JPH0795245A - Inter network connection system and communications system using same - Google Patents

Abstract

PURPOSE:To form an inter network connection method and the communications system capable of performing more effective inter-network communication by matching the preference control between networks having dissimilar preference control systems. CONSTITUTION:A transmission/reception part 100 to be connected to a network 190 capable of performing the preference control on the delay time and on the information abolition, when sending or repeating the variable length data with the quality class, makes an access to a preference order mapping circuit 170 in the processing which divides variable length data into data units by a data unit dividing/assembling circuit 120. In this case, the preference order is decided by referring to the mapping table to decide the information deciding abolition of mapping data and data unit from the quality class of the variable length data. The information is added to the data unit and sent from a cell access control circuit 140.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-network connection method for interconnecting networks having different priority control methods for communication data and a communication system using the same.

[0002]

2. Description of the Related Art As is well known, there are various priority control systems for the quality of communication data depending on the network.

For example, with respect to variable length data having a quality class, the data is decomposed into a plurality of fixed length / short data units (hereinafter, simply referred to as data units), and the data unit is referred from the quality class by referring to a mapping table. There is a method that performs priority control regarding delay time and information discarding, while there is a system that performs priority control only regarding delay time and does not perform priority control regarding information discarding, or variable length data does not have a quality class. Some networks do not perform any priority control.

In the case of interconnecting networks having these different priority control systems, the following inconveniences will occur if the priority control concerning delay time, information discarding, etc. is not consistent among the networks.

First, regarding the priority control regarding the delay time, there is a possibility that the required transmission delay time cannot be guaranteed. Regarding the priority control regarding information discarding, the same data unit may be set to be discardable in one network and not discardable in another network.

Further, when a data unit in which information discarding is permitted and a data unit in which information discarding is not permitted coexist, when the transmission network becomes overloaded and some data units are forced to discard information, retransmission is uniformly performed. Under the conditions to be performed, variable-length data that allows information discarding must be transmitted again from the beginning, which increases the processing time and effectively occupies the bandwidth of the transmission path to efficiently use the transmission network. Cannot be used.

Moreover, when the data unit which is allowed to discard information and the data unit which is not allowed are in the congestion state,
There was a possibility that even data units that could not be discarded would be uniformly discarded.

[0008]

As described above, in the conventional communication system, since the priority control is not matched between the networks, the intra-network delay time is increased when the communication is performed between the networks having different priority control methods. However, there is a problem that the priority control conditions such as information discarding in the network are not constant for each network, which causes deterioration of transmission quality and transmission efficiency over the entire network.

The present invention eliminates the above-mentioned problems and achieves the matching of the priority control methods between mutually connected networks having different priority control methods, and it is appropriate for each network regarding information delay time and information discarding. An object of the present invention is to provide an inter-network connection method capable of realizing more efficient inter-network communication through priority control and a communication system using the same.

[0010]

The first invention of this application provides a network for performing priority control in units of data units by a predetermined priority control system, and a network for performing priority control by a priority control system different from this network. In an inter-network connection method for mutually connecting and realizing data communication between these networks, a mapping table for correlating control conditions between different priority control methods is provided, and the mapping table is referred to. The feature is that priority control is performed while setting control conditions corresponding to the priority control method for each network.

The second invention of this application is such that a network for performing priority control in units of data units by a predetermined priority control system is connected to a network for performing priority control by a priority control system different from the network, In a communication system that performs data communication across networks, a control that represents a quality class in variable-length data that is input to a station that is connected to each of the networks and that controls the data transmission / reception function of the corresponding network in response to a transmission request or a relay request. A mapping table for determining a priority control condition suitable for the priority control method of each network from the information, and at the time of transmission, a data unit obtained from the data decomposed from the variable length data is determined by referring to the mapping table. And means for sending to the network by adding the information indicating the priority control condition, and based on the control information indicating the quality class added to the variable length data. Characterized in that so as to ensure consistency of the priority control conditions between networks.

The third invention of this application connects a network for performing priority control in units of data units by a predetermined priority control system to a network for performing priority control by a priority control system different from the network. In a communication system that performs data communication between the networks, a mapping table that correlates a priority control condition of a priority control method of an adjacent network with a relay station connected between the networks is referred to. And a conversion means for converting priority control conditions between adjacent networks, and when communicating between the adjacent networks, the priority control conditions are matched by converting the priority control conditions corresponding to the relay destination network. It is characterized by doing so.

[0013]

The state that the priority control methods are different means that the number of priorities and the priority standard are different, and so-called priority control conditions such as when controlling only delay time or only information discarding. Includes various combinations of differences.

