KR20040077249A - Method of Nonlinear traffic congestion control in eithernet - Google Patents

Abstract

PURPOSE: An apparatus and a method for controlling nonlinear traffic congestion in an Ethernet network are provided to reduce a system load by enabling each Ethernet switch to periodically transmit nonlinear burst traffics to a concentration Ethernet switch and the concentration Ethernet switch to prevent an overflow. CONSTITUTION: An overflow detector(10) sets an overflow threshold value for packets received from Ethernet switches. An overflow event generator(12) generates an overflow generation/release event and transmits it to a packet transmission permission token generator(14) and an overflow event receiver(20). A packet transmission permission token generator(14) periodically generates a packet transmission permission token and transmits it to a packet transmission permission token receiver(24). An overflow event receiver(20) receives the overflow generation/release event and informs a TCP connection controller(22) and a packet transmission flow controller(26). When the TCP connection controller(22) is informed the reception of overflow generation event from the overflow event receiver(20), it sets a TCP session connection between an Ethernet switch(200) and a concentration Ethernet switch(100). When the packet transmission permission token receiver(24) receives the packet transmission permission token from the packet transmission permission token generator(14), it requests packet transmission of an Ethernet switch from the packet transmission flow controller(26). The packet transmission flow controller(26) generates a queue for temporarily storing packets to be transmitted to the concentration Ethernet switch and then transmits packets according to a request from the packet transmission permission token receiver(24).

Description

Nonlinear traffic congestion control apparatus and method in Ethernet network {Method of Nonlinear traffic congestion control in eithernet}

The present invention relates to an apparatus and method for controlling nonlinear traffic congestion in an Ethernet switch network. More particularly, when an overflow occurs, a TCP session is established between an Ethernet switch and a converged Ethernet switch and UDP packets are transmitted through the TCP session. It relates to an apparatus and a method.

Ethernet is the most widely installed local area network technology, with dozens to hundreds of Mbps.

1 is a block diagram of a general Ethernet network.

The aggregation Ethernet switch 100 receives the packet from the lower Ethernet switch 200, aggregates it, and transfers the packet to another network. The Ethernet switch 200 has a plurality of ports, and accommodates each subscriber computer 200a through the ports.

The converged Ethernet switch or Ethernet switch temporarily stores the packets coming in through each port in the input buffer and transmits them to the destination. When the Ethernet switch is overloaded, the processing time of packets stored in the input buffer is delayed and the input buffer overflows. At this time, TCP packets are retransmitted among the packets that cannot be stored in the input buffer, but UDP packets are discarded. This is called data loss in Ethernet switches.

On the other hand, an example of an Ethernet network in which an Ethernet switch accommodates a large number of computers is an Internet PC room. Most of the users of the PC room use the game service, and the traffic generated by the game service is very bursty and is a non-linear 64 byte small UDP packet. Due to such a large number of small UDP packets, not only Ethernet switches installed in each PC room but also converged Ethernet switches of a telephone company (service provider) that aggregate and switch packets generated from these Ethernet switches are used to process these small packets. Overheading causes serious switch degradation.

In particular, when a large number of users accommodated in the Ethernet switch instantaneously use a service such as a game, packet loss occurs due to a decrease in the performance of the switch, and the reliability of the game service cannot be guaranteed.

In fact, the average amount of traffic generated in the PC room is only about 10% of the capacity of the Ethernet switch itself, but due to the characteristics of the traffic in the PC room, the Ethernet switch does not normally process the packet at the time of switching the PC room and discards the packet. Cases often occur. This problem is more affected by the aperiodic of bursted traffic than the bursty nature of the traffic. That is, the Ethernet switch is not heavily loaded with burst traffic with a certain period, but is heavily loaded by burst traffic with aperiodic, i.e., small 64 byte traffic that is bursted momentarily.

Conventionally, in order to solve this problem, a method has been proposed in which sufficient memory is provided in the Ethernet switch on the subscriber side and the aggregation Ethernet switch to allow a buffer on each interface connected to the Ethernet switch on each subscriber side. There is a problem of an increase in the price of the Ethernet switch due to the addition of memory.

In addition, most current Ethernet switches have one shared memory, so that traffic of each subscriber side is simultaneously processed in the shared memory, which is also a heavy load to handle bursty traffic in one shared memory. There is a problem that takes.

