# Patent

## Title
Customer premise equipment device-specific access-limiting for a cable modem and a customer premise equipment device

## Abstract

A method of initializing, provisioning, and managing a cable modem and a customer premise equipment device includes, prior to receiving the configuration file for the cable modem, providing an equipment identification message containing a description of the customer premise equipment device connected to the cable modem. In the case where the cable modem has yet to be provisioned, the configuration file received from the network server is a particular access-limiting configuration file that is selected from a group of access-limiting configuration files. The selection of the particular access-limiting configuration file is based on the description of the customer premise equipment device in the equipment identification message. This allows different devices to have different network restrictions or different walled gardens.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional application Ser. No. 60/739,472, filed on Nov. 23, 2005, which is hereby incorporated by reference. This application claims the benefit of U.S. provisional application Ser. No. 60/791,803, filed on Apr. 13, 2006, which is hereby incorporated by reference.


BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method of initializing, provisioning, and managing a cable modem and a customer premise equipment device. The invention further relates to cable modem configuration files, including the use of an access-limiting configuration file in a case where the cable modem has yet to be provisioned. The access-limiting configuration file restricts network access from the cable modem until the cable modem is provisioned.
2. Background Art
The modern hybrid fiber coax (HFC) network in its typical implementation includes fiber from the head end to the local network fiber node, and includes coax cable for the final signal distribution through a neighborhood. Modern two-way HFC infrastructures are capable of sending gigabytes of data per second to small pockets of homes in a narrowcast way.
Product and service offerings over broadband networks, including cable networks, have expanded in recent years. The cable networks are now used for additional products and services, for example, many cable networks now offer high speed data service in addition to video programming. In the modern HFC network, head end infrastructure may include a cable modem termination system (CMTS) for providing data over cable services in addition to video quadrature amplitude modulation (QAM) infrastructure for providing video content. The video QAMs may connect to various content sources, while the CMTS connects subscribers to the provider network. The provider network may include a variety of infrastructure for providing various services. For example, the provider network may include Domain Name System (DNS) servers, dynamic host configuration protocol (DHCP) servers, voice over Internet protocol (VOIP) gateways and soft switches for connecting to phone networks, among other systems for providing services to subscribers. Further, advances in network technology allow some functionality to be provided from locations upstream or downstream of the traditional head end.
At a subscriber location, a cable modem and a customer premise equipment device such as a set-top box communicate with the head end over the HFC network. Traditionally, the cable modem utilizes known initializing and provisioning techniques to obtain a network address and establish a connection to the provider network. For example, the data-over-cable service interface specifications (DOCSIS) specify various protocols for managing the connection of a cable modem to a CMTS. In a traditional application, the cable modem can obtain an IP address in an known manner, and customer premise equipment connected to the HFC network through the cable modem may obtain an IP address, for example, by utilizing DHCP.
In an existing method of initializing a cable modem, the cable modem connection to the CMTS is initialized, the cable modem is provided with a network address, and the cable modem receives a cable modem configuration file from a network server. The configuration file contains service provisioning information. In order to configure services, the cable modem passes certain contents of the configuration file to the CMTS, and the CMTS passes certain identifiers back to the cable modem.
Typically, a service provider restricts or limits access to the network by a cable modem until the service provider validates the cable modem through a provisioning process. In one approach, the service provider maintains a list of hardware addresses for validated cable modems. When a cable modem attempts to initialize, if the hardware address is in the list of valid cable modem hardware addresses, the cable modem is allowed normal access to network resources. In the case where a cable modem has yet to be provisioned, a restricted environment may be provided for the cable modem.
One approach to providing this restricted environment, referred to as a walled garden, involves a single, special configuration file provided in all cases where the cable modem has yet to be provisioned. This special configuration file restricts network access from the cable modem. After the cable modem is provisioned, the cable modem would then receive a regular configuration file as opposed to the special configuration file that keeps the cable modem within the walled garden. Although existing methods of initializing cable modems can limit network access for cable modems that have not been validated, a more comprehensive approach is needed as additional products and services are added in a modern HFC network.
For the foregoing reasons, there is a need for a method of initializing, provisioning, and managing a cable modem and a customer premise equipment device in which, in a case where the cable modem has yet to be provisioned, there is greater flexibility in providing restricted access.
SUMMARY OF THE INVENTION
In accordance with the invention, a method of initializing, provisioning, and managing a cable modem and a customer premise equipment device is provided. The customer premise equipment device is connected to the cable modem. The cable modem is connected to a cable modem termination system (CMTS). The CMTS is connected to a provider network.
The method includes initializing the cable modem connection to the CMTS, providing the cable modem with a network address, and the cable modem receiving a cable modem configuration file from a network server. The configuration file contains service provisioning information. The cable modem passes certain contents of the configuration file to the CMTS, and the CMTS passes certain identifiers back to the cable modem. These initial steps for initializing and provisioning the cable modem may take place in any suitable way.
In a case where the cable modem has yet to be provisioned, the configuration file is an access-limiting configuration file. The access-limiting configuration file restricts network access from the cable modem until the cable modem is provisioned. In accordance with the invention, prior to receiving the configuration file, the cable modem provides an equipment identification message. The equipment identification message contains a description of the customer premise equipment device connected to the cable modem. For example, when the customer premise equipment device is a network addressable set-top box, the equipment identification message describes the customer premise equipment device as the network addressable set-top box.
In accordance with the invention, the configuration file received from the network server, in the case where the cable modem has yet to be provisioned, is a particular access-limiting configuration file that is selected from a group of access-limiting configuration files. The selection of the particular access-limiting configuration file from the group is based on the description of the customer premise equipment device in the equipment identification message.
