# Patent

## Title
Method to block unauthorized network traffic in a cable data network

## Abstract

The present invention teaches methods and systems for subscriber blocking of unauthorized network traffic in a cable data network. The cable modem termination system (CMTS) incorporates a data gateway agent that filters unauthorized traffic thereby eliminating consumption based subscribers from being responsible for related service charges. Embodiments incorporate the use of packet filtering, hybrid stateful packet filtering, content filtering, application layer filtering and time based filtering. Greater acceptance of consumption based billing is achieved by having the filter settings directed by the subscriber.

## Background
FIELD OF THE INVENTION
The present invention relates to methods of enhancing cable Internet subscriber satisfaction by enforcing subscriber filtering requests at the cable modem termination system in a consumption based billing environment.
BACKGROUND OF THE INVENTION
The Internet, also termed the “information superhighway”, has revolutionized how data and information can be accessed. Presently, “online” information sources mirror most of the information available from traditional sources such as newspapers, reference books, databases and other public information sources. Users are also able to subscribe to private information sources, order goods and services and download information content and receive radio and television transmissions. Communications between users is also available and includes “chat” rooms, semi-private virtual area networks, telephone service (termed voice over Internet protocol or VoIP) and online competitive video gaming.
As uses of the Internet increase, users seek faster connection speeds and greater bandwidth. Cable data networks are becoming a preferred solution in providing high data transfer rates to users at attractive pricing. At increased bandwidth, user enjoyment is enhanced with shorter wait and download times.
Internet use typically involves accessing remote Internet servers for purposes of downloading information or digital files as well as uploading files and messages. Access is accomplished by connecting a subscriber terminal or terminal means to a cable data network that is in turn connected to the Internet. Terminal means include traditional terminals, personal computers (PC) and game console devices equipped with network connectivity.
Additional devices are used between the terminal means and the cable data network. Such devices include local networking electronic devices as well as electronic devices that connect a local network or terminal means to an external network such as a cable data network. Examples of local networking devices include network hubs, network switches, network bridges, network interface cards, and the like. Cable modems connect terminal means or a local network to the cable data network. They may incorporate other functions such as firewall, VoIP access, and network hubs.
As used herein, Customer Premises Equipment (CPE) includes terminal means (such as terminals, personal computer or game consoles), local networking devices and electronic devices to connect a local network to an external network such as a carrier network (i.e. cable modem).
As used herein a “cable network” is a Data-Over-Cable (DOC) Network, which includes a network constructed from coaxial cable as well as a hybrid fiber coaxial (HFC) network constructed with both fiber optical cabling and coaxial cable. Network carriers and their equipment providers have adopted industry standards in order to increase interchangeability and reduce manufacturing costs for network hardware. For example, DOC Carriers have adopted industry standards such as the Data Over Cable Service Interface Specification (DOCSIS). DOCSIS version 1.0 was issued in 1997 with hardware devices being certified starting in 1999. DOCSIS version 1.1 replaced version 1.0 in 1999-2001 and now accounts for the bulk of installed DOC network equipment.
FIG. 1 illustrates an example of such a typical DOCSIS-compliant network. Data packets are transmitted in a downstream direction from a cable modem termination system (CMTS) 21, which is located in headend 31 (or distribution hub) of a Carrier, over a coaxial cable 22 to respective cable modems (CMs) 14 of subscriber local networks. CMs may attach a single terminal means to the DOCSIS-compliant network or may further comprise electronics that function as a network hub (e.g. Ethernet hub) or router function. Cable modems may incorporate “firewall” software that is used to block undesirable accesses to the attached local network.
All of CMs 14 are attached by the coaxial cable 22 to the CMTS 21 in an inverted tree configuration, and each CM 14 connected to the coaxial cable 22 listens to all broadcasts from the CMTS 21 transmitted through the coaxial cable 22 for data packets addressed to it, and ignores all other data packets addressed to other CMs 14.
Theoretically, a CM 14 is capable of receiving data in the downstream direction over a 6 MHz channel with a maximum connection speed of 30-40 Mbps. Data packets also are transmitted in the upstream direction over a 2 MHz channel by the CMs 14 to the CMTS 21 typically using time division multiplexing (TDM) and at a maximum connection speed of 1.5-10 Mbps (up to 30 Mbps when DOCSIS version 2.0 is available)
The headend 31 in the DOCSIS Network includes a plurality of CMTSs, with each CMTS supporting multiple groups of CMs each connected together by a respective coaxial cable. Each such group of CMs connected to a CMTS defines a Shared Access Carrier Network, with the coaxial cable in each representing the shared communications medium.
Data transmission over a DOCSIS network can be thought of as a downstream data path and an upstream data path. Downstream paths normally refer to transmission from a web server to a terminal means, for example a terminal 11 or personal computer 12. Upstream data transmission is the opposite with data originating in terminal 11 or personal computer 12.
For purposes of this invention, customer premises equipment 20 includes the cable modems 14, terminals 11, personal computers 12 and related interconnections, power sources, etc.
FIG. 2 illustrates a cable network for a single cable modem hub 19. Such configurations have become particularly popular recently and include both wired and wireless (short distance FM) connections to terminal means. Characteristics of a DOCSIS compatible network include two-way transmission, a maximum 100-mile distance between the farthest cable modem and the cable modem termination system, and the coexistence with other services on the cable network.
