JP5252347B2 - Network system and communication plan server - Google Patents

Description

  The present invention relates to improving communication quality in a packet switched network.

  As a method for improving the quality of communication based on the Internet Protocol (IP), that is, QoS (Quality of Service), it is defined in the standard documents RFC 2212 and RFC 2215 of the Internet Engineering Task Force (IETF) which is an Internet standardization organization. Integrated Services (IntServ), and Differentiated Services (DiffServ) defined in IETF documents RFC2474, RFC2475, RFC2430, and the like. Currently, DiffServ suitable for large-scale networks is widely used.

  However, it is necessary to improve the quality of experience of the user in the communication service, that is, QoE (Quality of Experience). Improving QoE leads to an increase in user satisfaction.

  In order to improve QoE, it has been considered necessary to guarantee end-to-end QoS. ATM (Asynchronous Transfer Mode) has a mechanism for guaranteeing QoS between end points for each communication flow, but is not applicable to a large-scale communication service required today. In IntServ, QoS is guaranteed by securing resources such as routers in units of flows using RSVP (resource Reservation Protocol), which is a protocol defined by the IETF standard document RFC 1663. IntServ is a method for guaranteeing the QoS of communication for each flow in the Internet, but it cannot be applied to a large-scale network like ATM.

  On the other hand, DiffServ has made it possible to apply to a large-scale network by using not a flow unit but a unit class of flows. However, on the other hand, it was not a method that can guarantee the QoS between the end points.

  For this reason, DiffServ and IntServ are combined, that is, in a core network where it is difficult to control network traffic for each flow, DiffServ is used, and a terminal that can control each flow such as a LAN or an access network. In this network, a method using IntServ or a method equivalent thereto, for example, a method described in RFC2998 has been developed. In NGN (Next Generation Networks), which has already started services in some carriers, QoS guarantees between end points can be achieved by adopting a protocol that enables the above-described method. It is possible.

  Regarding the basic framework of NGN, ITU-T (International Telecommunication Union Telecommunication Standardization Sector), 3GPP (3rd Generation Partnership Project), ETSI (European Telecommunications Standards Institute) Have been discussed and standardized. In communication such as voice or video, the session control protocol SIP (Session Initiation Protocol) defined by the IETF standard document RFC3261 is often used. Therefore, in NGN, a mechanism called IMS (IP Multimedia Subsystem) for realizing QoS guarantee through communication using SIP is used.

  As a mechanism for QoS guarantee using SIP, there is a method of securing resources used for communication by RSDP (Session Description Protocol) message included in the SIP message and RSVP messaging combined with SIP messaging. Yes (see Non-Patent Document 1, for example). QoS parameters such as communication bandwidth and packet loss rate are described by using SDP messages for communication between end points and RSVP messages for securing router resources on the path connecting the end points. They can be communicated to the network, i.e., specify one QoS condition to be targeted. And they can be realized in the network.

  The SDP message includes a medium used for communication, that is, a distinction between audio and moving images, and information such as a codec used in the audio or moving images. The aforementioned media or codec is not always feasible at the communication partner. Therefore, in order to solve the above-mentioned problem, there is a method of describing an offer / answer model for negotiating establishment of a feasible medium or codec in an SDP message in SDP communication (see, for example, Non-Patent Document 2). . In other words, if the sender who sent the SIP INVITE request receives an SDP message containing the content exactly as requested by the receiver, the negotiation for establishment of the media or codec is established, but the SDP message containing other conditions is received. When this happens, the media or codec is changed.

In NGN, the QoS guarantee method in Non-Patent Document 1 is expanded, and a SIP server that mediates messaging is used only for communication between end points without necessarily using RSVP or a protocol equivalent thereto. There is a method that makes it possible to control resources and admission in a network by reading or rewriting an SDP message (for example, Non-Patent Document 3). In addition, there is a QoS guarantee method using SIP and SDP in a mobile phone environment (see, for example, Patent Document 1).
US Pat. No. 7,106,718 B2 Camarillo, G., Marshall, W., and Rosenberg, J., “Integration of Resource Management and Session Initiation Protocol (SIP)”, RFC 3312, IETF, October 2002. Rosenberg, J. and Schulzrinne, H., “An Offer / Answer Model with the Session Description Protocol (SDP)”, RFC 3264, IETF, June 2002. 3rdGenerationPartnershipProject (3GPP), “InternetProtocol (IP) multimediacallcontrolprotocolbasedonSessionInitiationProtocol (SIP) and SessionDescriptionProtocol (SDP); Stage3 (Release7)”, 3GPPTS24.229V7.3.0, March2006.

  Resources required in a specific communication session are not always constant from the start to the end of communication. For example, when the content to be transmitted is determined in advance, such as streaming, the required resource can be predicted and the communication schedule can be controlled. That is, by changing the QoS condition as the communication progresses, scheduling that can satisfy more users can be performed. Specifically, a plurality of schedules for realizing the QoE requested by the user can be prepared, or a continuously changing schedule can be defined by changing parameters.

  However, as described above, there are two problems that must be solved in order to change the QoS condition during communication according to the plan.

  First, the method used for conventional NGN requires session control messaging (reINVITE request) every time the QoS condition is changed. What the network server can know at the start of communication is the QoS request of the application at that time, what kind of QoS is requested by the application, and what schedule the requested QoS is going to be realized by do not know. For this reason, the network server may not be able to realize the optimum QoS or QoS for the application even at the start of communication or at the time of changing the QoS condition during communication. There is a problem that optimal control cannot be performed.

  In other words, the first problem is to realize a resource allocation plan that optimizes the QoE of the user for each user's communication, and to optimize the QoE of the entire user in the entire network. It is to realize the plan.

  Secondly, in order to realize the communication as described above, it is necessary to change the setting of the router during the communication in accordance with the change of the QoS condition. Therefore, it is necessary to eliminate the communication failure caused by the router setting change and reduce the overhead. Specifically, it is necessary to prevent the router from being overloaded by dynamically changing the queue configuration of the router, and to prevent packet loss due to queuing being stopped until the configuration change is completed. I must.

  In other words, the second problem is to be able to dynamically change QoS conditions such as bandwidth setting in the router output queue without imposing a heavy load on the router and causing problems such as packet loss. It is.

  The object of the present invention is to solve these problems.

A typical example of the present invention is as follows. That is, a computer, a network node, an application server for transmitting data necessary for an application executed on the computer to the computer, and a communication plan server for managing a plan of communication between the computer and the application server And a management server that manages a network to which the computer, the network node, and the application server are connected, wherein the application server is connected to the first processor and the first processor. A first non-volatile storage medium connected to the first processor, a first network interface connected to the network, the communication planning server comprising: a second processor; Connect with second processor A second storage medium connected to the network, a second network interface connected to the network, the management server including a third processor, a third memory connected to the third processor, the second A third non-volatile storage medium connected to three processors, a third network interface connected to the network, and the communication planning server is provided in the network for data stored in the application server The communication condition for determining the quality of the service to be stored is stored in the second storage medium, and the first quality condition which is a request by the user of the computer with respect to the quality of the application executed on the computer is received from the computer If, based on the communication conditions stored in said second storage medium, before Generating a plurality of communication plans including a plurality of communication conditions depending on time in a communication time from the start to the end of communication of an application executed on the computer for realizing the received first quality condition; The generated plurality of communication plans are transmitted to the management server, and when the plurality of communication plans are received, the management server is optimally selected from the received plurality of communication plans based on a communication state in the network. Selecting the communication plan, setting the network node in the communication time based on the selected communication plan , sending a quality response including the selected communication plan to the application server, and The server performs the calculation at the communication time according to the communication plan included in the quality response. Data necessary for an application executed on a computer is transmitted to the computer.

  According to the present invention, it is possible to realize a communication condition that optimizes the quality condition for the quality of the application requested by the user, and to optimize the quality condition of the entire user in the network in consideration of the bandwidth of the entire network. Communication conditions can be realized. In addition, the bandwidth setting of the queue at the output interface of the network node can be dynamically changed without causing problems such as packet loss.

  A first embodiment of the present invention will be described.

  According to the present embodiment, when moving image streaming is reproduced based on a request from a user, the QoE that is optimal for the user is realized, and the QoE that is optimal for the entire user in the network is realized.

  The main elements of QoE in video streaming are considered to be image quality, that is, resolution, less screen distortion, and shorter start-up time. Here, the start-up time is the time from the request for moving image reproduction until the reproduction of the moving image is started.

  In streaming, a receiving application typically buffers data for a few seconds to play a moving image in order to reduce jitter. Therefore, in order to improve QoE, it is important to transfer data without degrading the image quality of the content and shorten the time until the start of reproduction (hereinafter referred to as start-up time). In particular, the short start-up time is important when the user selects what is of interest from a plurality of contents and performs so-called zapping.

  In the present embodiment, ensuring the resolution and short start-up time are the main goals for improving QoE.

  FIG. 1 is a block diagram showing a network system configuration in the first embodiment of the present invention.

  An edge router 131 and an edge router 141 are connected to the core network 151. Each edge router 131, 141 may be a switch.

  When the core network 151 includes one or a plurality of core nodes, the edge routers 131 and 141 are connected to the core nodes or are connected by edge routers. The core network 151 may not include other devices, and the edge router 131 and the edge router 141 may be connected to each other.

