Method and system for improvement of network performance over asymmetic links
View Patent ↗A communications system includes a plurality of communications channels for transporting packets. The system also includes a gateway that is coupled to the communications channels. The gateway is configured to buffer a packet that is received over one of the communications channel from a first host in a queue and to determine a window value for maximizing transmission rate based upon occupancy of the queue. The gateway is configured to a second host according to a prescribed protocol to force use of the determined window value in the second host over another one of the communications channels. The present invention has particular applicability to an asymmetric bandwidth network, such as a two-way satellite system.
1. A method for providing proxying services, the method comprising:
buffering a packet received from a first host in a queue;
determining a window scale value for maximizing transmission rate based upon occupancy of the queue;
adding the window scale value to the packet to create a modified packet if the packet received from the first host does not already include any window scale value; and
transmitting the modified packet to a second host according to a prescribed protocol to force use of the determined window value in the second host.
2. The method according to claim 1 , further comprising:
reducing the window scale value when the occupancy of the queue exceeds a predetermined threshold.
3. The method according to claim 1 , further comprising:
transmitting an acknowledgement packet to the first host prior to receiving an associated acknowledgement from the second host.
4. The method according to claim 1 , wherein the transmitting step is performed over an asymmetric bandwidth network that provides a forward channel and a return channel that has a relatively lower bandwidth than the forward channel, the method further comprising:
receiving an acknowledgement packet from the second host over the return channel.
5. The method according to claim 4 , wherein the asymmetric bandwidth network is a two-way satellite communications network.
6. The method according to claim 1 , wherein the first host in the buffering step is configured to perform acknowledgement reduction to minimize transmission of acknowledgement packets.
7. The method according to claim 1 , wherein the prescribed protocol in the transmitting step is Transmission Control Protocol.
8. A method for exchanging packets with a host via a gateway, the method comprising:
receiving a packet from the gateway, the packet specifying a window scale value, wherein the gateway includes a queue for buffering packets from the host, the window scale value being set by the gateway in response to the gateway receiving the packet without the window scale value, the window scale value being set for maximal transmission rate based upon occupancy of the queue; and
communicating with the host based upon the received window scale value.
9. The method according to claim 8 , wherein the window scale value is reduced when the occupancy of the queue exceeds a predetermined threshold.
10. The method according to claim 8 , wherein the gateway is configured to perform spoofing to acknowledge receipt of packets from the host.
11. The method according to claim 8 , wherein the receiving step is performed over an asymmetric bandwidth network that provides a forward channel and a return channel that has a relatively lower bandwidth than the forward channel.
12. The method according to claim 11 , wherein the asymmetric bandwidth network is a two-way satellite communications network.
13. The method according to claim 8 , wherein the host is configured to perform acknowledgement reduction to minimize transmission of acknowledgement packets.
14. The method according to claim 8 , wherein communicating with the host includes communicating according to Transmission Control Protocol.
15. A network device for providing proxying services, the device comprising:
a queue for buffering a packet received from a first host;
a processor configured to (i) determine a window scale value for maximizing transmission rate based upon occupancy of the queue, and to (ii) add the window scale value to the packet to create a modified packet if the packet received from the first host does not already include any window scale value; and
a communication interface coupled to the processor and configured to transmit the modified packet to a second host according to a prescribed protocol to force use of the determined window scale value in the second host.
16. The device according to claim 15 , wherein the window scale value is reduced when the occupancy of the queue exceeds a predetermined threshold.
17. The device according to claim 15 , wherein the communication interface is configured to transmit an acknowledgement packet to the first host prior to receiving an associated acknowledgement from the second host.
18. The device according to claim 15 , wherein the transmitting step is performed over an asymmetric bandwidth network that provides a forward channel and a return channel that has a relatively lower bandwidth than the forward channel, the communication interface receiving an acknowledgement packet from the second host over the return channel.
19. The device according to claim 18 , wherein the asymmetric bandwidth network is a two-way satellite communications network.
20. The device according to claim 15 , wherein the first host is configured to perform acknowledgement reduction to minimize transmission of acknowledgement packets.
