JPH09116551A - Data packet transfer method and data packet transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transfer a data packet in response to a request service class and request service quality by continuing transfer of the data packet with a packet identifier to a virtual connection when a specific virtual connection is registered in a 1st cross reference table. SOLUTION: The device is provided with a data packet respectively section 11, a packet identifier read section 12, a packet container section 13, a data packet-virtual connection cross reference table storage section 14, a cross reference table update section 15, and a virtual connection monitor section 16. The packet container section 13 converts a data packet transferred from the packet identifier read section 12 into an ATM cell, and the cell is transferred to the virtual connection commanded by the cross reference storage section 14. When the virtual connection in which at least the packet identifier and either of the service class and the service quality are cross-referenced is registered in the cross reference storage section 14, the transfer of the data packet having the packet identifier to the virtual connection is continued.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data packet transfer apparatus and method for transmitting and receiving data packets such as IP datagrams using an ATM communication network.

[0002]

2. Description of the Related Art When communication is performed using the Internet, the data transmitted by the sender is IP (Internet Protocol).
It is converted into a data packet called an IP datagram defined at the col) level and delivered to the recipient.

Conventionally, the data packet delivery service defined by IP is unreliable, and is best-effort.
(Best-effort) system. That is, there is no guarantee regarding the delivery of the data packet (it may be lost, but no measures are taken), but I
P is a delivery system that enthusiastically attempts to deliver data packets. That is, no quality guarantee was made for the conventional delivery of IP level data packets.

On the other hand, in recent years, IETF (Internet
The Engineering Task Force) discusses providing quality for delivery of IP level data packets. As a result, at the present stage, the following 3
Types of services are defined.

Guaranteed Quality of Service This is a service that guarantees that all data packets are delivered to the other party within a fixed time. The required service specification (Rspec) is given as a transfer rate value. (S. S
henker, et al: "Specification of Guaranteed Quality o
f Service ", INTERNET-DRAFT, draft-ie
tf-intserv-guaranteed-svc-01.txt) Predictive Quality of Service This service guarantees that most data packets will be delivered to the other party within a certain time. The required service specification (Rspec) is given as a target delay value or a service level (1, 2, 3) (the smaller the service level value, the smaller the delay in delivery required). (S.
Shenker, et al: "Specification of Predictive Quality
of Service ", INTERNET-DRAFT, draft-
ietf-intserv-Predictive-svc-00.txt) Controlled Delay Quality of Service This is a service in which the data packet delivery delay is dynamically changed without providing a quantitative guarantee for the delay. Traditional Best
-It can be delivered in less time than the Effort service. The required service specification (Rspec) is given as a service level (1, 2, 3) (generally, a smaller service level value realizes delivery with less delay). (S. Shenker, et al .: "Specification of Controll
ed DeleyQuality of Service ", INTERNET-D
RAFT, draft-ietf-intserv-control-svc-01.txt)

[0006]

An ATM for exchanging and transferring in units of cells which are fixed length data packets.
(Asynchronous Transfer Mode) When the IP level data packet is delivered using the virtual connection set on the communication network, conventionally, it is not necessary to guarantee the service quality for the IP level data packet. However, only the method of accommodating data packets in a virtual connection, which does not consider the IP level quality when delivering data packets, has been considered.

The present invention has been made in consideration of the above circumstances, and when an IP level data packet is delivered through an ATM communication network, the IP level data packet follows the requested service type. An object of the present invention is to provide a data packet transfer device and method capable of accommodating a required quality of service in a virtual connection on an ATM communication network.

[0008]

The present invention (Claim 1) includes:
Predetermined protocol (eg Internet protocol)
A data packet conforming to the above is transmitted in the form of an ATM cell on a predetermined virtual connection (for example, VC,
A data packet transfer method for transferring to a VP), which receives a data packet or a control packet, and a packet identifier (for example, a combination of a source address of the data packet and a flow label of the data packet) in the received control packet and a service. Type (eg, Guaranteed Quali
ty of Service, Predictive Quality of Service, Co
ntrolled Delay Quality of Service) and at least one of service quality (for example, transfer rate value, target delay value, service level) and the virtual connection identifier of the selected virtual connection are registered in the first correspondence table, With reference to the packet identifier and the virtual connection identifier registered in the first correspondence table, the data packet of the corresponding packet identifier is transferred to the virtual connection of the corresponding virtual connection identifier and is newly sent. A virtual connection in which a packet identifier in a control packet and a packet identifier that satisfies a predetermined condition for at least one of service type and service quality and at least one of service type and service quality are associated with each other is the first connection. If the virtual connection is registered in the correspondence table of The data packet having the packet identifier is continuously transferred to the computer.

According to the present invention, a request at the data packet level is obtained by using a correspondence table for registering information about data packets of a predetermined protocol and information about virtual connections set on the ATM communication network in association with each other. Data packets can be accommodated on the virtual connection in consideration of the service type and the required service quality.

The present invention (Claim 2) can be provided in order to transfer the virtual connection identifier, the service class capable of providing the virtual connection, and the new data packet held by the virtual connection in the invention of claim 1. The remaining resource amount (for example, the remaining bandwidth amount) and the packet identifier of the data packet accommodated in the virtual connection are registered in association with each other in the second correspondence table, and are registered in the first correspondence table. When a control packet holding an unregistered packet identifier is received, the second correspondence table is referred to when selecting the virtual connection that should accommodate the data packet of the packet identifier,
A virtual packet that contains a data packet requesting the same service type as the service type in the control packet and that satisfies the condition that the quality of service in the control packet can be provided within the range of the remaining resource amount. When the connection is registered, it is decided to accommodate the data packet of the packet identifier in the virtual connection, and when the virtual connection satisfying the condition is not registered, the service type and service in the control packet A virtual connection capable of providing quality is registered in the first correspondence table in association with the packet identifier.

According to the present invention, the information about the resources of the virtual connection is registered in the correspondence table so that it is already set when a transfer request of a new data packet or a change of service type or service quality of an existing data packet is requested. It is possible to easily judge whether or not the service can be provided on the virtual connection (or already accommodated), and the ATM network resources can be efficiently used. As a result, it becomes possible to provide services at low cost.

According to the present invention (claim 3), in selecting the virtual connection in which the data packet having the packet identifier in the received control packet is to be accommodated, the service type in the control packet is selected. And the service quality, the service type is
The first service type that guarantees that all data packets are delivered to the destination within a fixed time (Guaranteed Q
, the ATM layer service class is CBR, has a maximum transfer rate that can provide a transfer rate not lower than the transfer rate value indicated by the quality of service, and has the packet identifier. A second service type (Predictive Quality of Service) that selects a virtual connection capable of accommodating only the data packet that the user has, and guarantees that the service type delivers almost all data packets to the destination within a fixed time )
, The ATM layer service class is CB when the quality of service is given as a target delay value.
When a virtual connection that is R (Constant Bit Rate) and is capable of providing the transfer rate required to achieve the target delay value is selected and the quality of service is given as the service level, the ATM layer For the purpose of selecting a virtual connection whose service class is CBR and satisfying the relationship with other service levels, and the above-mentioned service type does not give a quantitative guarantee for the packet delivery delay and thus discards the data packet. A third service type (Controll) that dynamically controls the packet delivery delay.
ed Delay Quality of Service), the ATM layer service class is ABR (Available Bit Rate)
And selecting a virtual connection that satisfies the relationship between the service level indicated by the quality of service in the control packet and another service level.

By associating a virtual connection with an IP level data packet according to the above policy, a service requested by the data packet when the Internet protocol level data packet is delivered through the ATM communication network. It is possible to accommodate the virtual connection in consideration of the type and the required service quality.

According to the present invention (claim 4), in the invention of claim 2, the packet identifier in the newly sent control packet matches that registered in the first correspondence table. When the service type in the control packet is different from the registered one, the first correspondence table and the second correspondence table are referred to, and the data packet of the packet identifier is set to the service type in the control packet. , If it is determined that the transfer to the virtual connection having the virtual connection identifier registered in association with the packet identifier is not appropriate, the transfer of the data packet having the packet identifier to the virtual connection is stopped. Data packet requesting the same service type as the service type in the control packet, and When a virtual connection that satisfies the condition that the quality of service in the control packet can be provided within the range of the resource amount is registered, it is decided to accommodate the data packet of the packet identifier in the virtual connection. When a virtual connection satisfying the condition is not registered, a virtual connection capable of providing the service type and the quality of service in the control packet is registered in the first correspondence table in association with the packet identifier. Characterize.

