JP2008288763A - Edge router device and session establishment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further reduce a system construction cost in a communication system which performs communication by using a communication terminal which is not provided with a function for processing a signal based on a prescribed communication protocol. <P>SOLUTION: Each of edge router devices 10A, 10B which are connected to a communication terminal transmitting a session establishment request with an opposite terminal through a first network and connected to a session control server through a second network is provided with a terminal communication means 14 for receiving the session establishment request transmitted from the communication terminal, a signal conversion means 16 for converting the session establishment request received by the terminal communication means 14 into a session control signal, a session control means 17 for transmitting the session control signal converted by the signal conversion means 16 to the session control server, and a communication band allocation judgment means 15 for judging whether a communication band is to be allocated or not on the basis of a policy 151 of the second network. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an edge router apparatus and a session establishment method for controlling signals transmitted / received via a plurality of networks.

An example of a system using SIP (Session Initiation Protocol) is described in Patent Document 1. In Patent Document 1, when a user terminal device requests video / audio data stored in a content distribution server, the terminal device requests establishment of a session with the content distribution server via the SIP server. The content distribution server notifies the SIP server of bandwidth information necessary for viewing video and audio, and the SIP server makes a bandwidth reservation request to the bandwidth control server according to the bandwidth information notified from the content distribution server. To the terminal device.
JP 2005-012655 A

  In the system described in Patent Document 1, a user terminal device includes a SIP protocol function unit that processes SIP.

  Further, in the case of a terminal device that does not have a SIP protocol function unit, a gateway installed in the user's home has a function of processing SIP, and the gateway transmits a session establishment request to the SIP server to replace the terminal device. To establish a session.

  In Patent Document 1, it is necessary for a user terminal device to include a SIP protocol function unit that processes SIP. In the case of a terminal device that does not have a SIP protocol function unit, a session cannot be established.

  In addition, when a gateway having a function of processing SIP is used, the gateway needs to be installed in each user's house, which causes costs.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to establish a system in a communication system that performs communication using a communication terminal that does not have a function of processing a signal that conforms to a predetermined communication protocol. An object of the present invention is to provide an edge router apparatus and a session establishment method that further reduce costs.

  The present invention is connected to a communication terminal that makes a session establishment request for securing a communication band necessary for a session with a partner terminal via a first network, and a session control server that secures the communication band, 2 is an edge router device connected via the network of 2, the terminal communication means for receiving the session establishment request transmitted from the communication terminal, and the session establishment request received by the terminal communication means Based on a policy of the second network, a signal conversion means for converting the control signal into a control signal, a session control means for transmitting the control signal of the session converted by the signal conversion means to the session control server, Communication band allocation determining means for determining whether or not to allocate.

  In addition, the present invention provides a session control server that is connected via a first network to a communication terminal that makes a session establishment request for securing a communication band necessary for a session with a counterpart terminal, and that secures the communication band. Session establishment method performed by an edge router device connected via a second network, wherein the edge router device receives the session establishment request transmitted from the communication terminal, and the reception step A signal conversion step for converting the session establishment request received in step 1 into a control signal for the session, a transmission step for transmitting the control signal for the session converted in the signal conversion step to the session control server, and the second step Determine whether to allocate the communication bandwidth based on network policy A communication band allocation determining step, is carried out.

  ADVANTAGE OF THE INVENTION According to this invention, in the communication system which communicates using the communication terminal which does not have the function which processes the signal based on a predetermined communication protocol, system construction cost can be reduced more.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a system configuration diagram of a communication system according to an embodiment of the present invention.

  As shown in the figure, an AV (Audio Visual) device 4A capable of storing video and / or audio (hereinafter, “video / audio”) data as a communication terminal in a LAN (first network) in the user A's home. A personal computer 5A and a home gateway (hereinafter referred to as “HGW”) 3A are connected. The AV device 4B, the personal computer 5B, and the HGW 3B are also connected as communication terminals to the LAN (first network) in the user B's home. The AV devices 4A and 4B provide video and audio such as digital television receivers and hard disk recorders, and can store video and audio data.

  Note that communication terminals such as AV devices 4A and 4B and personal computers 5A and 4B can each transmit and receive data. The communication terminal may be an information home appliance.

  The HGWs 3A and 3B connect a network 8 (second network) provided by a provider such as ISP (Internet Service Provider) and a home LAN, and communicate between communication terminals connected to the home LAN. And communication between a communication terminal connected to the home LAN and a communication device such as the SIP server 9 on the network 8 is enabled. The HGW 3 may be an inexpensive broadband router (BB router).

