Network switch employing a proxy to facilitate power savings in a telephone network

• US 9,065,685 B2
• Filed: 02/13/2009
• Issued: 06/23/2015
• Est. Priority Date: 02/13/2009
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Booth, Paul Norwood, Molenda, James Robert, Zanaty, Mohamed Kamel, Restrick, John Knight Jr.
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Moutaouakil, Mounir
• Application Number:
  US12/371,450
• Publication Number:
  US 20100208724A1
• Time in Patent Office: 2,321 Days
• US Class Current: 1/1
• CPC Class Codes: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

In an example embodiment, an IP phone is connected to a network switch that has an established communications channel to a call control server. The network switch acts as a proxy for the phone exchanging registration information that in effect keeps the phone registered while the phone itself can go to sleep as defined by periods of the day, periods where the phone is unused, or presence, which can then wake-up quickly with assistance from the switch. If the switch is not able to act as proxy, the phone can switch from sleep mode to “wake” up mode at predetermined intervals, such as every 30 seconds, in order to respond to keep alive packets from the call control server.

Claims

1. An apparatus, comprising:

a network interface having a signature resistance;

a telephone circuit coupled with the network interface;

power save logic coupled with the telephone circuit and with the network interface; and

a non-volatile memory coupled with the power save logic;

wherein the power save logic is configured to switch the telephone circuit between an active state and a power save state;

wherein the power save logic is further configured to selectively send a signal to an associated network switch coupled with the network interface indicating the telephone circuit is switching to the power save state and to store registration information in the non-volatile memory;

wherein the power save logic is configured to selectively change the signature resistance of the network interface to indicate to the associated network switch coupled with the network interface that the apparatus is switching from the active state to the power save state; and

wherein the power save logic is configured to selectively directly maintain an active network connection with an associated call control service for the apparatus when the apparatus is in the power save state and in an absence of the associated network switch acting as a proxy for maintaining the active network connection on behalf of the power save logic.

2. The apparatus as set forth in claim 1, wherein the power save logic is further configured to store an Internet Protocol (“

IP”

) address in the non-volatile memory.

3. The apparatus as set forth in claim 1, further comprising a user interface coupled to the telephone circuit and the power save logic, wherein the power save logic is further configured to switch the telephone circuit from the power save state to the active state upon detecting activity at the user interface.

4. The apparatus as set forth in claim 1, wherein the power save logic is further configured to switch the telephone circuit from the power save state to the active state responsive to receiving a signal on the network interface indicating an incoming call for the telephone circuit.

5. The apparatus as set forth in claim 1, wherein the power save logic is configured to switch the telephone circuit from the active state to the power save state responsive to one of a group consisting of determining a current time is within a predefined time period, and determining the telephone circuit has been idle for more than a predetermined time.

6. The apparatus set forth in claim 1, wherein the power save logic is operable to communicate via the network interface at a lower data rate while in power save state than while in the active state.

7. The apparatus set forth in claim 1, wherein:

the power save logic is operable to selectively directly maintain the active network connection when the apparatus is in the power save state and in the absence of the associated network switch acting as the proxy for maintaining the active network connection on behalf of the power save logic by periodically transitioning the apparatus between the active state where the network interface actively communicates with the associated call control service, and the power save state suspending the communicating.

8. A method, comprising:

initiating, by a telephone coupled with an associated network, a transition from an active state to a power save state;

sending a signal to an associated switch coupled with the telephone, the signal indicating the telephone is transitioning to the power save state;

storing registration information in a non-volatile memory;

changing a signature resistance at a network interface to indicate the transition to the power save state;

entering the power save state;

initiating an active keep-alive session between the associated switch and an associated call control center while the telephone is in the power save state; and

selectively directly maintaining, by the telephone, the keep-alive session in an absence of the associated switch acting as a proxy for maintaining the active keep-alive session on behalf of the telephone.

9. The method according to claim 8, wherein the storing further comprises storing an Internet Protocol (“

IP”

) address for the telephone in the non-volatile memory.

10. The method according to claim 8, further comprising initiating a transition from the power save state to the active state responsive to detecting activity at a user interface.

11. The method according to claim 8, further comprising initiating a transition from the power save state to the active state responsive to detecting a signal indicating an incoming phone call.

12. The method according to claim 8, further comprising:

initiating a transition from the power save state to the active state after a predetermined time period;

responding to a keep alive packet; and

returning to the power save state.

13. The method according to claim 8, wherein initiating the transition is responsive to determining a current time is within a predefined time period.

14. The method according to claim 8, wherein initiating the transition is responsive to detecting the telephone has been idle for greater than a predefined time period.

15. The method according to claim 8, wherein initiating the transition is responsive to receiving data indicating a user for the telephone is not present.