Here, with respect to the decision to stop the transfer, the information on the packet identifier and the remaining resource amount of the data packet accommodated in the corresponding virtual connection in the second correspondence table is updated.

Then, in response to the decision to accommodate the existing virtual connection, the information about the virtual connection in the second correspondence table is updated. On the other hand, when the setting of a new virtual connection is determined, information about the virtual connection is added to the second correspondence table. Also, when setting the new virtual connection, if the same virtual connection identifier is continuously used, or if a virtual connection that has been registered in the second correspondence table but is not used is selected, only the necessary items are updated. To do.

Of course, in any case, necessary items such as the service type and virtual connection identifier in the first correspondence table are updated. The present invention (Claim 5) is the same as that of the invention of Claim 2, in which the packet identifier and service type in the newly sent control packet are the same as those registered in the first correspondence table, When the quality of service in the control packet is different from the registered one, the first correspondence table and the second correspondence table are referred to, and the service quality is registered in association with the packet identifier. When it is possible to provide a data packet within the virtual connection having the connection identifier within a range that does not exceed the sum of the resource amount occupied by the virtual connection and the remaining resource amount of the virtual connection, the data packet of the packet identifier is continuously stored in the virtual connection. When it decides to accommodate and the new quality of service cannot be provided, the data packet of the packet identifier to the virtual connection is Data packet that decides to cancel the transfer of the packet and requests the same service type as the service type in the control packet, and within the range of the remaining resource amount, the service in the control packet. When a virtual connection satisfying the condition that the quality can be provided is registered, it is decided to accommodate the data packet of the packet identifier in the virtual connection, and the virtual connection satisfying the condition is not registered. At this time, the virtual connection capable of providing the service type and the quality of service in the control packet is associated with the packet identifier and registered in the first correspondence table.

Here, in response to the decision to accommodate the current virtual connection, the information about the virtual connection in the second correspondence table is updated. For the decision to cancel the transfer, the information on the packet identifier and the remaining resource amount of the data packet accommodated in the corresponding virtual connection in the second correspondence table is updated.

Then, in response to the decision to accommodate the existing virtual connection, the information about the virtual connection in the second correspondence table is updated. On the other hand, when the setting of a new virtual connection is determined, information about the virtual connection is added to the second correspondence table. Also, when setting the new virtual connection, if the same virtual connection identifier is continuously used, or if a virtual connection that has been registered in the second correspondence table but is not used is selected, only the necessary items are updated. To do.

Of course, in any case, necessary items such as the service quality and the virtual connection identifier in the first correspondence table are updated. According to the present invention (claim 6), in the invention of claim 2, 4 or 5, the service type and the service quality, the service class of the virtual connection and the virtual connection required when the service type and the service quality are provided. The amount of resources required for the connection is associated and registered in the third correspondence table, and from the third correspondence table, the service class of the virtual connection that provides the service type in the control packet and the control Acquiring information about the amount of resources required to provide the quality of service in the packet, based on the acquired information,
It is characterized in that whether or not the data packet having the packet identifier in the control packet can be accommodated in the existing virtual connection is determined.

According to the present invention, it is possible to obtain the required quality (service class, resource amount, etc.) for the virtual connection serving as the data packet accommodation destination at a higher speed. The present invention (claim 7) is the invention of claim 2, 4 or 5, wherein the service type and the service quality, and the service class of the virtual connection and the virtual connection required when the service type and the service quality are provided. The resource amount required for the connection and the identifier of the virtual connection set to accommodate the data packet requesting the service type and the service quality are associated and registered as the fourth correspondence table. , From the fourth correspondence table, the service class of the virtual connection that provides the service type in the control packet, the amount of resources required when providing the quality of service in the control packet, and the candidate virtual destination. Obtain information about the virtual connection identifier of the connection, and based on the obtained information Wherein the data packets having a packet identifier in the control packet performs a capacity determining whether or not within an existing virtual connection.

According to the present invention, it is possible to obtain the required quality (service class, resource amount, etc.) for a virtual connection that is a storage destination of a data packet at a higher speed. Further, it is possible to quickly search for a candidate for the virtual connection to be the accommodation destination, and as a result, it is possible to determine whether or not the data packet can be accommodated in the existing virtual connection at a higher speed.

The present invention (Claim 8) is a data packet transfer device for transferring a data packet according to a predetermined protocol to a predetermined virtual connection set in an ATM communication network in the form of an ATM cell. A unit for receiving a control packet, a packet identifier in the received control packet, and at least one of a service type and a quality of service, and selecting or setting a virtual connection that accommodates the data packet of the packet identifier. And a means for registering the packet identifier, at least one of the service type and the quality of service, and the virtual connection identifier of the selected or set virtual connection in association with each other, and the received data packet having the received data packet. Registered in association with the packet identifier Characterized by comprising a means for transferring the virtual connection of the virtual connection identifiers are.

According to the present invention, the information about the data packet of the predetermined protocol and the information about the virtual connection set on the ATM communication network are registered in association with each other, so that the requested service type and the request at the data packet level are registered. It becomes possible to accommodate a data packet on a virtual connection in consideration of quality of service.

According to the present invention (claim 9), a data packet transfer for transferring a data packet according to a predetermined protocol in the form of an ATM cell to a predetermined virtual connection set on an ATM communication network with at least the required quality of service. A data packet transfer method for a device, comprising monitoring at least the number of cells in a transfer waiting state at the start point of cell transfer of the virtual connection, and monitoring the virtual connection for the virtual connection set at least as a start point of cell transfer of the own device. Monitoring the cell transfer rate in the connection, based on the cell transfer rate value, or the cell delay value calculated from the cell transfer rate value and the number of cells in the transfer waiting state,
It is characterized by judging whether or not the quality of service to be provided in the virtual connection to be monitored has been achieved.

According to the present invention, it is possible to judge whether the service quality requested by the data packet is correctly provided by monitoring the service quality at the virtual connection level during the data packet transfer service. Becomes

According to the present invention (claim 10), in the invention of claim 9, when the upper limit value of the transfer rate value of the data packet is given as the quality of service required by the data packet, it is provided in the virtual connection. As the quality of service to be obtained, the upper limit value of the cell transfer rate value required to achieve the transfer rate value is obtained, and based on the magnitude relationship between the cell transfer rate value and the upper limit value obtained by the monitoring, It is characterized by determining whether or not the quality of service to be provided has been achieved.

According to the present invention (claim 11), in the invention of claim 9, when the upper limit value of the transfer delay value of the data packet is given as the quality of service required by the data packet, it is provided in the virtual connection. As the quality of service to be achieved, the upper limit value of the cell transfer delay value required for the virtual connection to achieve the transfer delay value is obtained, and the cell transfer rate value observed by the monitoring and the cell in the transfer waiting state are obtained. It is characterized in that whether or not the service quality to be provided is achieved is determined based on the magnitude relationship between the cell delay value calculated from the number and the upper limit value.

According to the present invention (claim 12), in the invention of claim 9, when a service level indicating the degree of the transfer delay value of the data packet to be achieved is given as the service quality required by the data packet. , A virtual connection containing a data packet requesting a different service level by calculating a cell delay value calculated from the cell transfer rate value observed by the monitoring and the number of cells in a transfer waiting state in each virtual connection. Whether the quality of service to be provided has been achieved by checking whether or not the magnitude relation of the cell delay values between the two match the magnitude relation of the degree of the transmission delay value of the data packet indicated by the service level. It is characterized by determining whether or not.

According to the present invention (claim 13), in the invention of any one of claims 9 to 12, when a virtual connection in which the quality of service required by the data packet is not achieved by the monitoring, Characterized in that a virtual connection holding a resource amount that exceeds the resource amount provided by the virtual connection is reconfigured, and a data packet accommodated in the original virtual connection is accommodated in the reconfigured virtual connection. To do.

According to the present invention, it is possible to provide a more reliable quality of service for a data packet. According to the present invention (Claim 14), when a virtual connection in which the quality of service required by the data packet is not achieved by the monitoring in the invention according to any one of Claims 9 to 12, a new virtual connection is newly created. A feature is that a connection is set, and the data packet accommodated in the original virtual connection is distributed to the newly set virtual connection and the original virtual connection and accommodated.

