Transmission system, delivery path controller, load information collecting device, and delivery path controlling method

• US 20050188073A1
• Filed: 04/01/2005
• Published: 08/25/2005
• Est. Priority Date: 02/13/2003
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kawamura, Nobuhiro, Nagata, Akira, Iawasaki, Takashi, Nakamichi, Koji, Nakamura, Katsuichi, Nomiyama, Seiji, Fukazawa, Mitsunori, Yamada, Akiko, Yamada, Hitoshi, Itagaki, Sugiko
• Granted Patent: US 7,890,656 B2
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/38 Flow based routing
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/10015 Access to distributed or replicated servers, e.g. using brokers
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/101 based on network conditions
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A transmission system, having a plurality of delivery server side routers which communicate with a plurality of delivery servers for delivering a content; and a client side router which communicates with a client device for receiving the content, is configured to include: a database for storing server load states of the plurality of delivery servers, and respective individual link load states for a plurality of delivery paths between the plurality of delivery server side routers and the client side router; and a path control unit for determining a minimum load state delivery path having a minimum load state among the plurality of delivery paths, based on sums of the server load states and the respective individual link load states stored in the database.

Claims

1. A transmission system having:

a plurality of delivery server side routers which communicate with a plurality of delivery servers for delivering a content; and

a client side router which communicates with a client device for receiving the content, the system comprising;

a database for storing server load states of the plurality of delivery servers, and respective individual link load states for a plurality of delivery paths defined between the plurality of delivery server side routers and the client side router; and

a path control unit for determining a minimum load state delivery path having a minimum load state among the plurality of delivery paths, based on sums of the server load states and the respective individual link load states stored in the database.

2. The transmission system as claimed in claim 1, further comprising a load information collecting unit capable of collecting at least either the server load states of the delivery servers or the respective individual link load states, and updating the database with the server load states or the respective individual link load states collected.

3. The transmission system as claimed in claim 1, wherein each of a plurality of routers, provided in the minimum load state delivery path determined by the path control unit, has a router control unit for setting a connection to delivery the content.

11. The delivery path controller as claimed in claim 3, wherein

the path control unit determines the minimum load state delivery path by using load states weighted for the respective individual link load states and the load states of the plurality of delivery servers, respectively.

4. A transmission system including a network having a plurality of delivery servers for delivering a content responding to a delivery request from a client device for receiving the content, the system comprising:

a database for storing server load states of the plurality of delivery servers, and respective individual link load states for a plurality of delivery paths defined between the plurality of delivery server side routers and the client side router;

a first collecting unit capable of collecting the server load states of the delivery servers and updating the database;

a second collecting unit capable of collecting the respective individual link load states and updating the database;

a path control unit for determining a minimum load state delivery path having a minimum load state among the plurality of delivery paths, based on sums of the server load states and the respective individual link load states stored in the database; and

a router control unit, for setting a connection to delivery the content, included in each of a plurality of routers provided in the minimum load state delivery path determined by the path control unit.

5. A delivery path controller in a transmission system having:

a plurality of delivery server side routers which communicate with a plurality of delivery servers for delivering a content; and

a client side router which communicates with a client device for receiving the content, the controller comprising;

a database for storing server load states of the plurality of delivery servers, and respective individual link load states for a plurality of delivery paths defined between the plurality of delivery server side routers and the client side router;

a path control unit for determining a minimum load state delivery path having a minimum load state among the plurality of delivery paths, based on sums of the server load states and the respective individual link load states stored in the database; and

a router control unit, for setting a connection to delivery the content, included in each of a plurality of routers provided in the minimum load state delivery path determined by the path control unit.

6. The delivery path controller as claimed in claim 5, wherein

for an individual link load state between adjacent routers among a plurality of routers through which a packet is transferred, the database stores bidirectional individual link load states in a first direction from one router to another router and in a second direction from the other router to the one router, and

by using at least either of the bidirectional individual link load states, the path control unit determines a set of a delivery server and a delivery path having such a load state that a sum of the individual link load state and the server load state is minimum, as the minimum load state delivery path.

7. The delivery path controller as claimed in claim 5, wherein

the path control unit determines the set of a delivery server and a delivery path by using individual link load states in directions from the plurality of delivery server side routers to the client side router or in directions from the client side router to the plurality of delivery server side routers for the plurality of delivery paths, respectively.

8. The delivery path controller as claimed in claim 5, wherein

the path control unit determines the set of a delivery server and a delivery path by using individual link load states in directions from a virtual node accessing to the plurality of delivery servers via virtual links, respectively, to the client side router.

9. The delivery path controller as claimed in claim 5, wherein

as a responding path from a delivery server, which has received a transfer request from the client side router, to the client side router, the path control unit determines a set of a delivery server, which is a delivery request transferring destination, and a delivery path, by using individual link load states in directions from the client side router to the plurality of delivery server side routers.

10. The delivery path controller as claimed in claim 5, wherein

as a responding path from a delivery server, which has received a transfer request from the client side router, to the client side router, the path control unit determines a set of a delivery server, which is a delivery request transferring destination, and a delivery path, by using individual link load states in directions from a virtual node accessing to the plurality of delivery servers via virtual links, respectively, to the client side router, as well as the individual link load states in directions from the client side router to the plurality of delivery server routers.

12. A load information collecting device in a transmission system having:

a plurality of delivery server side routers which communicate with a plurality of delivery servers for delivering a content; and

a client side router which communicates with a client device for receiving the content, the device comprising;

a database for storing server load states of the plurality of delivery servers, and respective individual link load states for a plurality of delivery paths defined between the plurality of delivery server side routers and the client side router; and

a path control unit for writing, into the database, the server load states collected from the delivery servers and individual link load states between adjacent routers collected from the adjacent routers among the plurality of routers.

13. A method for determining a delivery path in a transmission system having:

a plurality of delivery server side routers which communicate with a plurality of delivery servers for delivering a content; and

a client side router which communicates with a client device for receiving the content, the method comprising the steps of;

collecting server load states of the plurality of delivery servers;

collecting individual link load states between adjacent routers collected from the adjacent routers among the plurality of routers;

calculating sums of the server load states and the individual link load states collected, by using a Dijkstra method;

based on the sums, determining a minimum load state delivery path having a minimum load state among the plurality of delivery paths; and

setting a connection for delivering the content in each of a plurality of routers provided in the minimum load state delivery path determined.