KR20070072952A - Apparatus and method for providing congestion information in packet network - Google Patents

Abstract

A congestion information service device in a packet network and a method thereof are provided to effectively control congestion while packet loss caused by congestion is reduced and given bandwidths are sufficiently used. If a packet network is in congested state, a packet congestion marking unit(125) marks congestion information in a particular field of a received packet after receiving the packet transmitted by a transmission node(110). If the packet network is in the congested state, an acknowledgement congestion marking unit(225) marks congestion information in a particular field of a received response packet after receiving the response packet sent from a receiving node(130).

Description

Apparatus and method for providing congestion information in a packet network {APPARATUS AND METHOD FOR PROVIDING CONGESTION INFORMATION IN PACKET NETWORK}

1 is a diagram illustrating a process of marking congestion information in an existing intermediate node;

2 is a diagram illustrating a process of marking congestion information in an intermediate node according to an embodiment of the present invention;

3 is a flowchart illustrating an operation process of a packet congestion information marking unit of an intermediate node according to an embodiment of the present invention;

4 is a flowchart illustrating an operation process of a response congestion information marking unit of an intermediate node according to an embodiment of the present invention;

5 is a diagram comparing packet occupancy rate of a queue of a technology according to an embodiment of the present invention with packet occupancy rate of a queue of an existing technology, and

6 is a diagram comparing packet loss rate of a technique according to an embodiment of the present invention and packet loss ratio of a conventional technique.

The present invention relates to a packet network, and more particularly, to an apparatus and a method for transmitting congestion information by using an intermediate node between a transmitting and a receiving node.

The packet network has been developed by replacing the circuit network, which is the main method of communication, with the rapid use of the Internet.

In general, when a specific node communicates with a counterpart node using the packet network, the specific node, which is a transmitting node, controls so that the amount of data transmission being transmitted does not exceed the amount that can be handled by the receiving node. .

Song on the packet network. Receiving nodes can be intuitively distinguished, but since packet transmission and reception proceed in both directions, the transmitting node may be the receiving node and the receiving node may be the transmitting node as well.

The method of controlling the data transmission amount of the transmitting node to be an amount that can be processed by the receiving node is called flow control, and the flow control method mainly used is as follows.

Firstly, it is a stop-and-wait method, which means that a transmitting node can transmit only one frame at a time and the receiving node notifies whether transmission is possible.

Secondly, in the sliding window method, this means that the transmitting node can continuously transmit as many frames as the window size and the receiving node adjusts the window size to communicate.

When optimistically grasping the network state in the flow control, the end node transmits more traffic than the network can accept, thereby causing congestion in the network. On the contrary, pessimism may not fully utilize network resources.

1 illustrates a process of marking congestion information in an existing intermediate node.

Referring to FIG. 1, the packet congestion marking unit 125 of the intermediate node 120 indicates that congestion occurs by marking a specific field of a received packet header when congestion occurs during packet transmission.

The receiving node 130 receiving the marked packet may determine whether congestion occurs according to the marking or not, and transmits by marking whether the packet is congested.

Finally, the transmitting node 110 can solve the congestion on the packet network by adjusting the transmission speed by determining the congestion degree on the packet network according to the congestion information marked on the response packet.

For example, when congestion occurs, the intermediate node 120 marks whether the packet is congested in the IP packet header, and when the receiving node 130 receives the marked IP packet, ECN (Explicit Congestion Notification) of the TCP response packet is again. It is delivered to the transmitting node 110 by marking whether the flag is congested.

In the technique of FIG. 1, the time taken from the time of congestion to reducing the transmission speed is determined by an end-to-end delay. Therefore, when there is a low speed link on the path between the transmitting node 110 and the receiving node 130, there is a problem that effective congestion control is difficult.

For example, when the transmitting node 110 is in a wired network and the receiving node 130 is in a wireless network, the probability of congestion is high due to the low speed of the wireless network.

In this case, the congestion information is transmitted to the receiving node 130 through a low speed wireless network, and the receiving node 130 transmits the congestion information to the transmitting node 110 again through a low speed wireless network and a wired network. To pass).

Therefore, in order to transmit the fact of congestion from the time point of congestion to the transmitting node 110, the wireless network must pass twice. There is a problem with large delay time.

In addition, even if the reception node 130 is notified of congestion before congestion occurs, the reception node 130 has a problem that packet congestion may be avoided because of congestion due to a large delay time.

In addition, since the congestion control takes a lot of time, even after the transmitting node 110 or the receiving node 130 is out of congestion, it takes a long time to recover to the original normal speed, so that a given bandwidth cannot be utilized well. have.

Accordingly, an object of the present invention is to provide an apparatus and method for providing congestion information capable of fast congestion control in a packet network.

An apparatus of the present invention for solving the above problems is a device for providing congestion information of an intermediate node in a packet network consisting of a transmitting node, an intermediate node, and a receiving node, when the packet network is in a congestion state, the transmitting node After receiving the packet transmitted by the server, the packet congestion marking unit for marking congestion information in a specific field of the received packet, and when the packet network is in a congestion state, after receiving the response packet sent by the receiving node, And a response congestion marking unit for marking congestion information in a specific field of the received response packet.

