Method and apparatus for relaying packets based on class of service

• US 6,965,599 B1
• Filed: 11/17/2000
• Issued: 11/15/2005
• Est. Priority Date: 12/03/1999
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Torii, Koji, Sakurai, Hideshi
• Primary Examiner(s): Hsu, Alpus H.
• Assistant Examiner(s): KHUONG, LEE T
• Application Number:
  US09/714,295
• Time in Patent Office: 1,824 Days
• Field of Search: 370/219, 370/352, 370/389, 370/392, 370/401, 370/466, 370/475, 370/395.43, 709/223, 709/231, 709/245, 709/238, 709/239, 709/249
• US Class Current: 370/392
• 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 45/24 Multipath
• CPC Class Codes: H04L 45/302 Route determination based on requested QoS
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2517 using port numbers
• CPC Class Codes: H04L 61/255 Maintenance or indexing of mapping tables
• CPC Class Codes: H04L 61/2557 Translation policies or rules

Abstract

A packet relay apparatus is disposed that relays packets between an inside node and an outside IP network. A class processing unit classifies send packets to be relayed to the IP network and allocates different virtual IP addresses thereto. A send packet relay unit translates source addresses of the send packets to be relayed to the IP network into virtual IP addresses on a class by class basis, to establish classified IP communication paths. For reply packets from the IP network passing through communication paths on a class by class basis, a reply packet relay unit inversely translates destination virtual IP addresses into original addresses by reference to the results of address translation effected by the send packet relay unit.

Claims

1. A packet relay apparatus for relaying packets between a node and an IP network, said apparatus comprising:

a class processing unit arranged to classify send packets to be relayed to said IP network depending on the types of applications, said class processing unit making allocation of different virtual IP addresses on a class by class basis;

a send packet relay unit arranged to translate source addresses of said send packets to be relayed to said IP network into virtual IP addresses on a class by class basis, said send packet relay unit establishing IP communication paths on a class by class basis in said IP network; and

a reply packet relay unit arranged to inversely translate destination addresses of reply packets from said IP network passing through said IP communication paths on a class by class basis into original addresses by reference to the results of address translation effected by said send packet relay unit.

2. A packet relay apparatus for relaying packets between a node and an IP network, said apparatus comprising:

a class processing unit arranged to classify send packets to be relayed to said IP network depending on the types of applications, said class processing unit making allocation of different virtual IP addresses on a class by class basis;

a send packet relay unit arranged to translate source addresses of said send packets to be relayed to said IP network into virtual IP addresses on a class by class basis, said send packet relay unit establishing IP communication paths on a class by class basis in said IP network;

a reply packet relay unit arranged to inversely translate destination addresses of reply packets from said IP network passing through said IP communication paths on a class by class basis into original addresses by reference to the results of address translation effected by said send packet relay unit;

a class table having packet header information entered therein correspondingly to class names defining the types of said applications;

an address translation rule table having virtual IP addresses and path information entered therein correspondingly to said classes; and

an address translation table having therein entered the results of address translation from said packet source addresses to said virtual IP addresses; and

wherein

said send packet relay unit upon receipt of a send packet to said IP network refers to said address translation table to retrieve a source virtual IP address, said send packet relay unit if there is no entry in said address translation table determining a class by reference to said class table and thereafter referring to said address translation rule table to retrieve a virtual IP address corresponding to said class, said send packet relay unit translating a send packet source address into said retrieved virtual IP address to enter the result of said address translation into said address translation table, and wherein

said reply packet relay unit upon receipt of a reply packet from said IP network refers to said address translation table to retrieve a destination address corresponding to a destination virtual IP address, said reply packet relay unit inversely translating said destination virtual IP address of said packet into said retrieved destination address.

3. The apparatus according to claim 2, wherein

said class table has protocol types, send packet source addresses and port Nos. and reply packet source addresses and port Nos. entered correspondingly to said class names, and wherein

said class retrieval unit retrieves a class from a combination of a protocol type of a send packet to be relayed to said IP network and a port No.

4. The apparatus according to claim 3, wherein

said class table has class names of a business application entered in the form of combinations of send packet TCP protocols and port Nos., said class table having all of the combinations of the other protocol types of said send packets and source port Nos. entered by class names of a default application.

5. The apparatus according to claim 2, wherein

said address translation rule table has virtual IP addresses and gateway MAC addresses entered correspondingly to class names entered in said class table, and wherein said send packet relay unit retrieves a virtual IP address and a gateway MAC address corresponding to a class name retrieved from said address translation rule table.

6. The apparatus according to claim 2, wherein

said address translation table has pre-translation source addresses and port Nos. and post-translation virtual IP addresses and port Nos. entered correspondingly to protocol types, and wherein

said send packet relay unit translates a send packet source address into a virtual IP address retrieved from said address translation rule table or said address translation table, said send packet relay unit translating a destination MAC address into a gateway MAC address retrieved from said address translation rule table, and wherein

said reply packet relay unit inversely translates a destination virtual IP address received from said IP network into a pre-translation source address retrieved from said address translation table.

7. The apparatus according to claim 2, further comprising:

a communication path validation unit arranged to make a periodical validation of communication through a communication path of said IP network by use of said virtual IP address.

8. The apparatus according to claim 7, wherein

said communication path validation unit when detecting an abnormal of said communication path prohibits a retrieval of a class that uses said communication path, to make a changeover to use of a default communication path.

9. The apparatus according to claim 8, wherein

said class table includes a status indicative of usable or unusable, and wherein

said communication path validation unit when detecting an abnormal of said communication path sets unusable in said status of said class table to prohibit a class retrieval.

10. A method of relaying packets between an inside node and an outside IP network, said method comprising the steps of:

classifying send packets to be relayed to said IP network, depending on the types of applications, to allocate a different virtual IP address to each class;

translating source addresses of said send packets to be relayed to said IP network into virtual IP addresses on a class by class basis to establish IP communication paths on a class by class basis in said IP network; and

inversely translating destination addresses of reply packets from said IP network passing through said IP communication path on a class by class basis into original addresses by reference to the results of address translation in said send packet relaying step.