KR100273771B1 - Method of controlling available bitrate traffic - Google Patents

Abstract

The present invention relates to an asynchronous transmission mode network. In particular, by using a signaling channel to propose a new message and traffic parameter negotiation message flow diagram for controlling effective bit rate traffic in an asynchronous transmission mode network, network resource utilization efficiency can be improved quickly and accurately. An effective bit rate service setting process of controlling connection acceptance according to the service request by comparing the available bandwidth with the available bandwidth of the network when the effective bit rate service is requested, so as to provide an effective and effective effective bit rate service; In the asynchronous transmission mode network, an available bandwidth request and allocation process of allocating a band available in a network according to a bandwidth request message using a signal channel using an effective bit rate set in the effective bit rate service setting process is performed. The present invention relates to a effective bit rate traffic control method.

Description

Effective Bit Rate Traffic Control Method by Signal Channel in Asynchronous Transmission Mode Network

The present invention relates to an asynchronous transmission mode network. In particular, by using a signaling channel to propose a new message and traffic parameter negotiation message flow diagram for controlling effective bit rate traffic in an asynchronous transmission mode network, network resource utilization efficiency can be improved quickly and accurately. The present invention relates to a method for controlling effective bit rate traffic by a signal channel in an asynchronous transmission mode network capable of providing a high and effective effective bit rate service.

In general, in order to meet various demands of communication users, switching to a high speed transfer mode is required, and thus, in ITU-T and the like, a broadband integrated information communication network (Asynchronous Transfer Mode) is referred to as an ATM. Service Digital Network, hereinafter referred to as B-ISDN) is being standardized.

The ATM communication method is a high-speed packet switching method that combines the advantages of a real-time circuit switching method and a packet switching method capable of converting various communication speeds for information transmission and processing. It is an economical and efficient way of providing services.

In addition, in terms of transmission, it uses statistical time division multiplexing (STDM), which is capable of statistical processing, so it is an exchange and multiplexing technique of B-ISDN that effectively provides efficient network resources and various performance requirements. .

ATM services fall into three broad categories: first, the constant bit rate (hereinafter referred to as CBR) and the non-real-time variable bit rate (non-real-time), which guarantee quality of service (QOS) at the call setup stage. real-time Variable Bit Rate (hereinafter referred to as nrt-VBR), real-time Variable Bit Rate (hereinafter referred to as rt-VBR) service; An effective bit rate (hereinafter referred to as ABR) service transmitted by utilizing the available bandwidth of the remaining link used by the quality assurance service through such bandwidth allocation; And it can be divided into Unspecified Bit Rate (UBR) service which does not guarantee service performance by the network.

VBR service can be divided into rt-VBR and nrt-VBR according to transmission delay sensitivity. CBR and rt-VBR are mainly applied to real-time services such as audio and video, and nrt-VBR, ABR, and UBR services are non-real time. It is applied to service such as e-mail or file transfer.

The VBR service has the advantage of efficiently using the link through statistical multiplexing.However, in order to maximize the link utilization while ensuring the transmission quality of the VBR service, the network resource is reduced by efficient bandwidth allocation and transmission delay. Reducing the time occupied can increase the utilization efficiency of network resources.

Therefore, if the available bands generated by the VBR service are filled with ABR or UBR traffic, economical link can be used.

ABR services have been proposed at the ATM Forum Traffic Management Group meeting and ITU-T SG13, and are currently working on standardization of ABR and UBR services.

The ABR service is a non-real-time service, so users are expected to use the service at a low price. However, as a way to control the ABR service in the current network, resource management by data channel is carried out. The schemes for allocating available bandwidth using a cell have been proposed, which leads to longer network occupancy time, which results in longer network resource usage time.

Therefore, from a network operator's point of view, if the time occupying the network resource becomes longer, the fee cannot be expensive in terms of using the available bandwidth without guaranteeing relatively the Cost of Service Principle.

In the end, the cost is cheaper and the cost of using network resources is the most expensive.

