JP2005167897A - System, transmitting device, receiving device, and method for rtp packet communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a RTP (Realtime Transport Protocol) packet communication system capable of preventing eavesdropping. <P>SOLUTION: The RTP packet communication system comprises a RTP packet transmitting device 10 and a RTP packet receiving device 11, and conducts speech communications via an ETHERNET (R) network. The RTP packet transmitting device 10 is provided with a call setup means 8 for assigning a plurality of UDP (User Datagram Protocol) port numbers to one speech channel, and an RTP packet encoder 2 for encoding RTP packets at the plurality of UDP ports under an instruction from the call setup means 8. The RTP packet receiving device 11 is provided with a call setup means 9 for directing the decoding of only RTP packets at the plurality of UDP ports, and a RTP packet decoder 6 for decoding RTP packets only at UDP ports instructed by the call setup means 9. The system is characterized in that it conducts communication by the one speech channel using the plurality of UDP ports. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an RTP (Real-time Transport Protocol) packet communication system, an RTP packet transmission device, an RTP packet reception device, and an RTP packet communication method for performing voice communication in an IP network.

  A conventional RTP packet communication system exchanges port numbers of UDP (User Datagram Protocol) packets with each other in exchanging information about the ability to perform a voice call. At this time, one UDP port number for the RTP packet of the own terminal is transmitted to the partner terminal per channel of the voice communication path (for example, see Patent Document 1).

  Hereinafter, a conventional RTP packet communication system and its RTP packet communication method will be described with reference to the drawings. FIG. 2 is a block diagram of a conventional RTP packet communication system. In FIG. 2, 12 is an A / D converter, 13 is an RTP packet encoder, 14 is an ETHERNET (registered trademark) controller, 15 is an ETHERNET (registered trademark) network, 16 is an ETHERNET (registered trademark) controller, 17 is an RTP packet decoder, 18 is a D / A converter, 19 and 20 are call setting means, 21 is an RTP packet transmitter, and 22 is an RTP packet receiver. The RTP packet transmission device 21 and the RTP packet reception device 22 constitute an RTP packet communication device.

  First, in a first stage of setting communication, a call setting unit 19 transmits a call setting packet from the RTP packet transmitting device 21 to the RTP packet receiving device 22. That is, in the RTP packet transmitting apparatus 21, the call setting means 19 outputs a call setting packet indicating which UDP port number is used. At this time, the call setup packet indicates that a single UDP port number, for example, “8000” is used as the UDP port number. At the same time, the call setting means 19 outputs an encoder control command to the RTP packet encoder 13 in order to indicate the UDP port number to be used. The ETHERNET (registered trademark) controller 14 stores the call setting packet in the ETHERNET (registered trademark) packet and transmits it to the ETHERNET (registered trademark) network 15.

  In the RTP packet receiving device 22, the ETHERNET (registered trademark) controller 16 extracts a call setup packet from the ETHERNET (registered trademark) packet received from the ETHERNET (registered trademark) network 15 and outputs it. The call setting means 20 recognizes which UDP port number is used from the input call setting packet, and uses only the designated single UDP port number, in this case “8000”, to send the RTP packet. A decoder control command is output to the RTP packet decoder 17 so as to decode.

  In the second stage of making a voice call, an RTP packet is transmitted from the RTP packet transmitter 21 to the RTP packet receiver 22. In the RTP packet transmission device 21, the A / D converter 12 performs analog-digital conversion of the input analog audio 1 channel (1ch) signal and outputs it as PCM audio data. The RTP packet encoder 13 encodes the RTP packet using a single UDP port number indicated here by the encoder control command output from the call setting means 19, here “8000”. The ETHERNET (registered trademark) controller 14 stores the RTP packet in the ETHERNET (registered trademark) packet and transmits it to the ETHERNET (registered trademark) network 15.

