JP4099773B2 - IP multicast distribution source switching control system and method therefor, switching control server, switching control program, and recording medium recording the program - Google Patents

Description

  The present invention relates to a technique for making a multicast distribution server redundant and switching between an active stream and a standby stream when multicasting IP packets in an IP network.

  As a conventional IP multicast system, a multicast protocol is used to determine a route between a sender and a receiver by forwarding a reception request hop-by-hop. A method of determining a route by flooding is considered. Examples of the former include Non-Patent Documents 1 and 2, and examples of the latter include Non-Patent Documents 3 and 4.

  Further, as a conventional IP multicast distribution source control method, Japanese Patent Application No. 2003-297237 “IP multicast control method and apparatus” (hereinafter referred to as IP multicast control technology 1 according to the prior application) filed earlier by the present applicant, etc. There is.

  As shown in FIG. 17, the IP multicast control technique 1 according to the prior application includes a distribution source database that stores the IP address of the distribution server and a distribution monitoring server that monitors the distribution server. As shown in the operation example, when the distribution monitoring server monitors the distribution server and detects that the active distribution server has stopped operating, it notifies the distribution source database of the operation stop.

  On the other hand, the distribution source database, when notified that the active distribution server has stopped operating, sends the IP address of the distribution server that notifies the authentication server that authenticates the recipient from the stopped distribution server to the other Switching is realized by changing to a distribution server.

  For example, while the distribution server S1 (IP address S1) is operating, the authentication server acquires S1 from the distribution source database as distribution server information of the destination address G1, but when S1 stops, the distribution source database The stream is switched by changing the IP address of the distribution server notified to the original request to S2.

  Further, as the invention of the present applicant, the host accommodating router is provided with means for detecting packet reception interruption and means for changing the source IP address specified in the multicast participation request. As shown in Example 1, when the host accommodating router monitors the reception of multicast packets and detects the reception interruption of the active multicast packet, the destination of the multicast participation request is sent from the direction of the active distribution server to the standby system. There is one in which the stream is switched by changing in the direction of the distribution server (hereinafter referred to as IP multicast control technology 2).

  Further, as shown in operation example 2 of conventional method 2 in FIG. 20, the host accommodating router receives both the active and standby streams, selectively outputs only the active stream, and receives the active system. If disconnection is detected, a method of switching the output stream to a standby system is also considered.

RFC2362 draft-ietf-pim-sm-v2-new-07 RFC1075 draft-ietf-pim-dm-new-v2-01

  However, as a first problem, in the IP multicast control technique 1 according to the above-mentioned prior application, the authentication server is not able to acquire the information of the distribution server. Switching is not possible.

  Even when authentication is performed, if the device between the distribution server and the distribution server accommodating router fails in order to monitor the distribution server and detect a failure of the active distribution server, the stream stops. However, there is a problem that switching cannot be performed.

  Further, as the second problem, since the IP multicast control technique 2 is switched on the host accommodating router side, the first problem can be solved. However, as in the operation example 1 in FIG. In the method of switching from the active system to the standby system, there is a problem that the switching time from when the host accommodating router detects reception interruption of the working stream until the multicast participation request arrives at the distribution server accommodating router and switches is increased. Alternatively, as in the operation example 2 in FIG. 20, the method of distributing and switching both streams to the host accommodating router has a problem that twice as much bandwidth is required in the IP network.

  In view of the above circumstances, an object of the present invention is to solve the above-described problems and appropriately switch a multicast stream distribution source, and to provide a highly reliable multicast distribution source switching control system, a method therefor, a switching control server, and an IP multicast. A distribution source switching control program is provided.

  In order to solve the first problem, the present invention detects a failure when a device between the distribution server and the distribution server accommodating router fails by monitoring a multicast packet at the distribution server accommodating router. , The stream is switched.

  Further, in order to solve the second problem, the packet filter means of the distribution server accommodating router is set to transfer for the active stream and set to block for the standby stream, thereby reducing the transfer delay of the multicast participation request. The high-speed switching of the stream is realized. Furthermore, since only one of the working stream or the spare stream is transferred in the IP network, stream switching is realized with the minimum necessary bandwidth.

  In this way, when controlling the packet filter means of the distribution server accommodating router, it is considered that the distribution server accommodating router for the active stream and the distribution server accommodating router for the standby stream are different, and a plurality of distribution server accommodating routers are considered. A switching control means for controlling is provided in the IP network.

  In addition, monitoring the reception interruption of the active stream at the distribution server accommodating router and automatically switching to the standby stream is effective in reducing the time from the occurrence of the failure to the completion of the switching.

  In addition, when the delivery server is highly reliable, it is unlikely that the standby system will be disconnected when the delivery of the standby stream is started, and only the active stream is monitored for packet reception. This is effective in reducing the packet reception monitoring processing load.

  On the other hand, when the reliability of the distribution server is low, the standby system is also effective in preventing the situation that the stream after the switching is interrupted by monitoring the packet reception state.

  In addition, it is also effective from the viewpoint of monitoring the operation of the distribution server accommodating router itself that the distribution server accommodating router notifies the switching control means not of packet reception interruption but periodically notifies of packet reception. In this case, when no notification is received from a certain distribution server accommodating router, it is determined that the distribution server accommodating router itself is out of order, and the reliability is improved by switching the stream.

