JP4911609B2 - Packet communication control method and apparatus - Google Patents

Description

  The present invention relates to a packet communication control method and apparatus, and more particularly to a packet communication control method and apparatus for controlling real-time packet communication in an environment in which a plurality of packet networks are connected to each other.

  According to conventional real-time packet communication, packet transfer quality information is measured only between communication terminals. Therefore, information that can be measured is only between communication terminals, and it is difficult to individually grasp the packet transfer quality for each network even in an environment where a plurality of packet networks are connected to each other. Further, since communication is performed only between the communication terminals, only the communication terminal can grasp the packet transfer quality information between the communication terminals, and it is difficult for the network side device to obtain the information.

In response to such a technical problem, Patent Document 1 discloses a technique in which a communication terminal and network-side equipment cooperate to notify the communication terminal of individual quality for each network.
Japanese Patent Laid-Open No. 2005-73211

  In order to finely control real-time packet communication in an environment where a plurality of networks are connected to each other, it is necessary to grasp the packet transfer quality for each network. However, in the conventional method in which the communication terminal and the network side equipment cooperate to notify the communication terminal of the individual quality for each network, it is necessary to prepare a dedicated communication terminal and it is difficult to utilize the existing communication terminal Met.

  An object of the present invention is to solve the above-described problems of the prior art, perform communication control according to network quality without modifying an existing communication terminal, and provide a communication control method in packet communication that can provide a high-quality service And providing an apparatus.

  In order to achieve the above-described object, the present invention provides a packet communication control apparatus that controls packet communication performed by a pair of communication terminals via a plurality of packet networks, wherein the packet communication control apparatus is connected between the packet networks, Packet monitoring means for monitoring packets exchanged between communication terminals, quality detection means for detecting the quality of each packet network based on the monitoring results, and signaling packets exchanged between communication terminals, the quality monitoring results Packet modification means for modifying based on the above.

  According to the present invention, in a real-time packet communication type service that passes through a plurality of packet networks, quality is obtained for each packet network, and communication control considering the quality of each packet network is performed by modifying a signaling packet. It will be possible to provide high-quality services without modifying the communication terminal.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an example of a network environment to which a packet communication control device according to the present invention is applied. A pair of communication terminals 1 and 2 that communicate with each other are connected to each other via a communication control device 3. The real-time packets such as voice packets and image packets are exchanged via the two packet networks 10 and 20 thus prepared.

  The communication control device 3 monitors signaling packets, real-time communication packets, and real-time communication control packets exchanged between the communication terminals 1 and 2, and detects and calculates the quality of the packet networks 10 and 20. The communication control device 3 further determines optimum communication conditions based on the quality of the packet networks 10 and 20, and rewrites a part of the signaling packet based on the communication conditions, whereby the communication terminals 1, 2 and Similarly, the real-time packet communication via the packet networks 10 and 20 is controlled.

  FIG. 2 is a diagram schematically representing a method for detecting and calculating the quality of each packet network 10 and 20 in the communication control device 3, where a pair of communication terminals 1 and 2 are connected to each other such as voice data or the like. An example will be described in which real-time communication packets are exchanged by RTP (Real-time Transport Protocol) and real-time communication control packets are exchanged by RTCP (RTP Control Protocol).

  The communication control device 3 monitors the RTP packet transmitted from the communication terminal 1 to the communication terminal 2, and thus from the communication terminal 1 in the section A (mainly the packet network 10) connecting the communication terminal 1 and the communication control device 3. The quality Qa1 of the route to the communication control device 3 is detected. The communication control device 3 further monitors RTCP RR packets transmitted from the communication terminal 2 to the communication terminal 1. In this RTCP RR packet, as will be described in detail later, the quality of the path from the communication terminal 1 to the communication terminal 2 evaluated by the communication terminal 2 based on the packet received from the communication terminal 1 is registered. Based on the RTCP RR packet, the communication control device 3 detects the quality Qall1 of the route from the communication terminal 1 to the communication terminal 2 in all sections (section A + B) connecting the communication terminal 1 and the communication terminal 2. Then, by subtracting the quality Qa1 of the section A from the quality Qall1 of all routes, the communication control apparatus 3 changes to the communication terminal 2 in the section B (mainly the packet network 20) connecting the communication control apparatus 3 and the communication terminal 2. Find the quality Qb1 of the route to reach.

