Hosting a cable modem in a computer using a virtual bridge

• US 6,618,386 B1
• Filed: 08/10/1999
• Issued: 09/09/2003
• Est. Priority Date: 03/04/1999
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: WebTV Networks Inc. (Microsoft Corporation)
• Inventors: Liu, Jun, Parchem, John M., Shoff, Daniel J., Tjong, Soemin
• Primary Examiner(s): Jung, Min
• Application Number:
  US09/371,914
• Time in Patent Office: 1,491 Days
• Field of Search: 370/401, 370/419, 370/420, 370/421, 370/428, 370/469, 370/486, 370/487, 370/490, 370/389, 725/51, 725/109, 725/111
• US Class Current: 370/401
• CPC Class Codes: H04H 20/78 CATV [Community Antenna Television] systems
• CPC Class Codes: H04H 2201/70 characterised in that receivers can be addressed
• CPC Class Codes: H04L 12/2801 Broadband local area networks

Abstract

A computer system that hosts a cable modem is described. The cable modem may be used to send and receive messages over the Internet using a cable network managed by a cable operator. Unlike external modems, the cable modem uses the same CPU and memory that are used by the computer system'"'"'s operating system. However, the cable modem has a different network address than the computer system. When the cable modem receives a data packet having the network address of the cable modem, a cable modem driver forwards the packet to a protocol stack for the cable modem. When the cable modem receives a data packet having the network address of the computer system, the packet is forwarded to a different protocol stack for the computer system. Since the protocol stacks of the cable modem and computer system are different, direct communication from the computer system to the cable modem is not permitted.

Claims

1. A computer system that is configured to host a cable modem for receiving data packets over a cable network and to connect with customer premises equipment through a system network, the computer system comprising:

an operating system having a first network address;

a computer system protocol stack for enabling data to be communicated to and from the operating system of the computer system;

having a second network address that is different from the first network address;

a cable modem protocol stack for enabling data to be communicated to and from the cable modem;

a CPU that is utilized by both the operating system and the cable modem; and

a cable modem driver that is confined to forward data packets that are received by the cable modem from the cable network to one of the cable modem protocol stack and a bridging component based upon network addresses of the data packets and

wherein the bridging component is configured to direct any data packets that are received from the cable modem driver to one of the computer system protocol stack and the customer premises equipment based upon the network addresses of the data packets.

2. The computer system of claim 1, further comprising a memory device that is utilized by both the operating system and the cable modem.

3. The computer system of claim 1, wherein the cable modem is connected to a cable network.

4. The computer system of claim 1, wherein the cable modem is configured to receive data using a DOCSIS standard.

5. The computer system of claim 1, further including a buffer for storing the data packets received by the cable modem, and wherein forwarding the data packets includes acts of storing the data packets in the buffer and forwarding pointers corresponding to the data packets to the cable modem protocol stack and bridging component based upon network addresses of the data packets.

6. In a computer system that is configured to host a cable modem for receiving data packets over a cable network and to connect with customer premises equipment through a system network, a method for forwarding data packets received over the cable network to one of a cable modem protocol stack that enables communication to and from the cable modem, a computer system protocol stack that enables communication to and from the operating system of the computer system, and the customer premises equipment based upon network addresses assigned to the received data packets, the method comprising the acts of:

receiving, at the cable modem hosted by the computer system, a data packet having a network address corresponding to one of the cable modem, the computer system and customer premises equipment configured to connect with the computer system;

forwarding the data packet from the cable modem to a cable modem driver; and

based upon the network address of the data packet, forwarding the data packet from the cable modem driver to one of a cable modem protocol stack and a bridging component that is included in the computer system, such that the data packet is forwarded to the cable modem protocol stack only when the network address corresponds to the cable modem and such that the data packet is forwarded to the bridging component only when the network address does not correspond to the cable modem;

wherein the bridging component, upon a receipt of the data packet from the cable modem driver, is configured to forward the data packet the computer system protocol stack when the network address corresponds to the computer system and to forward the data packet to the customer premises equipment when the network address corresponds to the customer premises equipment.