  In the example shown in FIG. 1, the IP address of the edge router 131 is “10.10.11.1” and is directly or via a link connected to the network interface 132 having the interface number “1”. It is connected to the end user's computer 101 and computer 102 via other network devices.

  The computer 101 is assigned “10.10.21.10” as the IP address, and the computer 102 is assigned “10.10.21.15” as the IP address. The computer 101 and the computer 102 include a CPU (not shown), a main storage device (not shown), and a secondary storage device (not shown).

  The IP address of the edge router 141 is “10.10.12.1”, via a link connected to the network interface 142 whose interface number is “1”, directly or via another network device. The communication plan server 111 and the streaming server 121 are connected.

  The communication plan server 111 is assigned “10.10.22.11” as an IP address, and the communication plan server 111 includes a communication plan database 112. The streaming server 121 is assigned “10.10.22.12” as the IP address, and the streaming server 121 includes the content 122.

  The management server 152 is assigned with “10.10.23.31” as the IP address, and the management server 152 is connected to the edge routers 131 and 141 or other network devices included in the core network 151.

  FIG. 2A is a block diagram illustrating a hardware configuration of the communication plan server 111 according to the first embodiment of this invention.

  The communication plan server 111 includes a CPU 200, a main storage device 201, a secondary storage device 202, and a network interface 203. The main storage device 201 is a memory, for example. The secondary storage device 202 is, for example, an HDD. A communication plan database is provided on the secondary storage device 202 or an external device (not shown). The communication planning server 111 is connected to the edge router 141 via the network interface 203.

  FIG. 2B is a block diagram illustrating a hardware configuration of the streaming server 121 according to the first embodiment of this invention.

  The streaming server 121 includes a CPU 210, a main storage device 211, a secondary storage device 212, and a network interface 213. The main storage device 211 is a memory, for example. The secondary storage device 212 is, for example, an HDD. The content 122 is provided on the secondary storage device 212 or an external device (not shown). The streaming server 121 is connected to the edge router 141 via the network interface 213.

  FIG. 2C is a block diagram illustrating a hardware configuration of the management server 152 according to the first embodiment of this invention.

  The management server 152 includes a CPU 220, a main storage device 221, a secondary storage device 222, and a network interface 223. The main storage device 221 is, for example, a memory. The secondary storage device 222 is, for example, an HDD. A bandwidth management table 153 is provided on the secondary storage device 222 or an external device (not shown). The management server 152 is connected to the edge routers 131 and 141 or other network devices included in the core network 151 via the network interface 223.

  Next, a graphical user interface (GUI) for a user to input a request to an application at the start of a session and during the session will be described.

  FIG. 3A is a diagram illustrating a graphical user interface (GUI) for content selection according to the first embodiment of this invention. FIG. 3B is a diagram illustrating a graphical user interface (GUI) for selecting an initial quality according to the first embodiment of this invention. FIG. 3C is a diagram illustrating a graphical user interface (GUI) when a low resolution is selected according to the first embodiment of this invention. FIG. 3D is a diagram illustrating a graphical user interface (GUI) when a high resolution is selected according to the first embodiment of this invention. The GUI shown in FIGS. 3A to 3D is realized by the Web.

  The content selection screen 301 shown in FIG. 3A is a menu screen for the user to select specific content from the content displayed on the content selection screen 301. The content selection screen 301 is realized as an HTML page on a website. When the user selects content displayed on the content selection screen 301, the screen transitions to an initial quality selection screen 311 shown in FIG. 3B. That is, the content item displayed on the content selection screen 301 is expressed by a hyper link, and when one of the contents is selected (clicked), different parameters are specified, and CGI (Common) is displayed. The Gateway Interface program is started.

  The initial quality selection screen 311 displays a low resolution button 313 and a high resolution button 314. In other words, different QoE condition options are displayed. Note that the image quality improvement button 315 and the stop button 316 cannot be selected by the user in the initial quality setting. For example, it is conceivable that the button operation is invalid or not displayed. The user can select (click) either the low resolution button 313 or the high resolution button 314. Which button is selected by the user depends on which is most appropriate for the user depending on the difference in billing depending on the selection and the screen resolution or processing performance of the computer 101.

  When the user selects the low resolution button 313, the low resolution playback screen 321 is displayed, and when the user selects the high resolution button 314, the high resolution playback screen 331 is displayed. That is, depending on which button is operated, different parameters are designated and the CGI program is started.

  A playback screen 322 in the low-resolution playback screen 321 shown in FIG. 3C is a low-resolution moving image playback screen, and the playback screen 322 is realized as a Web plug-in. The playback screen 322 displays moving images that are received and played back by the moving image data transmitted from the streaming server 121. In the low-resolution playback screen 321, the low-resolution button 313 has been disabled because it has already been selected. That is, the user cannot operate (click) the low resolution button 313.

  The user can move to the high-resolution playback screen 331 by operating (clicking) the high-resolution button 314 while a moving image is being played back at a low image quality level. In addition, the user can improve the reproduced image quality by operating (clicking) the image quality improvement button 315 displayed on the low-resolution reproduction screen 321. The user can stop the reproduction of the moving image by operating (clicking) the stop button 316.

  A playback screen 332 in the high-resolution playback screen 331 shown in FIG. 3D is a high-resolution video playback screen, and the playback screen 332 is realized as a Web plug-in. The playback screen 332 displays moving images that are received and played back by the moving image data transmitted from the streaming server 121. In the high-resolution playback screen 331, the high-resolution button 314 has already been selected and is disabled. That is, the user cannot operate (click) the low resolution button 313.

  The user can move to the low-resolution playback screen 321 by operating (clicking) the low-resolution button 313 while the moving image is being played back with high image quality. Further, the user can improve the reproduced image quality by operating (clicking) the image quality improvement button 315 displayed on the high-resolution reproduction screen 331. The user can stop the reproduction of the moving image by operating (clicking) the stop button 316.

  As the QoE condition, it is possible to specify a startup time in addition to the resolution. For example, a button for selecting a QoE condition for which charging is large and startup is fast, and a button for selecting a QoE condition for which charging is small and startup is slow are selected for each initial quality. It can be displayed on the screen 311, the low resolution playback screen 321, and the high resolution playback screen 331.

  Processing generated by the operation in the graphical user interface shown in FIGS. 3A to 3D will be described later with reference to FIG.

  3A to 3D show the case where the CGI of the Web server is used as a method for realizing the CGI, but other methods such as a window system may be used.

  FIG. 4 is a sequence diagram showing a processing procedure in the network system when the user operates the low resolution button 313 or the high resolution button 314 at the start of the session or during the session in the first embodiment of the present invention. .

  This process is started when the Web browser operating on the computer 101 receives the quality request 401 from the user. The user's quality request 401 is generated by operating (clicking) either the low resolution button 313 or the high resolution button 314.

  The computer 101 that has received the quality request 401 by the user transmits the quality request 402 to the communication planning server 111. The quality request 402 includes a video identifier and QoE information. In the example shown in FIG. 4, the video identifier includes “life in venice” (corresponding to “live in Venice” on the initial quality selection screen 311), and the QoE information has a resolution of “800 × 450”. And “0.5 seconds” as the startup time. The quality request 402 may include other QoE information.

  The communication plan server 111 that has received the quality request 402 executes processing according to the procedure shown in FIG. 9A. Specifically, the management server 152 accesses the communication plan database 112 and transmits a quality request 403 including three communication plan proposals (see FIG. 8) of “Living in Venice”.

In the example shown in FIG. 4, an initial band, a startup time, a stationary band, and a maximum band are designated as a communication plan. Specifically, it is specified as follows.
Communication plan 1: (40M, 0.5 seconds, 5M, 5M)
Communication plan 2: (20M, 0.5 seconds, 7M, 7M)
Communication plan 3: (0, 0 seconds, 5M, 10M)
Details of the three communication plans transmitted to the management server 152 will be described later with reference to FIGS. 6A to 6C.

  The quality request 403 includes the IP address of the sender of the quality request 402 and the IP address of the receiver of the quality request 403 in addition to the communication plan. Specifically, the IP address of the sender is the IP address “10.10.21.10” of the computer 101, and the IP address of the receiver is the resolution of “life in Venice” specified in the quality request 402. Is the IP address “10.10.22.12” of the streaming server 121 that stores the file having “800 × 450”.

  The management server 152 that has received the quality request 403 executes processing according to the procedure shown in FIG. As a result, three messages of a bandwidth limit setting 404, a queuing setting 405, and a quality response 406 are transmitted. Specifically, the bandwidth limit setting 404 is transmitted to the edge router 141, the queuing setting 405 is transmitted to the edge router 131, and the quality response 406 is transmitted to the management server 152.

  The quality response 406 may be transmitted after the management server 152 receives a response that the edge router 141 completes the queue setting, or the moving image is played back at the time when the queue router processing of the edge router 141 is completed. It may be transmitted at the timing.

  The quality response 406 includes the communication plan draft selected by the management server 152. In the example illustrated in FIG. 4, the communication plan 1 is included in the quality response 406. If none of the transmitted communication plans is feasible, the management server 152 transmits a rejection response to the communication plan server 111 instead of the quality response 406.

  The bandwidth limit setting 404 includes a setting for limiting the traffic (moving image playback 409) in moving image streaming so as not to exceed the maximum bandwidth allowed when passing through the edge router 141.

