KR20000072520A - Method for transferring voice data with priority using QoS mechanism - Google Patents

Abstract

Through the implementation of VoIP Quality of Service (QoS) mechanism that allows VoIP voice packets to be extracted and transmitted on a per-object basis, the VoIP voice packets are first transmitted through an Internet Protocol (IP) -based network. Disclosed is a voice data priority transmission method using a QoS mechanism that enables high quality voice data transmission by reducing the possibility of multiple types of packets being mixed on a transmission line because many users share it.

According to the present invention, since VoIP voice packets are transmitted as one entity, it is possible to maintain continuity of voice in real time processing of voice packet decoding at a destination terminal, thereby enabling high quality voice service through the Internet.

Description

Method for transferring voice data with priority using QoS mechanism}

The present invention relates to a method of prioritizing voice data using a QOS mechanism. More particularly, when a VoIP voice packet is transmitted using an IP (Internet Protocol) based network, a VoIP quality of service (QoS) mechanism is used for a VoIP based user. It is located in the middle of the terminal and the router to distinguish VoIP voice packet and other packets by the above mechanism, and then extracts and transmits voice packets first and then transmits other packets. The present invention relates to a voice data priority transmission method using a QoS mechanism that reduces the possibility of kinds of packets being mixed on a transmission line and enables high quality voice data transmission.

VoIP is a term that refers to IP telephony technology for a set of facilities that deliver voice information using IP. In general, this means that voice information is sent in digital form within discrete packets, rather than a traditional protocol based on the circuit, such as PSTN, a public switched telephone network. The main advantage of VoIP and Internet telephony technology is that it integrates telephone service by utilizing existing IP network, allowing telephone users to receive long-distance and international phone service in internet and intranet environment with only local call charge.

VoIP uses Cisco Forums, Vocaltec, 3Com, and NetSpeak through the VoIP Forum to encourage the use of ITU-T H.323, the standard for transporting voice (sound) and video over IP over the public Internet or intranets within the enterprise. This was done by the efforts of major equipment manufacturers. The VoIP Forum also encouraged service standards to enable users to locate other users and to use touch phone signals for automatic phone distribution and voicemail.

In addition to the original IP functionality, VoIP uses Real-time Transfer Protocol (RTP) to support timely arrival of packets. Using public networks makes it difficult to guarantee current quality of service (QoS). Better service can be achieved by using a private network managed by an independent company or an Internet Telephony Service Provider.

To use VoIP, companies must install VoIP equipment, such as Cisco's AS5300 Access Server, at the gateway. The gateway receives voice data divided into packets from users in the company and sends it to other parts of the intranet or forwards them to a public switched telephone network (PSTN) using the T1 or E1 interface.

In order to implement the high quality service of VoIP, the effective design of the above-mentioned QoS mechanism is required. QoS on the Internet or other network can be measured, improved, and measured and improved to some extent. It is an idea. QoS has special meaning when it is necessary to continuously transmit high band video and multimedia information. It is very difficult to deliver this kind of content reliably over public networks (with best efforts as in other cases). Using the Internet's Resource reSerVation Protocol (RSVP), packets passing through the gateway host can be processed quickly according to predefined policies and reservation criteria. Using Asynchronous Transfer Mode (ATM), which allows companies or users to pre-select the quality of service, QoS is measured in the form of average delay at the gateway, delay in the group of cells, cell loss, and transmission error rate. And can be guaranteed.

1 illustrates a method of transmitting voice data to the Internet using VoIP.

In the first step, the speaker's analog voice signal is coded into pulse code modulation (PCM) bit stream data that has been sampled and quantized.

In the second step, a predetermined filtering algorithm is applied to remove the noise component of the coded bit stream (noise here includes not only simple noise but also all signals capable of distorting the normal speech signal). This step also applies a Voice-Activity Detection (VAD) algorithm to the bit stream to find the silence period. Compression on silent data can save transmission bandwidth.

In the third step, the bit stream data is compressed and framed in an International Telecommunication Union (ITU) standardized format.