According to the invention, different customer premise equipment devices have corresponding different access-limiting configuration files for use when provisioning has not yet occurred. For example, a subscriber gateway including an embedded set-top box and an embedded cable modem may receive a specific access-limiting configuration file when the cable modem has yet to be provisioned. On the other hand, some other customer premise equipment device may receive a different access-limiting configuration file when its cable modem has yet to be provisioned. In this way, different devices receive corresponding different restrictions to network resources when they are in the unprovisioned state. Put another way, different devices find themselves in different walled gardens.
It is appreciated that the equipment identification message may take any suitable form. As well, any suitable approach may be used to assure that the appropriate configuration file is received from the network server. For example, a trivial file transfer protocol (TFTP) server may serve the configuration files. Earlier in the initialization process, the cable modem is provided with the location of the server and appropriate configuration file to fetch. This appropriate configuration file is determined based on the equipment identification message provided by the cable modem during cable modem initialization.
At the more detailed level, the invention comprehends additional features. In one aspect, the access-limiting configuration file restricts access from the cable modem and directs any network content requests to a provisioning server. In various embodiments of the invention, various approaches may be taken to restrict network access, depending on the application. For example, when the network is an Internet protocol (IP) network including Domain Name System (DNS) servers, IP filtering and/or address resolution manipulation may be used to restrict access to the network, that is, to keep the device within its walled garden. For example, IP filtering may assure that only certain resources may be reached. For example, network address resolution manipulation may redirect all network content requests to the provisioning server.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a network diagram in accordance with a preferred embodiment of the invention; and
FIG. 2 illustrates initializing, provisioning, and managing a cable modem and a customer premise equipment device in the preferred embodiment of the invention.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1, the hybrid fiber coax (HFC) network 10 provides service to a plurality of subscribers. Each subscriber has a subscriber gateway 12. The subscriber gateway 12 is in the form of a next-generation set-top box and includes an embedded cable modem 14 and an embedded set-top box 16. The head end equipment includes cable modem termination system (CMTS) 20 and a plurality of video quadrature amplitude modulation (QAM) systems 22. Connector 18 illustrates the distribution of content from video QAMs 22 and data over cable from CMTS 20 over HFC network 10. In general, the HFC forward path spectrum includes a plurality of channels. Video QAMs 22 provide programming on the channels. Some channels are reserved for data over cable connections provided by CMTS 20. Video QAMs 22 receive content from any number of sources such as content sources 24.
It is appreciated that the architecture for the head end may vary. In FIG. 1, CMTS 20 connects to the provider Internet protocol (IP) network 30. Various services are provided to the subscribers; IP network 30 includes the appropriate infrastructure for the needed services. As shown, the network may include Domain Name System (DNS) server 32, dynamic host configuration protocol (DHCP) server 34, and voice over Internet protocol (VOIP) gateway 36 and soft switch 38 for connecting to a telephone network 40. The various servers may be located at the head end, or may be located at other locations connected to the provider network 30. Also, illustrated is trivial file transfer protocol (TFTP) server 64 which serves the configuration files.
With reference to FIGS. 1 and 2, a preferred embodiment of initializing, provisioning, and managing a cable modem and a customer premise equipment device is illustrated. The customer premise equipment device is depicted as an embedded set-top box 16, but may take other forms.
At block 50, the cable modem connection to the CMTS 20 is initialized. At block 52, the cable modem 14 advertises the description of the customer premise equipment device 16. This is the providing of the equipment identification message in the preferred embodiment. At block 54, the cable modem 14 is provided with a network address. In more detail, the cable modem 14 is initialized and provisioned using a suitable technique such as known DOCSIS techniques. At block 56, the cable modem 14 receives the cable modem configuration file, for example, from trivial file transfer protocol (TFTP) server 64. Specifically, in the case where the cable modem 14 has yet to be provisioned, a particular access-limiting configuration file that is selected from a group of access-limiting configuration files is received. The selection of the particular access-limiting configuration file from the group is based on the description of the customer premise equipment 16 in the equipment identification message. In this way, different devices may have different restrictions. Put another way, different devices have different walled gardens 66.
For example, one possible implementation is that each kind of CPE device has its own particular access-limiting configuration file that is used when the CPE device's cable modem is not yet provisioned to provide its own particular walled garden. In a straight forward implementation, each device's walled garden 66 contains only network resources related to device provisioning (possibly including self-provisioning). Further, in this example, a set-top box would be in a walled garden designed specifically for set-top boxes, while some other device would be in a walled garden designed specifically for that device. For example, a walled garden for STBs could contain access to certain video servers while some other device has a walled garden that does not include such access. Embodiments of the invention are about device-specific walled gardens implemented via device-specific configuration files that are selected based on an equipment identification message that advertises a description of a connected CPE device.
After the cable modem 14 receives the cable modem configuration file, services are configured. In the case where the cable modem 14 has yet to be provisioned, services, if any, are configured at block 58. At this point, the cable modem 14 has completed initialization, and is a manageable network element in the operator's IP network.
Generally, the initializing and provisioning may take place according to DOCSIS standards or any other suitable approach involving a downloaded configuration file; however, in accordance with the invention, the configuration file sent to the cable modem includes service provisioning information and further, in the case where the cable modem has yet to be provisioned, the configuration file is a particular access-limiting configuration file that is selected from a group of access-limiting configuration files. Put another way, different devices have different walled gardens or different network restrictions. This approach has many advantages. The equipment identification message may be provided in any appropriate way such that the cable modem can be notified of the appropriate configuration file to download from the network server. For example, the cable modem may advertise the description of the CPE device, that is, provide an equipment identification message, during a suitable dynamic configuration technique. A dynamic configuration response may include the name and location of the needed access-limiting configuration file.
It is appreciated that embodiments of the invention may involve any suitable underlying initializing and provisioning technique with different devices being provided with different access-limiting configuration files, that is, different devices having different walled gardens. Further, the cable modem and CMTS may take a variety of forms and the type of cable plant is not limited to coax cable or HFC arrangements.
While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.