An object of the present invention for solving the problems of the prior art as described above, when detecting the overflow of the buffer in the aggregation Ethernet switch, the Ethernet switch establishes a TCP session, and transmits UDP packets to the aggregation Ethernet switch through the TCP session It is to provide an apparatus and method for.

1 is a configuration diagram of a general Ethernet network,

2 is a block diagram of a nonlinear traffic congestion control apparatus according to the present invention;

3 is a data flow diagram between an aggregation Ethernet switch side and an Ethernet switch side according to the present invention;

4 is a flowchart illustrating a method for controlling nonlinear traffic congestion between an aggregation Ethernet switch and an Ethernet switch according to the present invention.

※ Explanation of code about main part of drawing ※

100: aggregation ethernet switch,

200: subscriber Ethernet switch,

10: overflow detector,

12: overflow event generator,

14: allow token send packet generator,

20: overflow event receiver,

22: TCP connection controller,

24: token receiver allowing packet transmission,

26: packet transmission flow regulator,

In order to achieve the above object, the present invention provides an Ethernet switch for transmitting a packet generated from a lower computer to a higher layer using a plurality of ports, and temporarily storing the packet transmitted from the Ethernet switch in its buffer. An apparatus for controlling traffic congestion between the aggregation Ethernet switch and the Ethernet switch in an Ethernet network including an aggregation Ethernet switch transmitting to another network, the apparatus comprising: an overflow detector for detecting whether the buffer overflows or is released; An overflow event generator for generating an overflow occurrence event when an overflow occurs in the buffer, and generating an overflow release event when the overflow is released; A TCP connection controller configured to establish a TCP session connection between the aggregation Ethernet switch and the Ethernet switch when the overflow occurrence event occurs; A packet transmission permission token generator for generating a packet transmission permission token that allows packet transmission through the TCP session when the overflow occurrence event occurs; And temporarily storing a UDP packet to be transmitted from the Ethernet switch to the aggregation Ethernet switch in a queue when the overflow occurrence event occurs, and when the packet transmission permission token occurs, the UDP packet stored in the queue is transmitted through the TCP session. Non-linear traffic congestion control device comprising a packet transmission flow regulator to be transmitted to the aggregation Ethernet switch.

The method of controlling traffic congestion between the aggregation Ethernet switch and the Ethernet switch, the method comprising: detecting whether or not the buffer overflows or occurs; Generating an overflow occurrence event when an overflow occurs in the buffer; A third step of establishing a TCP session connection between the Ethernet switch and the aggregation Ethernet switch and temporarily storing a UDP packet to be transmitted from the Ethernet switch to the aggregation Ethernet switch when the overflow occurrence event occurs; And a fourth step of transmitting the queued UDP packet to the aggregation Ethernet switch through the TCP session when a packet transmission permission token for allowing packet transmission through the TCP session is generated. Provides a congestion control method.

Hereinafter, an apparatus and method for controlling congestion of nonlinear traffic in an Ethernet network according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a nonlinear traffic congestion control apparatus according to the present invention.

This non-linear traffic congestion control apparatus includes an overflow detector 10, an overflow event generator 12, a packet transmission allowance token generator 14, an overflow event receiver 20, a TCP connection controller 22, and a packet transmission allowance. Token receiver 24 and packet transmission flow regulator 26;

The overflow detector 10, the overflow event generator 12, and the packet transmission permission token generator 14 are configured on the aggregation Ethernet switch 100 side, and the overflow event receiver 20, the TCP connection controller 22, The packet transmission permission token receiver 24 and the packet transmission flow regulator 26 are configured on the Ethernet switch 200 side.

The overflow detector 10 sets an overflow threshold for packets received from the Ethernet switches, which is set to 70% of the total buffer amount. After detecting whether an overflow occurs for a packet in a buffer (not shown), the overflow event generator 12 is notified whether the overflow occurs.

The overflow event generator 12 generates an overflow occurrence / release event and transmits it to the packet transmission permission token generator 14 and the overflow event receiver 20 according to whether an overflow occurs in the buffer.

The packet transmission permission token generator 14 periodically generates a packet transmission permission token and transmits it to the packet transmission permission token receiver 24 so that the Ethernet switch 200 can periodically transmit the packet to the aggregation Ethernet switch 100. do.

The overflow event receiver 20 receives the overflow occurrence / release event from the overflow event generator 12 and then notifies the TCP connection controller 22 and the packet transmission flow controller 26 of this.