  As a method of periodically notifying packet reception between the distribution server accommodating router and the switching control means, there are a method in which the router autonomously notifies and a method in which the switching control means requests the router to notify. The former method is effective in reducing the processing load of the switching control means when there are few distribution server accommodating routers in the IP network, and the latter method is effective when there are many distribution server accommodating routers in the IP network. This is effective in that the switching control means can distribute notification reception and smooth the processing load of the switching control means.

  In either method, as described above, if the distribution server is highly reliable, it is unlikely that the backup stream will be disconnected when the distribution of the backup stream is started, and only the active stream receives packets. By doing so, it is effective in reducing the packet reception monitoring processing load of the router.

  In addition, it is effective for high reliability to prepare a plurality of standby streams and select a stream for the active system according to the switching priority.

  In addition, when switching streams, a high-performance distribution server and an inexpensive distribution server for backup are deployed, and when a high-performance distribution server recovers, switching back to a stream from a high-performance distribution server is not possible. It is effective in terms of economic distribution system.

  In addition, if the blocking setting changed from the active system to the standby system is executed first, and the transfer setting of the stream from the standby system to the active system is executed later, the traffic of the original working system is not completely stopped. In the case of a partial failure, this is effective in that the influence on the terminal due to the mixing of the original working packet is prevented.

  Also, when switching from the standby system to the active system without storing the reception status for all multicast address sets, performing reception confirmation of the multicast address set to be switched to the active system is said to reduce the table amount. Effective in terms.

More specifically, the present invention employs the following configuration.
(1) The IP network is provided with a switching control unit having a table for storing the IP multicast distribution source switching system state, and the table for storing the switching system state includes an IP multicast address and a stream to which the IP multicast address is assigned. A source state IP address, a switching state indicating whether each source IP address is a source of a current stream or a source of a standby stream with an IP multicast address, and a distribution server to which each source IP address is assigned The IP address of the distribution server accommodating router to be stored is stored, and the switching control means, for the packet filter of the distribution server accommodating router, combines the IP multicast address and the source IP address (hereinafter referred to as the multicast address set). Every time) transfer setting or blocking setting In the table, for the multicast address set whose switching system state is changed from the standby system to the working system, forwarding setting is made to the packet filter of the distribution server accommodating router, or the switching system state is switched from the working system to the standby system. The multicast address set changed to the system is set to be blocked in the packet filter of the distribution server accommodating router.

(2) In the above (1), for each multicast address set, the distribution server accommodating router rejects reception of a packet whose destination IP address is an IP multicast address and whose source IP address is a source IP address of a multicast address set for each multicast address set. Means for detecting and notifying a packet reception interruption when the packet reception interruption is detected, and notifies the switching control means of the packet reception interruption of the stream of the multicast address set, and the switching control means notifies the multicast address notified of the reception interruption. Change the switch system status of the set from the active system to the standby system, and switch the status of one of the multicast address sets that have the same IP multicast address as the multicast address set that has been changed from the active system to the standby system. Change from active to active.

(3) In the above (2), the switching control means includes means for starting and stopping the means for detecting and notifying the packet reception interruption of the distribution server accommodating router for each multicast address set, and reserves the switching system state. Activating a means for detecting and notifying the packet reception interruption for the multicast address set changed from the active system to the active system, and receiving the packet for the multicast address set whose switching system status is changed from the active system to the standby system Stop the means to detect and notify disconnection.

(4) In the above (2), the table of the switching control means indicates a reception state indicating whether the distribution server accommodating router is receiving or has stopped receiving the packet assigned with each multicast address set. The means for storing and detecting and notifying the packet reception interruption for each multicast address set monitors the packet reception for each multicast address set, and when the packet reception interruption is detected, the multicast address set that has detected the reception interruption. To the switching control means, and the switching control means changes the reception state of the multicast address set notified of reception interruption to stop, and the multicast address set of which the reception state has been changed from reception to suspension is changed. If the switching system status is the active system, it is changed to the standby system, and the switching system is changed to the standby system. Multicast list address set received in the same IP multicast address and status to change one of the multicast address set is receiving a working system.

(5) In the above (1), the distribution server accommodating router comprises means for detecting packet reception for each multicast address set and means for notifying the multicast address set that the packet is being received. On the other hand, the multicast address set of the multicast packet being received is periodically notified at a predetermined time interval, and the switching control means receives the reception status of the multicast address set with the notification of reception in the table. Or the multicast address set switching status that has been changed from the reception status to the stop status. If it is the active system, change to the standby system, and change the switching system status to the standby system. Changing one of the multicast address set received state multicast list address set the same IP multicast address is being received in the active system.

(6) In the above (1), the distribution server accommodating router includes means for detecting packet reception for each multicast address set and means for notifying the multicast address set being received,
The switching control means includes means for requesting confirmation of multicast packet reception, and periodically confirms reception of the multicast packet at a predetermined time interval with respect to the distribution server accommodating router whose IP address is stored in the table. When the distribution server accommodating router receives the multicast packet reception confirmation request, the distribution server accommodating router notifies the switching control means of all the multicast address sets being received, and the switching control means notifies in the table The reception state of a certain multicast address set is stored as being received, or the reception state of a multicast address set that has not been notified within a certain predetermined time is stored as being stopped, and the reception state is changed from being received to being stopped The changed multicast address set switching status is the active status. The change to the standby system, to change one of the multicast address set is receiving condition received by the multicast list address set the same IP multicast address has been changed to the standby system to the working system.