  The network 8 provided by the provider is connected to an edge router device 10A, an edge router device 10B, and an SIP server 9 that secures a communication band necessary for a session.

  The SIP server 9 (session control server) is a server that performs call control in conformity with SIP (Session Initiation Protocol), and controls real-time communication between communication terminals. In this embodiment, SIP is used as a communication protocol, but the present invention is not limited to this, and other communication protocols may be used.

  The edge router devices 10A and 10B connect the network 8 provided by the provider to the LAN constructed by the user and the user's communication device, and are routers that relay the transferred packets.

  Note that the edge router device 10A can communicate with the HGW 3A, and the edge router device 10B can communicate with the HGW 3B. Note that the edge router device 10A can communicate with a plurality of devices as well as one HGW 3A installed in the user A's home. For example, it is possible to communicate with each HGW installed in a plurality of user homes (not shown). Similarly, the edge router device 10B can communicate with not only one HGW 3B installed in the user B house but also a plurality of devices.

  In the communication system shown in FIG. 1, the communication band is guaranteed in the network 8, and sufficient for each access line between the edge router devices 10A and 10B and the user premises (for example, HGW 3A and 3B). Bandwidth is allocated. Further, it is assumed that a communication band in which congestion does not occur is guaranteed on the access line in the upstream direction from the user home to the edge router devices 10A and 10B and in the downstream direction from the edge router devices 10A and 10B to the user home. .

  Further, the HGW 3A, the AV device 4A, and the personal computer 5A do not have a function of processing SIP. For this reason, the edge router device 10A has a function of processing the SIP and acts as a proxy for the SIP processing. Since the HGW 3B, the AV device 4B, and the personal computer 5B also do not have a function for processing SIP, the edge router device 10B acts as a proxy for the function for processing SIP.

  Next, the edge router apparatus of this embodiment will be described.

  FIG. 2 is a block diagram of the edge router devices 10A and 10B. The edge router devices 10A and 10B have a CPU, a ROM, and a RAM (not shown). The network interface 11 on the network 8 side, the network interface 12 on the HGW side, the packet relay unit 13, the terminal communication unit 14, and the communication band allocation determination unit 15 A signal conversion unit 16 and a session control unit 17.

  Note that the edge router device 10 is configured by, for example, a module of a program executed by a CPU, an integrated circuit, or a combination of integrated circuits.

  A network interface (hereinafter, “NWIF”) 11 communicates with the network 8, and the NWIF 12 communicates with a LAN or the like constructed by the HGWs 3 A and 3 B.

  The packet relay unit 13 has a routing table (not shown) that associates the destination address of the packet with the next transfer destination, and relays the packet received by the NWIF 11 or NWIF 12 to the next transfer destination according to the routing table.

  Further, since the packet relay unit 13 processes the packet when the destination address of the packet is addressed to itself, the packet relay unit 13 outputs the packet received via the NWIF 12 to the terminal communication unit 14 and receives the packet received via the NWIF 11 If so, it is output to the session control unit 17.

  The terminal communication unit 14 receives a packet transmitted from the communication terminal via the NWIF 12 and the packet relay unit 13. If the received packet is a message that needs to be converted into a SIP-compliant message (hereinafter, “SIP message”), the terminal communication unit 14 outputs the message to the signal conversion unit 16. For example, if the received packet is a session establishment request message (hereinafter referred to as a “session establishment request”) for securing a communication band necessary for a session with the counterpart terminal, the terminal communication unit 14 converts the message into a signal conversion unit. 16 is output.

  The communication band allocation determination unit 15 determines whether to allocate a communication band according to the network policy registered in the policy storage unit 151. The network policy includes restrictions and guidelines related to the operation of the network 8. Assume that the network administrator registers the network policy in the policy storage unit 151 in advance.

  For example, when there is a request for allocating a communication band from the SIP server 9, the communication band allocation determining unit 15 determines whether to allocate a communication band according to the network policy. Further, the communication band allocation determination unit 15 may determine whether to allocate the communication band indicated by the session establishment request received by the terminal communication unit 14 according to the network policy.

  The network policy may be, for example, a condition A in which an allowable bandwidth is set for each user or a condition B in which an allowable bandwidth is set according to the communication capability of the communication terminal. In addition, the network policy may be a condition C that represents a condition for not allocating a communication band when an integrated value of bands requested from a plurality of communication terminals exceeds a predetermined value.