In the RTP packet receiver 22, the ETHERNET (registered trademark) controller 16 extracts an RTP packet from the ETHERNET (registered trademark) packet received from the ETHERNET (registered trademark) network 15 and outputs the RTP packet. The RTP packet decoder 17 decodes only the RTP packet of the UDP port number indicated by the decoder control command output from the call setting means 20. The RTP packet decoded by the RTP packet decoder 17 is output as PCM audio data. The D / A converter 18 performs digital-analog conversion of the input PCM audio data, and outputs it as a signal for one analog audio channel.
JP 2002-335341 A

  The problem to be solved is that, in the conventional RTP packet communication system, the voice data is divided and packetized only in the RTP packet, and generally the physical layer is ETHERNET (registered trademark). Since it is realized using a network, it was possible to easily eavesdrop.

  The present invention is an RTP packet communication system that includes an RTP packet transmission device and an RTP packet reception device and performs voice communication via an ETHERNET (registered trademark) network. And a RTP packet encoder that encodes RTP packets at a plurality of UDP ports according to instructions from the first call setting means. There is provided a second call setting means for decoding only RTP packets of a plurality of UDP ports with respect to one channel, and an RTP packet decoder for decoding RTP packets only for the UDP ports designated by the second call setting means. Mainly communicate using multiple UDP ports And it features.

  The RTP packet communication system, the RTP packet transmission device, the RTP packet reception device, and the RTP packet communication method of the present invention have an advantage that they can communicate correctly between legitimate terminals and cannot be easily wiretapped.

  The present invention achieves the purpose of preventing eavesdropping of RTP packets by assigning a plurality of UDP ports to one channel of a voice communication path in an RTP session and communicating one channel of RTP packets using a plurality of UDP ports.

  In order to solve the above problems, a first invention is an RTP packet communication system that includes an RTP packet transmission device and an RTP packet reception device and performs voice communication via an ETHERNET (registered trademark) network. The packet transmitting apparatus includes a first call setting unit that assigns a plurality of UDP port numbers to one voice channel, and an RTP packet encoder that encodes RTP packets at a plurality of UDP ports according to instructions from the first call setting unit. In addition, the RTP packet receiving apparatus includes a second call setting unit that decodes only RTP packets of a plurality of UDP ports with respect to one voice channel, and an RTP that decodes RTP packets only at the UDP port designated by the second call setting unit. A packet decoder, and one audio channel for multiple UDP RTP packet communication system that performs communication using a port, and has the effect of being able to communicate correctly between a regular RTP packet transmitting device and an RTP packet receiving device, making it difficult to eavesdrop It is.

  The second invention is an invention subordinate to the first invention, wherein the first call setting means sets the UDP port number used by the voice channel for the first call setting means to set communication. The RTP packet transmitting device transmits an ETHERNET (registered trademark) packet storing the call setting packet to the RTP packet receiving device, and then stores the RTP packet for voice communication. This is an RTP packet communication system for transmitting packets, and has an effect that it cannot be easily eavesdropped.

  The third invention is an invention subordinate to the second invention, wherein the first call setting means encrypts and outputs the call setting packet and can be wiretapped more reliably. It has the effect of disappearing.

  A fourth invention is an RTP packet transmitting apparatus for performing RTP packet communication via an ETHERNET (registered trademark) network, wherein a call setting means for assigning a plurality of UDP port numbers to one voice channel, and an instruction from the call setting means The RTP packet transmission device includes an RTP packet encoder that encodes RTP packets with a plurality of UDP ports, and has an effect that it cannot be easily wiretapped.

  A fifth invention is an RTP packet receiving apparatus that performs RTP packet communication via an ETHERNET (registered trademark) network, and decodes only RTP packets of a plurality of UDP ports indicated by a call setting packet for one voice channel. The RTP packet receiving apparatus includes a call setting unit instructing to RTP and a RTP packet decoder that decodes RTP packets only at the UDP port instructed by the call setting unit, and has an effect that it cannot be easily wiretapped. is there.