The TCP connection controller 22 establishes a TCP session connection between the Ethernet switch 200 and the aggregation Ethernet switch 100 when the overflow event receiver 20 receives notification of the overflow occurrence event. Once such a TCP session connection is established, the Ethernet switch can send packets to the aggregation Ethernet switch using the TCP session.

When the packet transmission permission token receiver 24 receives the packet transmission permission token from the packet transmission permission token generator 14, it requests the packet transmission flow controller 26 to transmit the packet of the Ethernet switch.

In response to the packet transmission request, the packet transmission flow controller 26 creates a queue (not shown) that can temporarily store packets to be transmitted to the aggregation Ethernet switch, and requests the packet transmission allowance token receiver 24 according to the request. Perform the transfer.

3 is a data flow diagram between an aggregation Ethernet switch side and an Ethernet switch side according to the present invention.

When the aggregation Ethernet switch side notifies the Ethernet switch side of an overflow occurrence event, a TCP session connection is established between the aggregation Ethernet switch and the Ethernet switch. (S300, S302) The aggregation Ethernet switch side allows the packet transmission while the TCP session connection is established. When the token is transmitted to the Ethernet switch side, the Ethernet switch side transmits the UDP packet to the aggregation Ethernet switch using a TCP session (S304, S306).

When the overflow of the aggregation Ethernet switch buffer is released and the aggregation Ethernet switch side notifies the Ethernet switch side of the overflow release event, the TCP session connection between the aggregation Ethernet switch and the Ethernet switch is released (S308, S310). The UDP packet is transmitted using the scheme of S (S312).

4 is a flowchart illustrating a nonlinear traffic congestion control method between an aggregation Ethernet switch and an Ethernet switch according to the present invention.

The converged Ethernet switch temporarily stores packets transmitted from the Ethernet switch in a buffer and transmits them to another network. The nonlinear traffic congestion control apparatus according to the present invention detects whether or not an overflow occurs with respect to the buffer. That is, the occupancy amount A of the unprocessed packet of the aggregation Ethernet switch buffer is detected, and the overflow threshold B set to 70% of the total buffer amount is calculated. Then, it is detected whether the buffer overflow occurs by comparing the two values (A, B) (S400).

As a result of detecting whether the buffer overflow has occurred, it is recognized that the overflow has occurred when the packet occupancy amount A exceeds the overflow threshold B. (S402)

When the aggregated Ethernet switch buffer overflows, the UDP packet transmitted from the Ethernet switch is discarded, and since retransmission is not possible for the discarded UDP packet, in the present invention, when the buffer of the aggregated Ethernet switch overflows, Allow UDP packets to be sent over a TCP session.

This will be described in detail. When the buffer of the aggregation Ethernet switch overflows, the overflow event generator generates an overflow occurrence event and notifies the packet transmission permission token generator, the TCP connection controller and the packet transmission flow controller of the Ethernet switch side (S404).

When the TCP connection controller of the Ethernet switch side is notified of the overflow occurrence event through the overflow event receiver, the TCP connection controller establishes a TCP session connection between the Ethernet switch and the aggregation Ethernet switch (S406).

When the overflow transmission event is notified through the overflow event receiver, the packet transmission flow controller on the Ethernet switch side creates a queue to temporarily store UDP packets generated from the Ethernet switch, and temporarily stores the UDP packets to be generated in the queue. (S408)

On the other hand, the packet transmission allowable token generator on the aggregation Ethernet switch side periodically generates a token that allows packet transmission through the TCP session and transmits it to the packet transmission flow controller on the Ethernet switch side (S410).

When the packet transmission flow token is received through the packet transmission permission token receiver, the packet transmission flow controller on the Ethernet switch side transmits the UDP packet temporarily stored in the queue to the aggregation Ethernet switch using a TCP session.

As described above, the overflow detector also monitors the aggregation Ethernet switch buffer status while transmitting UDP packets using a TCP session.If the packet occupancy (A) of the buffer is lower than the overflow threshold (B), the buffer overflow previously It is checked whether the flow is in the flow state (S414). If it was not the buffer overflow state before, the flow returns to step S400 to continuously monitor the state of the buffer.

If the buffer overflow was previously released, the overflow event generator generates an overflow release event and sends it to the packet transmission allowance token generator and the TCP connection controller and packet transmission flow controller on the Ethernet switch side. (S416)

The packet send allow token generator stops generating packet send allow tokens. On the other hand, the TCP connection controller on the Ethernet switch side releases the TCP session connection between the preset Ethernet switch and the aggregation Ethernet switch (S418).