  For example, the maximum bandwidth is specified as “20 Mbps” in the communication plan 1, the maximum bandwidth is specified as “40 Mbps” in the communication plan 2, and the maximum bandwidth is specified as “10 Mbps” in the communication plan 3. However, if it is certain that the transmission band from the streaming server 121 is equal to or less than the specified maximum band, the band limit setting 404 is not necessary.

  The queuing setting 405 includes a setting for using a queue having a minimum guaranteed bandwidth to be secured by the network interface 132 of the edge router 131 in the moving image playback 409. For example, the communication plan 1 selects a queue with a minimum guaranteed bandwidth of “5 Mbps”, the communication plan 2 selects a queue with a minimum guaranteed bandwidth of “7 Mbps”, and the communication plan 3 has a minimum guaranteed bandwidth of “7 Mbps”. The queue that is “5 Mbps” is selected.

  The communication planning server 111 that has received the quality response 406 transmits the quality response 407 to the computer 101 according to the procedure shown in FIG. 9B. The quality response 407 includes the IP address of the streaming server 121 that stores the selected communication plan and the requested content. Further, the quality response 407 may include an address of a server (not shown) other than the streaming server 121. Note that if none of the transmitted communication plans is feasible, the communication plan server 111 transmits a rejection response to the computer 101 instead of the quality response 407.

  The computer 101 that has received the quality response 407 transmits a playback request 408 to the streaming server 121 according to the communication plan included in the received quality response 407. In the example illustrated in FIG. 4, the reproduction request 408 includes the communication plan 1.

  The streaming server 121 that has received the playback request 408 executes the video playback 409 according to the procedure shown in FIG. 11 based on the communication plan included in the received playback request 408.

  In the sequence shown in FIG. 4, the communication plan server 111 transmits all communication plan proposals to the management server 152 at once. The method described above has the advantage of being simple and having a short communication sequence. However, when there are a large number of communication plans to be transmitted, the amount of data transmitted by the communication plan server 111 increases. Therefore, five alternative methods for the communication plan server 111 to transmit the communication plan to the management server 152 are shown below. In the following description, a method in which the communication plan server 111 in FIG. 4 transmits a communication plan plan to the management server 152 is referred to as an original plan.

  In the first alternative, the communication plan server 111 selects an optimum one from the communication plan server 111 and transmits a quality request 403 including only the selected communication plan to the management server 152.

  The management server 152 determines whether or not the transmitted communication plan is appropriate. If it is determined that the communication plan is appropriate, the management server 152 sends a quality response 406 including the communication plan or an OK message to the communication plan server. If the communication plan is determined to be an inappropriate communication plan, a rejection response is transmitted to the communication plan server 111 instead of the quality response 406.

  The communication plan server 111 continues to transmit the alternative communication plan until the management server 152 receives the communication plan (the communication plan server 111 receives the quality response 406 or the OK message). If there is no communication plan to be transmitted, the communication plan server 111 transmits a rejection response to the computer 101 instead of the quality response 407.

  That is, as the first alternative, a communication plan is selected by negotiation between the communication plan server 111 and the management server 152. The first alternative has the advantage that the average traffic is reduced from the original.

  In the second alternative, the communication plan server 111 transmits one communication plan plan to which a parameter has been assigned to the management server 152, and the management server 152 calculates the optimum value of the assigned parameter to calculate the communication plan server 111. Send to.

  As communication plan proposals with parameters, for example, the communication plan proposals 1 and 2 are collectively set to (10 × (2 + α), 0.5 seconds, 5 + αM, 5 + αM) (α = 0, 2). Can be considered. Here, α is a parameter. If more communication plans can be compiled, the amount of transmission data can be reduced. Note that the communication plan server 111 determines the parameter and the communication plan to which the parameter is assigned.

  In other words, the second alternative has the advantage that the communication sequence is as short as the original and the amount of data to be transmitted is small.

  In the third alternative, the processing is executed according to a sequence as shown in FIG.

  FIG. 5 is a sequence diagram showing a modified example of the processing procedure in the network system when the user operates the low resolution button 313 or the high resolution button 314 at the start of the session or during the session in the first embodiment of the present invention. It is. Hereinafter, the difference from FIG. 4 will be mainly described.

  In the sequence illustrated in FIG. 5, a quality request 501, a quality request 502, a quality response 503, and a quality response 504 are used instead of the quality request 402, the quality request 403, the quality response 406, and the quality response 407. Other processing procedures are the same as those in FIG.

  In the sequence shown in FIG. 5, SIP is used for communication between the computer 101 and the communication plan server 111. In NGN IMS, SIP is used to secure resources, but the sequence shown in FIG. 5 is an extension of it. That is, session control by SIP is executed before session control by RTSP (playback request 409) at the start of a streaming session. The quality request 501 is a SIP INVITE message, and the communication partner is the communication plan server 111 which is a session control server.

  The quality request 501 includes an extended SDP message. In addition, the extended SDP message includes a video identifier, resolution, and startup time. The quality request 501 reaches the communication planning server 111 via the management server 152 that is a SIP server. Specifically, the management server 152 transfers the received quality request 501 as the quality request 502 to the communication planning server 111.

  The quality response 503 transmitted from the communication plan server 111 is a SIP OK response, and further includes a plurality of communication plan proposals. The management server 152 refers to a plurality of plans included in the quality response 503, selects an optimal communication plan, and transfers the quality response 504 including the selected communication plan to the computer 101 that is the SIP client. The quality response 504 differs from the quality response 503 in that it includes only one communication plan.

  In the fourth alternative, as in the first alternative in the sequence shown in FIG. 5, the quality response 503 includes the communication plan selected by the communication plan server 111 as the optimum one. When rejecting the communication plan, the management server 152 sends a SIP failure response to the computer 101 instead of the OK message as the quality response 504. That is, it is possible to negotiate between the management server 152 and the communication plan server 111 indirectly by exchanging a communication plan between the computer 101 and the communication plan server 111 according to the offer / answer model.

  In the fifth alternative, in the sequence shown in FIG. 5, the communication plan with parameters is included in the quality response 503 as in the second alternative. The management server 152 determines an optimal parameter value, and includes the determined parameter in the quality response 504, so that the computer 101 can receive the communication plan specified by the determined parameter value.

  The above is an explanation of an alternative method for the communication plan server 111 to transmit the communication plan to the management server 152.

  In the sequence shown in FIG. 4, after the quality request 402 and the quality request 403 are transmitted, the effect continues unless a request message for canceling the quality request 402 and the quality request 403 is transmitted. Specifically, the settings of the edge routers 131 and 141 by the bandwidth limit setting 404 and the queuing setting 405 are not released. Therefore, there is a problem that the resources of the edge routers 131 and 141 are not released unless a request message for canceling the setting of the edge routers 131 and 141 is transmitted.

  In order to solve the above-described problem, a method of including a timeout time in the quality request 402 and the quality request 403 can be considered. For example, when the quality request 402 includes “60 minutes” as the timeout time, the quality request 403 also includes the timeout time, and when the management server 152 measures the time and reaches 60 minutes, the bandwidth limit setting 404 and the queue are set. The setting of the edge routers 131 and 141 by the ing setting 405 is set to be invalidated.

  If a request message having the same content as the quality request 402 is transmitted from the computer 101 to the communication planning server 111 before the timeout time elapses, the timer is reset and the timeout time is extended. Therefore, when the user operates (clicks) the button, the user operates (clicks) the same button again after the quality request 401 is issued by the user and before the specified timeout period elapses. A request having the same content as the quality request 402 is issued, and the timeout time is extended. Thereby, the process shown in FIG. 12 is not required.

  FIG. 6A is a diagram for explaining a communication plan 1 in the first embodiment of the present invention. FIG. 6B is a diagram illustrating the communication plan 2 in the first embodiment of the present invention. FIG. 6C is a diagram illustrating the communication plan 3 according to the first embodiment of this invention.

  The communication plan 1 is a plan to transmit data at 20 Mbps for the first 0.5 seconds, and thereafter to transmit data at a constant rate of 7 Mbps (CBR (Constant Bit Rate)). However, the rate may actually be lower than 7 Mbps.

  The communication plan 2 is a plan for transmitting data at 40 Mbps only for the first 0.5 seconds and thereafter transmitting data at a constant rate of 5 Mbps.

  The reason why the fixed rate in the communication plan 2 is lower than that in the communication plan 1 is that in the present embodiment, the communication plan 1 assumes that the jitter buffer of the receiving-side application is 10 Mbit (1.25 MB). On the other hand, in the communication plan 2, it is assumed that the jitter buffer of the receiving side application is 20 Mbit (2.5 MB), so that the actual rate can be leveled. That is, in the communication plan 2, since a larger amount of data can be transmitted in advance when the playback rate increases due to, for example, the motion of a moving image to be played back becoming faster, the communication plan 2 is more constant than the communication plan 1. The rate can be lowered.

  Unlike the communication plan plans 1 and 2, the communication plan plan 3 transmits data at a constant rate of 5 Mbps from the beginning, and allows data to be transmitted at a rate of up to 10 Mbps. That is, the communication plan plan 3 is a plan to transmit by VBR (Variable Bit Rate).

