Of course, there is no such thing as confusion. For example, even if nodes 11 and 14 try to transmit to node 12 at the same time, since transmission to node 12 requires acquisition of token A12, only one node can transmit at 1:00, and node 1 is sent to node 12's receiving buffer.
There is no possibility that the transmission data of numbers 1 and 14 are mixed together. Note that the transmission capacity of slotted ring type LAN is extremely large (400Mbps = Gbps
), the transmission capacity of the node bus type LAN is small (10M
(bps, etc.), there is no way that the former cannot handle the latter's communication, so communication is possible if a token can be obtained.

[Problem to be solved by the invention]

The method shown in Figure 7, in which tokens are set corresponding to nodes, enables quick transmission with little waiting time, but the communication form within a communication group is limited to pp communication, and tokens in the conventional sense are Compared to communication groups that use , there is a problem in that intra-group broadcast communication becomes impossible. That is, if one token is assigned to one communication group, pp communication and relay communication are possible as shown in FIG. 6, but relay communication is not possible with a token corresponding to a node. In FIG. 6, in communication group A, node 11 acquires token A and performs pp communication with node 13, and in communication group B, node 17 acquires token B and communicates with nodes 15 and 16. This indicates that intra-group broadcast communication is being performed for the group.

An object of the present invention is to improve the above points, to increase communication efficiency by setting a large number of tokens, and to enable both pp communication and intra-group broadcast communication.

(Means for Solving the Problems) As shown in FIG. 1, in the present invention, communication devices (40, 41゜41,...
...) in the LAN includes an analysis selection section 50, a packet assembly/disassembly section 28, and a reception buffer for pp communication. A receiving buffer section 29a and a reception buffer section 29b for intra-group broadcast communication are provided.

The analysis selection unit 50 analyzes the contents of the data of the communication frame received from the communication device 40, and generates a pp communication token corresponding to each node or common to each node according to the destination node and communication form. Select the intra-group broadcast communication token.

Furthermore, when assembling and transmitting a packet from a communication frame, the packet assembling and disassembling unit 28 determines whether the packet is pp communication data or intra-group broadcast communication data in the attribute setting part in the packet header. Set. Furthermore, the packet header of the received packet is analyzed, and the receive buffer for storing the communication frame reconstructed from the packet is stored in the receive buffer section 29a for pp communication.
or the intra-group broadcast communication buffer section 29b.

[Effect]

In the present invention, tokens are used for each node and for broadcasting.

Therefore, in communication group A, there are tokens All to A14 for nodes 11 to 14, and token C for intra-group broadcasting, and the same applies to communication group B.

When a communication frame is sent from the communication device 40, the analysis and selection unit 50 determines the corresponding token based on the transmission destination information and communication type (pp or circular) information, and captures the determined token. Transmission is performed in

In this method, a node may receive a pp communication packet and a relay communication packet at the same time, but if you look at the attribute setting part of the packet header, you can tell whether it is pp communication or relay communication. Buffering is performed to the respective buffers 29a and 29b.

This process is performed by the packet assembly and disassembly section.

In this way, in the present invention, it is possible to set a large number of tokens (as many as the number of nodes) within a communication group, increasing communication efficiency, and since tokens for broadcasting are also set, broadcasting is possible. Since the receiving buffers are different for broadcast communication and broadcast communication, there will be no interference even if pp communication and broadcast communication are performed at the same time at a certain node.

〔Example〕

FIG. 2 shows details of the node device of the present invention. This node device 11 is a transmission line 10 of a slotted ring type LAN.
It performs data conversion between the communication device 40 and the communication device 40.

Reference numeral 21 denotes a transmission path synchronization detection unit, which extracts transmission path clocks and generates various timings by detecting synchronization of transmission frames on the ring transmission path 10, and distributes these to each block within the node. . 22 is a packet branching/insertion unit which analyzes the content of the packet header, branches the packet from the slot of the slotted ring type LAN, notifies the packet reception control unit 25 of reception, and branches the packet to the packet reception buffer unit 26. or inserts a packet from the communication frame reception buffer section 31 into the transmission path 10 in accordance with a request from the communication frame reception control/packet transmission control section 32.

Further, 23 is a timing counter section, which counts the transmission frame timing extracted by the transmission path synchronization detection section 21 in accordance with a counter reset instruction from the token inspection section 34. If the counter overflows before a counter reset instruction is received from the token checking unit 34, the token checking unit 34 is notified of this fact. Reference numeral 24 denotes a token detection section, which detects the slot use status of the token circulating on the transmission path and notifies the token inspection section 34 of this.