## Claims

1. A modem configuration method comprising:
receiving, at a modem termination server, a request for access from an unprovisioned modem; and
prior to the modem termination server fully provisioning the modem, the modem termination server partially provisioning the modem to grant different levels of temporary access to the server for different types of customer premise equipment serviced by the modem, wherein
a first level of temporary access allows a first type of customer premise equipment to use the modem to temporarily access a resource offered by the modem termination server while the modem is awaiting full provisioning, and
a second level of temporary access does not allow a second type of customer premise equipment to use the modem to access that resource offered by the modem termination server while the modem is awaiting full provisioning.

2. The method of claim 1 wherein the first type of customer premise equipment is a network addressable set-top box.

3. The method of claim 1, further comprising directing requests from the second type of customer premise equipment to use the modem to access the resource offered by the modem termination server while the modem is awaiting full provisioning to a provisioning server.

4. The method of claim 1, wherein not allowing the second type of customer premise equipment to use the modem to access the resource offered by the modem termination server while the modem is awaiting full provisioning includes restricting access from the modem using network address filtering.

5. The method of claim 1, wherein not allowing the second type of customer premise equipment to use the modem to access the resource offered by the modem termination server while the modem is awaiting full provisioning includes restricting access from the modem using network address resolution manipulation.

6. The method of claim 1 wherein the modem termination server is part of an Internet Protocol network.

7. The method of claim 1, further comprising:
prior to being fully provisioned, the modem receiving from the modem termination server a location of a configuration file, wherein the configuration file partially provisions the modem to grant different levels of temporary access to the server for different types of customer premise equipment serviced by the modem; and
the modem downloading the configuration file from the location.

8. The method of claim 1, further comprising:
downloading, from a modem termination server to a plurality of different unprovisioned modems, different configuration files, granting different levels of temporary access to the server, to the plurality of different unprovisioned modems based on types of customer premise equipment identified to the modem termination server by the different unprovisioned modems.

9. The method of claim 1, further comprising:
downloading different configuration files to implement different device-specific walled gardens for different customer premise equipment devices serviced by modems in an unprovisioned state.

10. The method of claim 2 wherein the set-top box and the modem are both embedded in a subscriber gateway.