JPH07131479A - Line concentrating device and method for recognizing and controlling node under its control - Google Patents

Abstract

PURPOSE:To correctly recognize connection relation even when the line concentration device is hierarchically connected by recording the transmission destination address of a frame for constitution recognition and erasing the frame from a transmission line when the frame is received. CONSTITUTION:A frame transmission part 20 of the line concentration device 10 has a constitution recognition frame transmission part 30 which sets its address as a transmission source address in the frame for constitution confirmation distinctive from other general frames and sends them. Further, a frame reception part 40 has a constitution confirmation frame reception part 50 which records transmission source address of the frame and erases the frame from the transmission line when the frame for constitution recognition is received. This constitution recognition frame transmission part 30 sends the frame for constitution recognition where its address is set to all ports P1-P3. Therefore, remote constitution management of the line concentrating device can be performed without requiring any operator and a management device which is flexibly applied to a network having many changes can be designed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concentrator and a subordinate node recognition control method for enabling concentrators to be recognized even when they are hierarchically connected.

[0002] In a network system, configuration information about what kind of device is connected and in what form is necessary for maintenance such as recovery and reconfiguration at the time of failure. It is also necessary as information when expanding or changing the system.

[0003]

2. Description of the Related Art FIG. 5 is a diagram for explaining a conventional technique and its problems. Here, the concentrator 10 is called a HUB, and is a concentrator that relays communication frames in 10BASE-T. 10BASE-T
Is a CSMA / CD type local area network (LAN) defined by ISO8802.3, which has a transmission line (physical layer) using a twisted pair cable. As shown in FIG. 5A, the concentrator 10 has a plurality of ports P1 to P3, and a plurality of nodes 62 to 64 can be connected to the ports.

When managing this concentrator (HUB),
If it is possible to remotely know which node is connected to which port, it becomes easier to perform HUB management from a remote place. As a method of knowing which port of the HUB is connected to which node, the HUB has a method of recording the source (SA) address of the received frame for each port and reading it from the remote. By knowing the SA address of the frame, the source of the frame can be uniquely determined, and the node connected to the port can be specified.

By the way, another HUB can be connected to the port of the HUB. This cascade connection allows up to 4 stages. In this case, recording the SA address alone does not work. This is because the SA address of the node below the connected HUB may be visible at that port. For this reason, currently, the number of times that SA address has changed is counted,
If the change occurs, it is determined that the HUB is connected to the port.

[0006]

In the above-mentioned conventional method, the HU that collects data is sent irregularly.
It depends on the frame from the node under B. Therefore, when the HUBs are cascade-connected, there is a problem that the connection relationship may not be correctly recognized.

For example, as shown in FIG.
The other HUB 11 is connected to the port P1 of node 10, the node N3 is connected to the port P2, and the node N4 is connected to the port P3.
Were connected. Further, it is assumed that the nodes N5 to N7 are connected to the HUB 11. The HUB 10 counts the number of times the SA address of the frame received via the port P1 changes, and if the SA address changes frequently, it recognizes that another HUB is connected under the port P1. However, when only one node, for example, the node N6 is communicating and the other nodes N5 and N7 are hardly communicating, the port P1 of the highest HUB 10 recognizes only the SA address of the lowest node N6. Will not do.

[0008] For example, the management device is remotely controlled by the HUB1.
Read the port information of 0, believe only that information and HU
When the connection relation of B is judged, the node N6 is connected to the port P1.
Will be mistakenly recognized as being connected, and the connection configuration will be judged as shown in FIG. Further HU
As B increases, the probability of erroneous connection increases.

The present invention seeks to solve the above problems, and in particular H
Even if the UBs are hierarchically connected, the purpose is to allow the connection relationship to be correctly recognized.

[0010]

FIG. 1 is a diagram for explaining the principle of the present invention. In FIG. 1, 10 and 11 are concentrators (HUBs) having a plurality of ports, 20 and 21 are frame transmitters that send out frames to transmission lines through the ports, and 30 is a specific frame for configuration recognition. Configuration recognition frame transmission units, 40 and 41 are frame reception units that receive frames from transmission paths through ports, 50 is a configuration recognition frame reception unit that receives and processes specific frames for configuration recognition, and 60 is Nodes such as terminals and P1 to P4 represent ports serving as signal transmission / reception ports.

The frame transmitting section 20 of the concentrator 10 has a configuration recognizing frame transmitting section 30 which sets the own address as a source address in a configuration recognizing frame which can be distinguished from other general frames and transmits the frame. Further, the frame receiving section 40 has a configuration recognition frame receiving section 50 which, when receiving the configuration recognition frame, records the source address of the frame and erases the frame from the transmission path.