Users of cable networks subscribe with the DOC carrier and select from various pricing arrangements for use of the network. For example, users may agree to a flat fee per month, flat fee per month by quality of service or maximum bandwidth provided, a charge for the amount of data transferred, a combination of data transfer charge and flat fee, etc. Although each pricing method has advantages and disadvantages, the data transfer charges are often preferred as more closely assessing costs of high data transfer to the consuming user. As a result, low data users can enjoy high speed Internet access without being penalized or subsidizing use by high data users. As used herein, “subscriber” refers to a user that has entered into a contractual relationship with a DOC carrier.
As used herein “consumption based billing” refers to DOC carriers applying data transfer charges to the account of cable network users. When implementing consumption based billing, the DOC carrier makes use of data transfer counters present in the CMTS. One or two counters are used for each cable modem attached to a particular CMTS. All data traffic through the CMTS to or from a particular cable modem is counted and charged to the user assigned that cable modem.
DOC carriers prefer consumption based billing as a method of avoiding placing data traffic limits on all subscribers. Instead of restricting high data subscribers (often after the fact), each subscriber is responsible to restrict their amount of data transfer or pay a higher invoice. The DOC carrier thus avoids having to monitor and police high data subscribers. Further, subscribers obtaining higher data throughput by modifying their cable modem or bypassing initialization settings are charged for the higher use even when the DOC carrier is not notified of the changes. With consumption based billing, subscribers are thus provided with an economic incentive to restrict the amount of data transfer.
Subscribers choosing to restrict the amount and type of data transfer to or from the Internet implement various filtering and blocking software algorithms (collectively “subscriber filtering”). These software algorithms include software operating in the CPE devices. For example, the cable modem hub may incorporate firewall software. Other software may run on terminal means and include computer-based firewalls, virus detection software, Spam blocking, restrictions to various “adult” Internet data, and the like.
Another example of subscriber filtering is software in the category of “stateful packet” filtering. U.S. Pat. No. 6,141,749 to Coss et al. describes the use of stateful packet filtering in computer firewalls. In general stateful packet filtering attempts to allow subscriber initiated Internet access while blocking non-subscriber initiated access, for example those from individuals attempting unauthorized access to CPE devices and data (i.e. hackers).
One impediment to subscriber acceptance of consumption based billing is that subscriber filtering occurs at the CPE location. Before subscriber filtering can block an undesired data transfer packet, it must first receive the data at a filtering location under subscriber control. With existing subscriber filtering this occurs in the firewall of the cable modem hub or in the terminal or computer means.
However, the subscriber is billed for all data transfer between the cable modem termination system (CMTS) and the cable modem hub, including data that is blocked or filtered by the subscriber. As a result subscribers are charged for data transfers that are unwanted and further beyond subscriber control. Hackers can target subscribers of a particular DOC carrier and create discontent by inflating consumption charges. While subscribers are normally receptive to consumption based billing, they are not receptive to paying for undesired or unwanted data traffic they are unable to prevent.
Thus it is desirable that a system and method be provided by DOC carriers that eliminate subscribers being charged for undesired or unwanted data traffic in a consumption based billing environment. As is demonstrated below, applicants have developed such a system and method that has additional benefits of reducing cable network load factors.
BRIEF SUMMARY OF THE INVENTION
The invention is an application and method designed to reduce or eliminate unauthorized network traffic in a cable data network with consumption based billing. The cable modem termination system (CMTS) filters and blocks data traffic not authorized by subscribers thereby eliminating consumption based charges associated with unwanted network traffic or network intrusions. The consumption based subscriber authorization settings and policies are enforced by a CMTS data gateway agent.
Market acceptance of consumption based billing is enhanced as subscribers are charged only for data traffic conforming to their settings. Separate methods are incorporated to provide static and dynamic editing of subscriber data filter settings.
Various embodiments of the invention incorporate differing methods to block or allow network traffic and include packet filtering, hybrid stateful packet filtering, content screening algorithms, application layer data filtering and time based filtering. The methods of the present invention further incorporate subscriber directed filtering of PacketCableTM data packets. Preferred methods and embodiments are compatible with DOCSIS specifications versions 1.0, 1.1 and 2.0.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a typical network as known in the art and using cable network connectivity;
FIG. 2 is a simplified schematic illustrating a combined cable modem/hub;
FIG. 3A illustrates a flow diagram of determining amount of data transfer for a subscriber using cable modem termination system counters;
FIG. 3B illustrates a flow diagram of determining amount of data transfer for a subscriber using cable modem counters;
FIG. 4 illustrates the Open Systems Interconnection Reference Model;
FIG. 5 illustrates the Department of Defense communications network model (also known as TCP/IP model);
FIG. 6 illustrates a flow diagram of a subscriber entering data transfer settings in a consumption based billing environment;
FIG. 7A illustrates a flow diagram of a subscriber changing data transfer settings in a consumption based billing environment in response to a rule violation message;
FIG. 7B illustrates a flow diagram of automatic changing data transfer settings in a consumption based billing environment in response to a rule violation message and subsequent to subscriber authorization;
FIG. 8A illustrates a flow diagram of a subscriber dynamically changing data transfer settings in a consumption based billing environment after receiving unwanted data;
FIG. 8B illustrates a flow diagram of automatic changing data transfer settings in a consumption based billing environment when subscriber dynamically requests change after receiving unwanted data;
FIG. 9 illustrates one embodiment of a Data Transfer Settings entry screen;
FIG. 10 illustrates one embodiment of a URL Filtering Categories selection entry screen;
FIG. 11 illustrates one embodiment of a URL Filtering Algorithm selection entry screen; and
FIG. 12 illustrates one embodiment of a Time Control Filtering selection entry screen.



DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to methods of enhancing cable Internet subscriber satisfaction by enforcing subscriber data transfer filtering requests at the DOC carrier headend in a consumption based billing environment. The DOC carrier provides a cable modem termination system gateway agent (CMTS gateway agent) that controls data transfers through a cable modem termination system based upon subscriber authorization selections. In preferred embodiments, the subscriber authorization selections are transmitted to the CMTS gateway agent in an encrypted or secure transmission packet.
DOC carriers may offer data over cable services on a “consumption based billing” basis. Subscribers to such services are charged or surcharged for the amount of data transfer between subscriber cable modem (or cable modem hub) and the DOC carrier cable modem termination system (CMTS). As used herein, “consumption based billing” refers to charging subscribers by any of the following methods: 1) calculating charge by applying a rate structure against total data transfer; 2) calculating charge as a basic service connection fee plus a surcharge calculated by applying a rate structure against total data transfer; 3) calculating charge as a basic service connection fee that includes a built-in allowance for data transfer plus a surcharge calculated by applying a rate structure against total data transfer exceeding the allowance; 4) calculating charge as a basic service connection fee for each terminal means connected plus a surcharge calculated by applying a rate structure against total data transfer; 5) calculating charge as a basic service connection fee for each terminal means connected that includes a built-in allowance for data transfer plus a surcharge calculated by applying a rate structure against total data transfer exceeding the allowance; or combinations of the above.
Rate structures may be a flat fee per bytes of data transfer or a varying rate structure. For example, a varying rate structure can depend upon the number of bytes of data transfer, or vary by type of data service flow (e.g. upstream data charged differently than downstream data, or data with certain transport characteristics such as low latency). When using a varying rate structure, a DOC carrier may use an equation to calculate the rate or a look-up table. Rate structures may further vary by contractual discounts negotiated, or type of service account (e.g. residential, business, base service, premium service, Voice over Internet Protocol (VoIP) enabled, etc.).
When implementing consumption based billing, the DOC carrier makes use of data transfer counters present in the CMTS. FIG. 3A illustrates how a DOC carrier may use such counters. The DOC carrier requests the subscriber's cable modem address 301 and retrieves the address from a data table 302. Normally the modem address is the modem's media access control (MAC) address. The CMTS maintains current data transfer counts for each connected cable modem. The current values associated with the cable modem are accessed 303 and archived as Current end-of-billing cycle values 304. In preparation for subscriber billing, prior end-of-billing cycle values are recalled 305 and the period data transfer consumption determined by difference 306, with the result forwarded to subscriber billing system 307.
Included in the method of FIG. 3A is the use of running counters in the CMTS. Other variations are possible, depending upon the desires of the DOC carrier. For example, instead of relying upon running counters, the counters could be reset after the current values are archived 304. The advantage of resetting counters is that billing periodic-to-date counter values are directly accessed, without the need for the difference step 306. The CMTS may also be utilized to provide running counters along with reset-able counters.
Other examples utilize data transfer counters resident in the cable modem. FIG. 3B. The example of FIG. 3B starts with requests for the subscriber's cable modem address 311 and retrieval of the address from a data table 312. A simple network management protocol (SNMP) command such as “show cable modem counters” is then transmitted to the appropriate cable modem 314. Optionally, the prior values of the cable modem counters can be archived 313 prior to transmitting the command. Archives are useful for data recovery in the event a failure occurs during the counter retrieval process.
Having received the SNMP command (e.g. show counters) 314, the subscriber's cable modem responds with current values of data transfer counters 315. Counters include total number of packets and bytes for both upload and download data transfers (i.e. four counters). The values are received by the CMTS and stored for subscriber billing 316. The counters may be reset to zero using a clear cable modem counters command 317. The counter retrieval process for the particular subscriber ends 318 and the process is then repeated for additional subscribers. As an alternate, the counters are not reset and current billing cycle data consumption is determined by difference.