Thereafter, the Ethernet switch transmits the UDP packet to the aggregation Ethernet switch using a unique scheme, and continuously monitors the aggregation Ethernet switch buffer status at the step S400 (S420).

While the invention has been described above based on the preferred embodiments thereof, these embodiments are intended to illustrate rather than limit the invention. It will be apparent to those skilled in the art that various changes, modifications, or adjustments to the above embodiments can be made without departing from the spirit of the invention. Therefore, the protection scope of the present invention will be limited only by the appended claims, and should be construed as including all such changes, modifications or adjustments.

As described above, according to the present invention, the aggregated Ethernet switch periodically transmits a token for allowing packet transmission to each Ethernet switch, and the Ethernet switch performs packet transmission through a TCP session connection establishment, whereby each Ethernet switch is nonlinear. Burst traffic can be sent periodically to the aggregation Ethernet switch, which can reduce system load by preventing overflow.

Claims (9)

Ethernet switch that transmits packets from lower computers to upper layers using multiple ports, and converged Ethernet switches that temporarily store packets from the Ethernet switches in their buffers and then transfer them to other networks. An apparatus for controlling traffic congestion between an aggregated Ethernet switch and an Ethernet switch in an Ethernet network, An overflow detector for detecting whether the buffer overflows or is released; An overflow event generator for generating an overflow occurrence event when an overflow occurs in the buffer, and generating an overflow release event when the overflow is released; A TCP connection controller configured to establish a TCP session connection between the aggregation Ethernet switch and the Ethernet switch when the overflow occurrence event occurs; A packet transmission permission token generator for generating a packet transmission permission token that allows packet transmission through the TCP session when the overflow occurrence event occurs; And When the overflow occurrence event occurs, the UDP packet to be transmitted from the Ethernet switch to the aggregation Ethernet switch is temporarily stored in a queue, and when the packet transmission permission token is generated, the UDP packet stored in the queue is aggregated through the TCP session. Non-linear traffic congestion control device comprising a packet transmission flow regulator to be sent to the Ethernet switch. The method of claim 1, And the TCP session connection is terminated when the overflow release event occurs, and the packet generated from the Ethernet switch is transmitted to the aggregation Ethernet switch in a unique transmission manner. The method of claim 1, And the packet transmission permission token generator periodically generates a packet transmission permission token according to a state of a buffer of the aggregation Ethernet switch. The method of claim 1, The overflow detector, the overflow event generator, and the packet transmission permission token generator are configured in the aggregation Ethernet switch, and the TCP connection controller and the packet transmission flow controller are configured in the Ethernet switch. Congestion control device. Ethernet switch that transmits packets from lower computers to upper layers using multiple ports, and converged Ethernet switches that temporarily store packets from the Ethernet switches in their buffers and then transfer them to other networks. In the Ethernet network to control traffic congestion between the aggregation Ethernet switch and the Ethernet switch, Detecting whether or not the buffer overflows; Generating an overflow occurrence event when an overflow occurs in the buffer; A third step of establishing a TCP session connection between the Ethernet switch and the aggregation Ethernet switch and temporarily storing a UDP packet to be transmitted from the Ethernet switch to the aggregation Ethernet switch when the overflow occurrence event occurs; And And a fourth step of transmitting the UDP packet stored in the queue to the aggregation Ethernet switch through the TCP session when a packet transmission permission token for transmitting the packet through the TCP session is generated. Control method. The method of claim 5, wherein The packet transmission permission token in the fourth step is generated periodically according to the state of the buffer of the aggregation Ethernet switch. The method of claim 5, wherein And generating an overflow release event when the overflow is cleared. The method of claim 7, wherein And terminating the TCP session connection when the overflow release event occurs, so that packets from the Ethernet switch are transmitted to the aggregation Ethernet switch in a unique manner. On the computer, A first step of detecting whether an overflow / release of a buffer of a converged Ethernet switch temporarily storing a packet transmitted from the Ethernet switch; Generating an overflow occurrence event when an overflow occurs in the buffer; Setting a TCP session connection between the Ethernet switch and the aggregation Ethernet switch when the overflow occurrence event occurs, and temporarily storing a UDP packet to be transmitted from the Ethernet switch to the aggregation Ethernet switch in a queue; And When a packet transmission permission token is generated that permits packet transmission through the TCP session, the program for executing the fourth step of transmitting the UDP packet stored in the queue to the aggregation Ethernet switch through the TCP session can be read by a computer. Recording media.