KR20030031668A - Network traffic control method in voip - Google Patents

Abstract

PURPOSE: A network traffic control method in VoIP(Voice over Internet Protocol) is provided to prevent an overload of a network by controlling a VAD(Voice Activity Detection) or a frame size according to a network traffic. CONSTITUTION: A controller checks an RTP header of transmitted and received data packet for a certain time period and calculates a network traffic measurement value(S100). If the network traffic measurement value is judged to belong to a first reference range(S110), the controller maximizes the frame size(S115). If the network traffic measurement value is judged to belong to a second reference range(S120), the controller controls the frame size to be a middle value(S125). If the network traffic measurement value is judged to belong to a third reference range, the controller minimizes the frame size(S130).

Description

Network traffic control method in ｏＩＰ {NETWORK TRAFFIC CONTROL METHOD IN VOIP}

The present invention relates to a method for guaranteeing the quality of service in VoIP, and more particularly, to a method of controlling network traffic in VoIP, which guarantees the quality of service by preventing a network overload by adjusting the VAD or frame size according to the network traffic. .

Voice over Internet Protocol (VoIP) is a term that refers to IP telephony technology for a series of facilities that use IP to convey voice information. In general, this means that voice information is sent in digital form in discrete packets, rather than traditional protocols based on circuits such as PSTN, a public switched telephone network.

In addition to the original IP functionality, VoIP uses Real Time Transfer Protocol (RTP) to support timely arrival of packets. Using public networks is difficult to guarantee current quality of service. Better service is provided by private networks managed by independent companies or Internet telephony service providers.

The IP packet arrives at the destination terminal through the Internet through the NIC and the router driven by the device driver of the source terminal and is transmitted by UDP / IP in the Internet network. VoIP voice packet data using UDP / IP Unlike other transmission problems, many types of packets are likely to be mixed on transmission lines because many users share circuits in a network. That is, the voice data packet of a specific user is not transmitted as a single object but is divided and inserted between different data packets. UDP may be lost during transmission, or the order may be changed. As a result, when decoding the voice data packet received by the destination terminal, a distortion of the voice is likely to occur, and thus the receiver may hear an unnatural voice.

This is because, in the transmission process of a voice data packet of a specific user, if the interval between the packet and the packet is too long, voice breakage may occur in the decoding process requiring real time processing.

In order to solve the above problems, a method of first selecting and transmitting a voice packet among various types of data packets or a method of designating a specific band for voice data has been proposed. There is a disadvantage that cannot be prevented.

Accordingly, the present invention has been created to solve the above-mentioned conventional problems, and calculates network traffic measurement values, and enables the VAD or adjusts the packet frame size according to the calculated network traffic measurement values. Its purpose is to provide a network traffic control method in.

One embodiment of the present invention for achieving the above object comprises a first step of digitizing the network traffic measurement value by a predetermined criterion according to the degree of loss and reception interval of data packets transmitted and received for a predetermined period; A second step of determining a reference range to which the measured network traffic measurement value belongs among a plurality of reference ranges classified and set by the size of the network traffic measurement value; And a third step of controlling the frame size of the data packet according to the reference range to which the network traffic measurement value belongs, to transmit and receive, and returning to the first step after a predetermined period of time.

1 is a first embodiment of a system for implementing a network traffic control method in VoIP according to the present invention;

2 is a second embodiment of a system for implementing a network traffic control method in VoIP according to the present invention;

3 is a flowchart illustrating a network traffic control method in VoIP according to the present invention.

** Description of symbols for the main parts of the drawing **

10: Internet 20: Internet Phone

30: gateway 40: gateway control device

50: telephone exchange 60: telephone

70: PSTN

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings.

In the present invention, as shown in Figure 1, a built-in system, without a PC to independently make a call to the Internet, a plurality of Internet phones 20 for controlling traffic is connected to the Internet 10 Introduce a first system configuration.