Although FIG. 3B uses SNMP commands, “show cable modem counters” and “clear cable modem counters”, other SNMP commands may be used. For example, the command “show cable modem verbose” will return counter values along with other cable modem parameters. Similarly, other commands may be used to reset cable modem counters. The use of CMTS commands will often permit identifying a cable modem by its MAC address or its current assigned Internet Protocol address.
CBB subscriber data transfer filtering occurs according to the data transfer settings stored for in the data transfer gateway agent. For each attached cable modem (CM), a subscriber having administrator privilege is established. The subscriber administrator is then permitted to edit data transfer settings or accept “default” setting.
The subscriber with administrator privilege is normally the individual having spending authority over Internet expenses. In this manner, the individual responsible for CBB costs can control those costs by using more restrictive data transfer settings. When less restrictive settings are desired, the administrator is responsible for the greater data transfer as well as the higher consumption costs.
Data transfer filtering settings for some embodiments of the present invention can be grouped into: filtering rules based upon the Internet communication protocols; filter rules based upon data contents; and a few special filtering rule options. The Internet data transfers occur in the form of data packets. Each data packet is encapsulated (i.e. enclosed with a header and ending) according to the protocols of the Internet hierarchy of communication. These encapsulations provide the first group of filtering options.
The Internet relies upon various standardized network communication protocols and standards. The Open Systems Interconnection Reference Model (OSI Model) was established by the International Standards Organization and is presented in FIG. 4. The OSI Model is hierarchical, with each “layer” functionally designated. Data packet transfer begins in uppermost Applications layer 407 of a sending device. Application layer 407 passes the data packet to Presentation layer 406 where an additional header is added to the data packet. Presentation layer 407 passes the data packet down the hierarchy with each layer adding its header until Physical layer 401 receives the data packet. Packet layer 401 merges the packet onto the network physical communication medium and the data continues toward the destination.
At the destination, the packets move up the OSI Model hierarchy. Physical layer 401 at the destination retrieves the data packet (with its headers) from the communication medium and passes it to Data Link layer 402. Receiving Data Link layer 402 examines the header that was added by sending Data Link layer 402. If the header does not match the destination Data Link layer address, the data packet is discarded. If the sending Data Link layer header does match, then receiving Data Link layer 402 strips off the data link layer header and forwards the packet to receiving Network layer 403. The layer steps are then repeated as the data packet is passed up the hierarchy to reach receiving Applications layer 407. In this manner, each layer of the sending device communicates with the same layer of the receiving device (i.e. peer-layer communication).
Applications layer 407 provides a means for application programs to access the system interconnection facilities. Application layer 407 considers data traffic as either being a sending message or a receiving message and avoids any of the details related to how the message gets from the sending device to the receiving device.
Presentation layer 406 formats data so that it is properly recognized by the receiving device. Translation services are provided, for example, between a transfer syntax and a local concrete syntax.
Session layer 405 is responsible for establishing connections and releasing them upon completion. It manages three types of “dialogs” between application programs. For example the dialog may allow two-way simultaneous interaction (both programs can send and receive data concurrently); two-way alternate interaction (programs take turns sending and receiving); or one-way interaction (one program sends, with other program receiving).
Transport layer 404 builds on the services of the lower layers to ensure reliable data transfers. For example, Transport layer 404 provides flow control, acknowledgments and retransmission of data when necessary. Transport layer 404 may also control the rate at which data transfer occurs to prevent network congestion.
Network layer 403 focuses upon making routing decisions and relaying data between devices. For example, it adds the appropriate network addresses to data packets.
