Route control device, system and route control method

1. A route control device configured to control a transfer destination in a plurality of transfer devices that are included in a network and that transfer packets flowing between a first information processing device and a second information processing device, the route control device comprising

a processor that:

detects that a session is to be newly established, on the basis of a copy of a packet of a protocol that controls a session transmitted prior to establishment of a session between the first information processing device and the second information processing device, the packet of the protocol being a packet that has been transferred between the first information processing device and the second information processing device;

selects a route with a light load from among a plurality of routes connecting the first information processing device and the second information processing device; and

makes a transfer device on a selected route establish a selected route.

2. The route control device according to claim 1 , wherein

the processor:

selects a route with a light load from among the plurality of routes before the session is established, and

makes a transfer device on a selected route establish a selected route before the session is established.

3. The route control device according to claim 1 , wherein

the processor selects a route with the load that is lightest.

4. The route control device according to claim 3 , wherein

the processor selects, when there are a plurality of routes with the load that is lightest, a route with a lower hop count from among the routes with the load that is the lightest.

5. The route control device according to claim 1 , wherein

the processor:

identifies a session that is a disconnection target on the basis of a packet that controls disconnection of the session, and

makes a transfer device cancel a route, the transfer device being on the route corresponding to the session that is a disconnection target.

6. The route control device according to claim 1 , wherein

the processor manages information on a session that is being established.

7. The route control device according to claim 6 , wherein

the processor identifies a piece of the information corresponding to a session that is a disconnection target from among pieces of the information on a session that is being established, on the basis of a packet that controls disconnection of the session, and deletes the identified information.

8. The route control device according to claim 1 , wherein

the protocol is Real Time Streaming Protocol (RTSP).

9. The route control device according to claim 1 , wherein

the protocol is Session Initiation Protocol (SIP).

10. A system comprising:

a plurality of transfer devices configured to transfer packets flowing between a first information processing device and a second information processing device;

a route control device configured to control a transmission destination in the plurality of transfer devices; and

a monitoring device configured to monitor the packets flowing between the first information processing device and the second information processing device, wherein

the route control device includes a first processor that:

detects that a session is to be newly established, on the basis of a copy of a packet of a protocol that controls a session transmitted prior to establishment of a session between the first information processing device and the second information processing device,

selects a route with a light load from among a plurality of routes connecting the first information processing device and the second information processing device; and

instructs a transfer device on a selected route to establish the selected route,

each of the plurality of transfer devices establishes a route in accordance with an instruction of establishment, and

the monitoring device includes a second processor that:

monitors a protocol of each of the packets;

extracts, on the basis of a result of the monitoring of the protocol, a packet of a protocol that controls the session from among the packets;

transmits a copy of the extracted packet to the route control device,

extracts, from among the packets and on the basis of the result of the monitoring of the protocol, a particular packet of a protocol that functions as a trigger for starting packet transmission in the session to be newly established;

temporarily holds the extracted particular packet; and

transmits the temporarily held packet to an inherent transmission destination after the selected route is established.

11. The system according to claim 10 , wherein

the first processor:

identifies a session that is a disconnection target on the basis of a packet that controls disconnection of the session, and

instructs a transfer device on a route corresponding to the session that is a disconnection target to disconnect the route, wherein

each of the plurality of transfer devices cancels a route that is established, in accordance with an instruction of cancellation.

12. The system according to claim 10 , wherein

the system is a video delivery system,

the protocol is real time streaming protocol (RTSP), and

the particular packet is a packet of a reproduction start request.

13. A route control method for a route control device configured to control a transfer destination in a plurality of transfer devices that are included in a network and that transfer packets flowing between a first information processing device and a second information processing device, the route control method comprising:

detecting that a session is to be newly established, on the basis of a copy of a packet of a protocol that controls a session transmitted prior to establishment of a session between the first information processing device and the second information processing device, the packet of the protocol being a packet that has been transferred between the first information processing device and the second information processing device;

selecting a route with a light load from among a plurality of routes connecting the first information processing device and the second information processing device; and

making a transfer device on a selected route establish a selected route.

14. A non-transitory computer-readable recording medium having stored therein a program for causing a computer to execute a process, the computer being of a route control device configured to control a transfer destination in a plurality of transfer devices that constitute a network and that transfer packets flowing between a first information processing device and a second information processing device and the process comprising:

detecting that a session is to be newly established, on the basis of a copy of a packet of a protocol that controls a session transmitted prior to establishment of a session between the first information processing device and the second information processing device, the packet of the protocol being a packet that has been transferred between the first information processing device and the second information processing device;

selecting a route with a light load from among a plurality of routes connecting the first information processing device and the second information processing device; and

making a transfer device on a selected route establish a selected route.