In the fourth step, the compressed voice frame is converted into an IP packet, and the conversion is performed in each of the following steps.

1. An RTP packet is created by adding a header related to a Real-time Transport Protocol (RTP) to a compressed voice frame.

2. UDP (User Datagram Protocol) related headers are added to the RTP packet together with the send and receive socket numbers to generate UDP packets.

3. An IP packet is generated by adding an IP header having the IP addresses of the sending and receiving gateways to the UDP packet.

In the fifth step, the generated IP packet is transmitted to the Internet. In the sixth step, the receiving VoIP system extracts the IP packet, the UDP packet, and the RTP packet, extracts the compressed voice frame, decodes the analog voice signal, and then decodes the voice signal. Will play.

The IP packet arrives at the destination terminal through the internet network through a network interface card (NIC) and a router (router) driven by the device driver of the source terminal, and is transmitted by UDP / IP in the internet network. The problem with the transmission of VoIP voice packet data using UDP / IP is that unlike UDP, since many users share circuits in a network, many packets are likely to be mixed on the transmission line. oriented way). That is, voice data packets (IP packets) of a specific user are not transmitted as a single object but are divided and inserted between other data packets (for example, voice data packets of other users and data packets other than voice). Is sent. As a result, when the voice data packet received by the destination terminal is decoded, the distortion of the voice is likely to occur, so that the receiver may hear an unnatural voice (because the packet and the packet during the transmission of the voice data packet of a specific user). If the interval is too long, the speech may be interrupted during the decoding process that requires real-time processing).

Accordingly, an object of the present invention is to provide a VoIP quality of service (QoS) mechanism for transmitting VoIP voice packets using an IP (Internet Protocol) based network. In the middle, it divides VoIP voice packet and other packet by the above mechanism, extracts the voice packet first and transmits it by one entity, and then transmits other packet, so that many users share circuits in UDP network. The present invention provides a voice data priority transmission method using a QoS mechanism that reduces the possibility of various types of packets being mixed on a transmission line and enables high quality voice data transmission.

1 illustrates a method of transmitting voice data to the Internet using VoIP.

2 is an exemplary diagram schematically illustrating a transmission aspect of a VoIP voice packet after undergoing QoS mechanism and classification;

3A is a flow diagram of a UDP protocol based classification method.

3b is a flow diagram of an RTP protocol based classification method.

3c is a flowchart of a speech codec information based classification method of a user terminal.

3d is a flow diagram of an IP address based classification method.

In order to achieve the above object, the voice data transmission method in the present invention is performed by the QoS mechanism schematically shown in FIG. This QoS mechanism is located between the user terminal and the router, and is implemented in the data link layer of Open Systems Interconnection (OSI).

QoS mechanism is composed of VoIP classifier, Queues (VoIP packet queue (VoPQ) + other packet queue (BEQ)), Priority scheduler as shown in FIG. VoIP classifier classifies packets coming from user terminal into VoIP related voice packets and other packets and inserts VoIP packets into VoPQ and inserts other packets into BEQ. Other packets are voice data packets of other users, data packets other than voice, and the like, as mentioned above. Priority scheduler gives priority to transmission of VoPQ packets and transmits packets of BEP prior to the transmission of VoPQ packets.

After all, the core of the present invention comes down to how VoIP classifier classifies VoIP voice packets.

In the method of classifying VoIP voice packets by VoIP classifier, the present invention proposes the following four proposals.

1. UDP protocol based classification method

A first step of determining whether an incoming packet is a VoIP packet; if the UDP packet is a UDP packet, a second step of transmitting a UDP packet to VoPQ; otherwise, a second step of transmitting an incoming packet to BEQ; And a third step of first transmitting the UDP packet.

2. The classification method based on RTP protocol

In the first step and the first step of determining that the incoming packet is a UDP packet, the VoIP classifier determines whether the UDP packet includes the RTP packet if it is a UDP packet, and if it is not the UDP packet, transmits the incoming packet to BEQ. In step 2 and step 2, if the RTP packet is included, the RTP packet is transmitted to VoPQ. If it is not included, the third step is transmitted to BEQ, and the fourth step in which the priority scheduler first transmits the RTP packet of VoPQ is performed. It is characterized by including.