  In the communication plans 1 and 2, the minimum bandwidth of 7 Mbps or 5 Mbps is guaranteed at portions other than the first 0.5 seconds, thereby preventing delay and packet loss.

  In communication plan 3, the minimum bandwidth of 10 Mbps is guaranteed, so that delay and packet loss can be prevented, but new requests cannot be accepted even though the network traffic is actually low. That is, a situation occurs in which reproduction is rejected by the admission control function of the network. Therefore, the minimum bandwidth is assumed to be lower than 10 Mbps, that is, scheduling that allows so-called overbooking is assumed.

  FIG. 7 is a diagram illustrating the relationship between the startup time, the amount of jitter buffer, and the steady band in the first embodiment of the present invention.

  A graph 701 in FIG. 7 represents the relationship between the time of the receiving application and the data amount of the reproduced moving image. Since the graph 701 is premised on VBR coding, the graph representing the relationship between the time of the receiving application and the data amount of the reproduced moving image is not a straight line.

  A graph 702 in FIG. 7 shows the relationship between the time of the reception application and the amount of moving image data to be transmitted in the communication plan 2, and the graph 703 shows the time of the reception application in the communication plan 1 and the data of the moving image to be transmitted and received The relationship with quantity is shown. In the communication plan plans 1 and 2, data to be transmitted / received is transmitted / received according to CBR, so the graphs 702 and 703 are represented by straight lines.

  When the straight lines of the graphs 702 and 703 appear on the right side of the thick line of the graph 701, the data is insufficient and playback stops. Don't be. Therefore, if the buffer size is reduced, the slope needs to be increased. That is, it is necessary to increase the steady band.

  FIG. 8 is a diagram illustrating an example of contents stored in the communication plan database 112 according to the first embodiment of this invention.

  The communication plan database 112 stores original data 800 of a communication plan for all contents stored in the streaming server 121.

  The original data 800 includes a video identifier 801, a server address 802, a resolution 803, and a communication plan 804.

  The video identifier 801 is an identifier for identifying a moving image. The server address 802 stores the IP address of the streaming server 121 that stores the content corresponding to the video identifier 801. If there are a plurality of streaming servers 121 that store the same content, the server address 802 stores the IP addresses of the plurality of streaming servers 121.

  A resolution 803 indicates the resolution of the moving image to be reproduced. That is, QoE conditions are stored. The communication plan draft 804 stores a communication plan draft composed of a triple of a minimum buffer amount, a steady band, and a maximum band. Note that the communication plan plans stored in the communication plan plan 804 are stored in a state of being arranged in order from the one with the best condition. For example, in the example shown in FIG. 8, communication plans with good conditions are stored in order from the left.

  The original data 800 includes two records of low resolution and high resolution for one video identifier 801. In the example illustrated in FIG. 8, the original data 800 includes records 811 to 818.

  The record 814 is a record corresponding to “Living in Venice”, and the communication plan 804 of the record corresponds to each of the three communication plans 1 to 3 shown in FIGS. 6A to 6C. Here, the minimum buffer amount is the minimum value of the amount of jitter buffer that the receiving-side application should have. The initial bandwidth is calculated by dividing the minimum buffer amount by the startup time. For example, if the minimum buffer amount is “20 Mbps” and the startup time is “0.5 seconds”, it is necessary to transmit the initial bandwidth as “40 Mbps” in order to fill the jitter buffer in 0.5 seconds. . Therefore, when the startup time is “0.5 seconds”, the communication plan plan 2 (20M, 5M, 5M) to (40M, 0.5M, 5M, 5M) included in the communication plan plan 804 of the record 814 is Generated.

  9A and 9B are flowcharts for explaining the processing of the communication plan server 111 according to the first embodiment of this invention.

  FIG. 9A shows a processing procedure 901 when the communication plan server 111 receives the quality request 402, and FIG. 9B shows a processing procedure 902 when the communication plan server 111 receives the quality response 406. Hereinafter, each processing procedure 901 and 902 will be described.

  In the processing procedure 901, first, in step 911, the communication plan server 111 that has received the quality request 402 uses the video identifier 801 and the resolution 803, such as “Llife in venice”, as a search key, and the communication plan draft 804. And the server address 802 are read out.

  Next, in step 912, the communication plan server 111 calculates an initial bandwidth from the minimum buffer amount included in the read communication plan draft 804 and the startup time included in the quality request 402. Specifically, the initial bandwidth is calculated by dividing the minimum buffer amount by the startup time. As a result, a communication plan is generated. In step 911, when the record 814 of FIG. 8 is read, the communication plan server 111 generates communication plan plans 1 to 3 shown in FIGS. 6A to 6C.

  In step 913, the communication plan server 111 transmits to the management server 152 a quality request 403 including a communication plan composed of an initial band, a startup time, a steady band, and a maximum band, and the process ends.

  In the processing procedure 902, the communication plan server 111 that has received the quality response 406 in step 921 transmits the quality response 407 to the quality request source (in this case, the computer 101), and ends the processing.

  FIG. 10 is a flowchart illustrating processing of the management server 152 according to the first embodiment of this invention.

  The management server 152 that has received the quality request 403 executes processing according to the processing procedure 1001. In step 1011, the management server 152 selects an optimum one from the communication plan drafts included in the quality request 403. Here, the list of communication plans included in the quality request 403 is arranged in order from the communication plan server 111 in the order of good conditions. There are various methods for the management server 152 to select the optimum one from the communication plans included in the quality request 403. Two methods are shown below.

  First, the first method of processing executed in step 1011 will be described. When the network is occupied by traffic that does not exceed the specified bandwidth value as in the communication plans 1 and 2 except for the first 0.5 seconds, the management server 152 By calculating the sum of the bandwidths related to the flow, it is possible to predict the communication amount almost accurately. Accordingly, when the sum of the calculated bandwidth and the initial bandwidth included in the communication plan is sufficiently smaller than the bandwidth of the link connected to the network interface 132, for example, 10 of the initial bandwidth of the communication plan is included. If there are more than twice, the communication plan is selected. A numerical value other than 10 times may be used.

  For example, when the bandwidth of the link is 1 Gbps and the calculated sum is 800 Mbps or less, the communication plan 1 whose initial bandwidth is “20 Mbps” can be selected.

  When the calculated sum of the steady bandwidths exceeds the bandwidth of the link, the management server 152 considers the next best communication plan. If any communication plan is not executable, the management server 152 rejects the request. That is, moving image streaming is rejected by admission control.

  Next, the second method of processing executed in Step 1011 will be described. Like the communication plan 3, the traffic may exceed the steady band (5 Mbps in the case of the communication plan 3), and there is traffic for which the management server 152 cannot predict at what timing the traffic will exceed the steady band. In this case, the management server 152 performs control according to the predicted value using the measured value of the traffic.

  In order to measure the traffic, IPFIX, which is a standard protocol of IETF, NetFlow, which is a protocol developed by Cisco, which is the predecessor of IPFIX, or SFlow, which is a protocol developed by InMon, can be used. With these protocols, the management server 152 can acquire the traffic volume statistics in the network interface 132 of the edge router 131 and calculate the bandwidth used based on the acquired traffic statistics.

  The management server 152 obtains a predicted bandwidth based on the calculated actual value. That is, the management server 152 sets the calculated actual value as the predicted value as it is. When the sum of the predicted value and the maximum bandwidth included in the communication plan is sufficiently smaller than the bandwidth of the link connected to the network interface 132, for example, 20 times the initial bandwidth of the communication plan with the predicted value If there are more, the communication plan is selected. A numerical value other than 20 times may be used.

  For example, if the link bandwidth is 1 Gbps and the calculated sum is 600 Mbps or less, the communication plan 1 with the initial bandwidth of “20 Mbps” can be selected.

  When the calculated sum exceeds the bandwidth of the link, the management server 152 considers the next best communication plan. If any communication plan is not executable, the management server 152 rejects the request. That is, moving image streaming is rejected by admission control.

  In the following description, it is assumed that traffic is measured using NetFlow. By using NetFlow, the router (in this case, the edge router 131, 141) periodically (eg every other minute) will receive a specific interface (in this case, the network interface 132, 142) of the router. ) Can be notified to the management server 152 for each type of traffic. By using the above-described function, the management server 152 can calculate the bandwidth of traffic output from the network interface 132 of the edge router 131 periodically.

Band Bu (c) assigned to class c at time t is estimated by the following equation based on the collection results up to the previous time t-1. However, in the first embodiment, since attention is paid to one class (streaming), c is omitted below.
(Formula 1) Bu = γ (1 + β) Ba + (1-α) Br
If the difference between the total bandwidth Bm (band assigned to the class) set in advance as a constant and Bu estimated by (Equation 1) is assignable, and these are below the new required bandwidth Can be assigned.

  In (Expression 1), Ba represents a bandwidth acquired by traffic measurement, and Br represents a sum of a stationary bandwidth or a maximum bandwidth for each traffic. That is, after the startup time has elapsed, the stationary band is selected for traffic that does not exceed the stationary band, and the maximum band is selected for traffic that follows the variable bit rate.

When QoS control by DiffServ is performed in the core network 151, information aggregated in units of traffic classes is acquired from NetFlow, but the acquired value calculates an exponential moving average according to the following equation: By smoothing.
(Expression 2) Ba (t) = αba (t) + (1−α) Ba (t−1)
Here, ba is a band value acquired from NetFlow. In this admission control method, it is necessary to use three parameters of adjusted α, β, and γ. Here, the parameters are as follows.