According to the present invention, it is possible to provide a more reliable quality of service for a data packet. The present invention (Claim 15) is a data packet transfer apparatus for transferring a data packet according to a predetermined protocol in the form of an ATM cell to a predetermined virtual connection set on an ATM communication network with at least the required quality of service. For at least a virtual connection that is set with its own device as the starting point of cell transfer, monitoring of the number of cells waiting for transfer at the starting point of cell transfer of the virtual connection and monitoring of the cell transfer rate in the virtual connection are performed. Quality of service to be provided in the virtual connection to be monitored based on the means for performing the cell transfer rate value or the cell delay value calculated from the cell transfer rate value and the number of cells in the transfer waiting state. And means for determining whether or not the above has been achieved.

According to the present invention, it is possible to judge whether the service quality requested by the data packet is correctly provided by monitoring the service quality at the virtual connection level during the data packet transfer service. Becomes

The present invention (Claim 16) is a data packet transfer method for transferring a data packet according to a predetermined protocol to a predetermined virtual connection set on an ATM communication network in the form of an ATM cell. The control packet is received, the packet identifier in the received control packet, at least one of the service type and the quality of service, and the virtual connection identifier of the selected virtual connection are registered in association with each other, and the registered packet identifier and virtual Referring to the connection identifier, the data packet of the corresponding packet identifier is transferred to the virtual connection of the corresponding virtual connection identifier, and the virtual connection is monitored and monitored by a method according to the registered service type or the quality of service. Virtual target Service quality to be provided is determined whether it is achieved in Nekushon, and updates the contents of the register in accordance with the determination result.

According to the present invention, the information about the data packet of the predetermined protocol and the information about the virtual connection set on the ATM communication network are registered in association with each other, and the virtual connection level of the virtual connection level is set during the data packet transfer service. Since the quality of service is monitored and the setting is changed to satisfy the request, the data packet is accommodated in the virtual connection and the reliable service is provided for the data packet in consideration of the required service type and the required service quality at the data packet level. It is possible to provide quality.

[0036]

Embodiments of the present invention will be described below with reference to the drawings. A data packet transfer device according to an embodiment of the present invention generally registers information related to a data packet and information related to a virtual connection in association with each other in order to provide a service type and a service quality required by a data packet to be transferred. The corresponding correspondence table is held (data packet-virtual connection correspondence table storage unit 14 in FIG. 1), and using this correspondence table, a virtual connection capable of providing the required service type and the required service quality is selected, and the virtual connection is selected. The relevant data packet is accommodated in the connection.

Here, the data packet is, for example, IP
(Internet Protocol) level data packet. The service type and the quality of service required by the data packet are as described above in the IE.
It represents a service type for delivery of IP-level data packets discussed in TF (Internet Engineering Task Force) and a service quality defined by each service type.

That is, the service types are: (1) Guaranteed Quality of Service (hereinafter referred to as GQS) Service that guarantees that all data packets are delivered to the destination within a fixed time (2) Predictive Quality of Service Service (hereinafter referred to as PQS) Service that guarantees that most data packets are delivered to the other party within a fixed time (3) Controlled Delay Quality of Service (hereinafter C
Described as DQS) A service in which the data packet delivery delay changes dynamically without providing a quantitative guarantee for the delay (conventional Best-Effor
It can be delivered in less time than the service).

In addition to these, Best-Effort (hereinafter referred to as BES; no quality guarantee as in the past) can be provided. Moreover, the service quality is given as a transfer rate value in (1) GQS. (2) In PQS, it is given as a target delay value or a service level (1, 2, 3; the smaller the service level value, the smaller the delay). (3) In CDQS, it is given as a service level (1, 2, 3; generally, the smaller the service level value, the smaller the delay).

In BES, the required quality of service is not defined. In the data packet transfer device of the present embodiment, for example, the first correspondence table shown in FIG. 2 and the second correspondence table shown in FIG. keeping.

FIG. 2 is a first diagram for holding information about data packets to be transmitted by the present data packet transfer device.
It is an example of the correspondence table of. In the first correspondence table, the identifier of the data packet, the service type {GQS, PQS, CDQS, BES} requested by the data packet and the service quality {transfer speed value, transfer delay value, service level}.
And an identifier of the virtual connection that is the accommodation destination of the data packet (for example, VCI (Virtual Connection Identif
ier)) is associated with and held. In FIG. 2,
S is the source address of the data packet, and L is the flow label of the data packet. Here, the combination of these two pieces of information S and L is used as the data packet identifier. In FIG. 2, the first correspondence table is represented in a form in which information is held in a memory (not shown).

FIG. 3 is an example of a second correspondence table that holds information about virtual connections set with the data packet transfer device as the starting point of cell transfer. In the second correspondence table, the virtual connection identifier, the service class of the virtual connection {CBR (Constant Bit Rate), V
BR (Variable Bit Rate), ABR (Available Bit)
Rate), UBR (Unspecified Bit Rate)}, the amount of resources that the connection can provide {service class is CB
Fixed bandwidth for R and UBR (PCR: Peak Cell Rat
e), maximum bandwidth (PCR), approved bandwidth (SCR: Sustainable Cell Rate) and burst tolerance (BT: Burst Tolerance) for VBR, maximum bandwidth (PCR) and minimum bandwidth (MCR) for ABR } And the residual resource amount (for example, the residual bandwidth amount) in the connection,
The identifier (combination of the source address S and the flow label L) of the data packet accommodated in the connection is held in association with each other. In FIG. 3, the second correspondence table is shown in a form in which information is held in a memory (not shown).

Further, as another correspondence table for registering the information about the data packet and the information about the virtual connection in association with each other in the data packet transfer apparatus of this embodiment,
It is preferable to further provide the third correspondence table shown in FIG. 4 or the fourth correspondence table shown in FIG.

FIG. 4 correlates the service type and service quality required by the data packet with the information about the service class of the virtual connection and the required resource amount (for example, bandwidth amount) necessary for providing the service. It is an example of a third correspondence table held.

FIG. 5 shows a service type and quality of service requested by a data packet, a service class of a virtual connection required to provide the service and a required resource amount (for example, bandwidth amount), and accommodation of the data packet. It is an example of a fourth correspondence table that holds information relating to the identifier of the previous candidate virtual connection in association with each other. In FIG. 5, all the corresponding items are registered in the virtual connection identifier column.

When the data packet transfer device of the present embodiment receives a control packet requesting transfer of a new data packet or change of the service type or quality of service of a data packet already in service, the information in the control packet is also updated. Then, new setting or updating of the association between the data packet and the virtual connection is performed. The control packet is, for example, RSVP (resource ReS
Reservation request message (erVation Protocol) (R
esv message).

In the data packet transfer device which has received the control packet, the information (data packet identifier, required service type, required service quality) regarding the corresponding data packet in the control packet is updated by the correspondence table updating unit (1 in FIG. 1).
5), the correspondence table updating unit has data packet information having the same identifier as the data packet identifier written in the received control packet, or the requested service type is a request in the control packet. Whether or not there is a virtual connection that accommodates a data packet that is the same as the service type is checked using the correspondence table in the data packet-virtual connection storage unit.

If there is no data packet information having the same identifier as the data packet identifier written in the received control packet, is there another data packet that is the same as the requested service type in the control packet? Whether or not it is checked using the first correspondence table. Then, when the data packet exists, the second correspondence table in the data packet-virtual connection correspondence table storage unit 14 is used to make a service request indicated by the control packet in the virtual connection accommodating the data packet. Determine whether it can be provided. If it can be provided, the data packet indicated by the received control packet is accommodated on the virtual connection. If it is not possible, a new virtual connection for accommodating the data packet indicated by the received control packet is newly set. , The information about the data packet and the information about the virtual connection are inserted or updated in the first correspondence table or the second correspondence table.

When there is data packet information having the same identifier as the data packet identifier described in the received control packet, the requested service type in the control packet is the data packet-virtual connection correspondence table storage unit 14. It is checked whether or not it is the same as the requested service type corresponding to the data packet described in the first correspondence table of. Then, when the requested service types are different, the accommodation of the data packet in the virtual connection shown in the first correspondence table is stopped, and the corresponding correspondence shown in the first correspondence table or the second correspondence table is satisfied. Information is erased, a virtual connection that can provide the required service type and the required quality of service described in the received control packet is searched for (if the existing connection cannot provide it, a new setting is made), and the above-mentioned data packet is related. The information and the information about the virtual connection are inserted or updated in the first correspondence table or the second correspondence table.