Data Link layer 402 is responsible for providing data transmission over a single connection from one system to another. Control mechanisms in Data Link layer 402 handle the transmission of frames over a physical circuit. This layer also controls how data is organized into “frames”. It commonly adds the media access control (MAC) address to data packets.
Physical layer 401 is responsible for the actual transmission of data across a physical circuit. It allows signals (e.g. electrical, optical, RF) to be exchanged between communicating devices.
In addition to the OSI Model for network communications, the Department of Defense Model (DoD Model) established a network communications model that is illustrated in FIG. 5. The DoD Model identifies four conceptual layers that build on Hardware layer 501. These layers are somewhat different than the OSI Model layers but can be related to OSI Model layers.
Network Interface Layer 502 of FIG. 5 is similar conceptually to OSI Model Physical layer 401 and Data Link layer 402. Similarly, Internet layer 503 approximates Network layer 403, DoD Transport layer 504 approximates OSI Model Transport layer 404 and DoD Application layer 507 approximates the combined functions of OSI Session layer 405, Presentation layer 406 and Application layer 407.
Network Interface layer 502 monitors the data transfer between a communication device and the network. It adds data packet header information relating to hardware addresses and defines protocols for the physical transmission of data. Examples of transmission protocols include Ethernet, fast Ethernet, token ring and fiber distributed data interface (FDDI). Examples of hardware addresses include cable modem media access address (MAC) and network interface card (NIC) addresses.
Internet layer 503 contains the protocols responsible for addressing and routing of data packets. Internet layer 503 includes the multiple protocols such as Internet Protocol (IP) and addressing (IP address), Address Resolution Protocol (ARP), Reverse Address Resolution Protocol (RARP), Inverse Address Resolution Protocol (InARP), Dynamic Address Resolution Protocol (DARP), Internet Protocol version 6 (IPv6) and proposed Internet Protocol version 7 (TP/IX). IP addresses vary with the version of IP, but most commonly have a network address in the form of “nnn.nnn.nnn.nnn” and a similar subnet mask.
One approach to data transfer settings in a consumption based billing environment is to make use of the distinct protocols of Internet layer 503. Such data transfer settings would be to allow or deny data depending upon which protocol is designated. For example, IP data could be allowed and RARP data blocked. However, such blocking data transfer of non-IP protocols is not always desirable. Often times, ARP and RARP are required by downstream Internet routing so that blocking such data packets could be problematic.
Instead of filtering according to types of Internet layer data, it is preferable to perform filtering based on the contents of the Internet layer. Specifically, the 32 bit source address and destination addresses of the Internet layer are used.
In a consumption based billing environment of the present invention, a cable modem termination system (CMTS) counts data transfers either destined to or sourced from a particular cable modem. CMTS will normally also restrict data transfers by requiring data packets to have an address matching one of the cable modems on a cable segment. Most models of CMTS currently in use have this type of “basic” data filtering.
In order to restrict Internet sites visited and prevent unwanted intrusions, cable CBB subscribers may utilize firewalls to filter data passing from cable modem. Firewalls may review the destination and source addresses to see if they are on a designated “allow” or “deny” list. This traditional firewall functionality is provided within the CPE boundary and within control of the CBB subscriber. In large organizations, additional firewall functions may be provided within CPE devices extended to a virtual private network (VPN).
In contrast to CPE device based firewall filtering, the present invention performs Internet address filtering at the CMTS that is under the control and operation of the DOC carrier. CBB subscribers direct the CMTS filtering of data transfers that affect their consumption billing. In addition, other filtering is controlled by the DOC carrier to protect cable network resources and prevent Internet abuses.
Returning to the network model of FIG. 5, the next higher layer is Transport layer 504. This layer shields upper-layer applications from complexities of the network. In most instances transport layer 504 will either be Transmission Control Protocol (TCP) or User Datagram Protocol (UDP). Table 1 indicates a more complete listing of transport protocols, as designated by the Internet Assigned Numbers Authority. As is apparent from Table 1, many different transport layer protocols are in use, yet all are separable according to the IP Protocol Number designator field.