(7) In the above (6), the switching control means specifies only a multicast address set whose switching system state is stored as active in the table, and stores the distribution server associated with the multicast address set. The distribution server accommodating router that has transmitted the multicast packet reception confirmation request to the router and has received the multicast packet reception confirmation request includes the multicast address set designated by the switching control unit among the multicast address sets of the multicast packet being received. Only the switching control means is notified.

(8) In any one of the above (4) to (6), the table of the switching control unit stores a switching priority for each multicast address set, and the switching control unit uses the switching system state as a current use. The multicast address set having the highest switching priority among the multicast address sets whose reception status is being received with the same IP multicast address as the multicast address set changed from the primary system to the standby system is changed to the active system.

(9) In the above (8), the distribution server accommodating router is provided with means for detecting the start of packet reception for each multicast address set, and switches the reception start of the multicast address set of the packet when the packet reception start is detected. The switching control means changes the reception status of the multicast address set whose switching priority is the same IP multicast address as the working multicast address set and higher switching priority from stopping to receiving. If this happens, the working multicast address set is changed to the standby system, the receiving status is changed from being stopped to receiving, and the switching status of the multicast address set having a higher switching priority is changed to the working status. And change.

(10) In any one of the above (6) to (9), the switching control means, when there is no multicast address set notification from the distribution server accommodating router within a predetermined time period, Change the reception status of all multicast address sets associated with the accommodating router to stop.

(11) In any one of the above (1) to (9), the switching control means is configured to provide a packet filter of the distribution server accommodating router for a multicast address set whose switching system state has been changed from a working system to a standby system. After confirming that the block is set to be blocked, the multicast address set whose switching system state has been changed from the standby system to the active system is transferred to the packet filter of the distribution server accommodating router.

(12) In any one of the above (1) to (3), when the switching control unit selects a multicast address set to be changed from a standby system to an active system, the reception confirmation of the multicast address set is received in the distribution This is performed on the server accommodating router.

(13) The switching control means that is connected to the IP network and includes a table that stores the switching system state transmits the IP multicast address and the stream to which the IP multicast address is assigned to the table that stores the switching system state. Accommodates the source IP address, the switching status indicating whether each source IP address is the source of the active stream of the IP multicast address or the source of the standby stream, and the distribution server to which each source IP address is assigned The switching system state is changed from the standby system in the table by the step of storing the IP address of the distribution server accommodating router and the means for setting forwarding or blocking for each multicast address set for the packet filter of the distribution server accommodating router. Multicast address changed to active The step of forwarding setting to the packet filter of the distribution server accommodating router for the set, or the step of setting the block to the packet filter of the distribution server accommodating router for the multicast address set whose switching system state has been changed from the active system to the standby system And have.

(14) In (13), the distribution server accommodating router detects, for each multicast address set, reception interruption of a packet whose destination IP address is an IP multicast address and whose source IP address is a source IP address of a multicast address set. If the packet reception interruption is detected by the notification means, the step of notifying the switching control means of packet reception interruption of the stream of the multicast address set, and the multicast address for which the switching control means is notified of the reception interruption. The step of changing the switching system state of the set from the active system to the standby system, and one switching system state of the multicast address set having the same IP multicast address as the multicast address set that has been changed from the active system to the standby system Reserve From a step of changing the current system.

(15) In the above (14), the switching control means uses means for starting and stopping the means for detecting and notifying packet reception interruption of the distribution server accommodating router for each multicast address set, and sets the switching system state to the standby system. Activating a means for detecting and notifying the packet reception interruption for the multicast address set changed from the active system to the active system, and the packet for the multicast address set whose switching system status is changed from the active system to the standby system And a step of stopping a means for detecting and notifying reception interruption.

(16) In the above (14), the table of the switching control means indicates a reception state indicating whether the distribution server accommodating router is receiving or has stopped receiving the packet assigned with each multicast address set. The step of storing and the means for detecting and notifying the packet reception interruption monitor the packet reception for each multicast address set for every multicast address set. A step of notifying the switching control means of the address set, a step of changing the reception state of the multicast address set in which the switching control means has been notified of reception interruption, and a state of reception being stopped from reception If the changed multicast address set switching status is active A step of changing to a standby system, a step of changing one of the multicast address sets whose reception status is being received at the same IP multicast address as the multicast address set that has been changed from the switching system to a standby system, to the active system; Have

(17) An IP multicast distribution source switching control program executed by a switching control server having a switching control means having a table for storing a switching system state of an IP multicast distribution source, the table storing the switching system state The IP multicast address, the source IP address of the stream to which the IP multicast address is assigned, and the switching indicating whether each source IP address is the source of the current stream or the source of the standby stream of the IP multicast address A process for storing a system state and an IP address of a distribution server accommodating router that accommodates a distribution server to which each source IP address is assigned; and the switching control means, wherein the switching system state is changed from a standby system to a working system in the table. For the multicast address set changed to Switching control includes processing for setting transfer to the packet filter of the distribution server accommodating router, and processing for setting blocking on the packet filter of the distribution server accommodating router for the multicast address set in which the switching system status is changed from the active system to the standby system. An IP multicast distribution source switching control program executed by a server.