The method of the present invention for solving the above problems is a method for providing congestion information of an intermediate node for a packet transmitted by a transmitting node in a packet network consisting of a transmitting node, an intermediate node, and a receiving node. Receiving, by the intermediate node, the transmitted packet; and, if the packet network is congested after the receiving process, marking the congestion information in a specific field of the received packet by the packet congestion marking unit of the intermediate node; And after the marking process, transmitting the marked packet to a receiving node.

According to another aspect of the present invention, there is provided a method of providing congestion information of an intermediate node with respect to a response packet transmitted by a receiving node in a packet network including a transmitting node, an intermediate node, and a receiving node. The intermediate node receives the response packet transmitted by the node, and if the packet network is congested after the receiving process, the congestion marking unit of the intermediate node provides congestion information to a specific field of the received response packet. Marking process, and after the marking process, characterized in that it comprises the step of transmitting the marked response packet to the transmitting node.

Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed descriptions of related well-known technologies or configurations will be omitted when it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention.

Hereinafter, the present invention will be described an apparatus and method for providing congestion information in a packet network.

2 illustrates a process of marking congestion information in an intermediate node according to an embodiment of the present invention.

Referring to FIG. 2, the function of the packet congestion marking unit 125 is the same as that of the packet congestion marking unit 125 of FIG. 1. That is, the intermediate node 220 checks whether the packet is congested or not. For example, if the packet is congested, the intermediate node 220 marks the packet header.

The response congestion marking unit 225 of the intermediate node 220 checks whether or not congestion is received when receiving a response packet. In case of congestion, the header of the response packet is marked as congestion. For example, set the "ECN-Echo" flag in the TCP response packet to 1.

3 is a flowchart illustrating an operation of a packet congestion information marking unit of an intermediate node according to an embodiment of the present invention.

Referring to FIG. 3, the packet congestion marking unit 125 of the intermediate node 220 checks whether the current network state is congested when the packet arrives in step 305, that is, when the packet is received in step 305. do.

If the network state is not in the congestion state in step 310, the flow proceeds to step 305.

If the network state is congested in step 310, the flow proceeds to step 315 to mark whether the packet is congested. Thereafter, the process from step 305 is repeated and the algorithm according to the present invention is terminated.

4 is a flowchart illustrating an operation of a response congestion information marking unit of an intermediate node according to an exemplary embodiment of the present invention.

Referring to FIG. 4, when the response packet arrives in step 405, that is, when the response packet is received in step 405, the response congestion marking unit 225 of the intermediate node 220 proceeds to step 410. Check for cognition.

If the network state is not at step 410, the process proceeds to step 405.

If the network state is congested in step 410, the process proceeds to step 415 and marks whether the network packet is congested in the header of the received response packet. Thereafter, the process from step 405 is repeated and the algorithm according to the present invention is terminated.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

5 compares the packet occupancy rate of a queue of a technology according to an embodiment of the present invention with the packet occupancy rate of a queue of a conventional technology.

Referring to FIG. 5, in the conventional method, the buffer overflow and the buffer unused state are repeatedly generated, but it can be confirmed that the buffer overflow or the buffer unused is hardly applied when the present invention is applied. In other words, you can see that you are using the given bandwidth faithfully.

6 compares the packet loss rate of a technique according to an embodiment of the present invention with the packet loss rate of a conventional technique.

Referring to FIG. 6, it can be seen that packet loss due to congestion is reduced compared to the existing technology when the present invention is applied.

As described above, the present invention has an advantage of enabling effective congestion control by quickly delivering congestion information. In addition, there is an advantage that can reduce the packet loss due to the congestion and use the given bandwidth faithfully.

Claims (10)

An apparatus for providing congestion information of an intermediate node in a packet network including a transmitting node, an intermediate node, and a receiving node, A packet congestion marking unit for marking congestion information in a specific field of the received packet after receiving a packet transmitted by the transmitting node when the packet network is congested; And a response congestion marking unit for marking congestion information in a specific field of the received response packet after receiving the response packet transmitted by the receiving node when the packet network is in a congestion state. The method of claim 1, And the packet congestion marking unit marks the congestion information on a specific field in the received packet header. The method of claim 1, And the response congestion marking unit marks the congestion information on a specific field in the received response packet header. The method of claim 1, And at least one intermediate node. In a packet network comprising a transmitting node, an intermediate node, and a receiving node, a method of providing congestion information of an intermediate node with respect to a packet transmitted by a transmitting node, Receiving, by the intermediate node, a packet transmitted by the transmitting node; After the receiving process, when the packet network is in a congestion state, marking the congestion information in a specific field of the received packet by the packet congestion marking unit of the intermediate node; And after the marking, transmitting the marked packet to a receiving node. The method of claim 5, And the packet congestion marking unit marks the congestion information on a specific field in the received packet header. The method of claim 5, And at least one said intermediate node. In a packet network comprising a transmitting node, an intermediate node, and a receiving node, a method for providing congestion information of an intermediate node with respect to a response packet transmitted by a receiving node, Receiving, by the intermediate node, a response packet transmitted by the receiving node; After the reception process, when the packet network is in a congestion state, marking the congestion information in a specific field of the response packet by the response congestion marking unit of the intermediate node; After the marking process, transmitting the marked response packet to a transmitting node. The method of claim 8, And the response congestion marking unit marks the congestion information on a specific field in the received response packet header. The method of claim 8, And at least one said intermediate node.

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