The packet reception control section 25 controls writing of data to the packet reception buffer section 26 in accordance with a packet reception instruction from the packet add/drop section 22 . Furthermore, in response to a request from the communication frame transmission control section 27, data reading from the packet reception buffer section 26 is controlled in order to disassemble packets and assemble communication frames. The packet reception buffer section 26 buffers the packets branched from the transmission path by the packet add/drop section 22 under the control of the packet reception control section 25 .

The communication frame transmission control section 27 reads out the packets stored in the packet reception buffer section 26 and, according to the packet header analysis result of the packet assembly/disassembly section 28, sends the packets to the pp communication frame transmission buffer section 29a or the frame for intra-group broadcast communication. It controls writing of communication frames to the transmission buffer section 29b. In addition, buffers 29a and 29b
When the assembly of the communication frame is completed, read control is performed to transmit the communication frame to the communication device 40 in accordance with a request from the external interface control unit 30.

The packet assembling and disassembling section 28 includes the packet receiving buffer section 2
6 is assembled into a communication frame, and the communication frame read from the communication frame reception buffer section 31 is disassembled into packets. When disassembling a packet, the packet header is analyzed to determine whether the packet is for pp communication or intra-group broadcast communication, and this is notified to the communication frame transmission control unit 27. When assembling a packet, packet header information notified from the communication definition table section 33 is added.

Communication frame transmission buffer units 29 a and 29 b c) Buffer the communication frames assembled by the packet assembly/disassembly unit 28 under the control of the communication frame transmission control unit 27 . The external interface control unit 30 controls the interface between a node and a communication device, and sends and receives communication frames.

The communication frame reception buffer section 31 performs buffering of communication frames according to reception instructions from the external interface control section 30 under the control of the communication frame reception control/packet transmission control section 32 .

The communication frame reception control/packet transmission control section 32 controls writing of communication frames into the communication frame reception buffer section 31 in accordance with reception instructions from the external interface control section 30 . Further, in order to transmit packets according to instructions from the token inspection section 34, control is performed to continuously output communication frames from the communication frame reception buffer section 31.

The communication definition table section 33 is a table in which tokens used for disassembling communication frames into packets and transmitting them and communication path definition information to be set in packet headers are set. Every time a communication frame is received by the communication frame reception buffer section 31 according to an instruction from the communication frame reception control/packet transmission control section 32, a token used for transmission is searched and the token inspection section 34 is notified. Also, according to instructions from the communication frame reception control/packet transmission control section 32, the packet header information retrieved at the same time as the token is generated in the packet assembly/disassembly section 28 to assemble the packet. The packet header information includes information indicating an attribute of whether the communication frame is a communication frame for pp communication or a communication frame for intra-group broadcast communication. These control section 32 and table section 33 constitute the analysis selection section shown in FIG.

The token inspection unit 34 acquires tokens used in communication frames waiting to be transmitted to the transmission path, monitors transmission waiting time, controls communication frame reception by acquiring tokens, instructs transmission to the packet transmission control unit 32, and holds tokens. , controls the release of tokens after transmission is completed. The usage status of each token is detected by the token detection section 24, and the timing counter section 23 monitors the transmission waiting time.

In the present invention, a communication group consisting of n nodes that perform transmission right arbitration on the ring of a slotted ring type LAN is provided with n P-2 communication tokens for the number of nodes and a token for intra-group broadcast communication. Defining one token, a total of n+1 tokens, each time a node receives a communication frame from the communication bag 240, it searches for its transmission destination and communication form, and performs transmission using the corresponding token. These tokens are prepared in the communication definition table section 33, and a corresponding token can be retrieved by searching for the destination and communication type. The receiving node determines whether the received packet is for pp communication or intra-group broadcast communication, buffers each packet separately in buffer units 29a and 29b, reconfigures it into a communication frame, and then communicates it. to the device 40.

In this way, multiple tokens can be defined for one communication group, which increases the communication efficiency of each node compared to the case of one token, and also enables p-2 communication and intra-group broadcast communication. be.

FIG. 3 shows an example in which the present invention is applied to a system in which a bridge device B is connected to a slotted ring type LAN to realize inter-LAN connection. 11 to 14 are nodes to which the present invention is applied, 10 is a transmission line of a slotted ring type LAN, and WS is a workstation of a communication terminal accommodated in the bus type LAN. 51 to 54 are LA of the bus type
N, which is a LAN defined by IEEE802.3.