  α is called a measurement value smoothing coefficient, and is a parameter that controls the smoothness of the moving average of traffic measurement values. β is called a bandwidth margin ratio and is a parameter for controlling a margin of admission control limit value with respect to a traffic measurement value (moving average). γ is called a measurement value contribution rate, and is a contribution rate of a measurement value related to a limit value of admission control ((1-γ) is a contribution rate of a declared value).

  According to (Expression 1), the management server 152 can perform admission control in consideration of both a bandwidth based on a user or application request and a bandwidth calculated from traffic measurement. As a result, compared to admission control performed only by the bandwidth based on the user or application request, when the traffic exceeding the steady bandwidth is increased, the start of a new session is suppressed, and the packet loss of the existing session and Since the increase in delay is suppressed, the designated QoE can be realized with a higher probability.

  Compared to admission control that is based only on the bandwidth calculated from traffic measurement, the number of traffic that exceeds the steady bandwidth increases or traffic that deviates from the steady bandwidth suddenly appears. Since admission control is performed in consideration of the maximum bandwidth in advance, the probability of occurrence of packet loss and delay increase in an existing session can be kept low. The above is the description of the processing executed in step 1011.

  Returning to the description of the processing procedure 1001.

  In step 1012, the management server 152 sets the initial bandwidth in the communication plan selected in step 1011 as the maximum bandwidth to the router on the streaming server 121 side, that is, the network interface 142 of the edge router 141. Specifically, the management server 152 transmits the bandwidth limit setting 404 to the edge router 141. In the example illustrated in FIG. 4, when the management server 152 selects the communication plan 2, the sender is “10.10.22.12” and the receiver is “10.10.21.10”. A bandwidth limit of “40 Mbps” is set in the edge router 141 for the flow.

  In step 1013, the management server 152 sets a queue whose minimum guaranteed bandwidth is the steady band in the communication plan selected in step 1011 in the user side router, that is, the network interface 132 of the edge router 131. Ensure that video streaming traffic at is in the selected queue. In order to realize the above-described operation, the following procedure is specifically performed.

  First, when the core network 151 is initialized, the management server 152 performs initial setting of the queue at the user-side exit interface (in this case, the network interface 132). For example, in the network interface 132, when the required minimum guaranteed bandwidth is three types of 5 Mbps, 7 Mbps, and 10 Mbps, and a maximum of 30 queues can be set, the management server 152 sets the following queues: Secure by initial setting. In other words, the management server 152 reserves 10 queues of 5 Mbps, 10 queues of 7 Mbps, and 10 queues of 10 Mbps. The reserved queue is not used until requested.

  Second, in step 1013, the management server selects a queue having the minimum guaranteed bandwidth designated by the selected communication plan from the queues secured by the initial setting. For example, when “5 Mbps” is designated as the minimum guaranteed bandwidth, one of the 5 Mbps queues secured by the initial setting is assigned. If there is no queue that matches the specified minimum guaranteed bandwidth, a queue having a minimum guaranteed bandwidth that is greater than the specified minimum guaranteed bandwidth is selected.

  As described above, instead of securing the queue in advance, a method of changing the configuration of the queue at the time of request and assigning a new queue is also conceivable. However, if the queue configuration is changed every time there is a request, packets to be queued may be discarded when the queue configuration is changed, or the edge router 131 may be heavily loaded due to reconfiguration. There is. As described above, the method of securing the queue in advance has an advantage that the packet is not lost when the queue is allocated and the overhead is small.

  In step 1014, the management server 152 transmits a quality response 406 including the selected communication plan to the communication plan server 111, and ends the process.

  FIG. 11 is a flowchart illustrating processing of the streaming server 121 according to the first embodiment of this invention.

  The streaming server 121 that has received the playback request 408 executes processing according to the processing procedure 1101.

  In step 1111, the streaming server 121 that has received the playback request 408 transmits moving image data according to the time specified in the initial band in the communication plan included in the playback request 408. For example, when the reproduction request 408 includes the communication plan 2, the designated initial bandwidth is “40 Mbps” and the designated startup time is “0.5 seconds”. The video data is transmitted to the computer 101 at a communication speed of 40 Mbps for 0.5 seconds.

  In step 1112, the streaming server 121 transmits the remaining moving image data according to the specified steady band and the maximum band. When the designated stationary band and maximum band are both “5 Mbps”, the streaming server 121 transmits moving image data in a range not exceeding 5 Mbps and so that the jitter buffer of the receiving-side application does not overflow.

  The streaming server 121 knows how much data is consumed at what time after the start of playback in the playback of each streaming content (it can be found by actually playing, but playback is not essential). The amount of data buffered in the jitter buffer of the receiving application can be estimated. Based on the estimation, the streaming server 121 controls transmission of moving image data so that the jitter buffer does not overflow.

  In addition, the moving image may stop or the playback speed may change in the receiving side application. In such a case, the protocol used for the playback request 408 and its response, for example, the protocol RTSP (Real-Time Streaming Protocol) of the IETF standard is used, or the video data and the protocol for its control, for example, By using the IETF standard protocols RTP (Real-time Transport Protocol) and RTCP (Real-Time Control Protocol), the streaming server 121 is notified from the computer 101 of how much playback is currently in progress. The server 121 can use the notified information for controlling the jitter buffer.

  FIG. 12 is a sequence diagram illustrating a processing procedure in the network system when the user operates (clicks) the stop button 316 in the first embodiment of the present invention.

  A user's stop request 1201 generated by operating (clicking) the stop button 316 is received by a Web browser operating on the computer 101. First, the computer 101 transmits a stop request 1202 to the streaming server 121 to stop transmission of moving image data from the streaming server 121.

  Subsequently, the computer 101 transmits a quality request 1203 to the communication plan server 111. The quality request 1203 includes a video identifier 801 necessary for identifying the corresponding request.

  The communication planning server 111 that has received the quality request 1203 transmits the quality request 1204 to the management server 152. The quality request 1204 includes the sender of the quality request 1203, that is, the IP address “10.10.21.10” of the computer 101.

  The management server 152 that has received the quality request 1204 transmits three messages of a quality response 1207, a bandwidth limit setting release 1205, and a queuing setting release 1206, respectively. Specifically, the quality response 1207 is transmitted to the communication planning server 111, the bandwidth limit setting cancellation 1205 is transmitted to the edge router 141, and the queuing setting cancellation 1206 is transmitted to the edge router 131. Further, the setting in the bandwidth limitation setting 404 is invalidated by the bandwidth limitation setting cancellation 1205, and the setting in the queuing setting 405 is invalidated by the queuing setting cancellation 1206.

  The communication planning server 111 that has received the quality response 1207 transmits a quality response 1208 to the computer 101. When the quality request 402 and the quality request 403 include a timeout time, the bandwidth limit setting cancellation 1205 and the queuing setting cancellation 1206 are not transmitted.

  Next, processing that occurs when the high resolution button 314 or the low resolution button 313 is operated (clicked) during reproduction will be described.

  When the high resolution button 314 or the low resolution button 313 is operated (clicked) during reproduction, the computer 101 first stops the moving image being reproduced. The procedure of the above-described processing is almost the same as the sequence diagram shown in FIG. 12, but a temporary stop request is transmitted instead of the stop request 1202.

  The streaming server 121 that has received the pause request stores the elapsed time from the start of the reproduction of the moving image to the stop, and starts the reproduction of the moving image having a different resolution. The sequence for reproducing a moving image is the same as that in FIG. 4, but a restart request is transmitted instead of the reproduction request 408. The streaming server 121 that has received the restart request starts the playback of the moving image from the place where it was paused based on the elapsed time from the start of the playback of the stored moving image to the stop. As a result, a moving image having a different resolution is reproduced from the point where the reproduction is just stopped.

  Note that the processing when the image quality improvement button 315 is operated (clicked) is executed according to the same sequence as in FIG. However, the quality request 401 by the user is an image quality improvement request, and the quality request 402 includes content representing “image quality improvement” instead of the resolution and the startup time. Further, if the communication plan already selected in the quality request 403 is a plan based on VBR, the plan is changed to a plan based on CBR. In the queuing setting 405, the management server 152 selects a queue suitable for a new communication plan due to a quality improvement request.

  In the present embodiment, when the minimum guaranteed bandwidth cannot be secured, the reproduction of the moving image is rejected and cannot be reproduced. When it is known that the network is congested and cannot be reproduced in advance, the high resolution button 314 is disabled, that is, the operation (clicking) cannot be performed, thereby preventing the user from performing a wasteful operation ( In the initial quality selection screen 311, the image quality improvement button 315 and the stop button 316 are disabled).

  Specifically, when the initial quality selection screen 311 and the low resolution playback screen 321 are generated, the communication plan server 111 generates these Web pages by CGI, and the communication plan server 111 communicates with the management server 152 in advance. Menu items (buttons) that cannot be realized can be invalidated by inquiring whether the plan can be realized. Note that the management server 152 can measure traffic in advance and can respond to the communication plan server 111 as to whether or not the communication plan can be realized based on the measurement result.