  For example, when the condition C is followed, the communication band allocation determination unit 15 does not allocate a communication band for a new session establishment request when an integrated value obtained by integrating the communication bands exceeds a predetermined value such as an allowable amount of the network 8. If the condition A is followed, the communication band allocation determination unit 15 determines that the integrated value obtained by integrating the communication band of the user ID included in the session establishment request exceeds the allowable band of the user ID set in the network policy. No communication bandwidth is allocated. Further, when the condition B is complied with, the communication band allocation determination unit 15 does not allocate a communication band when the communication band exceeds the allowable band corresponding to the communication capability of the communication terminal specified from the information included in the session establishment request or the like. . The network policy may be a combination of these conditions A, B, and C.

  The signal conversion unit 16 converts the message received by the terminal communication unit 14 into a session control signal, for example, a SIP message. In addition, the signal conversion unit 16 converts the SIP message received via the NWIF 11 into a message that can be processed by the communication terminal, and transmits the converted message via the NWIF 12.

  The session control unit 17 establishes a session on behalf of the communication terminal. For example, the session control unit 17 transmits a SIP message converted by the signal conversion unit 16 to the SIP server 9, and receives and processes the SIP message transmitted from the SIP server 9, thereby establishing a session between communication terminals. Let

  An example of the operation of the communication system of the present embodiment described above will be described.

  FIG. 3 is a sequence diagram showing the operation of the communication system of the present embodiment.

  In the illustrated sequence diagram, a predetermined video / audio (for example, a movie) stored in the AV device 4B of the user B is designated by the user A's personal computer 5A, and the user A sends the designated video / audio to the personal computer 5A. This shows the operation when viewing. The edge router device 10A and the edge router device 10B establish a session between the personal computer 5A and the AV device 4B. It is assumed that the video / audio data stored in the AV device 4B has a predetermined communication speed according to the quality and the degree of compression.

  First, the AV device 4B transmits a session establishment request for establishing a session with the personal computer 5A to the edge router device 10B. It is assumed that the session establishment request includes a communication band for securing a communication speed necessary for viewing the designated video signal. The session establishment request includes information indicating the user ID and the communication capability of the communication terminal (in the illustrated example, the AV device 4B and the personal computer 5A) in order to determine the above-described network policy condition A and condition B. It may be included.

  The terminal communication unit 14 of the edge router device 10B receives the session establishment request from the AV device 4B and outputs the session establishment request to the signal conversion unit 16. The signal conversion unit 16 converts the session establishment request into INVITE of the SIP message and outputs it to the session control unit 17 (S1). At this time, the signal conversion unit 16 describes information indicating the communication band included in the session establishment request in the description part of SDP (Session Description Protocol) of INVITE.

  The session control unit 17 of the edge router device 10B transmits the converted INVITE to the SIP server 9 (S2). The SIP server 9 transmits a bandwidth request for allocating a communication bandwidth to the edge router devices 10A and 10B in order to secure a communication bandwidth from the content of the transmitted INVITE. If necessary, the SIP server 9 may make a bandwidth request for allocating a communication bandwidth to a router in the target session path.

  The communication bandwidth allocation determination unit 15 of the edge router apparatus 10B that has received the bandwidth request from the SIP server 9 determines whether or not to allocate a communication bandwidth according to the network policy set in the policy storage unit 151 (S3). Similarly, the communication band allocation determination unit 15 of the edge router apparatus 10A that has received the bandwidth request from the SIP server 9 determines whether to allocate a communication band according to the network policy set in the policy storage unit 151 (S4). .

  When the edge router device 10B and the edge router device 10A both determine to allocate a communication band, each of the edge router devices 10A and 10B guarantees the allocated communication band, for example, by performing priority control of packets for the established session. Note that if the communication band allocation determination unit 15 of any of the edge router devices 10A and 10B determines not to allocate a communication band, the procedure for establishing a session becomes invalid.

  When the communication band is secured in the edge router device 10A and the edge router device 10B, the SIP server 9 continues to transmit INVITE to the edge router device 10A.

  The session control unit 17 of the edge router device 10 </ b> A receives the INVITE transmitted from the SIP server 9 and outputs it to the signal conversion unit 16. The signal conversion unit 16 converts INVITE into a session establishment request and outputs it to the terminal communication unit 14 (S5). The terminal communication unit 14 transmits the converted session establishment request to the personal computer 5A (S6).