  According to a sixth aspect of the present invention, a plurality of UDP port numbers are assigned to one voice channel, an RTP packet is encoded using a plurality of UDP ports for one voice channel, and an ETHERNET (registered trademark) packet storing the RTP packet is ETHERNET. It is an RTP packet communication method that transmits to the (registered trademark) network, decodes RTP packets obtained after reception only by a plurality of UDP ports, and outputs voice, and can communicate correctly with a legitimate partner terminal. It has an effect.

  A seventh aspect of the invention is an RTP packet communication method according to the sixth aspect of the invention, wherein a UDP port number is transmitted to a partner terminal using a call setup packet and then an RTP packet for voice communication is transmitted. There is an effect that communication can be performed correctly with a legitimate partner terminal.

  The eighth invention is an invention subordinate to the seventh invention, and is an RTP packet communication method for encrypting a call setup packet, and has an effect that wiretapping cannot be performed more reliably.

(Embodiment 1)
Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram of an RTP packet communication system according to Embodiment 1 of the present invention. In FIG. 1, 1 is an A / D converter, 2 is an RTP packet encoder, 3 is an ETHERNET (registered trademark) controller, 4 is an ETHERNET (registered trademark) network, 5 is an ETHERNET (registered trademark) controller, and 6 is an RTP packet decoder. 7 is a D / A converter, 8 is call setting means (first call setting means of the present invention), 9 is call setting means (second call setting means of the present invention), 10 is an RTP packet transmitter, and 11 is An RTP packet receiving device. The RTP packet transmission device 10 and the RTP packet reception device 11 constitute the RTP packet communication device of the first embodiment.

  First, in a first stage of setting communication, a call setting packet is transmitted from the RTP packet transmitting device 10 to the RTP packet receiving device 11. That is, in the RTP packet transmitting apparatus 10, the call setting unit 8 outputs a call setting packet indicating which UDP port number is used. At this time, the UDP port number is a plurality of UDP port numbers. In the first embodiment, the four UDP ports “8000”, “8002”, “8010”, “8016” shown in FIG. Indicated. Further, the call setup packet is encrypted so that the third party does not know which UDP port number is used. In order to execute this encryption, the call setting means 8 is provided with an encryption means.

  At the same time, the call setting unit 8 outputs an encoder control command to the RTP packet encoder 2 so as to encode the RTP packet using a plurality of UDP port numbers “8000”, “8002”, “8010”, and “8016” to be used. Further, the ETHERNET (registered trademark) controller 3 stores the call setting packet in the ETHERNET (registered trademark) packet and transmits it to the ETHERNET (registered trademark) network 4.

  In the RTP packet receiving device 11, the ETHERNET (registered trademark) controller 5 extracts the call setup packet from the ETHERNET (registered trademark) packet received from the ETHERNET (registered trademark) network 4 and outputs it. The call setting means 9 recognizes which of the plurality of UDP port numbers are used from the input call setting packet, and uses the plurality of UDP port numbers “8000”, “8002”, “8010”, “8016”. A decoder control command is output to the RTP packet decoder 6 so that the RTP packet is decoded using only the RTP packet. When the call setting means 8 performs encryption, the call setting means 9 is provided with a decryption means.

  In the second stage of making a voice call, an RTP packet is transmitted from the RTP packet transmitting device 10 to the RTP packet receiving device 11. In the RTP packet transmitting apparatus 10, the A / D converter 1 performs analog-digital conversion of the input analog audio 1 channel (1ch) signal and outputs it as PCM audio data. The RTP packet encoder 2 encodes the RTP packet using a plurality of UDP port numbers indicated by the encoder control command output from the call setting means 8. Encoding is performed so that RTP packets of consecutive sequence numbers use different UDP port numbers in order to prevent recognition as speech even if only a single UDP port number is decoded at any timing. The ETHERNET (registered trademark) controller 3 stores the RTP packet in the ETHERNET (registered trademark) packet and transmits it to the ETHERNET (registered trademark) network 4.