On the other hand, when the data packet identifiers are the same and the requested service types are the same, the control packet requests only the change of the service quality.
It is judged using the second correspondence table whether or not the changed required quality of service can be provided by the virtual connection shown in the correspondence table, and if it can be provided, the connection is continuously received. If the data packet indicated by the control packet is accommodated and cannot be provided, a virtual connection that can provide the required service type and the required service quality described in the control packet is searched for (if the existing connection cannot provide it). (For example, newly set), and the information about the data packet and the information about the virtual connection are inserted or updated in the first correspondence table or the second correspondence table.

If a third correspondence table as shown in FIG. 4 is provided in the data packet-virtual connection correspondence table storage unit 14, the third correspondence table is written in the above procedure. By using the information about the service class of virtual connection and the required resource amount (or cell transfer rate) required to accommodate the existing data packet, it is possible to newly determine whether the existing virtual connection can accommodate the data packet. The attributes (service class, resource amount, etc.) of the virtual connection when setting the virtual connection can be determined.

Alternatively, if a fourth correspondence table is provided in the data packet-virtual connection correspondence table storage unit 14, the virtual connection required for accommodating the data packet described in the fourth correspondence table will be described. By using the service class and the required resource amount (or cell transfer rate) and the information about the identifier of the virtual connection having these attributes, the selection of the candidate of the virtual connection to be the accommodation destination of the data packet and the accommodation of the candidate It is possible to determine whether or not it is possible.

Next, in the data packet transfer apparatus of this embodiment, a virtual connection monitoring unit (1 in FIGS. 1 and 6) for monitoring the quality of service provided at the cell level.
6). Then, based on the monitoring result by the virtual connection monitoring unit, it is determined whether or not the service type and the service quality required by the data packet are correctly provided.

In the virtual connection monitoring unit, the number of cells waiting to be accommodated in the virtual connection that accommodates the data packet, which has been cellized in the data packet transfer device (buffer 62 in FIG. 6).
The number of cells stored in each of 1 to 62n) and the transfer rate of cells to the connection (server 631 in FIG. 6)
Service rate at ~ 63n). And
Based on the above-mentioned two types of values and the cell transfer delay value on the connection calculated from them, it is determined whether the required quality of service of the data packet can be provided at the virtual connection level.

(1) When a transfer rate value is given as the required quality of service of a data packet, such as GQS, it is shown in the transfer rate value at the data packet level or the third correspondence table or the fourth correspondence table. The determination is made on the basis of the magnitude relationship between the required resource amount (cell transfer rate) and the cell transfer rate obtained by the virtual connection monitoring unit.

(2) When a transfer delay value is provided as the required quality of service of a data packet like PQS, for example, the transfer delay value and the cell transfer delay value obtained by the virtual connection monitoring unit are used. Judgment is made based on the size relationship.

(3) When a service level of transfer delay is given as the required service quality of a data packet such as PQS or CDQS, cell transfer in a connection accommodating a data packet whose quality is requested at the service level A delay value is calculated, and it is determined whether the relationship between the service level and the cell transfer delay value in the corresponding virtual connection is correctly established. For example, if the service level requested by the data packet A requires a lower delay than the service level requested by the data packet B, the data packet A
Must be smaller than the cell transfer delay value in the virtual connection b containing the data packet B.

When the virtual connection monitoring unit finds a virtual connection that does not satisfactorily provide the quality of service requested by the data packet by the above-described determination method, the virtual connection monitoring unit notifies the virtual connection to the correspondence table updating unit. Instructing a new setting of a virtual connection that can provide a resource amount that exceeds the resource amount held by, and a change (change to a newly set virtual connection) of a corresponding virtual connection of a data packet.

According to this embodiment, by using the correspondence table in which the information on the data packet of the predetermined protocol and the information on the virtual connection set on the ATM communication network are registered in association with each other, the data packet level Data packets can be accommodated on the virtual connection in consideration of the required service type and the required service quality.

Further, by registering the information on the virtual connection resource in the correspondence table, it has already been set (or already accommodated) at the time of a transfer request for a new data packet or a change request for the service type or service quality of an existing data packet. It is possible to easily judge whether or not the service can be provided on the virtual connection), and it is possible to efficiently use the ATM network resource.
As a result, it becomes possible to provide services at low cost.

By monitoring the service quality at the virtual connection level during the data packet transfer service, it becomes possible to judge whether the service quality requested by the data packet is correctly provided.

Further, by changing the quality of service of the accommodation virtual connection based on this judgment, it becomes possible to provide a more reliable quality of service for the data packet.

The embodiments of the present invention will be described in more detail below. FIG. 7 shows an example of a communication system configured by using a data packet communication node including the data packet transfer device according to this embodiment.

In FIG. 7, reference numeral 71 is an IP level virtual connection, 711 and 712 are terminals for transmitting IP data packets, 72 is an ATM communication network, 721 to 723 are data packet transfer devices (ATM exchanges), 731. ~ 7
33 is a virtual connection established on the ATM network, 74
Reference numeral 1742 indicates a data packet communication node. Terminal 7
In order to realize the IP data packet communication between 11, 712, in FIG.
42 to convert the IP data packet into a cell used in the ATM communication network to convert the virtual connections 731 to 73.
It is accommodated in 3 and transfers data. From the terminals 711 and 712, the communication system looks like that the communication of the IP data packet is performed using the virtual connection 71 at the IP level. The terminal 711 (71
A system in which 2) is directly connected to the data packet communication node 741 (742) is also conceivable.

FIG. 1 shows an example of the configuration of a data packet transfer device according to this embodiment. As shown in FIG. 1, this data packet transfer device includes a data packet receiving unit 11, a packet identifier reading unit 12, a packet accommodating unit 13, a data packet-virtual connection correspondence table storage unit 14, a correspondence table updating unit 15, and a virtual connection. The monitoring unit 16 is provided.

The data packet receiver 11 receives a data packet containing communication information issued by the user. The packet identifier reading unit 12 uses the data packet receiving unit 11
The identifier of the data packet received at is extracted.

The packet accommodating section 13 converts the data packet transferred from the packet identifier reading section 12 into an ATM cell and transfers the cell onto the virtual connection designated by the data packet-virtual connection correspondence table storage section 14. .

The data packet-virtual connection correspondence table storage unit 14 holds a correspondence table in which information about data packets and information about virtual connections are registered in association with each other, and the data packets extracted by the packet identifier reading unit 12 are stored. The virtual connection that should accommodate the data packet is searched for based on the identifier of (1).

The correspondence table updating unit 15 updates the contents of the data packet-virtual connection correspondence table storage unit 14 as necessary. The virtual connection monitoring unit 16 monitors the quality of service of each virtual connection, and requests the correspondence table update unit 15 to update the correspondence table in the data packet-virtual connection correspondence table storage unit 14 as necessary.

When a data packet arrives at the present data packet transfer device, the data packet receiving section 11 receives the data packet and the packet identifier reading section 12
At, the identifier of the data packet is extracted and passed to the data packet-virtual connection correspondence table storage unit 14. The data packet-virtual connection correspondence table storage unit 14 searches for the accommodation virtual connection of the data packet having the received identifier, and passes the identifier of the accommodation virtual connection to the packet accommodation unit 13. The packet storage unit 13 stores the received data packet on the virtual connection corresponding to the received identifier.

On the other hand, in the data packet transfer device,
When a control packet that contains a service request for a new data packet or a service change request for a data packet that is already in service (a request to change the requested service type or requested service quality) is received, transfer the corresponding data packet. Prior to the above, the information written in the control packet is passed to the correspondence table updating unit 15. The correspondence table updating unit 15 sets a new connection or changes the data packet accommodation destination connection based on the received information, and reflects the result in the correspondence table in the data packet-virtual connection correspondence table storage unit 14. After the correspondence table is updated,
The received control packet is sent from the packet accommodating unit 13 to the outside of the device.

Here, an example of the data packet identifier and the virtual connection identifier will be shown. FIG. 8 shows an outline of the format of the header part of the IP data packet. The format of the IP data packet shown in FIG. 8 is based on a specification called Internet Protocol Version 6 (IPv6).
ering, et al .: “Internet Protocol, Version 6 (IPv6)
Specification ", INTERNET-DRAFT, dra
See ft-ietf-ipngwg-ipv6-spec-02.txt).