  When a success message in response to the session establishment request is transmitted from the personal computer 5A, the terminal communication unit 14 of the edge router apparatus 10A receives the success message, and the signal conversion unit 16 converts the received success message into the SIP message. Is converted to “200 OK” (S7).

  Subsequently, the session control unit 17 of the edge router device 10A transmits the converted “200 OK” to the SIP server 9 (S8). The transmitted “200 OK” is relayed by the SIP server 9 and received by the edge router device 10B.

  The session control unit 17 of the edge router 10B receives the transmitted “200 OK”, and the signal conversion unit 16 converts the received “200 OK” into a success message (S9). Subsequently, the terminal communication unit 14 of the edge router device 10B transmits the converted success message to the AV device 4B (S10). Subsequent transmission / reception processing such as ACK, which is a SIP message, is the same as the conventional SIP-compliant procedure, and thus the description thereof is omitted here.

  Next, the sequence diagram of FIG. 4 will be described.

  FIG. 4 shows a modified example of the sequence diagram shown in FIG. 3, in which processing related to communication band allocation is made more efficient. As in the case described with reference to FIG. 3, it is assumed that the video / audio data stored in the AV device 4B has a predetermined communication speed in accordance with the quality and the degree of compression.

  First, the AV device 4B transmits a session establishment request for establishing a session with the personal computer 5A to the edge router device 10B. It is assumed that the session establishment request includes a communication band for ensuring a communication speed necessary for viewing the designated video and audio.

  The terminal communication unit 14 of the edge router device 10B receives the session establishment request and outputs the received session establishment request to the communication band allocation determination unit 15. The communication band allocation determination unit 15 determines whether to allocate the communication band included in the session establishment request according to the network policy of the policy storage unit 151 (S11).

  When it is determined that the communication band is allocated, the edge router device 10B guarantees the communication band. Then, the signal conversion unit 16 converts the SIP message into INVITE so as to satisfy the communication band allocated by the communication band allocation determination unit 15 (S12). For example, the signal conversion unit 16 describes information indicating the allocated communication band in the description portion of the INVITE SDP. If it is determined that no communication band is allocated, the procedure for establishing a session becomes invalid.

  The session control unit 17 of the edge router device 10B transmits the converted INVITE to the SIP server 9 (S13). The SIP server 9 transmits INVITE to the edge router device 10A. Note that the SIP server 9 may make a bandwidth request for allocating a communication bandwidth to a router in the path of the target session, if necessary, according to the transmitted INVITE.

  The session control unit 17 of the edge router device 10A receives the INVITE transmitted from the SIP server 9, and the communication band allocation determination unit 15 determines the communication band described in the received INVITE according to the network policy of the policy storage unit 151. It is determined whether or not to allocate (S14).

  If it is determined to allocate the communication band, the allocated communication band is guaranteed, and the signal conversion unit 16 converts INVITE into a session establishment request (S15). Then, the terminal communication unit 14 transmits the converted session establishment request to the personal computer 5A (S16). If it is determined that no communication band is allocated, the procedure for establishing a session becomes invalid.

  When a success message in response to the session establishment request is transmitted from the personal computer 5A, the terminal communication unit 14 of the edge router apparatus 10A receives the success message, and the signal conversion unit 16 converts the received success message into the SIP message. Is converted to “200 OK” (S17).

  Subsequently, the session control unit 17 of the edge router device 10A transmits the converted “200 OK” to the SIP server 9 (S18). The transmitted “200 OK” is relayed by the SIP server 9 and received by the edge router device 10B.

  Here, the session control unit 17 of the edge router apparatus 10B receives the transmitted “200 OK”, and the signal conversion unit 16 converts the received “200 OK” into a success message (S19). Subsequently, the terminal communication unit 14 of the edge router device 10B transmits the converted success message to the AV device 4B (S20). Subsequent transmission / reception processing such as ACK, which is a SIP message, is the same as the conventional SIP-compliant procedure, and thus the description thereof is omitted here.

  As described above, in the communication system according to the present embodiment, the edge router device performs mutual conversion of signals (SIP messages and the like) conforming to a predetermined communication protocol such as SIP. That is, it is not necessary for each of the HGWs 3A and 3B installed in each user's home to have a function of processing a signal compliant with a predetermined communication protocol. For this reason, in this embodiment, a communication system system that performs communication with guaranteed bandwidth using a communication terminal (HGW, AV equipment, personal computer, etc.) that does not have a function of processing a signal that complies with a predetermined communication protocol. Construction cost and system introduction cost can be reduced. Also, the SIP adaptation function in this communication system can be implemented using a non-SIP-compatible BB router or information home appliance.