(18) A computer-readable recording medium on which the IP multicast distribution source switching control program of (17) is recorded.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to switch the delivery source of a multicast stream appropriately, Thereby, the multicast delivery source switching control system which improved reliability, the method for it, a switching control server, and IP multicast delivery source switching control Program and a recording medium on which the program is recorded can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Example 1
A first embodiment of the present invention will be described with reference to the drawings.
1 is a diagram illustrating an example of a system configuration in the first embodiment of the present invention, FIG. 2 is a diagram illustrating an example of a configuration of a switching management table used in the first embodiment, and FIG. 3 is a diagram illustrating an operation example of the first embodiment. It is.

  As shown in FIG. 1, the system configuration example of the first embodiment includes a switching control server 1, an IP network 2, distribution server accommodating routers 3 and 4, distribution servers 5 and 6, and a host 7. . The switching control server 1 includes a switching control unit 11 and a switching management table 12.

  In this description, the case where there are two distribution server accommodating routers and two distribution servers has been described, but this is for clarification of explanation, and the same applies to three or more distribution server accommodating routers and distribution servers. It is not intended to limit the invention. Further, in this description, the case where the number of hosts is one has been described. However, this is also the case with two or more for clarity of explanation, and the number of hosts does not limit the present invention.

Next, a configuration example of the switching management table 12 of the switching control server 1 in this embodiment will be described with reference to FIG.
The switching management table 12a according to the first embodiment includes an IP multicast address, a transmission source IP address, a switching system state, and an IP address of a distribution server accommodating router.

Here, the meaning of the IP multicast address, the transmission source IP address, the switching system state, and the IP address of the distribution server accommodating router in the present invention will be described.
The “IP multicast address” is written in the destination address of the multicast packet and is, for example, G1 in this description.
The “source IP address” refers to the IP addresses of the distribution servers 5 and 6. For example, in this description, the IP address of the distribution server 1 (5) is S1, and the IP address of the distribution server 2 (6) is S2. .

The “switching system state” indicates whether the stream identified by the combination of the IP multicast address and the transmission source IP address is an active stream or a standby stream. For example, in FIG. 2, for G1, the stream transmitted from S1 is the active system, and the stream transmitted from S2 is the standby system.
As "IP address of distribution server accommodating router", as shown in FIG. 1, S1 is accommodated in R1, and S2 is accommodated in R2.

Next, a switching operation example of the first embodiment will be described with reference to FIG.
First, it is assumed that (S1, G1) is the active system and (S2, G1) is the standby system before switching (s1). Here, (S1, G1) means a multicast address set in which the IP multicast address is G1 and the source IP address is S1.

  The multicast stream of (S1, G1) and the multicast stream of (S2, G1) are always transmitted from the distribution server (s4, s5). In the distribution server accommodating router R1 (3) that accommodates S1, (S1, G1) is set to be forwarded (s2), and the multicast stream of (S1, G1) arrives at the host (s6, s7). In the distribution server accommodating router R2 (4) that accommodates S2, (S2, G1) is set to be blocked (s3), and the multicast stream (S2, G1) is discarded in the distribution server accommodating router R2 (4) Is done.

  In the switching management table, when (S1, G1) is changed from the active system to the standby system and (S2, G1) is changed from the standby system to the active system (s8), the respective distribution server accommodating routers are R1 and R2. And (S9, G1) is set to be cut off for the distribution server accommodating router R1 (3) that accommodates S1 (s9), while for the distribution server accommodating router R2 (4) that accommodates S2 Transfer setting (S2, G1) is performed (s10).

  Thereby, in the distribution server accommodating router R1 (3) accommodating S1, (S1, G1) is set to be blocked (s11), and the multicast stream of (S1, G1) is transmitted to the distribution server accommodating router R1 (3). Discarded. On the other hand, in the distribution server accommodating router R2 (4) that accommodates S2, (S2, G1) is set to be forwarded (s12), and the multicast stream of (S2, G1) arrives at the host (s15, s16).

(Example 2)
A second embodiment of the present invention will be described with reference to the drawings.
FIG. 4 is a diagram illustrating an operation example of the second embodiment. A system configuration example and a switching management table configuration example are the same as those in the first embodiment.

  First, in the state before switching, as in the first embodiment, (S1, G1) is the active system and (S2, G1) is the standby system.

The second embodiment is different from the first embodiment in that the active server (S1, G1) monitors the packet reception state (s17) by the distribution server accommodating router.
When the distribution server accommodating router R1 (3) detects the reception interruption of (S1, G1) (s18), it notifies the switching control server 1 (s19).

  When notified of the disconnection of (S1, G1), the switching control server 1 changes (S1, G1) from the active system to the standby system in the switching management table 12a. Also, the source IP address of the standby system is searched for G1, and if the switching management table 12a is FIG. 2, for example, S2 is detected, and (S2, G1) is changed from the standby system to the active system.

  Thereafter, in the distribution server accommodating router R1 (3) accommodating S1, the distribution server accommodating router R2 (4) accommodating S2 is set to be cut off by the same operation as in the first embodiment. (S2, G1) is set for transfer.

(Example 3)
A third embodiment of the present invention will be described with reference to the drawings.
FIG. 5 is a diagram illustrating an operation example of the third embodiment. The system configuration example and the switching management table configuration are the same as those in the first embodiment.

  The third embodiment is different from the second embodiment in that the switching control server 1 automatically starts and stops the packet reception monitoring unit of the distribution server accommodating router.

  In this embodiment, the switching control server 1 sets the distribution server accommodating router R1 (3) to block (S1, G1), sets the distribution server accommodating router R2 (4) to transfer (S2, G1), The reception monitoring of (S1, G1) is stopped (s20, s21, s22, s23), the reception monitoring of (S2, G1) is started (s24), and the reception start of (S2, G2) is started (s25).