  In the RTP packet receiver 11, the ETHERNET (registered trademark) controller 5 extracts an RTP packet from the ETHERNET (registered trademark) packet received from the ETHERNET (registered trademark) network 4 and outputs the RTP packet. The RTP packet decoder 6 decodes only the UDP port number indicated by the decoder control command output from the call setting means 9, here RTP packets of “8000”, “8002”, “8010”, “8016”. The RTP packet decoded by the RTP packet decoder 6 is output as PCM audio data. The D / A converter 7 performs digital / analog conversion of the input PCM audio data, and outputs it as a signal for one channel of analog audio (1ch).

  As is clear from the above description, in the RTP packet communication system and the RTP packet communication method of the present invention, it is difficult for a third party to know which of the plurality of UDP port numbers is used. Moreover, since it is realized only by software without additional hardware, the cost is not increased. Furthermore, since the RTP packet itself is not encrypted, the real-time property is not lost.

  The present invention can be used for an RTP packet communication system that performs voice communication over an IP network, particularly an RTP communication system, an RTP transmitter / receiver, and an RTP packet communication method that cannot be easily eavesdropped.

Block diagram of the RTP packet communication system in Embodiment 1 of the present invention Block diagram of a conventional RTP packet communication system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,12 A / D converter 2,13 RTP packet encoder 3,14 ETHERNET (registered trademark) controller 4,15 ETHERNET (registered trademark) network 5,16 ETHERNET (registered trademark) controller 6,17 RTP packet decoder 7,18 D / A converter 8, 9, 19, 20 Call setting means 10, 21 RTP packet transmitter 11, 22 RTP packet receiver

Claims (8)

An RTP packet communication system comprising an RTP packet transmitter and an RTP packet receiver, and performing voice communication via an ETHERNET (registered trademark) network, wherein the RTP packet transmitter includes a plurality of UDP ports for one voice channel A first call setting means for assigning a number; and an RTP packet encoder for encoding into RTP packets at a plurality of UDP ports according to an instruction from the first call setting means. There is provided a second call setting means for decoding only RTP packets of the plurality of UDP ports for one channel, and an RTP packet decoder for decoding RTP packets only for the UDP ports designated by the second call setting means. Channel communicates using multiple UDP ports RTP packet communications system according to claim Ukoto. The first call setting means outputs a call setting packet indicating a UDP port number used by a voice channel for setting communication, and the RTP packet transmitting device stores the call setting packet in the RTP packet receiving device. 2. The RTP packet communication system according to claim 1, wherein after the transmitted ETHERNET (registered trademark) packet is transmitted, an ETHERNET (registered trademark) packet storing an RTP packet for voice communication is transmitted. The RTP packet communication system according to claim 2, wherein the first call setting means encrypts and outputs the call setting packet. An RTP packet transmitting apparatus that performs RTP packet communication via an ETHERNET (registered trademark) network, wherein a call setting unit that allocates a plurality of UDP port numbers to one voice channel, and a plurality of UDP ports according to instructions of the call setting unit An RTP packet transmitter comprising: an RTP packet encoder that encodes an RTP packet. An RTP packet receiving apparatus that performs RTP packet communication via an ETHERNET (registered trademark) network, and is a call setting means for instructing to decode only RTP packets of a plurality of UDP ports indicated by a call setting packet for one voice channel And an RTP packet decoder for decoding the RTP packet only at the UDP port instructed by the call setting means. Assign multiple UDP port numbers to one voice channel, encode to RTP packet using multiple UDP ports per voice channel, and send ETHERNET (registered trademark) packet storing the RTP packet to ETHERNET (registered trademark) network An RTP packet communication method, comprising: transmitting and decoding an RTP packet obtained after reception only by the plurality of UDP ports and outputting a voice. 7. The RTP packet communication method according to claim 6, wherein a UDP port number is transmitted to a partner terminal using a call setting packet, and thereafter an RTP packet for voice communication is transmitted. 8. The RTP packet communication method according to claim 7, wherein the call setting packet is encrypted.

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