In FIG. 8, if the content of the version (81 in the figure) in the header of the IP data packet indicates IPv6, the flow label (24 bits) (82 in the figure) and the source address (128 bits) (FIG. 8) 83)
It is possible to uniquely identify the flow to which the data packet belongs by checking both values of Here, the set of the above flow label and source address is treated as an identifier of the IP data packet. In addition, IP
In versions of IP data packets prior to v6, there is no indication regarding the flow label (82 in the figure) (there is no concept of flow label), so in order to identify the flow to which each data packet belongs, in addition to the source address, It is necessary to use layer information located above the IP level.

As the identifier of the virtual connection set in the ATM network, the virtual connection is VP.
(Virtual Path) connection is VC
(Virtual Channel) Depending on whether it is a connection, VPI (VP Identifier; VP identifier)
Alternatively, VCI (VC Identifier) is used.

As the correspondence table provided in the data packet-virtual connection correspondence table storage unit 14, the first correspondence table, the second correspondence table, the third correspondence table or the fourth correspondence table as described above is used. Shall be retained.

As described above, FIG. 2 shows the information relating to the data packet being transferred by the data packet transfer device and the identifier of the virtual connection which is the accommodating destination of the data packet stored in association with each other. It is an example of the correspondence table of No. 1. The first correspondence table holds at least the following information.

Data packet identifier (set of source address (S) and flow label (L)) Requested service type (GQS, PQS, CDQS, BE
S) -Required service quality (transfer speed value, transfer delay value or service level) -Accommodation destination virtual connection (Virtual Connection; V)
C) Identifier (VPI / VCI) As described above, FIG. 3 shows information about a virtual connection that is set by using this data packet transfer device as a starting point of cell transfer, and an identifier of a data packet accommodated on the connection. It is an example of a second correspondence table that stores and is associated with. The second correspondence table holds at least the following information.

Virtual connection identifier (VPI and / or VCI) Virtual connection service class {CBR, VB
R, ABR, UBR} -Available bandwidth amount of virtual connection {CBR, UBR
For fixed bandwidth (PCR), for VBR maximum bandwidth (PCR), approved bandwidth (SCR) and burst tolerance (BT), and for ABR maximum bandwidth (PCR) and minimum bandwidth (PCR). MCR)}-Identifier of data packet to be accommodated-Remaining bandwidth amount (this value is updated based on the requested service quality of the data packet or based on the actual measurement value) By the way, the first correspondence table Although it is conceivable to hold each of the second and the second correspondence tables independently as described above, as shown in FIG. 9, the information columns in the other correspondence tables correspond to the respective information columns in the correspondence table. A method of holding it in the data packet-virtual connection correspondence table storage unit 14 in a form as referred to is also conceivable. In FIG. 9, the data packet described in the first correspondence table 91 and the second packet which is the accommodation destination of the data packet are included.
Both tables are provided in the form of bidirectionally referring to the virtual connection described in the correspondence table 92. Such a form can be realized by allocating a memory address to each information column in the correspondence table and storing the memory address in the one correspondence table in which the related information is written in the other correspondence table. For example, the accommodation destination VC identifier held in the first correspondence table is stored in the memory address in the second correspondence table in which the VC is stored, and the accommodation data packet held in the second correspondence table. The identifier may be replaced with the memory address in the first correspondence table in which the data packet is stored. As a result, it is possible to perform a high-speed search for the position where the information in the other correspondence table that is to be updated in accordance with the information update in the one correspondence table is held.

As described above, FIG. 4 shows the information about the data packet transferred by the data packet transfer device and the information about the service quality of the virtual connection required for accommodating the data packet. It is an example of the 3rd correspondence table which matches and memorize | stores. Third
The correspondence table holds at least the following information.

-Service type-Required service quality-Service class of virtual connection-Required bandwidth of virtual connection (bandwidth required in virtual connection to provide the required quality of service described above; in data packet transfer device) FIG. 5 shows information about data packets being transferred by the present data packet transfer device, as described above,
It is an example of a fourth correspondence table that stores the quality of service of the virtual connection required for accommodating the data packet and the information about the virtual connection identifier accommodating the data packet in association with each other. 4th
The correspondence table holds at least the following information.

-Requested service type-Requested service quality-Virtual connection service class-Virtual connection required bandwidth-Acceptance destination virtual connection identifier (virtual connection accommodating data packet having the above service type and service quality Identifier) If the third correspondence table or the fourth correspondence table is held,
The correspondence table updating unit 15 refers to the third correspondence table or the fourth correspondence table when a new data packet is requested to be transferred or when the requested service type and the requested service quality of the existing data packet are changed, so that the data It is possible to obtain the required quality for the virtual connection serving as the packet storage destination at a higher speed. Furthermore, in the fourth correspondence table, the data packet having the same service type and service quality is specified by clearly specifying the identifier of the virtual connection of the accommodation destination of the data packet having the desired service type and the desired service quality set. When the transfer request is made, it is possible to quickly search for a candidate for the virtual connection to be the accommodation destination, and as a result, it is possible to determine whether or not the data packet can be accommodated in the existing virtual connection at a higher speed. It should be noted that an implementation method is possible in which, in the accommodation virtual connection identifier column of the fourth correspondence table, the memory address in the second correspondence table in which the information regarding the virtual connection is described is entered.

By the way, even if a data packet requests the same service type and service quality, if the traffic characteristics of the data packet (defined by transfer rate, burst property, etc.) are different, in order to achieve the request. The required quality of service of the virtual connection may vary. Therefore, in the third correspondence table and the fourth correspondence table, a configuration example in which information regarding traffic characteristics is added is also considered. FIG. 10 shows traffic characteristics (Tspec (n)).
The following is an example of a third correspondence table in which the information of () is added. By using the correspondence table shown in FIG. 10 or the fourth correspondence table in which information about traffic characteristics is similarly added, in addition to the requested service type and quality of the data packet,
The accommodation destination virtual connection can be selected based on the traffic characteristics of the data packet.

Next, the operation of the data packet transfer device when receiving a control packet using the above correspondence table will be described. Data packet receiving unit 11 that has received the control packet
Then, if the received packet is recognized as a control packet, the identifier, the requested service type, and the requested service quality described in the data packet are extracted and passed to the correspondence table updating unit 15. On the basis of the received information, the correspondence table updating unit 15 extracts or newly sets a virtual connection capable of data packet transfer satisfying the request of the control packet according to the procedure shown in FIG. After that, the packet storage unit 13 transfers the control packet.

The procedure for extracting a virtual connection capable of transferring a data packet satisfying the service type and service quality requested by the control packet and setting a new virtual connection will be described below.

When the correspondence table updating unit 15 obtains the information in the control packet (step S11), the data packet having the same packet identifier as the packet identifier written in the control packet is stored in the first correspondence table. It is checked whether or not it exists (step S12). If the packet identifier exists, the service type requested by the data packet having this packet identifier is read from the first correspondence table, and it is checked whether this service type is the same as the one described in the control packet. (Step S13). If the service types are not the same, the virtual connection serving as the accommodation destination is changed, so that accommodation of the data packet having the identifier in the virtual connection shown in the first correspondence table is stopped (step S14).

If the service types are the same, information regarding the accommodation destination virtual connection shown in the first correspondence table is searched based on the second correspondence table (step S15), Based on the information such as the amount of remaining bandwidth shown in the correspondence table of No. 2, it is determined whether the requested service quality described in the control packet can be provided using the current accommodation destination virtual connection. Yes (step S1
6). If the required quality of service can be continuously provided in the virtual connection, the data packet is continuously accommodated in the virtual connection (step S17). On the other hand, if the requested quality of service cannot be provided, the accommodation destination virtual connection is changed, so that the accommodation of the data packet having the identifier in the virtual connection shown in the first correspondence table is canceled (step S18). ).

When an identifier of a data packet not written in the first correspondence table is received (N in step S12)
o) or when the requested service type and the quality of service cannot be provided by the virtual connection that was the accommodation destination (previous steps S14 and S18), it is checked whether or not there is a new virtual connection that is the accommodation destination ( Step S19).

Here, if the fourth correspondence table is included, it is possible to easily search for the virtual connection providing the required service type and the required service quality, and to obtain the information regarding the candidate virtual connection as the second correspondence. It is possible to judge whether or not the data packet described in the control packet can be accommodated in the corresponding virtual connection by extracting from the correspondence table.

As a result, if the requested quality of service cannot be provided by the existing virtual connection, a new virtual connection is set and the data packet is accommodated on the virtual connection (step S20). If the requested virtual service quality can be provided by the existing virtual connection, the data packet is accommodated on the relevant virtual connection (step S21).