  Similarly, the communication control device 3 monitors the RTP packet transmitted from the communication terminal 2 to the communication terminal 1 to detect the quality Qb2 of the route from the communication terminal 2 to the communication control device 3 in the section B. Further, the communication control device 3 detects the quality Qall2 of the route from the communication terminal 2 to the communication terminal 1 in all sections (section A + B) by monitoring the RTCP RR packet transmitted from the communication terminal 1 to the communication terminal 2. . Then, the quality Qa2 of the route from the communication control device 3 to the communication terminal 1 in the interval A is obtained by subtracting the quality Qb2 of the interval B from the quality Qall2 of all the routes.

  FIG. 3 is a functional block diagram showing the configuration of the main part of the communication control device 3. The first network connection interface 31 controls the connection between the communication control device 3 and one of the packet networks 10. The second network connection interface 32 controls the connection between the communication control device 3 and the other packet network 20. The packet monitor unit 33 monitors signaling packets, real-time communication packets (RTP packets), and real-time communication control packets (RTCP RR packets) exchanged between the communication terminals 1 and 2 via the two packet networks 10 and 20. .

  As described with reference to FIG. 2, the quality information calculation unit 34 monitors a real-time communication control packet (RTCP RR packet) transmitted from the communication terminal 2 to the communication terminal 1 and routes from the communication terminal 1 to the communication terminal 2. Detect quality Qall1. Similarly, a real-time communication control packet (RTCP RR packet) transmitted from the communication terminal 1 to the communication terminal 2 is monitored, and the quality Qall2 of the route from the wireless terminal 2 to the wireless terminal 1 is detected.

  FIG. 4 is a diagram showing the format of the RTCP RR packet, in which V (Version number) representing the protocol version and PT representing the RTCP packet type are registered in the header. The report block contains various quality information that represents packet transfer quality, such as packet drop rate, cumulative number of lost packets, packet interval jitter, latest transmission report time stamp (LSR), and latest transmission report elapsed time (DLSR). It is registered. The quality information calculation unit 34 detects the quality information registered in the report block of each RTCP RR packet as the quality Qall1 and Qall2 in each direction of all sections (section A + B).

  The quality information calculation unit 34 also detects the quality information of each section A and B for each item registered in the report block of the RTCP RR packet based on the real-time communication packet (RTP packet).

  The quality information calculation unit 34 further obtains the quality Qb1 of the route (section B) from the communication control device 3 to the communication terminal 2 by subtracting the quality Qa1 of the section A from the quality Qall1 of all routes. Similarly, the quality Qa2 of the route (section A) from the communication control device 3 to the communication terminal 1 is obtained by subtracting the quality Qb2 of the section B from the quality Qall2 of all paths.

  The communication condition determination unit 35 includes quality information already registered in the RTCP RR packet detected by the packet monitor unit 33, quality information calculated by the quality information calculation unit 34, and signaling detected by the packet monitor unit 33. Optimal communication conditions are determined based on the packet media information.

  In this embodiment, since the packet transfer quality can be detected not for the entire route but for each packet network that passes through, even if the quality of the entire route that can be detected based on the RTCP RR packet is degraded, the quality of each packet network is referred to. For example, it can be recognized in which packet network the quality degradation has occurred. For example, in the network environment of FIG. 1, when the packet network 10 includes a wireless section, the packet network 20 does not include a wireless section, and only the quality of the packet network 10 including the wireless section is deteriorated, the cause Is rain attenuation other than congestion, and it can be predicted that the effect of quality improvement is low even if the bandwidth is limited. In such a case, the communication condition that does not limit the bandwidth is determined.

  On the other hand, when the quality of the packet network 20 that does not include the wireless section is deteriorated, the cause is congestion, and if the bandwidth is limited, it can be predicted that the effect of quality improvement is high. In such a case, communication conditions for limiting the bandwidth are determined.

  Based on the communication conditions determined by the communication condition determining unit 35, the packet modifying unit 36 modifies the media information of the signaling packet in the call control protocol that passes through the packet networks 10 and 20 next. Communication conditions optimum for the quality of 10, 20 are set.

  FIG. 5 schematically shows an example of a call connection signaling packet modification method when SIP / SDP is adopted as a call control protocol and a call is made from the communication terminal 1 to the communication terminal 2 to start VoIP communication. FIG.