TABLE 1







Transport Layer Protocols with IP designation









IP Protocol




Number
Keyword
Description












51
AH
Authentication Header for IPv6


93
AX.25
AX.25 Frames


7
CBT
CBT


8
EGP
Exterior Gateway Protocol


50
ESP
Encap Security Payload for IPv


3
GGP
Gateway-to-Gateway


47
GRE
General Routing Encapsulation


20
HMP
Host Monitoring


1
ICMP
Internet Control Message


35
IDPR
Inter-Domain Policy Routing




Protocol


38
IDPR-CMTP
IDPR Control Message Transport


45
IDRP
Inter-Domain Routing Protocol


101
IFMP
Ipsilon Flow Management




Protocol


2
IGMP
Internet Group Management


4
IP
IP in IP (encapsulation)


67
IPPC
Internet Pluribus Packet Core


44
IPv6-Frag
Fragment Header for IPv6


58
IPv6-ICMP
ICMP for IPv6


28
IRTP
Internet Reliable Transaction


80
ISO-IP
ISO Internet Protocol


55
MOBILE
IP Mobility


92
MTP
Multicast Transport Protocol


54
NARP
NBMA Address Resolution Protoc


30
NETBLT
Bulk Data Transfer Protocol


11
NVP-II
Network Voice Protocol


89
OSPFIGP
OSPFIGP


113
PGM
PGM Reliable Transport Protocol


103
PIM
Protocol Independent Multicast


123
PTP
Performance Transparency




Protocol


27
RDP
Reliable Data Protocol


46
RSVP
Reservation Protocol


132
SCTP
Stream Control Transmission




Protocol


42
SDRP
Source Demand Routing Protocol


57
SKIP
Simple Key Management for IP


5
ST
Stream


6
TCP
Transmission Control


17
UDP
User Datagram


81
VMTP
Versatile Message Transaction




Protocol


112
VRRP
Virtual Router Redundancy




Protocol









Of the transport layer protocols listed in Table 1, by far the largest amount of Internet data transfers use either TCP or UDP. Recently, Streaming Control Transmission Protocol (SCTP) is also attaining high usage. TCP protocol provides connection-oriented data transfer with acknowledgments. It uses a data packet header comprising source port, destination port, sequence number, acknowledgment number, data offset, checksum, urgent pointer, options and padding. TCP takes large blocks of data from an application and breaks them into segments. It numbers and sequences each segment sot that the destination's TCP can put the segments back into the order that the application intended. After these data segments are sent, TCP on the sending device waits for an acknowledgment and retransmits segments not acknowledged.
In contrast to TCP, user datagram protocol (UDP) provides connectionless data transfer without acknowledgment. As a result the UDP data packet header is reduced to source port, destination port, length and checksum. UDP is often preferred when the application provides its own data transmission reliability methods. For example, Network File System (NFS) uses UDP and provides its own method of ensuring reliable data transfers.
SCTP protocol transports public switched telephone network (PSTN) signaling messages over IP networks (e.g. VoIP), as well as being used for broader applications. SCTP is a reliable transport protocol operating on top of a connectionless packet network such as IP. It offers the following services to its subscribers: acknowledged error-free non-duplicated transfer of subscriber data; data fragmentation to conform to discovered path maximum transmission unit (MTU) size; sequenced delivery of subscriber messages within multiple streams; optional order-of-arrival delivery of individual subscriber messages; optional bundling of multiple subscriber messages into a single SCTP packet; and multi-homing at either or both ends of an association.
Data filtering can be implemented based upon the transport layer protocol identifier. CBB subscribers can decide to allow, deny or restrict data packets based on their transport layer protocol identifier. For example, a subscriber may determine they have no need for GRE encapsulated packets that are often indicative of peer-to-peer or Internet connections between separate private networks. Similarly, a subscriber may filter out host monitoring (HM) to eliminate unwanted host polling or filter out SCTP traffic when voice over Internet will not be used.
Above transport layer 504 in the network model is application layer 507. In general, application layer 507 is where requests for data or services are processed. Each application layer 507 protocol is assigned a software “port” number. The Internet Assigned Numbers Authority (IANA) maintains a central database of port assignments (available at www.iana.org/assignments/protocol-numbers). A total of 65,536 ports are available for application layer protocols. An extension of the ports concept is the Internet “sockets.” Under TCP/IP protocol, application layer 507 creates “sockets” consisting of the IP address, TCP or UDP designator and port number.
Port number assignments are grouped into “Well Known Ports” (0 through 1023), “Registered Ports” (1024 through 49151) and dynamic or private ports (49152 through 65535). Table 2 identifies examples of Well Known Ports and Table 3 identifies examples of Registered Ports. Normally the IANA assigns the port number as both a UDP port and as a TCP port, regardless of whether both port forms will be used. For example, ports 20, 21 (FTP) and 80 (HTTP) are normally only used as TCP ports but are also assigned as UTP ports. Similarly, ports 69 (TFTP) and 161 (SNMP) are normally only used as UDP ports but are also assigned as TCP ports.