Finally, in accordance with the above operation, the contents of the first and second correspondence tables are updated (step S22). It should be noted that, when the virtual connection that is the accommodation destination of the data packet having the same identifier as the data packet is changed based on the information in the received control packet, the virtual connection identifier is changed as shown in FIG. Alternatively, only the attribute (service class, available bandwidth amount) of the virtual connection having the identifier is changed to suppress the update information amount of the contents of the first correspondence table. However, this method is effective only when the accommodation destination virtual connection does not accommodate a data packet having a different identifier (only a data packet having a unique identifier is accommodated).

Further, in order to reduce the time and effort of updating to insert the information about the connection into the second correspondence table every time a new virtual connection is newly set as the accommodation destination of the data packet, FIG. 13 is shown. Information about virtual connections that can be set by the data packet transfer device (virtual connection identifier, service class,
(Providable bandwidth amount) is held in advance in the second correspondence table, and when a control packet indicating a request for changing the service type and service quality is received, it is written in the first correspondence table. A method is conceivable in which only the identifier of the accommodation destination virtual connection is changed and the information about the virtual connection attribute in the second correspondence table is not updated. At this time, in the second correspondence table, it is desirable to provide an identification bit indicating whether or not the virtual connection entered in this table is currently set.

Next, an example of a policy for deciding what kind of virtual connection a data packet to be transferred is accommodated when various services defined by the IETF are given as requested service types will be shown.

(1) GQS (Guaranteed Quality of Se)
In case of rvice) In GQS, data packet delivery must be performed as requested. Therefore, the IP that belongs to this service
The data packet is accommodated in a CBR connection that can deliver data at a constant rate. Further, the virtual connection that accommodates the IP data packet belonging to this service only accommodates the IP data packet having a single identifier. This is because the delay fluctuation caused by accommodating the IP data packet having a plurality of identifiers increases the transfer delay of the data packet, and as a result, the request delay upper limit value may be exceeded.

If the control packet received at the data packet communication node requests GQS, the required quality of service in the control packet is checked. In the case of this service,
Since the transfer rate value is written, a CBR connection with a maximum rate (PCR) that can provide a rate that does not fall below this rate value is set, and information regarding this IP and information regarding this connection is set as an IP data packet-virtual. Fill in the correspondence table in the connection correspondence table storage unit 14.

(2) In case of PQS In PQS, data packet delivery according to the required quality must be performed "at a high probability". Therefore, in consideration of effective use of ATM communication network resources, IPs belonging to this service
For data packets, it is assumed that a plurality of IP data packets having different identifiers are accommodated on the same CBR connection. this is,
In this service, unlike GQS, I with a different identifier
This is because delay fluctuations that occur when accommodating P data packets are allowed.

When the control packet received by the data packet communication node requests PQS, the required quality of service in the control packet is checked. In the case of this service,
There are cases where the target delay value is written and cases where the service level is written.

When the target delay value is indicated, first, the transfer rate required to achieve the delay value is calculated at this node (or specified in the third or fourth correspondence table). Every other), the transfer to the CBR connection that can provide the transfer rate is attempted.

On the other hand, when the service level is given as the required quality of service, the data packet communication node accommodates the IP data packet using the CBR connection prepared for each level in advance. For example, service levels Level 1 to Level 3
It is assumed that the smaller the level value is, the smaller the delay in data packet delivery is required. In this case, in this node, a CBR connection is set for each level, and information regarding this connection is entered in advance in the third or fourth correspondence table. Considering the relationship of the delay values that should be established between the above levels, a CBR connection with a large PCR is used for an IP data packet with a small level value, and a small PCR is used for an IP data packet with a large level value. Have a CBR connection ready. Then, the data packet transfer device receiving the control packet reads the service level in the data packet, and outputs the CB corresponding to the level.
Plan to accommodate R connection.

(3) Case of CDQS In CDQS, the delay quality to be targeted is not given.
Therefore, in consideration of effective use of ATM communication network resources, a plurality of IP data packets having different identifiers are assigned to the same ABR for the IP data packets belonging to this service.
The mapping is to be accommodated on the connection. The ABR connection has a fixed bandwidth (PC
Unlike CBR connection that secures (equivalent to R),
It is a service in which the usable bandwidth changes dynamically depending on the congestion status of the network. In the ABR connection, cell transfer at a predetermined minimum rate (MCR) is guaranteed under any circumstances.

If the control packet received at the data packet communication node requests CDQS, the required quality of service in the control packet is checked. In the case of this service, the service level is described as the required service quality. At this time, the data packet transfer device uses the ABR connection prepared for each level in advance to accommodate the IP data packet. For example, it is assumed that the service levels from level 1 to level 3 are prepared, and that the smaller the level value, the more the data packet delivery with less delay is required. In this case, in this node, an ABR connection is set for each level, and information regarding this connection is entered in advance in the third or fourth correspondence table. Considering the relationship of the delay values that should be established between the above levels, an ABR connection with a large MCR / PCR is used for an IP data packet with a small level value, and an MCR connection is used for an IP data packet with a large level value. Prepare an ABR connection with a small / PCR. Then, the data packet communication node that has received the control packet reads the service level described in the data packet and attempts to accommodate it in the ABR connection corresponding to the level.

According to the procedure described above, the data packet transfer apparatus of this embodiment can select or set the virtual connection that can provide the service type and the quality of service requested by the data packet by the correspondence table updating unit 15. .

By the way, in the data packet transfer apparatus of this embodiment, the data packet is actually covered in addition to the above-mentioned means for providing the service type and service quality required by the data packet in the ATM communication network. It is desirable to include means for calculating the service quality at the virtual connection level, and means for changing the service quality provided in the virtual connection based on the calculation result. This makes it possible to more reliably provide the quality of service required by the data packet.

FIG. 6 shows an example of the configuration of the packet accommodating section 13 for accommodating data packets into ATM cells and accommodating them on a virtual connection, and the virtual connection monitoring section 16 for monitoring the quality of service covered by the cells.

The packet accommodating section 13 shown in FIG. 6 includes a data packet-cell section 61 and cell accumulating sections 621 to 62.
n, and cell transfer units 631 to 63n. In the figure, 641 to 64n are virtual connections for accommodating cells transferred by the cell transfer units 631 to 63n.

The data packet-cell conversion unit 61 converts the data packet transferred from the packet identifier reading unit 12 into an ATM cell, and the accommodating destination of the data packet notified from the data packet-virtual connection correspondence table storage unit 14. Transfer the cell to the virtual connection.

The cell accumulating units 621 to 62n have the virtual connection (V) corresponding to the data packet-cell converting unit 61.
The cell allocated to CI = X1 to Xn) is accommodated.

The cell transfer units 631 to 63n deliver the cells in the cell storage units 621 to 62n onto the virtual connection. The virtual connection monitoring unit 16 includes a cell storage unit 621.
To 62n, at least the number of cells accumulated (the number of accumulated cells) and the cell transfer rate in each of the cell transfer units 631 to 63n (the number of cells that can be transferred in a unit time) are monitored and provided by the virtual connection to be monitored. Calculate service quality. Are being monitored.

Also, from these values: -instantaneous transfer cell delay value = number of accumulated cells x (1 / cell transfer rate) + connection propagation delay-average transfer cell delay value = average value of instantaneous cell delay values within a fixed time At least the calculation is performed, and the adequacy of the service provided in the connection is determined based on the monitoring value (number of accumulated cells, cell transfer rate) and the calculated value (instantaneous / average transfer cell delay value). To do.

Here, the operation to be executed in the virtual connection monitoring unit 16 based on the quality of service requested by the data packet will be described. (1) When quality of service is given as a transfer rate, such as GQS. It is necessary to achieve the transfer rate value in a data packet by using the cell transfer rate value obtained by monitoring the cell transfer units 631 to 63n. Then, the cell transfer rate value is compared with the upper limit value. The cell transfer rate value obtained by the virtual connection monitoring unit 16 is determined depending on the bandwidth amount of the virtual connections 641 to 64n, which is the accommodation destination. The upper limit value of the cell transfer rate value to be compared is, for example, a value obtained by redisplaying the upper limit value of the transfer rate value for the data packet by the number of cells that can be transferred in a unit time. If the cell transfer rate value obtained in the virtual connection monitoring unit 16 is not sufficient to provide the upper limit of the requested cell transfer rate value, the virtual connection currently accommodating the data packet To newly set a virtual connection having a bandwidth amount exceeding the bandwidth amount held by, and to accommodate the data packet in the newly set virtual connection,
The correspondence table updating unit 15 is notified. Alternatively, apart from the current virtual connection accommodating the data packet, one or more virtual connections having at least the same service class (CBR, ABR, etc.) are newly set,
The data packet accommodated in the current virtual connection is transferred to the current virtual connection and the newly set virtual connection in packet identifier units (data packets having the same packet identifier are accommodated in the same virtual connection. ) So that it will be sorted and housed,
The correspondence table updating unit 15 is notified.