Example 4
A fourth embodiment of the present invention will be described with reference to the drawings.
6 is a system configuration example of the present embodiment, FIG. 7 is a configuration example of a switching management table used in the present embodiment, and FIG. 8 is a diagram illustrating an operation example of the present embodiment.

  The system configuration of the present invention is the same as that of the first embodiment. However, in this description, for the sake of clarity, the number of distribution servers and distribution server accommodating routers is three. However, the operation is the same for two sets as shown in FIG. 1, and the number of distribution servers and distribution server accommodating routers does not limit the present invention.

  In the switching management table 12b used in the fourth embodiment, as shown in FIG. 7, the reception state is added to the switching management table 12a in FIG.

  Next, an operation example of the fourth embodiment will be described. For example, as shown in FIG. 7, it is assumed that S1 is an active system, S2 and S3 are standby systems, S1 and S3 are receiving, and S2 is stopped for G1.

  It is assumed that the distribution server accommodating router R1 (3) detects the reception interruption of the stream (S1, G1) (s26). The distribution server accommodating router R1 (3) notifies the switching control server 1 of the reception interruption of (S1, G1) (s27).

  When notified of (S1, G1) reception interruption, the switching control server 1 changes the reception state of (S1, G1) in the switching management table 12a to stop (s28) and changes the switching system state to the standby system. Then, the blocking setting of (S1, G1) is performed on the distribution server accommodating router R1 (3) (s29, s30).

  Further, the switching control server 1 searches for the source IP address whose reception state is being received with respect to G1, extracts S3 accommodated in the distribution server accommodating router R3 (8), and distributes the distribution server accommodating router R3. The transfer setting of (S3, G1) is performed for (8) (s31, s32). Thereby, the multicast stream of (S3, G1) is transmitted to the host (s33).

(Example 5)
A fifth embodiment of the present invention will be described with reference to the drawings.
FIG. 9 is a diagram illustrating an operation example of the fifth embodiment. The system configuration example and the switching management table configuration example are the same as those in the fourth embodiment, as shown in FIGS.

  Similarly to the fourth embodiment, it is assumed that S1 is an active system, S2 and S3 are standby systems, S1 and S3 are receiving, and S2 is stopped with respect to G1. In the switching control unit 11 of the switching control server 1, a timer operates for each multicast address being received.

The distribution server accommodating router R1 (3) periodically transmits a reception notification to the switching control server 1 during reception of (S1, G1) (s34), and the distribution server accommodating router R3 (8) , G1), a reception notification is periodically transmitted to the switching control server 1 (s35). Further, since the distribution server accommodating router R2 (4) has no multicast being received, no notification of reception is made.
When receiving the (S1, G1) reception notification, the switching control server 1 updates the timer (S1, G1), and (S3, G1) when receiving the reception notification, updates the (S3, G1) timer ( s36).

  If reception of (S1, G1) is interrupted (s37), the distribution server accommodating router R1 (3) does not carry out (S1, G1) reception notification, and the switching management server 1 (S1, G1) The timer times out, and the reception state of (S1, G1) is changed to stop, and accordingly, the switching system state is changed from the active system to the standby system (s38). Subsequent operations are the same as those in the first embodiment.

(Example 6)
A sixth embodiment of the present invention will be described with reference to the drawings.
FIG. 10 is a diagram illustrating an operation example of the sixth embodiment. The system configuration example and the switching management table configuration example are the same as those in the fourth embodiment, as shown in FIGS.

  As in the fourth embodiment, it is assumed that S1 is the active system, S2 and S3 are the standby system, S1 and S3 are receiving, and S2 is stopped for G1. In the switching control unit 11 of the switching control server 1, a timer operates for each multicast address being received.

Unlike the fifth embodiment, the sixth embodiment differs from the fifth embodiment in that the switching control server 1 requests reception confirmation from the distribution server accommodating router.
When the switching control server 1 confirms the reception to the distribution server accommodating router R1 (3) (s39), the distribution server accommodating router R1 (3) notifies the switching control server 1 that the distribution server accommodating router R1 (3) is receiving (S1, G1). (S40).

  Further, when the switching control server 1 confirms reception to the distribution server accommodating router R3 (8) (s42), the switching server accommodating router R3 (8) is receiving (S3, G1) to the switching control server 1. Notification is made (s43). Even if the distribution server accommodating router R2 (4) receives the reception confirmation (s41), the distribution server accommodating router R2 (4) does not notify the reception because there is no multicast stream being received.

  The operation when (S1, G1) times out in the switching control server 1 (s44) is the same as that of the fifth embodiment.

(Example 7)
A seventh embodiment of the present invention will be described with reference to the drawings.
FIG. 11 is a diagram illustrating an operation example of the seventh embodiment. The system configuration example of the seventh embodiment is the same as that of FIG. 6 of the fourth embodiment, and the configuration example of the switching management table is the same as that of FIG.

  As in the fourth embodiment, it is assumed that S1 is the active system, S2 and S3 are the standby system, S1 and S3 are receiving, and S2 is stopped for G1. In the switching control unit 11 of the switching control server 1, a timer operates for each multicast address being received. The operation example of the seventh embodiment differs from the sixth embodiment in that the switching control server 1 performs reception confirmation only on the active system.