The Internet phone 20 includes a codec unit 25 for processing A / D conversion, D / A conversion, volume control, and analog switch functions, an Ethernet connection unit 21 for processing access to the Internet and a PC, and an internet communication network. A CPU 22 having control software installed in the ROM for performing and controlling telephone transmission / reception algorithms for access and voice communication, a digital signal processing unit 24 that processes noise control, and has a voice compression and restoration function; And a user interface unit 23 for processing data input and a handset unit 26 for inputting and outputting a user's voice.

This is because the CPU 22 includes the network traffic adjustment algorithm of the present invention, and the digital signal processor performs a voice detection function or a data packet by performing a function such as encoding / decoding and volume control according to the control signal of the CPU 22. Enable frame size adjustment.

In addition, the present invention below, as shown in Figure 2, when providing a VoIP service through a general telephone supporting a telephone service, a telephone exchange (connecting a plurality of ordinary telephones 60 and the PSTN 70 ( 50, a plurality of gateways 30 relaying data so that data can be transmitted between the telephone exchange 50 and the Internet 30, and a gateway control device 40 controlling the plurality of gateways 30. Introduce a second system configuration that is configured.

The gateway 30 may include a codec unit 34 that processes voice compression and restoration, A / D conversion, D / A conversion, volume control, and analog switch functions, and a plurality of Ethernet connection units that handle connections with the Internet and a PC ( 31), a CPU 32 in which control software is installed in the ROM to perform and control an algorithm for accessing an internet communication network and voice communication, a digital signal processing unit 33, and an FXO / FXS interface unit 23. It is composed.

This means that the gateway control device 40 includes a network traffic adjustment algorithm, and the gateway 30 controls the voice detection function and the data packet frame size according to the control signal from the gateway control device 40. Make adjustments.

And, it will be appreciated that the preferred embodiments of the present invention may include embodiments such as computer systems and computer program products programmed to execute the network traffic control method in VoIP in the system described above. In accordance with an embodiment of a computer system, a set of instructions for executing a method resides in one or more memories, which set as a computer program product in memory, such as, for example, a hard disk, until needed by the computer system. Can be stored.

3 is a flowchart illustrating a network traffic control method in VoIP according to the present invention.

Referring to FIG. 3, the present invention includes the steps of digitizing a network traffic measurement value (S100), determining a reference range to which the network traffic measurement value belongs, (S110, S120, S130), and the network traffic measurement value. After adjusting a frame size of the data packet according to a reference range to support transmission and reception or driving a voice detection unit, a step (S115, S125, S135) is fed back to the step (S100) after a certain period of time.

Since the method of the present invention is implemented by the Internet phone 20 and the gateway control device 40 on the first system and the second system, respectively, performing the same algorithm in each CPU, each CPU will be described as a controller. Let's do it.

The control unit calculates a network traffic measurement value by checking an RTP header of a data packet transmitted and received for a predetermined period of time (S100). Although not shown in the drawing, the process will be described in more detail as follows.

The RTP header includes a packet sequence number and a time stamp, so that the controller calculates a packet loss rate from the packet sequence number and calculates jitter based on a reception interval between data packets from the time stamp. As the load increases, both packet loss and jitter increase.

Therefore, network traffic can be represented by a sum of packet loss rate and a certain ratio of jitter as shown in Equation 1 below.

Network traffic measurement base = A * packet loss rate + B * jitter. (Equation 1)

Here, A and B are weighted numbers, and 0 = A = 1, O = B = 1, and A + B = 1, and if only the packet loss rate is to be calculated in the network load calculation, A = 1, If you set B = 0 and only jitter is calculated, set A = 0 and B = 1 to operate this system.

In consideration of both factors, A and B may be appropriately set within the given range.

Since network traffic has an irregular and rapidly changing property with time, there is a problem that the network traffic measurement base proposed by the present invention also changes irregularly with time. Therefore, the network traffic measurement value is calculated through Equation 2 below to solve the above problems and to ensure service quality.