(2) When the service quality is given as a transfer delay value like PQS, for example, the cell storage units 621 to 62n and the cell transfer units 631 to 63n.
Either the instantaneous / average transfer cell delay value calculated by observing is used to compare with the upper limit of the cell transfer delay value required to achieve the transfer delay value in the data packet. . The upper limit value of the cell transfer delay value to be compared is a cell necessary for achieving the upper limit value by, for example, a data packet transfer device (or a management unit of a communication system including the data packet transfer device). It is assumed that the transfer delay value is calculated for all virtual connections through which the data packet passes. If the transfer cell delay value obtained by the virtual connection monitoring unit 16 is not sufficient to provide the upper limit of the requested cell transfer delay value, the virtual connection currently accommodating the data packet. The correspondence table updating unit 15 is notified to newly set a virtual connection having a bandwidth amount that exceeds the bandwidth amount held by and store the data packet in the newly set virtual connection. Alternatively, apart from the current virtual connection accommodating the data packet, at least one virtual connection having at least the same service class (CBR, ABR, etc.) as this is newly set, and is set as the current virtual connection. The accommodated data packet to the current virtual connection and the newly set virtual connection,
The correspondence table update unit 15 is notified that the correspondence table update unit 15 should be sorted and accommodated in units of packet identifiers (so that data packets having the same packet identifier are accommodated in the same virtual connection).

(3) When quality of service is given as a service level such as PQS or CDQS First, the cell storage units 621 to 62n and the cell transfer units 631 to 631
Either the instantaneous / average transfer cell delay value calculated by monitoring 63n is calculated for each virtual connection that accommodates a data packet for which the service quality is given as the service level. Then, the calculated transfer cell delay value is the same as the delay value indicated by the service level between virtual connections accommodating data packets requesting different service levels. It is determined whether the transfer cell delay value is satisfied.
Explaining using a specific example, when the transfer cell delay value Da of the virtual connection Ca accommodating the service level a and the transfer cell delay value Db of the virtual connection Cb accommodating the service level b are given, in the service level a If the delay value is specified to be smaller than the delay value at the service level b, the relationship of Da ≦ Db must be established. Then, if the magnitude relation of the transfer cell delay values obtained in the virtual connection monitoring unit 16 is contrary to the magnitude relation of the service level of the requested data packet (when the relation Da> Db holds), the service The virtual connection having a bandwidth amount exceeding the bandwidth amount held by the virtual connection (Ca) accommodating the data packet requesting a smaller transfer delay at the level, and the virtual connection having the data packet reset The correspondence table updating unit 15 is notified to store the data in the table. Alternatively, in addition to the virtual connection (Ca) accommodating the data packet requesting a smaller transfer rate at the service level, at least one virtual connection having at least the same service class (CBR, ABR, etc.) is newly set. Then, the data packet accommodated in the virtual connection (Ca) is transferred to the virtual connection (Ca) and the newly set virtual connection in packet identifier units (data packets having the same packet identifier are the same virtual connection. Correspondence table update unit 1 so that it is sorted and stored.
Notify 5 It should be noted that a virtual connection having a bandwidth amount less than the bandwidth amount held by the virtual connection (Cb) accommodating the data packet requesting a larger transfer delay at the service level is newly set, and the data packet is newly added. An operation of notifying the correspondence table update unit 15 to accommodate the virtual connection that has been set is also conceivable. The present invention is not limited to the above-described embodiment, and can be implemented with various modifications within the technical scope.

[0112]

According to the present invention, by using the correspondence table for registering the information on the data packet of the predetermined protocol and the information on the virtual connection set on the ATM communication network in association with each other, at the data packet level. It becomes possible to accommodate the data packet on the virtual connection in consideration of the required service type and the required service quality.

Further, according to the present invention, by registering the information relating to the resources of the virtual connection in the correspondence table, it is already set when a transfer request of a new data packet or a service type or service quality change request of an existing data packet is requested. It is possible to easily judge whether or not it is possible to provide the service on the virtual connection that is (or has already been accommodated), and it is possible to efficiently use the ATM network resource. As a result, it becomes possible to provide services at low cost.

Further, according to the present invention, it is possible to judge whether the quality of service requested by the data packet is correctly provided by monitoring the quality of service at the virtual connection level during the data packet transfer service. Is possible.

Further, by changing the quality of service of the accommodation virtual connection based on this judgment, it becomes possible to provide a more reliable quality of service for the data packet.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a data packet transfer device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a first correspondence table.

FIG. 3 is a diagram showing an example of a second correspondence table.

FIG. 4 is a diagram showing an example of a third correspondence table.

FIG. 5 is a diagram showing an example of a fourth correspondence table.

FIG. 6 is a diagram showing an example of a packet storage unit and a virtual connection monitoring unit.

FIG. 7 is a diagram showing an example of a communication system to which a data packet communication node including the data packet transfer device according to the embodiment is applied.

FIG. 8 is a schematic diagram of a header part of an IP data packet.

FIG. 9 is a diagram for explaining the correspondence between the first correspondence table and the second correspondence table.

FIG. 10 is a diagram showing an example of a third correspondence table to which traffic characteristic information of data packets is added.

FIG. 11 is a flowchart showing a schematic operation of the embodiment.

FIG. 12 is a diagram for explaining an update process of the first correspondence table and the second correspondence table.

FIG. 13 is a diagram for explaining an update process of the first correspondence table and the second correspondence table.

[Explanation of symbols]

 11 ... Data packet receiving section 12 ... Packet identifier reading section 13 ... Packet accommodating section 14 ... Data packet-virtual connection correspondence table storage section 15 ... Correspondence table updating section 16 ... Virtual connection monitoring section 61 ... Packet-cellizing section 621-62n Cell storage units 631 to 63n Cell transfer units 711 and 712 Terminals 72 ATM communication networks 721 to 723 ATM switches 741 and 742 Data packet communication nodes

Claims (16)