  The communication terminal 1 requests the desired codec method by describing the following media information in the SDP (Session Description Protocol) part of the call connection signaling packet (INVITE). Media information (1) to (3) indicates that a connection with G.711 (64 kbps) or G.729 (8 kbps) is required for audio, and media information (4) and (5) is H for video. This indicates that a connection with .261 is requested.

(1) m = audio 50000 RTP / AVP 0 18
(2) a = rtpmap: 0 PCMU / 8000
(3) a = rtpmap: 18 G729 / 8000
(4) m = video 51000 RTP / AVP 31
(5) a = rtpmap: 31 H261 / 90000

  In the communication control device 3, the INVITE request is referred to by the packet monitor unit 33, and the request content is notified to the communication condition determining unit 35. Here, if the quality calculated by the quality information calculation unit 34 is deteriorated and it is determined that band limitation is effective for the improvement, the communication condition determination unit 35 determines that the communication terminal 1 is related to voice. Only the connection at G.711 (64 kbps) is requested, and the media information is modified as described below and transmitted to the communication terminal 2 so that there is no request for video.

(1) m = audio 50000 RTP / AVP 0 18
(2) a = rtpmap: 18 G729 / 8000

  In response to the media information modified INVITE request, the communication terminal 2 includes the following media information (1) and (2) indicating that connection with G.711 (64 kbps) is possible for voice. A connection signaling packet (200 OK) is returned.

(1) m = audio 50000 RTP / AVP 0 18
(2) a = rtpmap: 18 G729 / 8000

  In the communication control device 3, the 200 OK response is referred to by the packet monitor unit 33, and the response content is notified to the communication condition determining unit 35. The communication condition determination unit 35 can connect the media information of the 200 OK response sent back to the communication terminal 1 to the packet modification unit 36 with respect to the voice in G.711 (64 kbps) but G.729 (8 kbps). It is instructed to change to the following contents (1) to (5) to the effect that the connection is impossible, and that the connection is impossible for the video.

(1) m = audio 50000 RTP / AVP 0 18
(2) a = inactive
(3) a = rtpmap: 18 G729 / 8000
(4) m = video 0 RTP / AVP 31
(5) a = inactive

  The packet modifying unit 36 modifies the media information of the 200 OK response returned from the communication terminal 2 as described above, and transmits it to the communication terminal 1.

  In the above-described embodiment, it is assumed that the media information is rewritten in the call connection signaling packet (INVITE and 200 OK) exchanged between wireless terminals when starting a session, and the communication conditions are changed from the beginning of the next session. Although described above, the present invention is not limited to this, and it is possible to change communication conditions in the middle of a session by modifying media information in a signaling packet exchanged for alive monitoring in each session. May be.

  FIG. 6 is a diagram schematically showing an example of another modification method of the signaling packet. When serious congestion is detected on the route from the communication control device 3 to the communication terminal 2, communication is performed. By returning a call connection rejection (Temporarily Unavailable) signaling packet from the communication control device 3 to the communication terminal 1 without notifying the communication terminal 2 of the call connection signaling packet received from the terminal 1. The connection itself may be prohibited. Alternatively, a call connection refusal signaling packet may be returned in response to the alive monitoring signaling packet received from the communication terminal.

  FIG. 7 is a functional block diagram showing a configuration of another embodiment of the communication control device 3, and the same reference numerals as those described above represent the same or equivalent parts.

  The present embodiment is characterized in that a quality information notifying unit 37 for transmitting the quality information calculated by the quality information calculating unit 34 to a quality management server provided on the network is provided. The quality management server collects and manages the quality information of each packet network from each communication control device 3, while providing the quality information of each packet network in response to a request from each communication control device 3. Each communication control device 3 accesses the quality management server, for example, when quality information is insufficient because one of the communication terminals does not support RTCP, acquires the insufficient quality information, The communication condition of each communication terminal is determined based on the quality information detected in step 1 and the quality information acquired from the quality management server, and the signaling packet is modified based on the determination result.

  In addition, since the telecommunications carrier that manages the network can easily recognize the quality of each packet network simply by referring to the quality management server, the quality information can be applied to applications other than real-time communication, for example. Become.