The configuration recognition frame transmission unit 30 transmits the configuration recognition frame in which its own address is set to all the ports P1 to P3 periodically at a predetermined interval or according to a remote instruction from a management device or the like. .

Further, when the frame receiving section 40 receives a frame, it judges whether or not it is a configuration recognition frame, and if it is recognized as a configuration recognition frame, then the configuration recognition frame reception section 50 As a result, the source address in the frame is recorded as a subordinate HUB address, and it is recognized that another concentrator is connected to the port that received the frame. The received configuration recognition frame is erased without propagating it to another.

The connection information of each port recorded by each concentrator 10 and 11 is collected by a superordinate management device (not shown), and the management device outputs system configuration information based on the collected connection information. This makes it possible to manage the system configuration.

[0015]

A big problem of the prior art is that the node directly below the port of the HUB is not clear. To do this, the HUBs must recognize each other and determine their relationship. However, if it is done in the upper layer of HUB itself, it is expected that the processing load of software will be considerably increased. The problems are summarized below.

First, in the conventional method, the frame transmitted by a certain node may arrive at the ports of a plurality of HUBs. That is, when the HUBs are cascade-connected, the frame transmitted as shown in FIG.
Go through multiple ports on the UB. For this reason, the same SA address is recognized at several locations at the same time, which makes it difficult to determine the configuration during cascade connection.

Further, in the conventional method, the HU is provided below the port.
There is no way to directly know not only whether B is directly connected, but also the existence of HUB. From these two facts, it is understood that the SA address recorded for each port may be unique in the entire network. That is, the SA address of the node under the HUB does not have to propagate to the higher HUB. However, unless the frame is propagated to the upper HUB, it does not function as a HUB.

Therefore, consider recognizing only the SA address of a specific frame and determining the configuration. That is,
In the present invention, only a specific frame is not propagated to the upper level, and only the SA address is recorded. This makes it possible to determine that the SA address is connected directly below the HUB port. This solves the above two problems. However, each HUB needs a function of transmitting and receiving a specific frame for configuration recognition.

On the other hand, for a general node that is not a HUB, the connection configuration can be sufficiently grasped only by the conventional method. This is because it is possible to determine that a general node is connected to the port to which the HUB is not directly connected, if only the connection relationship of the HUB is known.

From the above points, in the present invention, the configuration recognition frame transmission unit 30 and the configuration recognition frame reception unit 40
Is provided in the HUB so that the HUB cascade connection can be recognized by transmitting / receiving the configuration recognition frame.

[0021]

EXAMPLE An example of the concentrator (HUB) in 10BASE-T will be described below as an example of the present invention.

FIG. 2 shows an example of the structure of a frame for structure recognition used in the embodiment of the present invention. In this method, it is necessary to transmit a dedicated frame for configuration recognition, and when it receives the frame at the port of the HUB, it is necessary to prevent the propagation to others. that is,
It is simpler and more realistic to do at the MAC layer.
That is, a special MAC address for determining the HUB connection is defined. The MAC layer is a medium access control layer that defines the most basic frame format, transmission / reception control method, and the like, and the MAC frame includes a destination address and a transmission source (SA) as shown in FIG. )address,
It consists of data length or type value and data part.

As shown in FIG. 2B, the configuration recognition frame has a configuration recognition address in the destination address portion, that is, an M specially defined to determine the connection of the HUB.
Set the AC address. It can be a group address or a global address. When a frame addressed to that address is received at the HUB port, the SA address is recorded as the HUB address immediately below, and the frame itself is removed from the transmission path by causing a jam or the like. HU
The SA address is recorded in the frames other than those addressed to the B address, and the number of changes is recorded.

The data part of the configuration recognition frame need not be specified in particular, but it is also effective to add the transmission time and upper layer information. The HUB transmits the frame for configuration recognition periodically or when there is a remote instruction from another.

FIG. 3 is an explanatory diagram of a data collection method according to a remote instruction from the management device. In FIG. 3, a in parentheses
a, ab, ac and ad represent addresses. Port P1
The (?) Symbol in P4 indicates that the address of the device connected to the port is unknown.

When the management device 70 on the network collects the data in order to create the system configuration diagram,
As shown in FIG. 3 (A), HUB1 in the network
A configuration recognition frame transmission instruction is sent to 0 and 11. This transmission instruction can be performed by using, for example, SNMP.