  Furthermore, after the initial quality selection screen 311, the low resolution playback screen 321, and the high resolution playback screen 331 are displayed, the state of the network changes, and this can be realized when the screens 311, 321, and 331 are displayed. Menu items may become unrealizable, or conversely, when the screens 311, 321, and 331 are displayed, menu items that could not be realized may become realizable.

  In order to cope with the above-described case, the displayed screens 311, 321, and 331 are periodically refreshed, that is, the management server 152 is inquired of whether or not the menu item can be realized at that time, and the display is updated accordingly. can do. The above is the description of the first embodiment of the present invention.

  Hereinafter, a second embodiment of the present invention will be described.

  FIG. 13 is a block diagram showing a network system configuration in the second embodiment of the present invention. Hereinafter, the difference from the first embodiment will be mainly described.

  1 is different from FIG. 1 in that an HGW (home gateway) 1301 for connecting the computers 101 and 102 and the edge router 131 on the network is provided, and the HGW 1301 is not provided with the communication plan server 111. A measurement control server 1302 is included. Other configurations are the same as those in FIG.

  FIGS. 14A and 14B are diagrams illustrating a graphical user interface (GUI) for inputting a quality request to the network in the second embodiment of the present invention. The example shown in FIGS. 14A and 14B is a GUI for inputting a quality request when the application is not limited to a specific application.

  In the quality menu 1401 shown in FIG. 14A, a quality improvement button 1402 and a cancel button 1403 are displayed. The user operates (clicks) the quality improvement button 1402 to improve the quality in any application in use. If the user wants to cancel the requested quality improvement, the user operates (clicks) the cancel button 1403.

  In the quality menu 1411 shown in FIG. 14B, a sound quality improvement button 1412, an image quality improvement button 1413, a Web speed-up button 1414, and a cancel button 1415 are displayed. Specifically, in an arbitrary application being played back, the user operates (clicks) the sound quality improvement button 1412 when desiring to improve the sound quality. In addition, in an arbitrary application being played back, the user operates (clicks) the image quality improvement button 1413 when desiring to improve the image quality. When the user uses a Web browser or Web service and desires to improve these responses, the user operates (clicks) the Web acceleration button 1414. If the user wants to cancel the requested quality improvement, the user operates (clicks) the cancel button 1415.

  In the present embodiment, it is assumed that DiffServ is used for QoS guarantee in the core network 151. Traffic in the core network 151 is classified into a conversation class, a streaming class, a Web class, and a best effort class, and resources such as queues of the edge routers 131 and 141 are assigned to each class.

  For example, in the network interface 132 of the edge router 131, a high priority queue is assigned to the conversation class, and the bandwidth is divided among a plurality of low priority queues for other traffic. That is, so-called LLQ (Low Latency Queuing) is applied.

  Accordingly, the minimum guaranteed bandwidth is set for each of the streaming class, the web class, and the best effort class. Further, the maximum bandwidth is determined for the traffic of the conversation class so that the conversation class does not compress other classes, and admission control is performed so as not to exceed the maximum bandwidth. Note that when there is no traffic that requires preferential processing such as a conversation class, scheduling consisting only of WFQ instead of LLQ may be specified.

  FIG. 15 shows a second embodiment of the present invention, in which a user can use a quality improvement button 1402, a sound quality improvement button 1412, an image quality improvement button 1413, a web acceleration button 1414, or a cancel button 1415 while the user is using any application. It is a sequence diagram which shows the process sequence in a network system when operating.

  The user's quality request 1501 is generated by operating (clicking) any one of the buttons (quality improvement button 1402, sound quality improvement button 1412, image quality improvement button 1413, Web acceleration button 1414, and cancel button 1415). The Web browser operating on the computer 101 receives the event.

  The computer 101 that has received the quality request 1501 by the user transmits the quality request 1502 to the measurement control server 1302. The quality request 1502 includes the media type and QoE information corresponding to the operated (clicked) button.

  When the quality improvement button 1402 is operated (clicked), the media type included in the quality request 1502 includes a value indicating that it is unknown, or the media type is omitted. When the sound quality improvement button 1412 is operated (clicked), the type of media is “voice”. When the image quality improvement button 1413 is operated (clicked), the media type is “moving image”. Although “image quality” may indicate a still image, it is assumed here that the image quality is a moving image on the premise that a moving image service is provided. When the Web acceleration button 1414 is operated (clicked), the type of media is “Web”.

  When the quality improvement button 1402, the sound quality improvement button 1412, or the image quality improvement button 1413 is operated (clicked), the QoE information included in the quality request 1502 is “high quality”. When the web acceleration button 1414 is operated (clicked), the QoE information included in the quality request 1502 is “acceleration response”.

  The measurement control server 1302 that has received the quality request 1502 executes processing according to the procedure shown in FIG. That is, the measurement control server 1302 generates a quality request 1503 based on the content included in the quality request 1502 and transmits the generated quality request 1503 to the management server 152.

  Specifically, the measurement control server 1302 uses the traffic measurement information measured by the HGW 1301, identifies the traffic class of the corresponding DiffServ from the type of media included in the quality request 1502, and determines the identified traffic class. It is included in the quality request 1503. Further, a bandwidth to be guaranteed is calculated based on the QoE information included in the quality request 1502 and the traffic measurement information measured by the HGW 1301, and the calculated bandwidth is included in the quality request 1503. Further, the measurement control server 1302 includes the sender of the quality request 1502, that is, the IP address “10.10.21.10” of the computer 101 in the quality request 1503.

  The management server 152 that has received the quality request 1503 performs processing according to the procedure shown in FIG. Specifically, the management server 152 transmits a queuing setting 1504 to the edge router 131 and transmits a quality response 1505 to the measurement control server 1302. The quality response 1505 includes a reserved bandwidth value. The queuing setting 1504 includes information for setting a queue in the edge router 131.

  The edge router is configured so that the queue having the bandwidth specified in the queuing setting 1504 as the minimum guaranteed bandwidth is used for the traffic of the class specified in the queuing setting 1504 by the queuing setting 1504. 131 network interfaces 132 are set.

  As a result, when the user requests to improve the sound quality, the sound quality is improved by securing a band for the conversational voice or streaming voice used at that time. Further, when the user requests image quality improvement, the image quality is improved by securing a bandwidth for the conversational video or streaming video used at that time.

  Further, when the user requests web speeding up, the response speed is improved by securing a bandwidth for web traffic.

  The measurement control server 1302 that has received the quality response 1505 transmits a quality response 1506 to the computer 101. Similar to the quality response 1505, the quality response 1506 includes a reserved bandwidth value.

  Next, traffic measurement performed by the HGW 1301 will be described.

  The HGW 1301 monitors a packet passing through the HGW 1301, and if the passing packet is a UDP packet, it further determines whether or not it is an RTP packet.

  If it is determined that the packet is an RTP packet, the HGW 1301 further determines whether the packet uses an audio codec in the IETF standard or the de facto standard, or uses a video codec, and uses the audio codec. Packets determined to be used are classified as audio packets, and packets determined to be using the moving image codec are classified as moving image packets.

  Further, the HGW 1301 determines whether or not the TCP packet is an HTTP packet, and classifies the packet determined to be an HTTP packet as a Web packet. Packets that are not audio packets, moving image packets, or Web packets are classified as other packets. The HGW 1301 classifies the four types of packets as described above based on traffic measurement.

  For each type of packet described above, the HGW 1301 further counts the data amount of the packet from the edge router 131 toward the computer 101 for each DSCP (DiffServ Code Point) included in the IP packet, and measures the traffic amount.

  It is assumed that DiffServ EFPB (Expanded Forwarding Per-Hop-Behavior) is used for conversation and AF3PHB (Assured Forwarding 3 Per-Hope-Havior) is used for streaming. That is, conversation and streaming can be distinguished by DSCP.

  As a result, the bandwidth used for each type of traffic in the HGW 1301 for voice, video, Web, and other traffic can be calculated. If no packet loss occurs in the HGW 1301, the calculated used bandwidth is equal to the used bandwidth in the network interface 132.

  The traffic measurement method described above is based on the premise that the HGW 1301 measures traffic. However, the edge router 131 can also perform traffic measurement. That is, the measurement control server 1302 receives the traffic measurement information in the network interface 132 from the edge router 131 using a protocol such as IPFIX, NetFlow, or SFlow, and based on the received traffic measurement information, the network interface 132. The bandwidth of output traffic at is calculated for each type of traffic.

  However, since a router basically operates in the IP layer, it often does not have an RTP packet analysis function. Therefore, the router can distinguish whether it is conversation or streaming by DSCP, but the above method cannot distinguish whether it is voice or video. Therefore, it is necessary to take a method such as estimating whether it is voice or moving image from the packet size (the voice packet is relatively small, several hundred bytes or less, and almost 100 bytes or less depending on the protocol).

  Thus, when the edge router 131 performs traffic measurement, the HGW 1301 is not necessarily required. The measurement control server 1302 can exist independently of the HGW 1301, and can be included in the management server 152, for example. When the measurement control server 1302 is included in the management server 152, the quality request 1503 and the quality response 1505 can be realized by calling a function in the program and returning from the function.

  FIG. 16A and FIG. 16B are flowcharts for explaining processing of the measurement control server 1302 according to the second embodiment of this invention.

  FIG. 16A shows a processing procedure 1601 when the quality request 1502 is received, and FIG. 16B shows a processing procedure 1621 when the quality response 1506 is received. Hereinafter, the processing procedures 1601 and 1621 will be described.