  The operation when (S1, G1) times out is the same as in the third embodiment. That is, (S1, G1) blocking setting is performed on the distribution server accommodating router R1 (3) (s45 to s47), and (S1, G1) reception monitoring is stopped (s48 to s49). The (S3, G1) transfer setting is made in the distribution server accommodating router R3 (8) (s50 to s52), and (S3, G1) reception monitoring is started (s53 to s54).

(Example 8)
An eighth embodiment of the present invention will be described with reference to the drawings.
FIG. 12 is a configuration example of a switching management table used in the eighth embodiment. The switching management table 12c used in the eighth embodiment has a priority added to the switching management table 12b in the fourth embodiment.

The example of FIG. 12 shows a method in which the priority is higher as the number is smaller, but there is also a method in which the priority is higher as the number is larger, and the priority assignment method does not limit the present invention.
In the eighth embodiment, when the switching control server 1 selects (S, G) to be changed from the plurality of standby systems to the active system, the switch (S, G) being received has the highest priority. select. Specifically, in the example of FIG. 12, since the priority of (S2, G1) is the highest among the standby systems being received, (S2, G1) is changed to the active system.

Example 9
A ninth embodiment of the present invention will be described with reference to the drawings.
FIG. 13 is a diagram illustrating an operation example of the ninth embodiment. A configuration example of the switching management table is the same as that of FIG.

  In the ninth embodiment, the distribution server accommodating router notifies the switching control server 1 when reception of the stopped multicast stream is started, and the priority of the multicast address set changed from the stop to the reception is In the case where the priority is higher than the priority of the source IP address of the active system, the point of switching to the source IP address having a higher priority is different from the eighth embodiment.

  Specifically, in the diagram showing the operation example of FIG. 13, when the switching control server 1 detects the reception interruption of the active system (S1, G1) (s55), it switches the active system to (S2, G1) ( s56 to s60). After that, when recovery of (S1, G1) is detected (s61, s62), since S1 has a higher priority than G2, the active system is again set to (S1, G1). ) (S63 to s67).

(Example 10)
A tenth embodiment of the present invention will be described with reference to the drawings.
FIG. 14 is a diagram illustrating a configuration example of a switching management table used in the tenth embodiment. The system configuration of the tenth embodiment is the same as that of FIG.

  The switching control server 1 operates a monitoring timer for each distribution server accommodating router. When the switching control server 1 receives any notification from the distribution server accommodating router (s68), it updates the timer (s69). However, when the timer times out (s70), the switching control server 1 changes all (S, G) accommodated in the distribution server accommodating router to be stopped (s71).

(Example 11)
Example 11 of the present invention will be described with reference to the drawings.
FIG. 15 is a diagram illustrating an operation example of the eleventh embodiment. In the eleventh embodiment, when the active system is switched from (S1, G1) to (S2, G1), the switching control server 1 performs the blocking setting of (S1, G1) (s72 to s75) and (S1, G1). ) After confirming the completion of the cutoff setting (s76), the transfer setting of (S2, G1) is performed (s77 to s79). Although the above points are different from the first embodiment, other operations are the same as those of the first embodiment.

(Example 12)
A twelfth embodiment of the present invention will be described with reference to the drawings.
FIG. 16 is a diagram illustrating an operation example of the twelfth embodiment. The configuration example of the switching management table is the same as that of FIG.

In the diagram illustrating the operation example in FIG. 16, it is assumed that the active system is (S1, G1) and the standby system is (S2, G1) and (S3, G1) with respect to G1 (s80).
The distribution server accommodating router R1 (3) detects the reception interruption of the active system (S1, G1) (s81), notifies the switching control server 1 of the reception interruption (s82), and the switching control server 1 (S2, When G1) is selected as the switching destination candidate (s83), the reception confirmation of (S2, G1) is performed with respect to the distribution server accommodating router R2 (4) (s84).

  When the distribution server accommodating router R2 (4) notifies that (S2, G1) has not been received (s85), the switching control server 1 selects (S3, G1) as the next candidate (s86), and distributes it. The server accommodating router R3 (8) confirms reception of (S3, G1) (s87). When the reception notification (S3, G1) is received from the distribution server accommodating router R3 (8) (s88), (S3, G1) is selected as the switching destination and changed to the active system (s89).

  The processing procedure performed by the switching control server described above can be program-coded and recorded on a computer-readable recording medium and distributed, or distributed to users via a network such as the Internet.

It is a system configuration example of Example 1 of the present invention. It is a switching management table structural example of Example 1 of this invention. It is a figure which shows the operation example of Example 1 of this invention. It is a figure which shows the operation example of Example 2 of this invention. It is a figure which shows the operation example of Example 3 of this invention. It is a system configuration example of Example 4 of the present invention. It is a switching management table structural example of Example 4 of this invention. It is a figure which shows the operation example of Example 4 of this invention. It is a figure which shows the operation example of Example 5 of this invention. It is a figure which shows the operation example of Example 6 of this invention. It is a figure which shows the operation example of Example 7 of this invention. It is a switching management table structural example of Example 8 of this invention. It is a figure which shows the operation example of Example 9 of this invention. It is a figure which shows the operation example of Example 10 of this invention. It is a figure which shows the operation example of Example 11 of this invention. It is a figure which shows the operation example of Example 12 of this invention. It is a system configuration example of conventional method 1. It is a figure which shows the operation example of the conventional system 1. It is a figure which shows the operation example 1 of the conventional system 2. It is a figure which shows the operation example 2 of the conventional system 2.