7. The method of claim 6, wherein the act of forwarding the data packet from the cable modem comprises the acts of:

storing the data packet in a buffer included m the computer system; and

forwarding a pointer to the data packet from the cable modem to the bridging component.

8. The method of claim 6, wherein the act of forwarding the data packet from the cable modem to a bridging component comprises the acts of:

resolving the address at the cable modem driver so as to identify that the cable modem is not the recipient of the data packet, and

forwarding the data packet from the cable modem driver to the bridging component.

9. The method of claim 8, wherein the data packet is a first data packet, and wherein the address is a first address, the method further comprising the acts of:

receiving, at the cable modem hosted by the computer system, a second data packet having a second address corresponding to the cable modem;

resolving the second address at the cable modem driver so as to identify the cable modem as the recipient of the second data packet; and

forwarding data included in the second data packet from the cable modem driver to a cable modem protocol stack included in the computer system.

10. The method of claim 6, wherein the data packet is a first data packet, and wherein the address is a first address, the method further comprising the acts of:

receiving, at the cable modem hosted by the computer system, a second data packet having a second address corresponding to an item of customer premises equipment networked to the computer system;

forwarding the second data packet from the cable modem to the bridging component included in the computer system;

resolving the second address at the bridging component so as to identify the item of customer premises equipment as a recipient of the second data packet; and

forwarding data included in the second data packet from the bridging component to the item of customer premises equipment.

11. A computer program product for use in a computer system that is configured to host a cable modem for receiving data packets over a cable network and to connect with customer premises equipment through a system network, the computer program product comprising one or more computer-readable medium comprising computer-executable instructions for implementing a method for forwarding data packets received over the cable network to one of a cable modem protocol stack that enables communication to and from the cable modem a computer system protocol stack that enables communication to and from the operating system of the computer system, and the customer premises equipment based upon network addresses assigned to the received data packets, the method comprising the acts of:

receiving, at the cable modem hosted by the computer system, a data packet having a network address corresponding to one of the cable modem the computer system and customer premises equipment configured to connect with the computer system;

forwarding the data packet from the cable modem to a cable modem driver; and

based upon the network address of the data packet, forwarding the data packet from the cable modem driver to one of a cable modem protocol stack and a bridging component that is included in the computer system, such that the data packet is forwarded to the cable modem protocol stack only when the network address corresponds to the cable modem and such that the data racket is forwarded to the bridging component only when the network address does not correspond to the cable modem,

wherein the bridging component, upon a receipt of the data packet from the cable modem driver, is configured to forward the data packet to the computer system protocol stack when the network address corresponds to the computer system and to forward the data packet to the customer premises equipment when the network address corresponds to the customer premises equipment.

12. The computer program product as recited in claim 11, wherein the act of forwarding a data packet includes acts of:

storing the data packet in a buffer included in the computer system; and

forwarding a pointer associated with the data packet to the bridging component included in the computer system.

13. The computer program product as recited in claim 11, wherein the act of forwarding a data packet to the bridging component comprises acts of:

resolving the address at the cable modem driver included in the computer system so as to identify that the cable modem is not a recipient of the data packet; and

forwarding the data packet from the cable modem driver to the bridging component.

14. The computer program product as recited in claim 13, wherein the data packet is a first data packet, and wherein the address is a first address, the method further including acts of:

forwarding a second data packet received at the cable modem to the cable modem driver included in the computer system, the second data packet having a second address;

resolving the second address at the cable modem driver so as to identify the cable modem as the recipient of the second data packet; and

forwarding data included in the second data packet from the cable modem driver to a cable modem protocol stack included in the computer system.

15. The computer program product as recited in claim 11, wherein the data packet is a first data packet, and wherein the address is a first address, the method further including acts of:

forwarding a second data packet received at the cable modem to a bridging component included in the computer system, the second data packet having a second address;

resolving the second address at the bridging component so as to identify the item of customer premises equipment as a recipient of the second data packet; and

forwarding data included in the second data packet from the bridging component to the item of customer premises equipment.