21. The device according to claim 15 , wherein the prescribed protocol is Transmission Control Protocol.
22. A communications system comprising:
a plurality of communications channels for transporting packets; and
a gateway coupled to the communications channels, the gateway being configured to (i) buffer a packet received over one of the communications channel from a first host in a queue, (ii) determine a window scale value for maximizing transmission rate based upon occupancy of the queue; and
(iii) add the window scale value to the packet to create a modified packet if the packet received from the first host does not already include any window scale value,
wherein the gateway is configured to transmit the modified packet to a second host according to a prescribed protocol to force use of the determined window scale value in the second host over another one of the communications channels.
23. The system according to claim 22 , wherein the window scale value is reduced when the occupancy of the queue exceeds a predetermined threshold.
24. The system according to claim 22 , wherein the gateway is configured to perform spoofing to acknowledge receipt of packets from the host.
25. The system according to claim 22 , wherein the other one of the communications channel is an asymmetric channel that includes a forward channel and a return channel, the return channel has a relatively lower bandwidth than the forward channel.
26. The system according to claim 25 , wherein the asymmetric channel is provided by a two-way satellite communications network.
27. The system according to claim 22 , wherein the first host is configured to perform acknowledgement reduction to minimize transmission of acknowledgement packets.
28. The system according to claim 22 , wherein the prescribed protocol is Transmission Control Protocol.
29. A network device for providing proxying services, the device comprising:
means for buffering a packet received from a first host;
means for (i) determining a window scale value for maximizing transmission rate based upon occupancy of the buffering means, and for (ii) adding the window scale value to the packet to create a modified packet if the packet received from the first host does not already include any window scale value; and
means for transmitting the modified packet to a second host according to a prescribed protocol to force use of the determined window scale value in the second host.
30. The device according to claim 29 , further comprising:
means for reducing the window scale value when the occupancy of the buffering means exceeds a predetermined threshold.
31. The device according to claim 29 , further comprising:
means for transmitting an acknowledgement packet to the first host prior to receiving an associated acknowledgement from the second host.
32. The device according to claim 29 , wherein the transmitting means is coupled to an asymmetric bandwidth network that provides a forward channel and a return channel that has a relatively lower bandwidth than the forward channel, the device further comprising:
means for receiving an acknowledgement packet from the second host over the return channel.
33. The device according to claim 32 , wherein the asymmetric bandwidth network is a two-way satellite communications network.
34. The device according to claim 29 , wherein the first host is configured to perform acknowledgement reduction to minimize transmission of acknowledgement packets.
35. The device according to claim 29 , wherein the prescribed protocol is Transmission Control Protocol.
36. A computer-readable medium carrying one or more sequences of one or more instructions for providing proxying services, the one or more sequences of one or more instructions including instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of:
buffering a packet received from a first host in a queue;
determining a window scale value for maximizing transmission rate based upon occupancy of the queue;
adding the window scale value to the packet to create a modified packet if the packet received from the first host does not already include any window scale value; and transmitting the modified packet to a second host according to a prescribed protocol to force use of the determined window scale value in the second host.
37. The computer-readable medium according to claim 36 , wherein the one or more processors further perform the step of:
reducing the window scale value when the occupancy of the queue exceeds a predetermined threshold.
38. The computer-readable medium according to claim 36 , wherein the one or more processors further perform the step of:
transmitting an acknowledgement packet to the first host prior to receiving an associated acknowledgement from the second host.
39. The computer-readable medium according to claim 36 , wherein the transmitting step is performed over an asymmetric bandwidth network that provides a forward channel and a return channel that has a relatively lower bandwidth than the forward channel, the one or more processors further performing the step of:
receiving an acknowledgement packet from the second host over the return channel.
40. The computer-readable medium according to claim 39 , wherein the asymmetric bandwidth network is a two-way satellite communications network.
41. The computer-readable medium according to claim 36 , wherein the first host in the buffering step is configured to perform acknowledgement reduction to minimize transmission of acknowledgement packets.
42. The computer-readable medium according to claim 36 , wherein the prescribed protocol in the transmitting step is Transmission Control Protocol.