TABLE 2







Well Known TCP/IP and UDP/IP Port Assignments










Number/



Keyword
Protocol
Description





msp
 18/tcp
Message Send Protocol


msp
 18/udp
Message Send Protocol


ftp-data
 20/tcp
File Transfer [Default Data]


ftp-data
 20/udp
File Transfer [Default Data]


ftp
 21/tcp
File Transfer [Control]


ftp
 21/udp
File Transfer [Control]


ssh
 22/tcp
SSH Remote Login Protocol


ssh
 22/udp
SSH Remote Login Protocol


telnet
 23/tcp
Telnet


telnet
 23/udp
Telnet


smtp
 25/tcp
Simple Mail Transfer


smtp
 25/udp
Simple Mail Transfer


domain
 53/tcp
Domain Name Server


domain
 53/udp
Domain Name Server


bootps
 67/tcp
Bootstrap Protocol Server


bootps
 67/udp
Bootstrap Protocol Server


bootpc
 68/tcp
Bootstrap Protocol Client


bootpc
 68/udp
Bootstrap Protocol Client


tftp
 69/tcp
Trivial File Transfer


tftp
 69/udp
Trivial File Transfer


gopher
 70/tcp
Gopher


gopher
 70/udp
Gopher


http
 80/tcp
World Wide Web HTTP


http
 80/udp
World Wide Web HTTP


xfer
 82/tcp
XFER Utility


xfer
 82/udp
XFER Utility


ctf
 84/tcp
Common Trace Facility


ctf
 84/udp
Common Trace Facility



106/tcp
Unauthorized use by insecure poppassd




protocol


rtelnet
107/tcp
Remote Telnet Service


rtelnet
107/udp
Remote Telnet Service


snagas
108/tcp
SNA Gateway Access Server


snagas
108/udp
SNA Gateway Access Server


pop2
109/tcp
Post Office Protocol - Vers. 2


pop2
109/udp
Post Office Protocol - Vers. 2


pop3
110/tcp
Post Office Protocol - Vers. 3


pop3
110/udp
Post Office Protocol - Vers. 2


audionews
114/tcp
Post Office Protocol - Vers. 3


audionews
114/udp
Audio News Multicast


sftp
115/tcp
Simple File Transfer Protocol


sftp
115/udp
Simple File Transfer Protocol


nntp
119/tcp
Network News Transfer Protocol


nntp
119/udp
Network News Transfer Protocol


imap
143/tcp
Internet Message Access Protocol


imap
143/udp
Internet Message Access Protocol


bftp
152/tcp
Background File Transfer Program


bftp
152/udp
Background File Transfer Program


sgmp
153/tcp
Simple Gateway Monitoring Protocol


sgmp
153/udp
Simple Gateway Monitoring Protocol


snmp
161/tcp
Simple Network Management Protocol


snmp
161/udp
Simple Network Management Protocol


irc
194/tcp
Internet Relay Chat Protocol


irc
194/udp
Internet Relay Chat Protocol


mftp
349/tcp
mftp


mftp
349/udp
mftp


nnsp
433/tcp
NNSP


nnsp
433/udp
NNSP


mobileip-agent
434/tcp
MobileIP-Agent


mobileip-agent
434/udp
MobileIP-Agent


conference
531/tcp
chat


conference
531/udp
chat


netnews
532/tcp
readnews


netnews
532/udp
readnews


netwall
533/tcp
netwall for emergency broadcasts


netwall
533/udp
netwall for emergency broadcasts


ftp-agent
574/tcp
FTP Software Agent System


ftp-agent
574/udp
FTP Software Agent System









