Cost reduction of NAT connection state keep-alive

• US 20080225865A1
• Filed: 03/12/2007
• Published: 09/18/2008
• Est. Priority Date: 03/12/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Herzog, Shai
• Granted Patent: US 8,023,432 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04L 61/2553 Binding renewal aspects, e.g. using keep-alive messages
• CPC Class Codes: H04L 61/256 NAT traversal
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 76/25 Maintenance of established connections
• CPC Class Codes: H04W 92/02 Inter-networking arrangements
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Keep-alive processing for NAT devices and reducing power consumption in wireless clients. A server driven keep-alive mechanism facilitates keep-alive messages to a NAT device currently providing a connection to a mobile client to refresh the NAT state, thereby reducing or eliminating power consumption in a wireless device to respond to the connection with keep-alive packets. In one instance, keep-alive packets are sent to the NAT device to reset the NAT timeout timer, and then to the mobile client. The client responds only when expected keep-alive packets are not received at the client. In another instance, keep-alive packets reset the NAT timer to maintain the connection but are dropped or self-destruct before reaching the mobile client thereby providing the optimum power conservation in the mobile device. Thus, the client is not forced into extra client activity to send or receive wireless data, thereby draining the battery.

Claims

1. A computer-implemented system that facilitates connection management, comprising:

a boundary component for maintaining a connection between a private client of an internal network and an external network; and

a network component of the external network for sending a keep-alive packet to the boundary component, the boundary component maintaining the connection to the private client based on the keep-alive packet.

2. The system of claim 1, wherein network component is a server of the external network that sends the keep-alive packet to the boundary component to reset a keep-alive timeout counter thereof.

3. The system of claim 1, wherein the private client does not respond to the network component after receiving the keep-alive packet.

4. The system of claim 1, wherein the private client responds to the network component when the keep-alive packet is not received at the private client.

5. The system of claim 1, wherein the boundary component drops the keep-alive packet so that the packet fails to reach the private client.

6. The system of claim 1, wherein the private client is a mobile client or a wireless computing device.

7. The system of claim 1, wherein the boundary component includes network address translation for translating an IP address of the external network to an internal IP address of the internal network.

8. The system of claim 1, wherein the boundary component receives keep-alive packets only from the network component.

9. The system of claim 1, wherein the keep-alive packet sent by the network component includes a protocol number, a source IP address, a source port number, a destination IP address, and a destination port number.

10. The system of claim 1, wherein the network component is a communications server that facilitates communications for the private client, which is an IP-capable cell phone, the communications server interrogates the boundary component for enhanced keep-alive packet processing capability.

11. A computer-implemented method of managing a communications connection, comprising:

establishing an IP connection between an external network and a wireless device of an internal network via a network boundary device;

receiving a keep-alive packet from the external network into the network boundary component;

resetting a connection timer when the keep-alive packet is received; and

maintaining the IP connection between the external network and the wireless device via the network boundary component based on receipt of the keep-alive packet only from the external network.

12. The method of claim 11, further comprising receiving a response from the wireless device when the keep-alive packet is not received at the wireless device.

13. The method of claim 11, further comprising computing a time-to-live (TTL) value based on transit time of the keep-alive packet to the network boundary device and setting the TTL value in the keep-alive packet for dropping the packet.

14. The method of claim 11, further comprising configuring the keep-alive packet to include an nTTL value which when processed by the network boundary component terminates the keep-alive packet at the boundary component such that the wireless device does not receive the keep-alive packet.

15. The method of claim 11, further comprising interrogating the network boundary component, which is a NAT router, to determine if the router can handle enhanced keep-alive packet processing that drops the keep-alive packet before reaching the wireless client.

16. The method of claim 11, further comprising monitoring the IP connection of the network boundary component based on utilization of an enhanced keep-alive packet processing mode, and automatically changing to a standard keep-alive packet processing mode based on reduced quality in connection state.

17. The method of claim 11, further comprising managing multiple connections of the boundary component concurrently by receiving keep-alive packets from the external network to maintain state of corresponding connections.

18. A system, comprising:

means for establishing an IP connection between a public network and a mobile client of a private network;

means for sending keep-alive packets to the means for establishing the IP connection;

means for resetting a connection timer when the keep-alive packet is received; and

means for maintaining the IP connection between the external network and the mobile client via the means for establishing the IP connection based on receipt of the keep-alive packet only from the means for sending keep-alive packets.

19. The system of claim 18, further comprising means for configuring the keep-alive packets to terminate before reaching the mobile client.

20. The system of claim 18, wherein the mobile client sends a negative acknowledgment when a keep-alive packet is not received.