1 shows a conventional ABR traffic control method. As shown in FIG. 1, in this method, the transmitter 1 transmits one forward RM cell 2 to the network every time a predetermined number of cells are transmitted. Algorithm for adjusting its Allowed Cell Rate according to the information carried by the backward RM cell 4 returned from (3), wherein the source 1 transmits N data cells and then the RM cell 2 ) And reduce the transmission rate by a certain rate after every data cell transmission before receiving this RM cell in the reverse direction.

This method compensates for the reduced transmission rate so far when the RM cell transmitted from the source is received via the destination again with a Congestion Indication (hereinafter referred to as CI) as "0" (CI = 0). In addition, the transmission speed can be increased beyond that.

On the other hand, if the received RM cell indicates that the network congestion state is "CI = 1", it continues to decrease without increasing the transmission speed.

This is a method to recover from the congestion state by reducing the input traffic to the network when the network is congested.

This method does not make full use of the available bandwidth as it controls the increase and decrease of a certain amount dynamically and dynamically, rather than adaptively controlling the available bandwidth of the link when the transmission rate of the source changes. Since the used RM cell is added to the data channel, the processing speed is slowed down and the data rate is decided by the returning RM cell. Therefore, the changed situation of the network cannot be known in real time. This results in worse results, and defines only the highest transmission rate (Peak Cell Rate, hereinafter referred to as PCR) and the lowest transmission rate (hereinafter, referred to as MCR) for the RM cell, and determines the available bandwidth using this. Therefore, it transmits at the maximum data rate, and then again depending on the time of transmission at the minimum data rate Because of the time-varying available bandwidth, there is a bit down problem.If the RM cell is lost during transmission, the call control function is lost in the network. There was a problem that occurred.

Accordingly, the present invention has been devised to solve the above-mentioned problems, and allocates available bandwidth efficiently and dynamically by using a signal channel instead of using a data channel when controlling effective bit rate traffic in an asynchronous transmission mode network. An object of the present invention is to provide a method for controlling effective bit rate traffic by a signaling channel in an asynchronous transmission mode network.

1 is a diagram illustrating a effective bit rate traffic control method according to a general method;

2 is a flowchart illustrating a procedure for setting an ABR service according to the present invention;

3 is a flowchart illustrating an available bandwidth request and allocation procedure after the ABR service is set up according to the present invention;

4 is a message flow diagram for a traffic parameter negotiation that can use the network resources according to the present invention.

<Description of reference numerals for the main parts of the drawings>

10: sender 20: receiver

30: ATM network

In order to achieve the above object, the present invention provides an effective bit rate service setting process of controlling connection acceptance according to a service request by comparing the available bandwidth with the available bandwidth of a network when an effective bit rate service request is made; It is characterized in that it consists of an available bandwidth request and allocation process for allocating the available bandwidth in the network according to the bandwidth request message by using the signal channel to the effective bit rate set in the effective bit rate service setting process.

The effective bit rate service setting process may include a first step of requesting a new effective bit rate service; Requesting a new effective bit rate service, a second step of requesting free bandwidth that can be provided in the current network; A third step of comparing the bandwidth required in the second step with the available bandwidth provided by the current network; A fourth step of sending a service reception request to a sender in a call proceeding message when the free bandwidth is larger than the requested bandwidth; In the network, a fifth step of informing the bandwidth manager that the bandwidth manager allocated the bandwidth required in the free bandwidth; A sixth step of requesting a change in the change spare bandwidth; On the other hand, when the bandwidth required by the second step is larger than the free band, the seventh step of rejecting call acceptance; An eighth step of transmitting a release message is characterized in that it operates sequentially.

In the available bandwidth request and allocation process, after the effective bit rate service call is accepted in the network during the effective bit rate service setting process, a request for an available bandwidth of the network is received from a sender through a bandwidth request message from a source. The first step; A second step of requesting the bandwidth manager for the currently available spare bandwidth according to the available band of the network received in the first step; Receiving a free bandwidth from the bandwidth manager; A fourth step of determining an allocated bandwidth in the network according to the number of effective bit rate services after the free bandwidth is received in the third step; In step 4, the bandwidth allocated message is notified to the sender through a bandwidth allocation message, and the operation is sequentially performed in a fifth step of transitioning to a standby state for processing the next bandwidth request message.

