JPH07312605A - Network node system - Google Patents

Abstract

PURPOSE:To house much more nodes in a system where plural node devices are connected by virtual pathes. CONSTITUTION:For node devices N1-N3 inside a node group G1, the virtual pathes are spread in the shape of a mesh. For node devices N4-N6 inside a node group G2, the virtual pathes are spread in the shape of a mesh as well. The virtual path is spread from the node group G1 to any addressed node device. Then, the same virtual path identifier is allocated from all the node devices inside the node group to the addressed node device outside the group and while using this virtual path identifier, the node devices are communicated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network node system, for example, ATM (Asyncrono).
(us Transfer Mode: Asynchronous Transfer Mode) This is applicable to a network node system.

[0002]

2. Description of the Related Art In recent years, research and development of ATM communication systems have been actively conducted. FIG. 2 is an explanatory diagram of an example of an ATM network node system for performing communication control using the conventional ATM network.

In FIG. 2, six nodes N21 ...
N26 is shown. Communication terminals T11 to T1n to T61 to T6n are connected to the nodes N21 to N26, respectively. Further, the nodes N21 to N26 are also connected to the ATM network 100. Furthermore, the nodes N21 to
N26 is connected in a mesh by a virtual path (VP) 200.

In such a system, the node N2
1 to N26 transfer the ATM cells sent from the communication terminals T11 to T6n to the destination node through the VP 200, and the ATM cells are transferred from the destination node to the destination communication terminal.

[0005]

However, in the system as described above, when the number of nodes is M, the number of virtual paths VP is M × (M−1) / 2.

For example, when M = 6, the number of VPs is 15
Becomes Further, when M = 10, the number of VPs becomes 45. Further, when M = 100, the number of VPs is 4950. Furthermore, if M = 500, then the number of VPs is 12
It becomes 4750.

Therefore, as the system scale increases, a huge number of virtual paths VP are required. Therefore, there is a problem that the number of nodes that can be accommodated in the system is limited.

From the above, it has been demanded to provide a system mechanism capable of accommodating more node devices with a limited virtual path identifier.

[0009]

[Means for Solving the Problems]

(1) The present invention relates to a plurality of node devices (for example, ATM
Switching equipment, ATM exchanges, ATM exchanges, etc.)
In the network node system in which the two are connected by a virtual path, it was realized with the following characteristic configuration.

That is, a plurality of node devices are grouped to form some node groups. Then, a virtual path is formed in a mesh shape between the node devices in each node group, and the same virtual path identifier is set from all the node devices in each node group to the node devices in other node groups. By establishing a virtual path, the above-mentioned problem is solved.

(1a) In the above configuration (1), the virtual channel identifiers for the virtual channels accommodated in the respective virtual paths are assigned to the node devices so that they do not overlap, and the assigned virtual channel identifiers are assigned. It is preferable to assign it to the terminal device accommodated in the node device.

(1b) Furthermore, in the configuration of (1) or (1a), a connection management means for managing the usage status of the virtual channel identifier in each node device is provided, and the connection management means is provided in response to a request from each node device. Is
It is also preferable to give a virtual channel identifier to each node.

[0013]

According to the configuration of the present invention (1), a virtual path is established from a plurality of node devices to a destination node device by using the same virtual path identifier, and between node devices in the same node group, Also, in communication with a node device outside the node group, by transferring information by identifying the virtual path identifier, the number of node devices that can be accommodated in the system can be increased compared to the conventional case.

Further, by adopting the configuration of (1a) described above, even if information is transferred from a plurality of node devices to one destination node device by using the same virtual path identifier, each node device of a transmission source Since the virtual channel identifiers are different, the virtual path identifier and virtual channel identifier in the destination node device are unique, and there is no concern that they will be duplicated in each terminal device.

Further, by adopting the configuration of (1b) described above, it is possible to allocate more virtual channel identifiers to a node device that requires more virtual channel identifiers.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings.

"System Configuration": FIG. 1 is a configuration diagram of an ATM network node system of the first embodiment.
In FIG. 1, this ATM network node system is configured by dividing node devices into a node group G1 and a node group G2. The node group G1 is composed of node devices N1 to N3. On the other hand, the node group G2 includes the node device N4.
.About.N6.

The terminals T11 to T1n are connected to the node device N1 of the node group G1. Further, the node device N2 of the node group G1 is connected to the terminal T
21 to T2n are connected. Furthermore, the terminals T31 to T3n are connected to the node device N3 of the node group G1.

On the other hand, the node device N of the node group G2
4 are connected to terminals T41 to 4n. Further, the node device N5 of the node group G2 has terminals T51 to
T5n is connected. Furthermore, the node group G
Terminals T61 to T6n are connected to the second node device N6.

"Group configuration": In this ATM network system, "a characteristic is that node devices within the same node group are connected in a mesh by virtual paths VP as shown in FIG. Is. Then, as shown in FIGS. 4 and 5, for node devices outside the node group, communication is performed from all node devices within the node group to destination node devices outside the node group by the same virtual path identifier VPI. The feature is that it is done. "Inter-node connection": FIG. 4 is an explanatory diagram of inter-node connection of the first embodiment. In FIG. 4, the connection by the virtual path VP from the node group G1 to the node device of G2 outside the node group is shown. The virtual path identifier VPI1 is assigned to the virtual path VP from the node devices N1, N2, N3 in the node group G1 to the node device N4 in the node group G2.