In the present invention, a mapping table for determining the priority order regarding delay time, information discarding, etc. is provided in each network for which priority control is performed, and this mapping table is provided between networks having different priority control methods. By associating according to the priority control condition, the priority control for the transmission delay time and the information discarding, etc. is achieved, and it is possible to guarantee the quality of the data unit communicated between the networks of different priority control methods. .

[0015]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The target of this embodiment is a network that performs both priority control regarding delay time and information discarding, a network such as the CSMA / CD system that does not perform any existing priority control, and a network that performs only priority control regarding delay time. Interconnects are envisioned.

In the present invention, first, regarding a network capable of priority control regarding delay time and information discarding, when a station that controls data transmission / reception of the network transmits or relays variable length data having a quality class, By referring to the mapping table for determining the priority order regarding the delay time of the data unit and the mapping table for determining the discardability information of the data unit from the quality class in the process of decomposing the data into the data unit. The priority is determined, and the information is added to the data unit and transmitted.

Here, when the number of priorities and the priority standard are different among the networks, the mapping tables are matched so that the qualities corresponding to the priorities of the networks can be associated with each other. In this way, the station can dynamically control the delay time, information discardability, etc. for each variable length data.

Further, for a network that does not perform either or both of the delay time and the priority control regarding information discarding, the mapping of the network that performs priority control with a specific priority order corresponding to the delay time of each network and the quality of information discarding. By assigning to the table, the network that performs priority control and the network that does not perform priority control are matched.

The present invention is not limited to the above network connection,
It can also be applied to general network connections with different priority control methods.

In the following description, the operation of the transmission / reception unit of the network that performs priority control for both the delay time and the information discard quality will be first extended, and then the network and the existing network for which neither priority control will be performed and delay This section describes the connection method when interconnecting with a network that performs only priority control regarding time.

First, the transmission operation of the station connected to the network for performing priority control on both the delay time and the information discard will be described. FIG. 1 shows a block diagram of the transmitting / receiving unit 100 of the station, and FIG. 2 shows the transmitting / receiving unit 100.
3 is a functional block diagram of a data unit disassembly / assembly circuit 120 in FIG. In addition, Figure 3 shows this data unit decomposition
6 is an example of a hierarchical diagram showing how variable length data is decomposed into fixed length data units (cells) in the assembly circuit 120. FIG.

When the transmission / reception unit 100 receives a transmission request of variable length data from the terminal 180 which handles variable length data via the signal line 110 or a transmission request of variable length data for relaying from another network 181, the variable length data is transmitted. The transmission request variable length data 210 (see FIG. 3) including the data information part 213, the destination address 211, the transmission source 212, and the quality class 214 is sent to the data unit disassembly / assembly circuit 120.

The data unit disassembling / assembling circuit 120 is
When the transmission request variable length data 210 is received via the signal line 110, first, in the variable length data generation unit 1211 of the transmission unit 121 (see FIG. 2), the delay time of the transmission length requested variable length data and information discard priority are given. The quality class 214 is sent to the priority mapping circuit 170 via the signal line 160 to determine the rank.

At the same time, a header and a trailer 221 including a destination address 211, a source address 212, a quality class 214, and other information 222 such as data length, which are required for receiving processing, are added to the variable length data information section 213. Then, the variable length data 220 is generated. Further, in order to decompose the variable length data 220 into the segments 223, 224, 225, the variable length data 220 is transferred to the variable length data decomposition unit 1212.

In the variable length data decomposition unit 1212, the variable length data 220 is converted into 44 octet fixed length segments 22.
It is decomposed into 3, 224 and 225. Note that the variable length data length is not an integer multiple of the segment length (44 octets),
If the end data 226 is less than 44 octets, a pad 227 is added to adjust the segment length.

Decomposed segments 223, 224, 2
25 is a BOM (Beginning of Message) segment 223 and an EOM (End of Message) segment 22 for the beginning and end segments for distinguishing at the time of reception.
5, the other middle segment is COM (Continuation of
Message) segment 224.

When the variable length data length is less than 44 octets, the data length is adjusted by adding a pad like the EOM segment 225 to generate a segment. Such segments are especially SSM
(Single Segment Message) It is distinguished by calling it a segment.

These disassembled segments 223, 22
4, 225 are then sent to the intermediate cell generator 1213. In the intermediate cell generation unit 1213, the intermediate cell information unit 23
A segment type 23, which is information for distinguishing the BOM, COM, EOM, and SSM segments necessary for the reception processing in the segments 223, 224, and 225 that are 1
3, a sequence number 234 indicating the order of the segment decomposed from the variable length data, a message identifier 235 for discriminating from which variable length data the segment is decomposed, a payload length indicating the length of the data part excluding the pad A header including information such as 236 and a trailer 232 are added to generate an intermediate cell 230.