  Further, in the communication system of the present embodiment, it is assumed that the communication band is guaranteed without causing congestion on the access line in the uplink direction and the downlink direction. However, the HGW 3A, 3B has a flow rate restriction for the access line in the downlink direction. Even if congestion cannot be achieved, the edge router devices 10A and 10B preferentially control downlink packets, so that the communication bandwidth of the session can be guaranteed.

  Further, in the edge router device of the present embodiment, it is determined whether or not to allocate a communication band based on a network policy. Thus, for example, when the allowable bandwidth condition B corresponding to each communication terminal is used for the network policy, the allowable bandwidth corresponding to the communication capability of the communication terminal can be set as the allowable bandwidth to be accepted. That is, the allowable bandwidth to be accepted can be matched with the communication capability of the communication terminal.

  In addition, when the condition C that does not allocate a communication band is used in the network policy when the integrated value of the band requested from a plurality of communication terminals exceeds a predetermined value, the integrated value of the integrated communication band exceeds the predetermined value Is not assigned a communication band for a new session establishment request. As a result, when the predetermined value is the maximum bandwidth of the edge router device, the communication bandwidth is not accepted beyond the maximum bandwidth of the edge router device, and the predetermined value is set as a bandwidth (allowable value) due to operation restrictions of the network 8. In this case, communication can be performed within the operational restrictions.

  Further, when the condition A for setting the allowable bandwidth for each user is used in the network policy, it is possible to prevent a predetermined user from occupying the network.

  In addition, this invention is not limited to the said embodiment, Many deformation | transformation are possible within the range of the summary. For example, in the above-described embodiment, video / audio data communication has been described as an example through a session between the personal computer 5A and the AV device 4B. However, the present invention is not limited to video / audio data communication. For example, when the communication terminal is an IP phone, it may be audio data communication between IP phones, and the communication mode between the communication terminals is limited. Not what you want.

1 is a system configuration diagram of a communication system according to an embodiment of the present invention. It is a block diagram which shows the structure of the edge router of embodiment of this invention. It is a sequence diagram which shows operation | movement of a communication system. It is a sequence diagram of the modification which shows operation | movement of a communication system.

Explanation of symbols

3A, 3B Home gateway 4A, 4B AV equipment 5A, 5B Personal computer 8 Network 9 SIP server 10A, 10B Edge router 11,12 Network interface 13 Packet relay unit 14 Terminal communication unit 15 Communication band allocation unit 16 Signal conversion unit 17 Session control unit

Claims (6)

A session control server that secures the communication bandwidth and a second network are connected to a communication terminal that makes a session establishment request for securing a communication bandwidth necessary for a session with a partner terminal via the first network. An edge router device connected via
Terminal communication means for receiving the session establishment request transmitted from the communication terminal;
Signal conversion means for converting the session establishment request received by the terminal communication means into a control signal for the session;
Session control means for transmitting a control signal of the session converted by the signal conversion means to the session control server;
An edge router apparatus comprising: a communication band allocation determining unit that determines whether to allocate the communication band based on a policy of the second network. The edge router apparatus according to claim 1, wherein the session control signal is a SIP message compliant with SIP. The edge router according to claim 1, wherein the policy includes an allowable bandwidth condition corresponding to each user who uses the communication terminal. The edge router according to claim 1, wherein the policy includes an allowable bandwidth condition corresponding to a communication capability of the communication terminal. The edge router device according to claim 1, wherein the policy includes a condition that the communication band is not allocated when an integrated value of bands requested from the plurality of communication terminals exceeds a predetermined value. A session control server that secures the communication bandwidth and a second network are connected to a communication terminal that makes a session establishment request for securing a communication bandwidth necessary for a session with a partner terminal via the first network. A session establishment method performed by an edge router device connected via
The edge router device is:
Receiving the session establishment request transmitted from the communication terminal;
A signal conversion step of converting the session establishment request received in the reception step into a control signal of the session;
A transmission step of transmitting the control signal of the session converted in the signal conversion step to the session control server;
And a communication band allocation determination step of determining whether to allocate the communication band based on a policy of the second network.

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