3. The classification method based on the codec information of the user terminal

In the first step and the first step of determining that the incoming packet is a VoIP packet, if the UDP packet is a UDP packet, it is determined whether the RTP packet is included in the UDP packet. If the result of the determination in step 2 and step 2 includes the RTP packet, the third and third step of determining whether the codec information embedded in the RTP packet is information related to VoIP. If it is information, it transmits an RTP packet to VoPQ, and if it is not included, the fourth step of transmitting to BEQ, and the priority scheduler includes a fifth step of transmitting the RTP packet of VoPQ first.

4. IP address based classification method

A first step of judging that a packet to which a VoIP classifier flows is a UDP packet; a second step of judging whether a destination IP address included in a UDP packet is an address of a VoIP support system if the UDP packet is determined as a result of the first step; If the destination IP address corresponds to the address of the VoIP support system, it is determined whether the RTP packet is included in the UDP packet. If not, the RTP result of the third and third steps of transmitting the UDP packet to BEQ is determined. If the packet data is included, the RTP packet is transmitted to VoPQ if the codec information is information related to VoIP as a result of the determination in the fourth and fourth steps of determining whether the codec information embedded in the RTP packet data is VoIP related information. If not, the fifth step of transmitting to BEQ, the priority scheduler is characterized in that it comprises a sixth step of transmitting the RTP packet of VoPQ first.

Hereinafter, detailed operations of the respective cases will be described with reference to the accompanying drawings.

3A shows a flowchart of a UDP protocol based classification method.

In step S10 of determining that an incoming packet is a UDP packet, the VoIP classifier determines whether the incoming packet is data based on the UDP protocol by referring to whether or not the UDP related packet is included in the incoming packet. The reason for judging that an incoming packet is a UDP packet is that, as mentioned above, when a VoIP voice packet is transmitted through the Internet, UDP protocol related data is attached to the voice packet. Because of the high probability of having.

As a result of the determination in step S10, if the UDP packet transmits the UDP packet to VoPQ (S11), otherwise the incoming packet to BEQ (S12) has a high probability that the UDP packet has a VoIP voice packet as mentioned above. Priority is given to UDP packets and placed in VoPQ. Data not in UDP packets is placed in BEQ.

In step S13, in which the priority scheduler first transmits the UDP packet of VoPQ, the priority scheduler first transmits the packet priority arranged in VoPQ, and then transmits the packet arranged in BEQ.

Weighted Fair Queueing (WFQ) and Weighted First In First Out (FIFO) algorithms can be used to prioritize packets placed in VoPQ, and this also applies to the various classification methods mentioned below. do.

3b shows a flowchart of the RTP protocol based classification method.

If it is determined that the incoming packet is a UDP packet (S20) and then the determination result in step S20, it is determined whether the UDP packet contains the RTP packet (S21). Transfer to BEQ (S22). The reason why the S21 determines whether the RTP packet is included is that when the VoIP voice packet is transmitted through the Internet, as described above, UDP protocol related data is attached to the voice packet, and RTP related data comes first before UDP protocol related data is attached. Attached. That is, the RTP packet is included in the UDP packet. This means that the probability of having a VoIP voice packet is higher than that of the UDP-based classification method, since the transmission of the voice packet necessarily involves an RTP packet. (In the UDP-based classification method, a UDP packet must include an RTP packet. Is not).

As a result of the determination in step S21, if the RTP packet is included, the RTP packet is transmitted to VoPQ (S23). If not, the UDP packet is transmitted to BEQ (S24). Priority scheduler prioritizes the RTP packet of VoPQ and transmits the packet arranged in BEQ first (S25).

3c shows a flowchart of a classification method based on voice codec information of a user terminal.

In communications engineering, the term codec is used in reference to integrated circuits or chips that perform data conversion. Codec types combine analog-to-digital conversion or digital-to-analog conversion in one chip. A typical example of a codec is the modem, which is most widely used for personal and business purposes.