Then, these intermediate cells 230, which later become the cell information section 241, are given priority (delay time, discard possibility).
The delay time priority 242 and the discard availability priority 243 received from the mapping circuit 170 via the signal line 161.
At the same time, it is sent to the cell access control circuit 140 as a transmission request cell 240 via the signal line 130.

In the above processing, when the priority mapping circuit 170 receives the quality class 214 from the data unit disassembling / assembling circuit 120, it refers to the delay time mapping table 310 and the discard possibility mapping table 320 as shown in FIG. Thus, the corresponding delay time priority 242 and discard possibility priority 243 are determined, and the determined priority is returned to the data unit disassembly / assembly circuit 120. Therefore, the data units (cells) 250 decomposed from the same variable length data 220 have the same priority.

Also, a priority mapping circuit 1 having mapping tables 310 and 320 as shown in FIG.
Reference numeral 70 is an example of the configuration in which both the delay time and the discard propriety are preferentially controlled. However, depending on the network, it is conceivable that only the delay time or the discard propriety is preferentially controlled. In this case, the priority control is given. The configuration has only the mapping table regarding the quality to be controlled.

After that, the data unit disassembly / assembly circuit 1
As shown in FIG. 3, the cell access control circuit 140 that has received the transmission request cell 240 from the information requesting unit 20 transmits information 252 for controlling access to the cell, a virtual path identifier indicating a communication path or channel in the network, and a virtual channel identifier (Virtual Path). Id
entifier (VPI) / Virtual Channel Identifier (VCI) 25
3, delay time priority 242 and discardability priority 243
The cell 250 in which the header 251 including the information such as is added to the cell information section 241 is finally sent to the transmission network 190 via the transmission medium 150 corresponding to the delay time priority 242.

Next, the transmitting / receiving unit 100 of each station when receiving
The operation of will be described. Upon receiving the cell from the transmission network 190, the cell access control circuit 140 first receives the cell header 2
Virtual path identifier and virtual channel identifier (VPI / VC
I) 253 is checked to determine whether it is the cell 250 addressed to itself.

If it is addressed to its own station, the information section 241 of the receiving cell
That is, the intermediate cell 230 is extracted and sent to the data unit disassembling / assembling circuit 120. In the data unit disassembling / assembling circuit 120, the variable length data assembling unit 1221 of the receiving unit 122 (see FIG. 2) first receives the header of the intermediate cell 230 and the segment type 23 in the trailer.
Examine 3.

If the segment type 233 is the BOM type and the destination address 211 in the information part 231 thereof matches the address set in the local station for receiving in advance, the message identifier 235 of the intermediate cell 230 is registered. , CO having the same message identifier 235 thereafter
The segments 224 and 225, which are the information parts of the M and EOM type intermediate cells 230, are assigned to the EOM type intermediate cells 230.
Appends in sequence number 234 in order until it receives, and assembles the variable length data 220.

However, when appending the information section 226 of the EOM segment 225, the information section 231 defined by the payload length 236 existing in the trailer 232 is added.
Append only.

If the segment type 233 is SSM and the destination address 211 matches the preset address, the information part of the payload length 236 remains the variable length data 220 regardless of the sequence number 234 and the message identifier 235. Becomes

The generated variable length data 220 is then subjected to a variable length data information extraction unit 1222 to separate a destination address 211, a source address 212, a header including a quality class 214, and a trailer 221 to obtain variable length data information. The part 213 is extracted and finally sent to the terminal 180 having the destination address 211 via the signal line 111,
Alternatively, it is relayed to another network at the relay station.

Based on the transmission / reception operation of the transmission / reception unit 100 of the station described above, the priority control regarding the delay time and information discarding becomes possible.

Next, an example of priority control in the case where a network for performing priority control for both the delay time and the information discarding quality as described above and a network of a priority control system different from this network are interconnected are shown in FIG. Will be described with reference to.

In FIG. 5, the network 510 is a network that performs priority control on both the delay time and the information discard quality, and the network 52
0 is a network that performs only priority control regarding delay time, and network 530 is a network that does not perform priority control for both qualities such as the existing CSMA / CD system. Although each net is drawn in a ring shape, the form of each net is not limited to a ring.