Explanation of symbols

1: switching control server 11: switching control unit 12 (12a to 12c): switching control table 2: IP network 3: distribution server accommodating router R1
4: Distribution server accommodating router R2
5: Distribution server S1
6: Distribution server S2
7: Host 8: Distribution server accommodating router R3
9: Distribution server S3

Claims (18)

Provided in the IP network is a switching control means having a table for storing the IP multicast distribution source switching system state,
The table for storing the switching system state includes an IP multicast address, a transmission source IP address of the stream to which the IP multicast address is assigned, and whether each transmission source IP address is a transmission source of an active stream with an IP multicast address. Stores the switching status indicating whether it is the source of the stream, and the IP address of the distribution server accommodating router that accommodates the distribution server to which each source IP address is assigned,
The switching control means comprises means for forwarding setting or blocking setting for each combination of an IP multicast address and a source IP address (hereinafter referred to as a multicast address set) for the packet filter of the distribution server accommodating router, In the table, the multicast address set whose switching system status has been changed from the standby system to the working system is set to be transferred to the packet filter of the distribution server accommodating router, or the switching system status has been changed from the working system to the standby system. An IP multicast distribution source switching control system, wherein a multicast address set is set to be blocked in a packet filter of the distribution server accommodating router. In the IP multicast distribution source switching control system according to claim 1,
The distribution server accommodating router includes means for detecting and notifying, for each multicast address set, a reception interruption of a packet whose destination IP address is an IP multicast address and whose source IP address is a source IP address of a multicast address set. When the reception interruption is detected, the switching control means is notified of the packet reception interruption of the stream of the multicast address set,
The switching control unit changes the switching system state of the multicast address set notified of reception interruption from the active system to the standby system, and uses the same IP multicast address as the multicast address set that has been changed from the active system to the standby system. An IP multicast distribution source switching control system, wherein a switching system state of a multicast address set is changed from a standby system to an active system. In the IP multicast distribution source switching control system according to claim 2,
The switching control means includes means for starting and stopping a means for detecting and notifying packet reception interruption of the distribution server accommodating router for each multicast address set, and a multicast address whose switching system status is changed from a standby system to a working system Starts the means for detecting and notifying the packet reception interruption for the set, and stops the means for detecting and notifying the packet reception interruption for the multicast address set whose switching system state is changed from the active system to the standby system. An IP multicast distribution source switching control system. In the IP multicast distribution source switching control system according to claim 2,
The table of the switching control means stores a reception state indicating whether the distribution server accommodating router is receiving or has stopped receiving the packet to which each multicast address set is assigned,
The means for detecting and notifying the packet reception interruption monitors the packet reception for each multicast address set for each multicast address set, and when the packet reception interruption is detected, switches the multicast address set in which the reception interruption is detected. Notify the control means,
The switching control means changes the reception state of the multicast address set notified of reception interruption to stopped, and if the switching state of the multicast address set changed from receiving to stopping is the active system It is characterized by changing to a standby system, and changing one of the multicast address sets whose reception state is being received with the same IP multicast address as the multicast address set that has been changed to the standby system to the active system IP multicast distribution source switching control system. In the IP multicast distribution source switching control system according to claim 1,
The distribution server accommodating router includes means for detecting packet reception for each multicast address set, and means for notifying a multicast address set in which a packet is being received. A multicast address set is periodically notified at predetermined time intervals,
The switching control means stores the reception state of a multicast address set with a notification of reception in the table as being received, or stops the reception state of a multicast address set with no notification of reception within a predetermined time period. If the switching status of the multicast address set changed from receiving to stopping is changed to the standby system, the multicast address set is changed to the standby system, and the switching status is changed to the standby system. An IP multicast distribution source switching control system, wherein one of multicast address sets whose reception state is being received at the same IP multicast address is changed to an active system. In the IP multicast distribution source switching control system according to claim 1,
The distribution server accommodating router comprises means for detecting packet reception for each multicast address set, and means for notifying the multicast address set being received,
The switching control means includes means for requesting confirmation of multicast packet reception, and periodically confirms reception of the multicast packet at a predetermined time interval with respect to the distribution server accommodating router whose IP address is stored in the table. Send a request,
The distribution server accommodating router, when receiving a multicast packet reception confirmation request, notifies all the multicast address sets being received to the switching control means,
In the table, the switching control means stores the reception state of a multicast address set with notification as being received, or stores the reception state of a multicast address set without notification within a certain predetermined time as being stopped. If the switching state of the multicast address set that has been changed from receiving to stopping is changed to the standby system, the receiving state is changed to the standby system, and the receiving state is set to the same IP multicast address as the multicast address set that has been changed to the standby system. An IP multicast distribution source switching control system, wherein one of multicast address sets being received is changed to an active system. In the IP multicast distribution source switching control system according to claim 6,
The switching control means designates only a multicast address set whose switching system state is stored as active in the table, and sends a multicast packet reception confirmation request to a distribution server accommodating router associated with the multicast address set. Send
The distribution server accommodating router that has received the multicast packet reception confirmation request notifies the switching control unit of only the multicast address set designated by the switching control unit among the multicast address sets of the multicast packet being received. An IP multicast distribution source switching control system. In the IP multicast distribution source switching control system according to any one of claims 4 to 6,
The table of the switching control means stores switching priority for each multicast address set,
The switching control means has the highest switching priority among the multicast address sets whose reception status is being received with the same IP multicast address as the multicast address set whose switching status is changed from the active status to the standby status. An IP multicast distribution source switching control system, wherein a multicast address set is changed to an active system. In the IP multicast distribution source switching control system according to claim 8,