The VoIP classifier determines that the incoming packet is a UDP packet (S30). If the determination result in S30 is a UDP packet, it is determined whether the RTP packet is included in the UDP packet (S31), and if it is not a UDP packet, the incoming packet is transmitted to BEQ (S32). If the result of the determination in step S31 includes the RTP packet, it is determined whether the codec information embedded in the RTP packet is information related to VoIP (S33). Since the VoIP-based voice codec operates based on the G.722 and G.723 standards, It is determined whether the codec information contained in the RTP packet is information related to VoIP by whether the codec information includes information related to the above standard. Therefore, the codec information-based classification method has a higher probability of having a VoIP voice packet than in the above two methods (in the RTP-based classification method, the voice packet is not necessarily VoIP-based). If it is determined in step S31 that the RTP packet is not included, the UDP packet is transmitted to BEQ (S34).

As a result of the determination in step S33, if the codec information is VoIP related information, an RTP packet is transmitted to VoPQ (S35), and if it is not included, it is transmitted to BEQ (S36). The priority scheduler first transmits the RTP packet of VoPQ and then transmits the packet stored in the BEQ (S37).

3d shows a flowchart of an IP address based classification method.

The VoIP classifier determines that the incoming packet is a UDP packet (S40). If the determination result in step S40 is a UDP packet, it is determined whether a destination IP address included in the UDP packet is an address of a VoIP support terminal (S41). This is a database by constructing a database of IP addresses of terminals using VoIP services in a system implementing a QoS mechanism. Search to determine if the destination IP address is the address of the VoIP enabled terminal. If the incoming packet is not a UDP packet, the incoming packet is transmitted to BEQ (S42).

If it is determined in step S41 that the destination IP address corresponds to the address of the VoIP support system, it is determined whether the RTP packet is included in the UDP packet (S43). If not, the UDP packet is transmitted to the BEQ (S44). If the determination result in step S43 includes the RTP packet data, it is determined whether the codec information embedded in the RTP packet data is VoIP related information (S45). The determination method is the same as described above. If the RTP packet data is not included as a result of the determination in step S43, the UDP packet is transmitted to BEQ (S46). As a result of the determination in step S45, if the codec information is information related to VoIP, the RTP packet is transmitted to VoPQ (S47), and if it is not included, it is transmitted to BEQ (S48). The priority scheduler first transmits the RTP packet of VoPQ and then transmits the packet stored in the BEQ (S49).

2 schematically illustrates a transmission mode of the VoIP voice packet after the classification by the four cases described above.

While preferred embodiments of the invention have been described in detail above, those of ordinary skill in the art will appreciate that the invention may be modified without departing from the spirit and scope of the invention as defined in the appended claims. It will be appreciated that modifications or variations may be made. Thus, modifications to the foregoing embodiments of the invention will not depart from the teachings of the invention.

Implementing the present invention has the following effects.

Since voice packets are first selected and transmitted from various types of data packets flowing from the user terminal, other types of data may not be interrupted, and thus, the accuracy of voice packet decoding processing requiring real-time processing may be ensured. Not only can the reliability be significantly increased, but also the reliability of other multimedia data services can be increased. In addition, the present invention can facilitate the popularization of VoIP, which has the advantage of low call price, because high-quality voice services are available through the Internet.

Claims (5)