H upon receiving an instruction to send a frame for configuration recognition
The UBs 10 and 11 generate a configuration recognition frame as shown in FIG. 2B and send it to the transmission path. The SA for the configuration recognition frame transmitted by the HUB 10 is "a".
c ”is set, and“ ab ”is set as the SA address of the configuration recognition frame transmitted by the HUB 11.
As shown in FIG. 3B, when the HUB 11 receives the configuration recognition frame sent from the HUB 10 at the port P3, the HUB 11 addresses the port P3 with the SA address set in the configuration recognition frame. ac
Recognizes that the HUB is connected. Similarly, H
The UB 10 recognizes that the HUB with the address ab is connected to the port P1.

If this received configuration recognition frame is transmitted to another as it is, confusion will occur if the HUBs are cascade-connected. Therefore, the HUBs 10 and 11 that have received the configuration recognition frame, after recording the address of the device connected to the received port, discard the frame without transferring it to another.

As described above, the information as shown in FIG. 3C is set to each port of each HUB 10 and 11. The port P to which the general nodes 40 and 41 are connected
For 2 and P4, the address of the connection device is recognized and recorded by a conventional method when a general frame is received. When the management device 70 collects the port information, the existing SNMP protocol or the like is used to collect the port information from the HUBs 10 and 11. From these information, HUB1
It can be seen that 0 (address ac) and HUB 11 (address ab) are cascade-connected, and the management device 70 can create a network connection configuration diagram. Note that the process of creating the connection configuration diagram after acquiring the information can be realized by well-known technology, and thus detailed description thereof will be omitted.

FIG. 4 is a control flowchart of the HUB according to the embodiment of the present invention. If a frame is received in the frame reception waiting state of step S1, step S2
Go to. If you receive the destination address in the frame,
Go to step S3. In step S3, the destination address is checked and it is a specially defined M for configuration recognition.
If it is an AC address, the process proceeds to step S5. Otherwise, in step S4, the received frame is relayed to another port.

In step S5, the source address in the frame for configuration recognition is received, and the process proceeds to step S6. When the source address is received, the source address is recorded in the port information storage memory as a HUB under the target port. After that, in step S7, the received configuration recognition frame is erased from the transmission path, and the next frame reception waiting state is entered.

[0032]

As described above, according to the present invention,
It becomes possible to recognize the cascade connection of the concentrators, which cannot be recognized by the conventional method. Therefore, remote configuration management of the concentrator can be performed without requiring human labor, and a management device (manager) capable of flexibly coping with a network that changes a lot can be designed.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a diagram showing a configuration example of a configuration recognition frame used in an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a data collection method according to a remote instruction from the management device.

FIG. 4 is a control flowchart of a HUB according to an embodiment of the present invention.

FIG. 5 is a diagram for explaining a conventional technique and its problems.

[Explanation of symbols]

 10, 11 Concentrator 20, 21 Frame transmission unit 30 Configuration recognition frame transmission unit 40, 41 Frame reception unit 50 Configuration recognition frame reception unit 60 Nodes P1 to P4 ports

Claims (5)

[Claims] 1. A concentrator (10) having a plurality of ports (P1, P2, ...) For transmitting and receiving a frame for communication, and another concentrator (11) may be connected to the end of the port. In, in the frame for configuration recognition that can be distinguished from other general frames,
A means (30) for setting and transmitting the own address as the source address, and a means (50) for recording the source address of the frame when the configuration recognition frame is received and erasing the frame from the transmission path. And a line concentrator. 2. A network system in which a plurality of nodes for communication and a concentrator having a plurality of ports for transmitting and receiving frames for communication are connected, wherein the concentrator is a node of a communication destination or another concentrator. In a system that relays communication with a device, a concentrator that transmits a configuration recognition frame with its own address set and receives the configuration recognition frame is a configuration recognition frame between the concentrators. When this is recognized, the concentrator connected to the port of the own device is recognized by the source address, and the frame is erased without propagating the frame to another node. . 3. The subordinate node recognition control method for a concentrator according to claim 2, wherein the configuration recognition frame is periodically generated and transmitted. . 4. The subordinate node recognition control method for a concentrator according to claim 2, wherein the configuration recognition frame is generated and transmitted by a remote instruction from another device. Subordinate node recognition control method. 5. The subordinate node recognition control method for a concentrator according to claim 2, claim 3, or claim 4, wherein connection information of each port recorded by each concentrator is collected by a higher-level management device and collected. A method for controlling subordinate node recognition of a concentrator, wherein system configuration information is output based on the established connection information.