Further, the node devices N1, N2, N
The virtual path identifier VPI2 is assigned to the virtual path VP from 3 to the node device N5. Furthermore, a virtual path identifier VPI3 is assigned to the virtual path VP from the node devices N1, N2, N3 to the node device N6. Communication is performed using these virtual path identifiers VPI1 to VPI3.

FIG. 5 is an explanatory diagram of the connection between nodes according to the first embodiment. In FIG. 5, the connection by the virtual path VP from the node group G2 to G1 outside the node group is shown. Then, the node device N4 in the group G2,
The virtual path identifier VPI1 is assigned to the virtual path VP from N5 and N6 to the node device N1 of the node group G1.

The virtual path VP from the node devices N4, N5, N6 to the node device N2 is a virtual path identifier V.
PI2 is assigned. Furthermore, the node device N4,
A virtual path identifier VPI3 is assigned to the virtual path VP from N5 and N6 to the node device N3. Communication is performed using these virtual path identifiers VPI1 to VPI3.

"With this configuration, ATM cells can be transferred only by identifying the virtual path identifier VPI in the communication between the node devices in the node group and in the communication with the node devices outside the node group. It will be. In addition, “in communication to a node device outside the node group, it becomes possible to manage the virtual path VP for each node group. Furthermore, “for each node device that communicates with the destination node outside the node group using the same virtual path identifier VPI, each node device among the virtual channels VC accommodated in the virtual path VP is used. The possible virtual channel identifiers VCI are assigned in advance so as not to overlap. "ATM cell header structure": Therefore, FIG.
U (International Telecommu
Nation Union) -T Recommendation I. 3 shows the header structure of the ATM cell defined by 361.
16 bits are allocated to the virtual channel identifier VCI. A virtual path VP from the node group G1 to the node device N4 of the node group G2 will be described as a method of pre-allocating the virtual channel identifier VCI to each node device.

Therefore, the virtual channel identifier VCI in which the upper 2 bits of the virtual channel identifier VCI are 00 and 01 can be used for the node device N1. For the node device N2, the virtual channel identifier VC
Virtual channel identifier VC whose upper 2 bits of I are 10
I can be used. Further, for the node device N3, the upper 2 bits of the virtual channel identifier VCI are 11
The virtual channel identifier VCI that can be used by each node device is allocated in advance so that the virtual channel identifier VCI can be used.

Further, it is assumed that the communication terminal connected to each node device is configured so that the virtual path identifier VPI and the virtual channel identifier VCI can be assigned from the corresponding node device.

With this configuration, even if ATM cells are transferred from a plurality of node devices to one destination node device using the same virtual path identifier VPI, the virtual channel identifier VCI for each source node device , The virtual channel identifier VCI and the virtual path identifier VPI in the destination node device are unique. Further, "Since the virtual channel identifier VCI that can be used in each node device is determined, each node device can independently assign the virtual channel identifier VCI to a call request from a communication terminal. Therefore, there is no concern that the terminals T11 to T6n will be used in duplicate.

(Effects of First Embodiment) According to the ATM network node system of the first embodiment described above, when node devices are connected by a virtual path, the same applies from a plurality of node devices to a destination node device. Virtual path identifier VP
By adopting a configuration in which the ATM cell is transmitted by I, the number of node devices that can be accommodated in the system can be increased.

That is, for example, in the conventional method, as shown in FIG. 2, if six node devices are connected by virtual paths VP, 15 virtual paths VP are required.

For example, it is assumed that six node devices are physically connected in a straight line as shown in FIG. FIG. 11A is an example of VPI allocation according to the conventional technique. Then, as shown in FIG. 11A, when the node devices are connected in a mesh, ten virtual path identifiers VPI1 to VPI10 are required. Therefore, if realized by the mechanism of the above-described embodiment, as shown in FIG. 11B, since the node devices N1 to N6 can be connected by the six virtual path identifiers VPI1 to VPI6, the node can be made with a smaller virtual path identifier VPI. It is possible to connect the devices.

From the above, a small virtual path V
With the number of P, more node devices can be accommodated than in the conventional case. This makes ATM efficient
A network node system can be realized.

"Second embodiment": In the above-mentioned first embodiment, "node devices N1 to N6 are connected to the node group G".
The example of setting the virtual path VP separately for 1 and G2 has been described. In the second embodiment, the configuration of the mechanism for changing the node group depending on the destination node device will be described with reference to FIGS. 7 to 9. To do.

Therefore, in FIG. 3 of the above-mentioned first embodiment, the virtual path VP is set up from the node group G1 to the node device 4 of the node group G2. , The node devices N1 to N
3 and N5 to N6 as one node group G3,
The virtual path identifier VPI11 is set for the node device 4 to set the virtual path VP.