  In the processing procedure 1601, first, in step 1611, the measurement control server 1302 obtains a traffic class candidate from the media type included in the quality request 1502. For example, if the media type is “voice” or “video”, the traffic class is conversation or streaming.

  In step 1612, the measurement control server 1302 obtains traffic measurement results for all pairs of media types and traffic class candidates.

  In step 1613, the measurement control server 1302 identifies a traffic class having quality degradation based on the traffic measurement result.

  Specifically, when the type of media is “voice”, the determination is made as follows. The measurement control server 1302 determines whether the conversation traffic that combines the voice and the moving image has a margin compared to the bandwidth allocated to the traffic or whether the allocated bandwidth is tight. Further, the measurement control server 1302 determines whether the streaming traffic including the voice and the moving image has a margin compared to the bandwidth allocated to the traffic or whether the allocated bandwidth is tight. .

  When the conversation traffic is the most congested, the measurement control server 1302 specifies that the conversation voice is a traffic class with quality degradation. When the streaming traffic is most congested, the measurement control server 1302 identifies a traffic class in which the quality of streaming audio is degraded.

  Even when the type of media is “moving image”, if the conversation traffic is the most congested, the measurement control server 1302 specifies that the conversation moving image is a traffic class with degraded quality. If the streaming traffic is most congested, the streaming video is identified as a traffic class with degraded quality.

  Here, which of the plurality of classes is most congested can be determined by using one of the following three methods.

  The first method determines that the higher the ratio of the total bandwidth used by all the traffic of any class to the allowed bandwidth, the more congested the bandwidth.

  The second method determines that a class having a large packet loss is more congested by measuring the packet loss. In a UDP flow in which a packet includes a sequence number as in the RTP flow, if there is a packet loss, the sequence number becomes discrete, so that the packet loss rate can be obtained.

  The third method is to determine that a class having a large delay is more congested by measuring the delay. When a time stamp is included in a packet, as in the case of audio and video flows configured by RTP and RTCP, the sending computer 101, that is, if streaming, the streaming server 121 and the HGW 1301 are connected to the IETF standard clock. The delay can be measured by synchronizing using the NTP (Network Time Protocol) which is a protocol.

  In step 1614, the measurement control server 1302 estimates a bandwidth necessary for quality assurance. That is, the measurement control server 1302 sets a bandwidth that is twice as much as the currently used bandwidth for the traffic class identified as having quality degradation. For example, when the video quality streaming is degraded and the average bandwidth of “3 Mbps” is used, “6 Mbps” is allocated as the guaranteed bandwidth for the video streaming.

  In step 1615, the measurement control server 1302 transmits to the management server 152 a quality request 1503 that includes the content determined by the above-described processing, and ends the processing.

  In the processing procedure 1621, the measurement control server 1302 that has received the quality response 1505 in step 1622 transmits the quality response 1506 to the computer 101 that is the quality request source, and ends the processing.

  FIG. 17 is a flowchart illustrating processing of the management server 152 according to the second embodiment of this invention. The management server 152 executes processing according to the processing procedure 1701.

  In step 1702, the management server 152 that has received the quality request 1503 transmits the queuing setting 1504 to the user side router, that is, the edge router 131, thereby designating the egress of the edge router 131 in the queuing setting 1504. Set the guaranteed bandwidth as the minimum guaranteed bandwidth.

  In step 1503, the management server 152 transmits a quality response 1505 to the measurement control server 1302. When the bandwidth specified in the quality request 1503 is secured, a message indicating permission is transmitted as the quality response 1505 to the measurement control server 1302, and when the bandwidth specified in the quality request 1503 is not secured, the quality response 1505 is rejected. A message to represent is transmitted to the measurement control server 1302.

  Next, processing when the cancel buttons 1403 and 1415 are operated (clicked) will be described. The communication sequence when cancel buttons 1403 and 1415 are operated (clicked) is the same as that shown in FIG. However, the quality request 1501 by the user is a cancel request, and the queuing setting 1504 is a request for canceling the queuing setting. As a result, the network setting returns to the state before the request button such as the quality improvement button 1402 is operated (clicked).

  The quality improvement button 1402, the sound quality improvement button 1412, the image quality improvement button 1413, or the web acceleration button 1414 has no effect when the network resources necessary for improving the quality corresponding to each button are not secured. In the above case, in order to avoid unnecessary user input, the following may be performed.

  The measurement control server 1302 displays the quality menu 1401 or 1411 on the computer 101 using CGI. At that time, the measurement control server 1302 inquires of the management server 152 whether or not the quality improvement is possible by operating (clicking) each quality improvement button displayed on the quality menu 1401 or 1411. . When there is a response from the management server 152 that quality cannot be improved, the measurement control server 1302 invalidates the corresponding button. The measurement control server 1302 can display the latest status on the computer 101 by inquiring of the management server 152 and refreshing the page.

  In addition, since the effect obtained by operating (clicking) the buttons for improving each quality displayed on the quality menu 1401 or 1411 is difficult for the user to understand, a message display field is provided below the quality menus 1401 and 1411. Thus, the measurement control server 1302 can interpret the result fed back from the management server 152 and display it on the computer 101. The following contents can be displayed on the computer 101 according to the response from the management server 152 and the processing contents of the measurement control server 1302.

  First, when the measurement control server 1302 specifies conversation voice as the cause of quality degradation, if there is a permission response from the management server 152, “successful improvement of conversation sound quality” is displayed in the message display column described above. Is done. If there is a rejection response from the management server 152, the message display column described above displays “The conversation sound quality improvement has failed”.

  Second, when the measurement control server 1302 identifies streaming audio as the cause of quality degradation, if there is a permission response from the management server 152, the message display column displays “Successful improvement in streaming sound quality”. Is done. If there is a rejection response from the management server 152, the message display field described above displays “Streaming sound quality improvement failed”.

  Third, when the measurement control server 1302 identifies a conversational video as a cause of quality degradation, if the management server 152 receives a permission response, the message display column displays “Successfully improved conversation image quality”. Is done. If there is a refusal response from the management server 152, “The conversation image quality improvement has failed” is displayed in the message display section described above.

  Fourth, when the measurement control server 1302 identifies a streaming video as a cause of quality degradation, if there is a response of permission from the management server 152, “Successful streaming image quality improvement” is displayed in the message display column described above. Is done. If there is a refusal response from the management server 152, the message display field described above displays "Streaming image quality improvement has failed".

It is a block diagram which shows the network system structure in the 1st Embodiment of this invention. It is a block diagram explaining the hardware constitutions of the communication plan server in the 1st Embodiment of this invention. It is a block diagram explaining the hardware constitutions of the streaming server in the 1st Embodiment of this invention. It is a block diagram explaining the hardware constitutions of the management server in the 1st Embodiment of this invention. It is a figure explaining the graphical user interface (GUI) for content selection in the 1st Embodiment of this invention. It is a figure explaining the graphical user interface (GUI) for selecting the initial quality in the 1st Embodiment of this invention. It is a figure explaining the graphical user interface (GUI) at the time of selecting the low resolution in the 1st Embodiment of this invention. It is a figure explaining the graphical user interface (GUI) at the time of selecting the high resolution in the 1st Embodiment of this invention. FIG. 7 is a sequence diagram illustrating a processing procedure in the network system when a user operates a low resolution button or a high resolution button at the start of a session or during a session in the first embodiment of the present invention. FIG. 9 is a sequence diagram illustrating a modified example of a processing procedure in the network system when a user operates a low resolution button or a high resolution button at the start of a session or during a session in the first embodiment of the present invention. It is a figure explaining the communication plan 1 in the 1st Embodiment of this invention. It is a figure explaining the communication plan 2 in the 1st Embodiment of this invention. It is a figure explaining the communication plan 3 in the 1st Embodiment of this invention. It is a figure explaining the relationship between the amount of startup time and the amount of jitter buffers, and a stationary band in the 1st Embodiment of this invention. It is a figure which shows an example of the content which the communication plan database of the 1st Embodiment of this invention stores. It is a flowchart explaining the process of the communication plan server of the 1st Embodiment of this invention. It is a flowchart explaining the process of the communication plan server of the 1st Embodiment of this invention. It is a flowchart explaining the process of the management server of the 1st Embodiment of this invention. It is a flowchart explaining the process of the streaming server of the 1st Embodiment of this invention. In the 1st Embodiment of this invention, it is a sequence diagram explaining the process sequence in a network system when a user operates a stop button (clicks). It is a block diagram which shows the network system structure in the 2nd Embodiment of this invention. It is a figure explaining the graphical user interface (GUI) for inputting the quality requirement to the network in the 2nd Embodiment of this invention. It is a figure explaining the graphical user interface (GUI) for inputting the quality requirement to the network in the 2nd Embodiment of this invention. In the second embodiment of the present invention, the processing in the network system when the user operates the quality improvement button, the sound quality improvement button, the image quality improvement button, the Web acceleration button, or the cancel button while using any application It is a sequence diagram which shows a procedure. It is a flowchart explaining the process of the measurement control server of the 2nd Embodiment of this invention. It is a flowchart explaining the process of the measurement control server of the 2nd Embodiment of this invention. It is a flowchart explaining the process of the management server of the 2nd Embodiment of this invention.