The operation principle according to the present invention will be described in detail as follows.

2 shows a connection acceptance control procedure according to a free bandwidth of a network when a new ABR service is requested. As shown in FIG. 2, when a new ABR service is requested (S11), the traffic manager provides the bandwidth manager with the available bandwidth available in the current network. (S12)

The bandwidth requested by the transmitter is compared with the bandwidth provided by the current network (S13). When the free bandwidth is larger than the requested bandwidth, the service acceptance request is sent to the transmitter by a call proceeding message (S14).

Meanwhile, the network notifies the bandwidth manager that the bandwidth manager allocates the bandwidth required in the free bandwidth (S15) and requests a change of the change free bandwidth (S16).

However, if the bandwidth required by the transmitting source is larger than the free band, the call is rejected (S17), and a release message is sent to the transmitting source (S18).

In the existing proposed paper, since the information about the spare band is obtained through the RM cell returning after the connection acceptance, it is difficult to accurately calculate the spare band due to transmission delay and loss of the RM cell.

Therefore, in the present invention, if an bandwidth is requested by a bandwidth request message using a signal channel after connection admission control for efficient bandwidth management of the ABR service, bandwidth allocation is possible for the bandwidth available in the network. As a scheme for allocating through a message, the band management procedure proposed in FIG. 3 is performed to enable possible bandwidth allocation in a network.

In FIG. 3, when the ABR service call is accepted in the network, when a request for an available band of the network is received from the sender through a bandwidth request message from the sender (S21), the traffic manager is currently free to the bandwidth manager. Require bandwidth (S22)

When the free bandwidth is received from the bandwidth manager as described above (S23), the network determines the allocated bandwidth according to the number of ABR services (S24).

In this case, the determination of the allocated bandwidth may be evenly distributed or may be given a weight.

First, the method of equal distribution is the same as the following equation (1).

<Equation 1>

Allocated bandwidth

Where 1 to n represent the number of ABR services.

How to put the weight (Weight) is shown in the following equation (2).

<Equation 2>

Allocated bandwidth

Where 1 to n represent the number of ABR services.

The bandwidth request currently received is calculated by calculating the bandwidth according to the bandwidth allocation algorithm for each ABR service according to Equation 1 and Equation 2, and informing the traffic manager of the bandwidth currently available in the network. Request) The ABR service that sent the message informs the sender of the current allocated bandwidth through a bandwidth allocted message, and is placed in a waiting state to process the next bandwidth request message.

4 is a message flow diagram for traffic parameter negotiation that can use economical network resources devised in the present invention for controlling ABR traffic using a signaling channel.

First, when the setup message A1 is transmitted from the transmission source 10 to the ATM network 20, the ATM network 20 transmits a call setup message A2 to the transmission source 10 and simultaneously receives the reception source 30. Send a network status inquiry message (A3).

The receiving source 30 receiving the network status inquiry message A3 from the ATM network 20 transmits a network status response message A4 to the ATM network 20, and receives the network status from the receiving source 30. The ATM network 20 receiving the response message A4 transmits a setup message A5 to the receiving source 30.

The sender 10 receiving the setup message A5 from the ATM network 20 transmits a call setup message A6 to the ATM network 20 and simultaneously transmits an alert message A7. The ATM network 20 receiving the alert message A7 from 10 transmits the alert message A8 to the sender 10.

On the other hand, when the reception source 30 transmits a connection message A9 to the ATM network 20 in the above state, the ATM network 20 sends a connection confirmation message A10 to the reception source 30. In addition to the transmission and transmits the access message (A11) to the sender (10).

When a connection confirmation message A12 is transmitted from the transmission source 10 to the ATM network 20, the ATM network 20 and the transmission / reception sources 10 and 30 are connected, and thus call processing is performed to use network resources. Is completed.

In order to control ABR traffic as described above, ABR call setting is made, and after the connection acknowledgment (Connect Ack) signal is transmitted, the available bandwidth is requested from the source 10 to the ATM network 20 at regular intervals. In order to transmit the bandwidth request message A13, the ATM network 20 receiving the message transmits a bandwidth allocated message A14. In addition to the transmission to the transmission source 10, and to check the current transmission rate and service compatibility of the network side, and transmits the network status inquiry message (A15) to the receiving source (30).