Further, FIG. 8 shows node devices N1 to N4 and N6.
Are set as one node group G4, the virtual path identifier VPI12 for the node device 5 is set, and the virtual path VP is set. Further, FIG. 9 shows the node devices N1 to N1.
N5 as one node group G5, the node device 6
The virtual path identifier VPI13 is set for the virtual path VP.

(Effects of the Second Embodiment): In this way, "a node group can be freely configured by the destination node device. By this, it is considered that the node group can be freely configured even when the number of node devices is increased.

Therefore, it is possible to accommodate more nodes than in the conventional case. As a result, an ATM network node system can be efficiently realized.

[Third Embodiment]: Further, in the above-mentioned first embodiment, a virtual channel VC that can be used in the virtual channel VC accommodated in the virtual path VP from the node group G1 to the node device N4 of the node group G2. An identifier VCI is assigned to each node device in advance,
Although each node device N1 to N3 has a configuration in which only the assigned virtual channel identifier VCI is used, "In the third embodiment, depending on the use status of the virtual channel identifier VCI of each node device, The configuration is such that a virtual channel identifier VCI is assigned. Therefore, a specific description will be given with reference to the block diagram of the ATM network node system in FIG. First, the node devices N1 to N3 of the node group G6 and the node devices N4 to N6 of the node group G7 are connected to the connection management function unit 10, and each node device N1.
~ N6 are connected by a virtual path VP.

(From node group G6 to node device N4
Virtual path): First, of the virtual channels VC accommodated in the virtual path, the connection management function unit 10
Is, for example, the upper 4 bits of the 16 bits that identify the virtual channel identifier VCI for the node device N1 are 0.
000 virtual channel identifiers VCIs are assigned.

Further, a virtual channel identifier VCI whose upper 4 bits are 0001 is assigned to the node device N2. Furthermore, a virtual channel identifier VCI whose upper 4 bits are 0010 is assigned to the node device N3.

If the virtual channel identifier VCI assigned to the node device N1 runs short, the node device N1 requests the connection management function unit 10 to assign a new virtual channel identifier VCI. Don't get up

Then, the connection management function unit 10 allocates the unassigned virtual channel identifier VCI for the requested virtual path VP to the node device N1, if any. For example, in this case, the upper 4 bits of the virtual channel identifier VCI gives the node device N1 permission to use the virtual channel identifier VCI of 0011.

(Effect of the third embodiment): With the above-mentioned configuration, it becomes possible to allocate more virtual channel identifiers VCI to a node that requires more virtual channel identifiers VCI. .

As a result, the ATM network node system can be efficiently realized.

(Other Embodiments) (1) In the above embodiments, the node device may be applied to, for example, an ATM exchange (ATM exchange device), an ATM exchange station, or an aggregate of ATM exchange stations. You can

(2) Further, although the number of node devices is set to 6, it is considered that the system is actually formed with a larger number of node devices, but in that case, the number of virtual path identifiers VPI is smaller. Can be formed.

(3) Further, as the terminal device, various devices such as a workstation, a facsimile device, a telephone device, a video device, and an information processing device can be used.

[0047]

As described above, according to the network node system of the present invention, a plurality of node devices are grouped to form some node groups, and the node devices in each node group are meshed. It is possible to accommodate a larger number of node devices by setting a virtual path and setting the same virtual path identifier from all the node devices in each node group to the node devices of other node groups and setting the virtual path. it can.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an ATM network system according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a conventional example.

FIG. 3 is an explanatory diagram of a group configuration according to the first embodiment.

FIG. 4 is an explanatory diagram of connections between nodes according to the first embodiment.

FIG. 5 is an explanatory diagram of connections between nodes according to the first embodiment.

FIG. 6 is an explanatory diagram of an ATM cell header of an embodiment.

FIG. 7 is an explanatory diagram of node groups according to the second embodiment.

FIG. 8 is an explanatory diagram of node groups according to the second embodiment.

FIG. 9 is an explanatory diagram of node groups according to the second embodiment.

FIG. 10 is a configuration diagram of an ATM network system of a third embodiment.

FIG. 11 is an explanatory diagram for explaining the effect of the first embodiment.

[Explanation of symbols]

G1, G2 ... Node groups, N1 to N6 ... Node devices, T11 to T6n ... Terminals.

Continued Front Page (72) Inventor Satoshi Matsunaga 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (3)

[Claims] 1. In a network node system in which a plurality of node devices are connected by a virtual path, the plurality of node devices are grouped to form some node groups, and the node devices in each node group are connected to each other. Is a network node system in which a virtual path is formed in a mesh shape, and the same virtual path identifier is set from all the node devices in each node group to the node devices of other node groups to create a virtual path. 2. The network node system according to claim 1, wherein a virtual channel identifier for a virtual channel accommodated in each virtual path is assigned to each node device so as not to overlap, and the assigned virtual channel identifier is assigned to the node. A network node system characterized by being assigned to a terminal device contained in a device. 3. The network node system according to claim 1, further comprising connection management means for managing the usage status of the virtual identifier in each node device, wherein the connection management means responds to a request from each node device. A network node system characterized by giving a virtual channel identifier to each node.