FIG. 4 shows an example of the format of a communication frame and a form of communication within a communication group according to the contents of the communication frame in this embodiment. DA is the destination address, SA is the source address, LLC PDU! ;I'LLC data, F
e2 is a frame check sequence. To give an example of the number of bytes, DA is 6 bytes, SA is also 6 bytes, LLC
PDU is 46-150o hide, Fe2 is 4 bytes. The destination address DA consists of an individual/broadcast indicator field I10, a local/universal definition indicator field L/U, and the remaining 46 bits of the address. Communication forms include p-2 communication and broadcast,
When it is pp, the L/U beam becomes ``■'' and the I/G becomes ■. Other than that, it is the same report.

Within a communication group, tokens for each node for pp communication, tokens A1 to A14 in FIG. 3, and token C for inter-group broadcasting are defined.

The analysis of the communication form performed by the node for each communication frame is performed based on the contents of the first two bits of the DA section of the communication frame.

For example, in the node 11 of FIG. 3, the communication definition table section 33 analyzes the communication frame received from the bridge device, and it can be determined that the communication frame is addressed to the node 12. As a result, the packet assembly/disassembly unit 28 is notified of the destination address as the packet header information and the communication mode as p-2 communication. At the same time, a request to acquire the token A12 is issued to the token inspection unit 34, and the token inspection unit 34
acquires token A12. p-2 from node 11 to node 12 due to the acquisition of token A12
Communication is carried out.

In addition, when node 13 acquires token A14, p-2 communication from node 13 to node 14 occurs, and when node 12 acquires token C, node 1
Intra-group broadcast communication from node 2 to nodes 11, 14 and 13 can be executed simultaneously in parallel.

For example, at the node 14, the pp communication packet from the node 13 and the intra-group broadcast communication packet from the node 12 arrive at the same time. The node 14 disassembles the mixed packets accumulated in the packet reception buffer section 26 and reconstructs a communication frame. The packet assembling and disassembling unit 28 analyzes the packet header of the received packet in accordance with a request from the packet reception control unit 25 to process the received packet. As a result, packets for pp communication are written to the frame transmission buffer section 29a for pp communication according to the communication form of each packet, and packets for intra-group broadcast communication are written to the frame transmission buffer section 29b for intra-group broadcast communication. Write to. When data for one communication frame has been written to either of the communication frame transmission buffer units, the communication frame transmission control unit 27 notifies the external interface control unit 30 of this and causes the communication frame to be transmitted to the bridge device. conduct.

〔Effect of the invention〕

As explained above, in the present invention, the slotted ring type L
In a node that is connected to the AN and has the function of selecting a token for each communication frame processing, a communication group consisting of n nodes is divided into groups with pp communication tokens for the number of nodes (n). By defining a total of n+1 tokens, including one token for internal broadcast communication, each time a node receives a communication frame from a communication device, it searches for the destination and communication format, and performs transmission using the corresponding token. It also has a function to determine whether the received packet is for P-2 communication or intra-group broadcast communication, buffer each packet separately, and reassemble it into a communication frame, so it is possible to combine it into one communication group. It is possible to define multiple tokens for each node, which has the effect of increasing the communication efficiency of each node within the communication group, and the communication form (p-p The advantage is that communication and intra-group broadcast communication) can be realized as well.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the principle of the present invention, Fig. 2 is a block diagram showing the configuration of a node of the invention, Fig. 3 is an explanatory diagram showing an example of communication of the invention, and Fig. 4 is a diagram of the communication format and form. Explanatory diagrams FIGS. 5 to 7 are explanatory diagrams of examples of token usage. In FIG. 1, 10 is a transmission path, 11 to 17 are nodes, 40 is a communication device, 28 is a packet assembly/disassembly section, 29a and 29b are buffers, and 50 is an analysis selection section.

Claims (1)

[Claims] 1. A large number of communication devices (
40) in the LAN, analyzes the content of the data of the communication frame received from the communication device, and generates a communication token between each node according to the destination node and communication form. Alternatively, an analysis selection unit (50
), and when assembling and transmitting a packet from a communication frame, it sets whether the packet is communication data between each node or broadcast communication data within a group in the attribute setting part in the packet header, and also sets the received packet. A packet assembly/disassembly unit (28) that analyzes the packet header of a packet and selects a reception buffer for storing a communication frame reconstructed from the packet based on its attributes; and a reception buffer unit for pp communication as the reception buffer. (
29a) and intra-group broadcast communication reception buffer section (
29b) A node device with a token control function.