The distribution server accommodating router includes means for detecting the start of packet reception for each multicast address set, and when detecting the start of packet reception, notifies the switching control means of the start of reception of the multicast address set of the packet,
The switching control means is configured to switch the active state when the receiving state of the multicast address set having the same IP multicast address as the working multicast address set and the higher switching priority is changed from being stopped to being received. The multicast address set of the system is changed to the standby system, the reception state is changed from being stopped to being received, and the switching system state of the multicast address set having a higher switching priority is changed to the active system. An IP multicast distribution source switching control system. In the IP multicast distribution source switching control system according to any one of claims 6 to 9,
The switching control means stops the reception state of all multicast address sets associated with the distribution server accommodating router when there is no multicast address set notification from the distribution server accommodating router within a predetermined period of time. An IP multicast distribution source switching control system characterized by being changed to The IP multicast distribution source switching control system according to any one of claims 1 to 9,
The switching control means confirms that the multicast address set whose switching system state has been changed from the working system to the standby system is set to be blocked in the packet filter of the distribution server accommodating router, and then the switching system state is set to the standby system. An IP multicast distribution source switching control system, wherein transfer setting is set to the packet filter of the distribution server accommodating router for the multicast address set changed from the active system to the active system. In the IP multicast distribution source switching control system according to any one of claims 1 to 3,
The switching control means, when selecting a multicast address set to be changed from a standby system to an active system, confirms reception of the multicast address set to the distribution server accommodating router. Multicast distribution source switching control system. The switch control means connected to the IP network and provided with a table for storing the switching system state includes the IP multicast address and the source IP address of the stream to which the IP multicast address is assigned in the table for storing the switching system state. And a switching system state indicating whether each transmission source IP address is a transmission source of an active stream or a backup stream of an IP multicast address, and a distribution server accommodating a distribution server to which each transmission source IP address is assigned The switching system state is changed from the standby system to the active system in the table by the step of storing the IP address of the router and the means for setting the forwarding or blocking for each multicast address set for the packet filter of the distribution server accommodating router. Modified multicast address set A step of forwarding setting to the packet filter of the distribution server accommodating router, or a step of blocking setting to the packet filter of the distribution server accommodating router for a multicast address set whose switching system state has been changed from the active system to the standby system; An IP multicast distribution source switching control method characterized by comprising: In the IP multicast distribution source switching control method according to claim 13,
The distribution server accommodating router detects a packet reception interruption for each multicast address set and notifies the reception interruption of the packet whose destination IP address is the IP multicast address and the transmission source IP address is the transmission source IP address of the multicast address set. Detecting the packet reception interruption of the stream of the multicast address set to the switching control means,
The switching control means changes the switching system state of the multicast address set notified of reception interruption from the active system to the standby system, and the same IP multicast as the multicast address set that has been changed from the active system to the standby system An IP multicast distribution source switching control method, comprising: changing a switching system state of a multicast address set as an address from a standby system to an active system. The IP multicast distribution source switching control method according to claim 14,
A multicast address set in which the switching control means uses means for starting and stopping the means for detecting and notifying packet reception interruption of the distribution server accommodating router for each multicast address set, and the switching system state is changed from the standby system to the active system In response, a step of activating a means for detecting and notifying the packet reception interruption, and a means for detecting and notifying the packet reception interruption for a multicast address set whose switching system state has been changed from the active system to the standby system. An IP multicast distribution source switching control method comprising: a step of stopping. The IP multicast distribution source switching control method according to claim 14,
A table of the switching control means for storing a reception state indicating whether a distribution server accommodating router is receiving or stopping reception of a packet assigned with each multicast address set;
The means for detecting and notifying the packet reception interruption, for all multicast address sets, monitors the packet reception for each multicast address set, and when the packet reception interruption is detected, the multicast address set in which the reception interruption is detected, Notifying the switching control means;
The switching control unit changes the reception state of the multicast address set notified of reception interruption to the stop state, and the switching state of the multicast address set changed from the reception state to the stop state is the active system. If there is a step to change to the standby system, and one of the multicast address sets whose reception status is being received with the same IP multicast address as the multicast address set that has changed the switching system to the standby system, is changed to the active system. An IP multicast distribution source switching control method. An IP multicast distribution source switching control program executed by a switching control server having a switching control means having a table for storing a switching system state of an IP multicast distribution source,
In the table storing the switching system state, an IP multicast address, a source IP address of a stream to which the IP multicast address is assigned, and whether each source IP address is a source of an active stream with an IP multicast address or a standby system A process for storing a switching system state indicating whether the stream is a transmission source, an IP address of a distribution server accommodating router accommodating a distribution server to which each transmission source IP address is assigned, and the switching control means switching in the table For the multicast address set whose system status has been changed from the standby system to the active system, the processing for forwarding setting to the packet filter of the distribution server accommodating router, and the multicast address set whose switching system status has been changed from the active system to the standby system The packet of the distribution server accommodating router The process for blocking set to preparative filter, IP multicast distribution source switching control program executed by the switching control server.   18. A computer-readable recording medium on which the IP multicast distribution source switching control program according to claim 17 is recorded.

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