Explanation of symbols

101, 102 Computer 111 Communication plan server 112 Communication plan database 121 Streaming server 122 Content 131 Edge router 132 Network interface 141 Edge router 142 Network interface 151 Core network 152 Management server 153 Bandwidth management table 200 CPU
201 Main storage device 202 Secondary storage device 203 Network interface 210 CPU
211 Main storage device 212 Secondary storage device 213 Network interface 220 CPU
221 Main storage device 222 Secondary storage device 223 Network interface 301 Content selection screen 311 Initial quality selection screen 313 Low resolution button 314 High resolution button 315 Image quality improvement button 316 Stop button 321 Low resolution playback screen 322 Playback screen 331 High resolution playback screen 332 Playback screen 701 to 703 Graph 800 Original data 801 Video identifier 802 Server address 803 Resolution 804 Communication plan 811 to 818 Record 1301 HGW
1302 Measurement control server 1401 Quality menu 1402 Quality improvement button 1403 Cancel button 1411 Quality menu 1412 Sound quality improvement button 1413 Image quality improvement button 1414 Web acceleration button 1415 Cancel button

Claims (19)

A computer, a network node, an application server that transmits data necessary for an application executed on the computer to the computer, and a communication plan server that manages a plan of communication between the computer and the application server; A network system comprising a management server that manages a network to which the computer, the network node, and the application server are connected,
The application server includes a first processor, a first memory connected to the first processor, a first nonvolatile storage medium connected to the first processor, and a first memory connected to the network. 1 network interface,
The communication plan server includes a second processor, a second storage medium connected to the second processor, and a second network interface connected to the network,
The management server includes a third processor, a third memory connected to the third processor, a third nonvolatile storage medium connected to the third processor, and a third memory connected to the network. 3 network interfaces,
The communication plan server
Storing communication conditions for determining quality of service provided in the network for data stored in the application server in the second storage medium;
When receiving from the computer a first quality condition, which is a request by a user of the computer for the quality of an application executed on the computer , based on the communication condition stored in the second storage medium, To generate a plurality of communication plans including a plurality of time-dependent communication conditions in a communication time from the start to the end of communication of an application executed on the computer for realizing the received first quality condition,
Sending the generated plurality of communication plans to the management server;
The management server
When receiving the plurality of communication plans , based on the communication state in the network , select the optimal communication plan from the received plurality of communication plans,
Based on the selected communication plan, setting for the network node in the communication time,
Sending a quality response including the selected communication plan to the application server;
The network system, wherein the application server transmits data necessary for an application executed on the computer to the computer during the communication time according to the communication plan included in the quality response. The data required for the application executed on the computer is streaming data,
The communication plan is:
The initial band indicating the transmission amount of the data to be transmitted at the start of communication of the application,
An initial time indicating a time width in which the data is transmitted to the computer according to the transmission amount indicated by the initial band ;
A stationary band that is smaller than the initial band after the initial time elapses and indicates a transmission amount of the data transmitted during execution of the application,
The plurality of communication plans are arranged in an optimal order for realizing the first quality condition,
The management server
Calculate the sum of all currently connected bandwidths,
Comparing the calculated sum of bands and the sum of initial bands included in the communication plan with the total bandwidth allowed in the network node;
The communication plan is selected as an optimal condition when a sum of the calculated bands and a sum of initial bands included in the communication plan are smaller than a total band allowed in the network node. Item 4. The network system according to Item 1. The application server is
Receiving the communication plan selected by the management server;
In the initial time indicated duration included in the communication program thus received, and transmit the data according to the transmission amount shown in the initial band included in the communication plan was received;
The network system according to claim 2, wherein after the initial time included in the received communication plan has elapsed, the data is transmitted according to a transmission amount indicated in a stationary band included in the communication plan . The network system according to claim 2, wherein the communication plan further includes a time-out period indicating a valid time for setting the network system based on the selected communication plan .   If the communication plan server receives a second quality condition having the same content as the first quality condition from the computer before the timeout time elapses, the timeout time count is initialized, The network system according to claim 4, wherein the time-out time is newly counted from the time when the second quality condition is received. The data required for the application executed on the computer is streaming data,
The communication plan is:
A steady band indicating a transmission amount of the data transmitted when the application is executed;
A maximum bandwidth indicating a maximum allowable transmission amount of the data transmitted when the application is executed,
The management server
Calculate the sum of the predicted bandwidth from the bandwidth of all currently connected communications,
Comparing the calculated total sum of predicted bands and the sum of the maximum bands included in the communication plan with the total bandwidth allowed in the network node;
When the sum of the calculated predicted bands and the sum of the maximum bands included in the communication plan is smaller than the total band allowed in the network node, the communication plan is selected as an optimum communication plan. The network system according to claim 1. The application server is
Receiving the communication plan determined by the management server;
The network system according to claim 6, wherein the data is transmitted by variable bit rate communication designated by a stationary band and the maximum band included in the received communication plan . The first quality request transmitted from the computer is transmitted to the communication planning server via the management server,
The communication plan server includes the plurality of communication plans in the quality response to the first quality request, and transmits to the computer.
The quality response is transmitted to the computer via the management server,
The management server, when sending the quality response to the computer, select the best the communication plan from among the plurality of communication plan included in the quality response,
The network system according to claim 1, wherein the quality response including the selected communication plan is transmitted to the computer. When the communication plan server transmits the plurality of communication plans to the management server, the communication plan server selects the communication plan that can optimally realize the first quality condition from the plurality of communication plans ;
Sending the selected communication plan to the management server;
The management server
Determine whether the received communication plan is optimal,
If it is determined that it is not optimal, a rejection response indicating that the received communication plan is not optimal is sent to the communication plan server;
The communication plan server, when receiving the rejection response, selects the communication plan that can optimally realize the first quality condition next, and transmits the communication plan to the management server. Item 9. The network system according to Item 2 or 8. Network system according to claim 1 wherein the communication planning server is that when transmitting the plurality of communication planned to the management server, and transmits at once the plurality of communication planned. The communication plan server, characterized in that transmitted when transmitting the plurality of communication planned to the management server, the is determined by the determined parameters and condition by communications planning server, a plurality of communication planned The network system according to claim 1. The network node assigns a queue having a plurality of different guaranteed bandwidths at an output interface of the network node;
The management server
Selecting a queue having a guaranteed bandwidth necessary for realizing the selected communication plan from the queue of the network node;
The network system according to claim 1, wherein the network node performs queuing setting so that the data transmitted from the network node to the computer enters the selected queue. The plurality of queues having different guaranteed bandwidths include a first queue and a second queue,
The first queue has a guaranteed bandwidth greater than the second queue;
When the queue having the guaranteed bandwidth necessary for realizing the selected communication plan is equal to or less than the guaranteed bandwidth of the first queue and greater than the guaranteed bandwidth of the second queue, the first queue Select a queue having a guaranteed bandwidth necessary for realizing the selected communication plan from the queue,
Queues with guaranteed bandwidth required to achieve the selected communication program is equal to or smaller than the guaranteed bandwidth of the second queue have, from the second queue, for implementing the selected communication scheme 13. The network system according to claim 12, wherein a queue having a guaranteed bandwidth required for the network is selected. Traffic in the network system is classified into a plurality of classes,
The communication plan server specifies a first class including the specific medium from the plurality of classes when the plurality of traffics of the specific medium are different classes of traffic, respectively.
The management server executes the queuing setting of the network node so that the data including the first class enters the selected queue when the queuing setting of the network node is executed. The network system according to claim 12. When the communication plan server specifies the first class including the specific medium from the plurality of classes, the traffic including the specific medium in any of the classes is a bandwidth allocated to the class. Identify the class that consumes the most,
The network system according to claim 14, wherein the specified class is specified as a first class including the specific medium. The calculator includes a display unit,
The network system according to claim 1, wherein the display unit displays an item for setting a quality condition requested by a user of the computer.   The network system according to claim 16, wherein the display unit displays information indicating whether or not the transmitted quality condition is realized.   A computer, a network node, an application server that transmits data necessary for an application executed on the computer to the computer, and a communication plan server that manages a plan of communication between the computer and the application server; A communication planning server in a network system comprising a management server for managing a network to which the computer, the network node and the application server are connected;
  The communication plan server
  A processor, a memory connected to the processor, a nonvolatile storage medium connected to the processor, and a network interface connected to the network;
  Storing communication conditions for determining quality of service provided in the network for data stored in the application server;
  The computer for realizing the received quality condition based on the communication condition when a quality condition which is a request by a user of the computer with respect to the quality of an application executed on the computer is received from the computer In the communication time from the start of communication to the end of communication of the application executed above, generate multiple communication plans including multiple communication conditions depending on time,
  Sending the generated plurality of communication plans to the management server;
  A communication plan server for transmitting a quality response to the transmitted communication plan to the computer.   The data required for the application executed on the computer is streaming data,
  The communication plan is:
  An initial band indicating a transmission amount of the data transmitted at the start of communication of the application;
  An initial time indicating a time width in which the data is transmitted to the computer in the initial band; and
  A stationary band that is smaller than the initial band after the initial time elapses and indicates a transmission amount of the data transmitted during execution of the application,
  The communication plan server according to claim 18, wherein the plurality of communication conditions are arranged in an optimum order for realizing the quality condition.