It is the figure which showed an example of the network environment to which the communication control apparatus which concerns on this invention is applied. It is the figure which expressed typically the method of detecting and calculating the quality of each packet network. It is the functional block diagram which showed the structure of the principal part of a communication control apparatus. It is the figure which showed the format of the RTCP RR packet. It is the figure which expressed typically an example of the modification method of a signaling packet. It is the figure which expressed typically an example of the other modification method of a signaling packet. It is the functional block diagram which showed the structure of other embodiment of a communication control apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 ... Communication terminal, 3 ... Communication control apparatus, 10, 20 ... Packet network, 31 ... 1st network connection interface, 32 ... 2nd network connection interface, 33 ... Packet monitor part, 34 ... Quality information calculation part, 35 ... communication condition determination unit, 36 ... packet modification unit, 37 ... quality information notification unit

Claims (11)

In a packet communication control apparatus for controlling packet communication performed via a plurality of packet networks, a pair of communication terminals exchange media information with each other to request a codec method .
The packet communication control device is connected between packet networks;
Packet monitoring means for monitoring packets exchanged between communication terminals;
Quality detection means for detecting the quality of each packet network based on the monitoring results;
Communication condition determining means for determining the communication condition of each communication terminal based on the detected quality of each packet network;
The signaling packet exchanged between the communication terminals is modified based on the communication condition so that media information for adopting a common codec method according to the determined communication condition is transmitted to each communication terminal. A packet communication control device comprising packet modification means.   2. The packet communication control apparatus according to claim 1, wherein the packet modifying unit modifies media information registered in a call connection signaling packet.   2. The packet communication control apparatus according to claim 1, wherein the packet modification unit modifies media information registered in a signaling packet for alive monitoring.   2. The packet communication control device according to claim 1, wherein the packet modification unit returns a call connection rejection signaling packet to the call connection signaling packet.   2. The packet communication control apparatus according to claim 1, wherein the packet modification means returns a call connection refusal signaling packet to the alive monitoring signaling packet. The packet monitoring means monitors a real-time communication packet and a real-time communication control packet;
The quality detection means is
Means for detecting the quality of the first route from each communication terminal to each packet communication control device via each packet network based on the monitoring result of the real-time communication packet;
Means for detecting the quality of the second path between the communication terminals based on the monitoring result of the real-time communication control packet;
Based on the quality of the first path through each packet network from the quality and the communication terminal of the second path between the communication terminal to a packet communication control device, via each packet network from the packet communication control device The packet communication control device according to claim 1, further comprising means for calculating a quality of a third route to each communication terminal.   The communication condition determining means, when the quality detecting means detects a deterioration in quality of the second route,
  One of the first route and the third route corresponding to the second route includes a wireless section, and the quality detection unit detects a deterioration in quality, and the other does not include a wireless section, and the quality If quality degradation is not detected by the detection means, determine the communication conditions that do not limit the bandwidth,
  If at least one of the first route and the third route corresponding to the second route does not include a wireless section and a quality deterioration is detected by the quality detection unit, the bandwidth is limited. The packet communication control device according to claim 6, wherein communication conditions to be determined are determined. The quality of the detected respective packet network, a packet communication control device according to any one of claims 1 to 7, characterized in that it further comprises means for notifying the quality management server provided separately on the packet network . Means for obtaining quality information of each packet network from the quality management server;
9. The packet communication control device according to claim 8 , wherein the communication condition determining means determines a communication condition based on the detected quality of each packet network and quality information acquired from the quality management server. In a packet communication control method in which a pair of communication terminals exchange media information with each other to request a codec method and control packet communication performed via a plurality of packet networks.
A procedure for monitoring packets exchanged between communication terminals between packet networks;
Detecting the quality of each packet network based on the monitoring results;
Determining communication conditions of each communication terminal based on the detected quality information of each packet network;
The signaling packet exchanged between the communication terminals is modified based on the communication condition so that media information for adopting a common codec method according to the determined communication condition is transmitted to each communication terminal. And a packet communication control method. The procedure for detecting the quality comprises:
A procedure for detecting the quality of the route from each communication terminal to the packet communication control device via each packet network based on the monitoring result of the real-time communication packet;
A procedure for detecting the quality of the route between communication terminals based on the monitoring result of the real-time communication control packet,
Based on the quality of the route between the communication terminals and the quality of the route from each communication terminal to the packet communication control device via each packet network, the communication from the packet communication control device to each communication terminal via each packet network The packet communication control method according to claim 10 , further comprising a step of calculating route quality.

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