After receiving the network status inquiry message A15 from the ATM network 20, the reception source 30 transmits a network status response message A16 to the ATM network 20, and then bandwidths to the ATM network 20. Send a request message (A17).

When the bandwidth request message A17 is transmitted from the reception source 30, the ATM network 20 transmits a bandwidth allocation message A18 according to the bandwidth request message A17 received from the reception source 10. .

The sender 10 transmits a teardown message A19 to the ATM network 20, and when a recovery completion message A20 is transmitted from the ATM network 20, the ATM network 20 receives the receiver ( 30, the dismantling message A21 is transmitted, and the recovery completion message A22 is received from the receiving source 30 to complete the operation.

Therefore, since the source 10 transmits the available bandwidth using this information, negotiation of the available bandwidth is possible in real time, thereby enabling economical and efficient ABR service control.

Here, the detailed operations according to the bandwidth request messages A13 and A17 are as described in detail with reference to FIG. 2, and the detailed operations according to the bandwidth allocation messages A14 and A18 are as described in detail with reference to FIG. 3. Therefore, detailed description thereof is omitted.

Table 1 shows a bandwidth request message and a bandwidth allocated message proposed in the present invention for controlling ABR traffic using a signaling channel.

Table 1 Bandwidth Request / Allocated Messages for ABR Traffic Control

Information element Direction Type Octets Bits Protocol Identifier Call Reference Message Type Message Length Network Status: BECN Cell Network Status: Congestion Indication Network Status: Stable Permitted Rate (ECR) Current Rate (CCR) Minimum Rate (MCR) Queue Length Continuous Number Reservation both both both both both both both both both both both both both M M M M M M M M M M M M M M 1 2 ~ 5 6 ~ 7 8 ~ 9 10 10 10 11 ~ 12 13 ~ 14 15 ~ 16 17 ~ 20 21-24 25 ~ 53 all all all all 5 ~ 8 3 ~ 4 1 ~ 2 all all all all all all

As shown in Table 1, the details of the bandwidth request message and the bandwidth allocated message for controlling ABR traffic using a signal channel are described below.

The two messages have the same contents, except that the message names differ depending on the sender.

1) Protocol Discriminator

The purpose of the protocol identifier is to control user messages and other messages with this specification.

2) Call reference

To identify a call at the local user network interface that applies a special message.

3) Message type

The purpose of the message type is to indicate the function of the message to be sent.

It consists of 2 Octets (No. 6 ~ 7 Octets), the first Octet (No. 6 Octet) is used to distinguish Call Establishment Message, Call Clearing Message, Miscellaneous Message, and the other Octet (No. 7 Octet) is BECN. (Backward Explicit Congestion Notification), Congestion indication (hereinafter referred to as CI), No-increase (NI) is used to distinguish, the remaining bits are reserved.

(1) Backward Explicit Congestion Notification (BECC)

This bit is to distinguish that a bandwidth request message was generated by the sender.

(2) Congestion indication (hereinafter referred to as CI)

This bit is to indicate that congestion is imminent in the forward pass.

(3) No-increase (NI)

When used in combination with the CI bit, it is intended to instruct the sender to continue transmitting at the current rate.

This is when the network is in a stable state.

However, if CI = 0 and NI = 0, the transmission rate can be increased at the source; if CI = 0 and NI = 1, the allowed cell rate is not increased.

4) Explicit Cell Rate (hereinafter referred to as ECR)

In this field the value of the negotiated maximum rate is recorded by the sender.

This value is reduced upon notification of the rate allowed at the exchange.

The ECR value received by the source will clearly determine the maximum rate of the source.

The ECR value is calculated as in Equation 3 below.

<Equation 3>

0≤m≤31and0≤k≤511

5) Current cell rate (hereinafter referred to as CCR)

The CCR field contains information on the allowed transmission rate by the bandwidth request message transmitted by the sender.

The information in this field can optionally be used to calculate the ECR.