Network traffic measure

= Average of network traffic measurement base values over a period of time

+ Variance of network traffic measurement base value over a certain time interval (Equation 2)

The control unit sets a predetermined number of reference ranges according to the size of the network traffic measurement value as follows in order to adjust the network traffic according to the network traffic measurement value calculated by Equation (2).

** Reference range **

0 <network traffic measurement = first threshold ...... first range

First reference value <network traffic measurement value = second reference value ... second range

Second reference value <network traffic measurement value ... third range

The controller determines which of the first to third ranges the network traffic measurement value calculated in step S100 is to adjust the frame size.

That is, a large packet is likely to be lost in a situation where network traffic is high. Therefore, the smaller the packet size, the smaller the probability of packet loss.

First, when it is determined that the network traffic measurement value belongs to the first range (S110), the frame size is maximized (S115).

If it is determined that the measured value of the network traffic belongs to the second range (S120), the frame size is adjusted to an intermediate value (S125).

As a result of the determination of S120, when the network traffic measurement value falls within the third range, the frame size is minimized (S130).

However, the method of dividing one large packet into several smaller packets increases the load of the control unit, so that the network traffic measurement value falls within the third range and enables the VAD when the data packet increases.

The voice activity detection (VAD) refers to a method of sending a simple data indicating that the caller does not send a voice packet or is silent when the caller is silent to listen to the other party.

Using the method as described above, there is an advantage that can significantly reduce the RTP data transmitted to the network, but may have a disadvantage that you may feel a slight disconnection when the end of the silent period is over.

However, the degradation of service quality due to the call disconnection by using the VAD is much less than the degradation of voice quality due to packet loss.

After performing the steps S115, S125, and S130, the network traffic measurement value is calculated according to Equation 2 using the network traffic measurement base value calculated and stored for a predetermined period of time for performing the above-described process. Feedback.

The present invention is not limited to the embodiments described above, and various modifications and changes can be made by those skilled in the art, which are included in the spirit and scope of the present invention as defined in the appended claims.

As described above, the method for controlling network traffic in VoIP according to the present invention has the effect of reducing the network load and ensuring the quality of service.

Claims (4)

A first step of quantifying network traffic measurement values according to a predetermined criterion according to the degree of loss and reception interval of data packets transmitted and received for a predetermined period; A second step of determining a reference range to which the measured network traffic measurement value belongs among a plurality of reference ranges classified and set by the size of the network traffic measurement value; And a third step of controlling the frame size of the data packet according to the reference range to which the network traffic measurement value belongs, to transmit and receive, and returning to the first step after a predetermined period of time. How to control network traffic. The method of claim 1, wherein the first step Calculating a network traffic measurement base value by summing packet loss rate and jitter calculated by checking the packet sequence number and time stamp included in the RTP header of the transmitted and received data packets according to a predetermined ratio (1-1) )Wow; And calculating (1-2) a network traffic measurement value comprising a sum of an average and a variance of the network traffic measurement base values calculated for a predetermined time. The method of claim 1 or 2, wherein the second step When the network traffic measurement value is within the maximum reference range, the VAD for detecting the voice packet is not activated in the transmitted and received data packet to transmit the data indicating that the detected voice packet is not transmitted or that it is a silent period. A method for controlling network traffic in VoIP, which is enabled. The method of claim 1 or 2, wherein the first step is Based on the packet loss rate calculated by checking the packet sequence number and the jitter which is the reception interval between data packets calculated from the time stamp, the network traffic measurement base value is calculated according to Equation 1 below. Network traffic measurement method according to claim 1). Network traffic measurement base = A * packet loss rate + B * jitter. (Equation 1) Network traffic measure = Average of network traffic measurement base values over a period of time + Variance of network traffic measurement base value over a certain time interval (Equation 2)