The relay station 540 is a station that relays between the network 510 and the network 520. Regarding the delay time priority control, the network 510 and the network 52 having different delay time priority numbers or different priority standards.
Data units that cross over 0 are associated with each other in a mapping table, and the quality classes are converted and relayed so that the quality can be mutually guaranteed.

Regarding the information discardability priority control, the network 52
For a data unit from 0 to network 510, network 510
A specific quality class 214 that satisfies the quality regarding information discardability in the network 520 is provided in the mapping table on the side for priority control, and the network 520 prioritizes information discardability for data units from the network 510 to the network 520. Do not control. That is, since the network 520 does not have a discard availability mapping table, the discard availability priority information is not reflected in the priority control of the network 520.

On the other hand, the relay station 550 includes the networks 510 and 530.
Since the network 530 does not control the priority control at all, the delay time and the discard possibility are the same as the priority control regarding the information discardability of the relay station 540 (priority control is not reflected). Become.

The relay process in the system having such a configuration will be described by taking the relay station 540 as an example. The configuration of relay station 540 in this case is shown in FIG. This relay station 5
At 40, the data unit (cell) 250 from the network 510 in the relay from the network 510 to the network 520 is assembled and quality class 214 via the cell access control circuit 140 and the data unit disassembly / assembly circuit 120 in the transmission / reception unit 100. , Destination address 211, source address 212,
After extracting the variable length data information part 213, the signal lines 111 and 6
10 to the variable length data generation circuit 620 in the transmission / reception unit 600 on the network 520 side.

The variable-length data generation circuit 620 refers to the delay time priority mapping circuit 630 to determine the delay time priority, and then adds a header including a destination address 211, a source address 212, and other access control information. Generate variable length data with.

After that, the variable length data is accessed and relayed to the network 520 by the variable length data access control circuit 621 according to the access method defined by the network 520. Since information discard feasibility priority control is not performed in the network 520, the discard feasibility priority order on the network 510 side is not reflected.

On the other hand, the relay from the network 520 to the network 510 is as follows. The variable length data received by the variable length data access control circuit 621 in the transmission / reception unit 600 from the network 520 is extracted by the variable length data generation circuit 620 into the quality class, the destination address 211, the source address 212, and the variable length data information unit 213. After that, it is sent to the transmission / reception unit 100 on the network 510 side via the signal lines 611 and 110.

In the priority control mapping circuit 170 in the transmitter / receiver 100, since the quality class on the network 520 side does not have the discardability priority information, the quality class 214 assigned in advance corresponding to the information discardability quality on the network 520 side is assigned. Is set, and the network 510 is accessed and relayed as described above.

With respect to the relay station 550, relay transmission between the networks 510 and 530 can be realized by the same processing as the priority control regarding the discard possibility of the relay station 540. Further, interconnection of networks having other different priority control methods can also be realized by applying the above connection example.

Note that the example of FIG. 6 depicts the case where the networks are interconnected, but it is also possible to directly accommodate the terminal 180 that handles variable-length data as shown in FIG. In addition, it goes without saying that the present invention can be variously modified without departing from the gist described above.

[0052]

As described above, according to the present invention,
A mapping table that associates the priority control conditions between the priority control methods of adjacent networks is provided, and the priority control according to each network is performed while converting the priority control conditions based on the mapping table. Optimal priority control can be performed for each network when communicating across data units, and high transmission quality of data units can be maintained, while unnecessary data retransmission and information discard due to congestion of the transmission network are not allowed. It has an excellent advantage that it can contribute to improvement of transmission efficiency while preventing disposal.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a transceiver unit of a station connected to a network of a communication system according to an embodiment of the present invention.

2 is a data unit disassembly of the transmission / reception unit shown in FIG.
The block diagram which shows one Example of an assembly circuit.

FIG. 3 is a cell hierarchy diagram showing a flow of cell disassembly / assembly processing of the data unit disassembly / assembly circuit shown in FIG.

FIG. 4 is a diagram showing an example of a mapping table provided in the priority mapping circuit of the transceiver station shown in FIG.

FIG. 5 is a diagram showing an inter-network connection configuration of a communication system according to another embodiment of the present invention.

6 is a block diagram showing a configuration of an inter-network relay station of the communication system shown in FIG.