The same format and coding as the ECR field applies to the CCR field.

6) Minimum cell rate (hereinafter referred to as MCR)

This field contains the minimum data rate required for the connection peak.

The information in this field can optionally be used to calculate the ECR value.

The same format and coding as the ECR field applies to the MCR field.

7) Queue length

Cue length parameters are optionally supported by network elements.

Indicates the maximum number of current cells waiting for access between network elements that support this parameter.

The assigned network element records the current value of that field as the maximum value of this field and the number of cells is given as waiting to be connected in this network element.

0 is specified by the sender.

If a network element does not know the number of cells waiting to be connected to a given buffer in that network element, the network element will leave a field invariant.

8) Squence number

This field is a serial number that is increased as the sender sends a continuous bandwidth request. Source / Virtual Source optionally uses a serial number field.

The case where this field is applied is as follows.

(1) The consecutive number is always present in the bandwidth request message.

(2) Incremented each time a sender sends a bandwidth request message.

The sender does not use a serial number field whose value is set to zero.

As described in detail above, the present invention uses the out-band method in which the signal channel and the data channel are separated, so that the control of the ABR traffic can be controlled through the signal channel and the RM cell returned through the network can be used. Since there is no need for transmission delay, it is possible to know the changed situation on the network in real time, to calculate the accurate transmission rate, and to increase the link utilization rate, thus enabling efficient and economical use of network resources. .

In addition, in providing ABR services using the remaining bandwidth used by CBR or VBR, it is possible to provide services at a low price since it can reduce network occupancy time without fear of data loss.

In addition, preferred embodiments of the present invention are disclosed for the purpose of illustration, and those skilled in the art will be able to make various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the following claims Should be seen.

Claims (5)

An effective bit rate service setting process of controlling connection acceptance according to a service request by comparing the available bandwidth of the network with the required bandwidth when an effective bit rate service request is made; In the asynchronous transmission mode network, an available bandwidth request and allocation process is performed by allocating an effective bit rate set in the effective bit rate service setting process through a bandwidth allocation message. Effective bit rate traffic control method by signaling channel. The method of claim 1, The effective bit rate service setting process, A first step of requesting a new effective bit rate service; Requesting a new effective bit rate service, a second step of requesting free bandwidth that can be provided in the current network; A third step of comparing the bandwidth required in the second step with the available bandwidth provided by the current network; A fourth step of sending a service reception request to a sender in a call proceeding message when the free bandwidth is larger than the requested bandwidth; In the network, a fifth step of informing the bandwidth manager that the bandwidth manager allocated the bandwidth required in the free bandwidth; A sixth step of requesting a change in the change spare bandwidth; On the other hand, when the bandwidth required by the second step is larger than the free band, the seventh step of rejecting call acceptance; An effective bit rate traffic control method using a signaling channel in an asynchronous transmission mode network, characterized in that the sequential operation is performed in the eighth step of transmitting a release message. The method of claim 1, The available bandwidth request and allocation process, A first step of accepting a request for an available band of a network through a bandwidth request message from a source after an effective bit rate service call is accepted in a network in the effective bit rate service setting process; A second step of requesting the bandwidth manager for the currently available spare bandwidth according to the available band of the network received in the first step; Receiving a free bandwidth from the bandwidth manager; A fourth step of determining an allocated bandwidth in the network according to the number of effective bit rate services after the free bandwidth is received in the third step; In step 4, the bandwidth is notified to the sender through the bandwidth allocation message, and the process proceeds to the fifth step of switching to the standby state to process the next bandwidth request message. Effective bit rate traffic control method. The method of claim 3, wherein The method for determining the allocated bandwidth in the fourth step is using the following equation, Allocated bandwidth Where 1 to n are the number of ABR services Effective bit rate traffic control method using a signal channel in an asynchronous transmission mode network, characterized in that the equal distribution. The method of claim 3, wherein The method for determining the allocated bandwidth in the fourth step using the following equation, Allocated bandwidth Where 1 to n are the number of ABR services. Effective bit rate traffic control method using a signal channel in an asynchronous transmission mode network, characterized in that the weight (Weight).