VoIP classifier which classifies packets coming from user terminals into Voice over Internet Protocol (VoIP) related voice packets and other packets, VoIP packet queue (VoPQ) to temporarily store the VoIP related voice packets and other to temporarily store the other packets Quality of Service (QoS) including a queue consisting of a packet queue (BEQ) and a priority scheduler that prioritizes transmission of the VoIP related voice packet to the Internet by giving priority to a VoIP related voice packet stored in the VoIP packet queue. In the voice data priority transmission method using a mechanism: A first step of the VoIP classifier determining that the incoming packet is a User Datagram Protocol (UDP) packet; A second step of transmitting the UDP packet to the VoPQ if the UDP packet is a result of the determination in the first step; And And a third step of the priority scheduler transmitting the UDP packet of the VoPQ first. VoIP classifier which classifies packets coming from user terminals into Voice over Internet Protocol (VoIP) related voice packets and other packets, VoIP packet queue (VoPQ) to temporarily store the VoIP related voice packets and other to temporarily store the other packets Quality of Service (QoS) including a queue consisting of a packet queue (BEQ) and a priority scheduler that prioritizes transmission of the VoIP related voice packet to the Internet by giving priority to a VoIP related voice packet stored in the VoIP packet queue. In the voice data priority transmission method using a mechanism: A first step of the VoIP classifier determining that the incoming packet is a User Datagram Protocol (UDP) packet; A second step of determining whether the UDP packet includes a Real-time Transport Protocol (RTP) packet if the UDP packet is a result of the determination in the first step; and transmitting the incoming packet data to the BEQ if the UDP packet is not a UDP packet; A third step of transmitting the RTP packet to the VoPQ if the RTP packet is included as a result of the determination in the second step; and transmitting the UDP packet to the BEQ if it is not included; And And a fourth step in which the priority scheduler first transmits the RTP packet data of the VoPQ. VoIP classifier which classifies packets coming from user terminals into Voice over Internet Protocol (VoIP) related voice packets and other packets, VoIP packet queue (VoPQ) to temporarily store the VoIP related voice packets and other to temporarily store the other packets Quality of Service (QoS) including a queue consisting of a packet queue (BEQ) and a priority scheduler that prioritizes transmission of the VoIP related voice packet to the Internet by giving priority to a VoIP related voice packet stored in the VoIP packet queue. In the voice data priority transmission method using a mechanism: A first step of the VoIP classifier determining that the incoming packet is a User Datagram Protocol (UDP) packet; Determining whether the UDP packet includes a Real-time Transport Protocol (RTP) packet if the UDP packet is a result of the determination in the first step; and transmitting the incoming packet to the BEQ if the UDP packet is not a UDP packet; If it is determined in the second step that the RTP packet is included, it is determined whether the codec information of the user terminal embedded in the RTP packet is information related to VoIP. If the RTP packet is not included, the UDP packet is determined. Transmitting to the BEQ; A fourth step of transmitting the RTP packet to the VoPQ if the codec information is VoIP related information as a result of the determination in the third step; And And a fifth step of the priority scheduler transmitting the RTP packet of the VoPQ first. VoIP classifier which classifies packets coming from user terminals into Voice over Internet Protocol (VoIP) related voice packets and other packets, VoIP packet queue (VoPQ) to temporarily store the VoIP related voice packets and other to temporarily store the other packets Quality of Service (QoS) including a queue consisting of a packet queue (BEQ) and a priority scheduler that prioritizes transmission of the VoIP related voice packet to the Internet by giving priority to a VoIP related voice packet stored in the VoIP packet queue. In the voice data priority transmission method using a mechanism: A first step of the VoIP classifier determining that the incoming packet is a User Datagram Protocol (UDP) packet; A second step of determining whether the destination IP address included in the UDP packet is an address of a VoIP support system if the determination result in the first step is a UDP packet, and if the UDP packet is not a UDP packet, transmitting the incoming packet to the BEQ; As a result of the determination in the second step, if the destination IP address corresponds to the address of the VoIP support system, it is determined whether the UDP packet includes a Real-time Transport Protocol (RTP) packet. Transmitting to the third step; Determining that the codec information of the terminal embedded in the RTP packet is information related to VoIP when the RTP packet is included as a result of the determination in the third step; and transmitting the UDP packet to the BEQ if it is not included. ; A fifth step of transmitting the RTP packet to the VoPQ if the codec information is VoIP related information as a result of the determination in the fourth step; And And a sixth step in which the priority scheduler first transmits the RTP packet of the VoPQ. 5. The method of claim 4, wherein the address determination of the second step comprises constructing an IP address database of a terminal using a VoIP service in a system in which the QoS mechanism is implemented, and searching for the database. VoIP based voice data transmission method characterized in that the recognition.