Load balancing with direct terminal response
View Patent ↗Generally, a terminal can access a resource selection device to access a content source, the content source being structured and arranged to respond directly to the terminal. For example, a PC (“personal computer”) may be pointed at a load-balancing switch. The load balancing switch translates the PC's traffic and directs the PC traffic to a server (or switch) providing streaming services. The server responds directly to the terminal, but uses the IP address/identity of the load-balancing switch with which the terminal is communicating.
1. A resource selection device, the device comprising:
a first communications interface structured and arranged to receive a first packet from a first device, the first packet having a source IP address of the first device and a destination IP address corresponding to a virtual resource address for the resource selection device;
a first switching processor structured and arranged to half network address translate the first packet into a translated packet having a destination IP address corresponding to a source IP address related to a content source and a source IP address corresponding to the source IP address of the first device; and
a second communications interface structured and arranged to transmit the translated packet to the content source with the appearance of origination from the first device so that the content source may respond to the translated packet with a response packet that has a destination IP address of the first device and a source IP address of the resource selection device.
2. The device of claim 1 wherein the resource selection device is structured and arranged to load balance between two or more content sources.
3. The device of claim 2 wherein the resource selection device load balances to find the content source that is closest to the first device.
4. The device of claim 3 wherein the content source is defined to be closest to the first device based on the proximity of a domain name server for the first device to the content source.
5. The device of claim 4 wherein proximity is measured based on logical distance.
6. The device of claim 2 wherein the content sources are on different IP broadcast domains.
7. The device of claim 1 wherein the resource selection device is a switch.
8. The device of claim 1 wherein the content source is a duplicating switch structured and arranged to enable access to one or more streams of datagrams.
9. The device of claim 1 wherein the first device includes a terminal.
10. The device of claim 9 wherein transmission of the response packet does not require intervention of the resource selection device.
11. A method to load balance content sources comprising:
receiving a first packet from a first device, the first packet having a source IP address of the first device and a destination IP address corresponding to a virtual resource address for a resource selection device;
half network address translating the first packet into a translated packet having a destination IP address corresponding to a source IP address related to a content source and a source IP address corresponding to the source IP address of the first device; and
transmitting the translated packet to the content source with the appearance of origination from the first device so that the content source may respond to the translated packet with a response packet that has a destination IP address of the first device and a source IP address of the resource selection device.
12. The method of claim 11 further comprising selecting one of several content sources to receive the translated packet.
13. The method of claim 12 wherein selecting one of several content sources includes finding the content source that is closest to the first device.
14. The method of claim 13 wherein finding the content source closest to the first device includes finding the content source closest to the first device based on a proximity of a domain name server for the first device to the content source.
15. The method of claim 14 wherein proximity is measured based on logical distance.
16. The method of claim 12 wherein the content sources are on different IP broadcast domains.
17. The method of claim 11 wherein the resource selection device is a switch.
18. The method of claim 11 wherein the content source is a duplicating switch structured and arranged to enable access to one or more streams of datagrams.
19. The method of claim 11 wherein the first device includes a terminal.
20. The method of claim 19 wherein transmission of the response packet does not require intervention of the resource selection device.
21. A resource selection device comprising:
means for receiving a first packet from a first device, the first packet having a source IP address of the first device and a destination IP address corresponding to a virtual resource address for the resource selection device;
means for half network address translating the first packet into a translated packet having a destination IP address corresponding to a source IP address related to a content source and a source IP address corresponding to the source IP address of the first device; and means for transmitting the translated packet to the content source with the appearance of origination from the first device so that the content source may respond to the translated packet with a response packet that has a destination IP address of the first device and a source IP address of the resource selection device.
22. A data processing system comprising:
a resource selection device structured and arranged to:
receive a first packet from a first device, the first packet having a source IP address of the first device and a destination IP address of the resource selection device,
half network address translate the destination address of the first packet from the IP address of the resource selection device to an IP address of a content source while having preserved the source address of the first packet as an IP address of the first device from which the first packet was received,
transmit the first packet that has been half network translated to the content source; and
the content source structured and arranged to:
receive from the resource selection device the first packet that has been half network address translated,
assemble one or more response packets with information pertaining to information in the first packet with a source IP address corresponding to the IP address of the resource selection device and a destination IP address corresponding to the IP address of the first device; and
transmit the response packets.