[Explanation of symbols]

 100 Transmitter / receiver 110 Transmission request variable length data transmission line 111 Transmission request variable length data reception line 120 Data unit disassembling / assembling circuit 121 Transmitter 1211 Variable length data generator 1212 Variable length data disassembler 1213 Intermediate cell generator 122 Receiver 1221 Variable length data assembling unit 1222 Variable length data information extraction unit 130 Data unit transmission line 131 Data unit reception line 140 Cell access control circuit 150 Transmission transmission medium with priority 151 Reception transmission medium with priority 160 Variable length data priority Signal line 161 Delay time priority, discard priority Signal line 170 Priority mapping circuit 180 Terminal 190 Transmission network 310 Delay time priority mapping table 320 Discardability mapping table 510 Delay time and information discard priority Transmission network A 520 that performs control Transmission network B 530 that performs delay time priority control Transmission network C 540 that does not perform priority control C 540 Network AB relay station 550 Network AC relay station 600 Transmit / receive unit on network 520 side 610 Transmission on network 520 side Request variable length data transmission line 611 Transmission request variable length data reception line on the network 520 side 620 Variable length data generation circuit 621 Variable length data access control circuit 630 Delay time priority mapping circuit 640 Variable length data transmission line 641 Variable length data reception line

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H04L 29/06 9371-5K H04L 13/00 305 D

Claims (12)

[Claims] 1. A network for performing priority control in units of data units according to a predetermined priority control system and a network for performing priority control by a priority control system different from this network are mutually connected, and data communication between these networks is performed. In the inter-network connection method for realizing, a mapping table for correlating control conditions between different priority control methods is provided, and the control conditions corresponding to the priority control method for each network by referring to the mapping table An inter-network connection method characterized by performing priority control while setting. 2. The priority control method includes a delay priority control method for performing priority control of intra-network delay time based on at least one intra-network delay time priority level, and an intra-network based on at least one intra-network information discard priority level. The inter-network connection method according to claim 1, further comprising at least a discard priority control method for performing priority control of information discard. 3. A delay priority control method, a discard priority control method, and a method in which priority control based on any of these methods is not performed, or a combination of any two or all combinations are provided. The network connection method according to claim 1 or 2, wherein the networks are connected. 4. The data unit is a fixed-length data unit in which predetermined control information is added to short data obtained by decomposing variable-length data, and is the same as the data unit decomposed from the same variable-length data. 4. The inter-network connection method according to claim 1, wherein the priority control method is applied. 5. A communication for connecting a network for performing priority control in units of data units by a predetermined priority control system to a network for performing priority control by a priority control system different from the network, and for performing data communication across the networks. In the system, the priority control method of each network is changed from the control information indicating the quality class in the variable-length data input with the transmission request or the relay request to the station that is connected to each network and controls the data transmission / reception function of the corresponding network. A mapping table for determining a matching priority control condition, and information indicating a priority control condition determined by referring to the mapping table for a data unit obtained from short data decomposed from the variable length data during transmission. And a means for sending to the network, and matching of priority control conditions between the networks based on the control information indicating the quality class added to the variable length data. A communication system characterized in that 6. The priority control method includes a delay priority control method for performing priority control of intra-network delay time based on at least one intra-network delay time priority level, and an intra-network based on at least one intra-network information discard priority level. The communication system according to claim 5, further comprising at least a discard priority control method for performing priority control of information discard. 7. A delay priority control method, a discard priority control method, and a method in which priority control based on any of these methods is not performed, or a combination of any two or all combinations are obtained. The communication system according to claim 5 or 6, wherein a network is connected. 8. The data unit is a fixed-length data unit formed by combining a predetermined number of data obtained by decomposing variable-length data, and the same priority control is applied to data units decomposed from the same variable-length data. The communication system according to any one of claims 5 to 7, wherein a method is applied. 9. A network for performing priority control in units of data units according to a predetermined priority control system is connected to a network for performing priority control by a priority control system different from the network, and data communication between the networks is performed. In the communication system to perform, a mapping table that correlates the priority control conditions of the priority control method of the adjacent networks to the relay stations connected between the networks, and the priority control condition between the adjacent networks by referring to the mapping table. And communication means for converting the priority control method by converting the priority control condition corresponding to the relay destination network when communicating between adjacent networks. system. 10. The priority control method includes a delay priority control method for performing priority control of intra-network delay time based on at least one intra-network delay time priority level, and an intra-network based on at least one intra-network information discard priority level. The communication system according to claim 9, wherein at least a discard priority control method for performing priority control of information discard is included. 11. A delay priority control method, a discard priority control method, and a method in which priority control based on any of these methods is not performed, or a combination of any two or all combinations are provided. The communication system according to claim 9 or 10, wherein a network is connected. 12. The data unit is a fixed-length data unit formed by combining a predetermined number of pieces of data obtained by decomposing variable-length data, and the same priority control is applied to data units decomposed from the same variable-length data. The system is applied, The communication system as described in any one of Claims 9-11.