[Claims] 1. A data packet transfer method for transferring a data packet according to a predetermined protocol in the form of an ATM cell to a predetermined virtual connection set on an ATM communication network, which receives and receives a data packet or a control packet. The packet identifier in the control packet, at least one of the service type and the quality of service, and the virtual connection identifier of the selected virtual connection are associated and registered in the first correspondence table, and registered in the first correspondence table. Referring to the packet identifier and the virtual connection identifier, the data packet having the corresponding packet identifier is transferred to the virtual connection having the corresponding virtual connection identifier, and the packet identifier in the newly sent control packet and the service type And / or quality of service When a virtual connection in which a packet identifier that satisfies a predetermined condition for and is associated with at least one of a service type and a service quality is registered in the first correspondence table, A data packet transfer method comprising continuing the transfer of a data packet having the packet identifier. 2. The virtual connection identifier, the service class that can be provided by the virtual connection, the amount of remaining resources that can be provided for the transfer of new data packets held by the virtual connection, and the virtual connection that is accommodated in the virtual connection. If a control packet that holds a packet identifier that is not registered in the first correspondence table is received in advance by being registered in the second correspondence table in association with the packet identifier of the data packet In selecting a virtual connection to accommodate a data packet, the second correspondence table is referred to, a data packet requesting the same service type as the service type in the control packet is accommodated, and the residual resource amount is Within the range of the condition that the quality of service in the control packet can be provided. When the virtual connection to be registered is registered, it is decided to accommodate the data packet of the packet identifier in the virtual connection, and when the virtual connection satisfying the condition is not registered, the service type in the control packet 2. The data packet transfer method according to claim 1, further comprising: registering a virtual connection capable of providing a quality of service in the first correspondence table in association with the packet identifier. 3. When selecting a virtual connection in which a data packet having the received packet identifier in the control packet is to be accommodated, the service type and the quality of service in the control packet are referred to, and the service type is fixed. If the first service type guarantees that all data packets are delivered to the destination in time, the ATM layer service class is C
A virtual connection that is BR, has a maximum transfer rate that can provide a transfer rate that is not lower than the transfer rate value indicated by the quality of service, and can accommodate only data packets having the packet identifier is selected. When the service type is a second service type that guarantees that almost all data packets are delivered to the destination within a fixed time, when the service quality is given as a target delay value, ATM When the layer service class is CBR, and a virtual connection capable of providing a transfer rate required to achieve the target delay value is selected, and the quality of service is given as a service level, the ATM layer・ Class of service is CB
A virtual connection that is R and satisfies the relationship with another service level is selected, and the service type does not give a quantitative guarantee for the packet delivery delay, and the packet delivery delay is set for the purpose of preventing data packet discard. If the third service type is dynamically controlled, the ATM layer service class is ABR, and the virtual level satisfies the relationship between the service level indicated by the quality of service in the control packet and another service level. The data packet transfer method according to claim 1, wherein a connection is selected. 4. The packet identifier in the newly sent control packet matches the one registered in the first correspondence table, and the service type in the control packet is different from the registered one. In this case, referring to the first correspondence table and the second correspondence table, the virtual connection in which the data packet of the packet identifier is registered in association with the packet identifier in the service type in the control packet When it is determined that the transfer to the virtual connection having the identifier is not appropriate, it is decided to stop the transfer of the data packet having the packet identifier to the virtual connection, and the service type in the control packet is the same. Data packet requesting the service type of, and within the range of the remaining resource amount within the control packet When a virtual connection satisfying the condition that service quality can be provided is registered, it is determined that the data packet of the packet identifier is accommodated in the virtual connection, and the virtual connection satisfying the condition is registered. When not present, the data packet transfer according to claim 2, wherein the virtual connection capable of providing the service type and the service quality in the control packet is registered in the first correspondence table in association with the packet identifier. Method. 5. The packet identifier and service type in the newly sent control packet match those registered in the first correspondence table, and the quality of service in the control packet is registered. If different from the first,
And the second correspondence table, the quality of service is occupied by the virtual connection having the virtual connection identifier registered in association with the packet identifier and the residual of the virtual connection. When it is possible to provide within a range that does not exceed the sum of the resource amount, it is decided to continuously accommodate the data packet of the packet identifier in the virtual connection, and when new service quality cannot be provided, the virtual It is decided to cancel the transfer of the data packet of the packet identifier to the connection, accommodates the data packet requesting the same service type as the service type in the control packet, and within the range of the remaining resource amount. Virtual connection satisfying the condition that the quality of service in the control packet can be provided. When a virtual connection satisfying the condition is not registered, the service type and service in the control packet are determined when the virtual connection satisfying the condition is registered. The data packet transfer method according to claim 2, wherein a virtual connection capable of providing quality is registered in the first correspondence table in association with the packet identifier. 6. A service class and a quality of service are associated with a service class of a virtual connection required for providing the service type and the quality of service, and an amount of resources required in the virtual connection. And the amount of resources required when providing the service class of the virtual connection that provides the service type in the control packet and the quality of service in the control packet from the third correspondence table. Information relating to the control packet is acquired, and whether the data packet having the packet identifier in the control packet can be accommodated in the existing virtual connection is determined based on the acquired information. The data packet transfer method described in 2, 4, or 5. 7. A service type and a service quality, a service class of a virtual connection required to provide the service type and the service quality, an amount of resources required in the virtual connection, the service type and the The virtual connection identifier set for accommodating the data packet requesting the quality of service is associated and registered in the fourth correspondence table. From the fourth correspondence table, the service in the control packet is registered. Acquiring information about the service class of the virtual connection that provides the type, the amount of resources required when providing the quality of service in the control packet, and the virtual connection identifier of the virtual connection that is a candidate for accommodation, and the acquired information On the basis of the packet identifier in the control packet. Tapaketto a data packet transfer method according to claim 2, 4 or 5, characterized in that it is determined whether or not receivable in the existing virtual connections. 8. A data packet transfer device for transferring a data packet conforming to a predetermined protocol to a predetermined virtual connection set on an ATM communication network in the form of an ATM cell, and a means for receiving the data packet and the control packet. A means for selecting or setting a virtual connection in which the data packet of the packet identifier is accommodated by referring to the packet identifier in the received control packet and at least one of the service type and the quality of service; and the packet identifier, A means for registering at least one of the service type and the quality of service and the virtual connection identifier of the selected or set virtual connection in association with each other, and registering the received data packet in association with the packet identifier of the data packet. Virtual connection And a means for transferring to a virtual connection having a packet identifier. 9. A data packet transfer method of a data packet transfer device for transferring a data packet according to a predetermined protocol in the form of an ATM cell to a predetermined virtual connection set on an ATM communication network with at least required quality of service. Therefore, at least for the virtual connection that is set as the cell transfer start point of the own device, the number of cells waiting for transfer at the cell transfer start point of the virtual connection is monitored and the cell transfer rate of the virtual connection is monitored. The cell transfer rate value, or based on a cell delay value calculated from the cell transfer rate value and the number of cells in the transfer waiting state, the service quality to be provided in the virtual connection to be monitored is A method for transferring a data packet, which comprises determining whether or not the data packet has been achieved. 10. When the upper limit value of the transfer rate value of the data packet is given as the service quality required by the data packet, the transfer rate value is achieved as the service quality to be provided in the virtual connection. Obtaining the upper limit of the required cell transfer rate value, based on the magnitude relationship between the cell transfer rate value obtained by the monitoring and the upper limit value, it is determined whether or not the service quality to be provided has been achieved. The data packet transfer method according to claim 9, wherein 11. To achieve the transfer delay value as the service quality to be provided in the virtual connection when an upper limit value of the transfer delay value of the data packet is given as the service quality required by the data packet. An upper limit value of the cell transfer delay value required for the virtual connection is obtained, and a cell delay value calculated from the cell transfer rate value observed by the monitoring and the number of cells in the transfer waiting state, and the upper limit value. 10. The data packet transfer method according to claim 9, wherein it is determined whether or not the quality of service to be provided has been achieved based on the magnitude relationship with. 12. A cell transfer rate value observed by the monitoring and a transfer wait when a service level indicating a degree of a transfer delay value of a data packet to be achieved is given as a service quality required by the data packet. The cell delay value calculated from the number of cells in the state is calculated for each virtual connection, and the size relation of the cell delay values between the virtual connections accommodating data packets requesting different service levels depends on the service level. 10. It is determined whether or not the quality of service to be provided has been achieved by checking whether or not it matches the magnitude relation of the degree of the transfer delay value of the data packet shown in FIG. Data packet transfer method described. 13. When a virtual connection in which the quality of service requested by the data packet has not been achieved by the monitoring, the virtual connection holding a resource amount that exceeds the resource amount provided by the virtual connection is reset. 13. The data packet transfer method according to claim 9, wherein the data packet accommodated in the original virtual connection is accommodated in the reset virtual connection. 14. When a virtual connection in which the quality of service requested by the data packet is not achieved by the monitoring, a new virtual connection is set and the data packet accommodated in the original virtual connection is set. 13. The data packet transfer method according to claim 9, wherein the newly set virtual connection and the original virtual connection are distributed and accommodated. 15. A data packet transfer device for transferring a data packet conforming to a predetermined protocol in the form of an ATM cell to a predetermined virtual connection set on an ATM communication network with at least the required quality of service. A means for monitoring the number of cells in a transfer waiting state at the cell transfer start point of the virtual connection and the cell transfer rate of the virtual connection for the virtual connection set by using the device as the cell transfer start point, Based on the cell transfer rate value or the cell delay value calculated from the cell transfer rate value and the number of cells in the transfer waiting state, the service quality to be provided in the virtual connection to be monitored is achieved. And a means for determining whether or not there is a data packet transfer device. 16. A data packet transfer method for transferring a data packet according to a predetermined protocol in the form of an ATM cell to a predetermined virtual connection set on an ATM communication network, which receives and receives a data packet or a control packet. The packet identifier in the control packet, at least one of the service type and the quality of service, and the virtual connection identifier of the selected virtual connection are registered in association with each other, and the registered packet identifier and virtual connection identifier are referred to, Transfers the data packet of the corresponding packet identifier to the virtual connection of the corresponding virtual connection identifier, monitors the virtual connection by a method according to the registered service type or the quality of service, and A data packet transfer method, comprising: determining whether or not the service quality to be provided is achieved, and updating the contents of the registration according to the result of this determination.