Registered port numbers may be used in local networks as private port assignments. However, such use may conflict with the registered port numbers that companies and other users have registered with the Internet Corporation for Assigned Names and Numbers (ICANN). Formerly registration was done with IANA. Registered ports are used by public servers using TCP or UDP as the contact port for unknown users. Examples include Sun's NEO Object Request Broker (port numbers 1047 and 1048) and Shockwave (port number 1626). Table 3 lists many of the registered ports currently in use. Normally registered ports are associated with one of the eight bolded Table 1 transport layer protocols







TABLE 3







Registered Port Assignments










Number/



Keyword
Protocol
Description





3com-njack-1
5264/tcp
3Com Network Jack Port 1


3com-njack-1
5264/udp
3Com Network Jack Port 1


adobeserver-1
1102/tcp
ADOBE SERVER 1


adobeserver-1
1102/udp
ADOBE SERVER 1


aol
5190/tcp
America-Online


aol
5190/udp
America-Online


brcm-comm-port
3188/tcp
Broadcom Port


brcm-comm-port
3188/udp
Broadcom Port


cncp
1636/tcp
CableNet Control Protocol


cncp
1636/udp
CableNet Control Protocol


cap
1026/tcp
Calender Access Protocol


cap
1026/udp
Calender Access Protocol


cp-cluster
8116/tcp
Check Point Clustering


cp-cluster
8116/udp
Check Point Clustering


cinegrfx-lm
1743/tcp
Cinema Graphics License


cinegrfx-lm
1743/udp
Cinema Graphics License


cisco-net-mgmt
1741/tcp
Cisco-net-mgmt


cisco-net-mgmt
1741/udp
Cisco-net-mgmt


cma
1050/tcp
CORBA Management Agent


cma
1050/udp
CORBA Management Agent


dellwebadmin-1
1278/tcp
Dell Web Admin 1


dellwebadmin-1
1278/udp
Dell Web Admin 1


dccm
5679/tcp
Direct Cable Connect Manager


dccm
5679/udp
Direct Cable Connect Manager


directplay
2234/tcp
DirectPlay


directplay
2234/udp
DirectPlay


ddt
1052/tcp
Dynamic DNS Tools


ddt
1052/udp
Dynamic DNS Tools


epc
1267/tcp
eTrust Policy Compliance


epc
1267/udp
eTrust Policy Compliance


ecp
3134/tcp
Extensible Code Protocol


ecp
3134/udp
Extensible Code Protocol


femis
1776/tcp
Federal Emergency Management




Info. Sys.


femis
1776/udp
Federal Emergency Management




Info. Sys.


fpitp
1045/tcp
Fingerprint Image Transfer




Protocol


fpitp
1045/udp
Fingerprint Image Transfer




Protocol


redstorm_join
2346/tcp
Game Connection Port


redstorm_join
2346/udp
Game Connection Port


ggz
5688/tcp
GGZ Gaming Zone


ggz
5688/udp
GGZ Gaming Zone


gnunet
2086/tcp
GNUnet


gnunet
2086/udp
GNUnet


gnutella-rtr
6347/tcp
gnutella-rtr


gnutella-rtr
6347/udp
gnutella-rtr


gnutella-svc
6346/tcp
gnutella-svc


gnutella-svc
6346/udp
gnutella-svc


hp-server
5225/tcp
HP Server


hp-server
5225/udp
HP Server


http-alt
8008/tcp
HTTP Alternate


http-alt
8008/udp
HTTP Alternate


http-alt
8080/tcp
HTTP Alternate


http-alt
8080/udp
HTTP Alternate


ibm-cics
1435/tcp
IBM CICS


ibm-cics
1435/udp
IBM CICS


ibm-pps
1376/tcp
IBM Person to Person


ibm-pps
1376/udp
IBM Person to Person


ibm_wrless_lan
1461/tcp
IBM Wireless LAN


ibm_wrless_lan
1461/udp
IBM Wireless LAN


iims
4800/tcp
Icona Instant Messenging


iims
4800/udp
Icona Instant Messenging


ischat
1336/tcp
Instant Service Chat


ischat
1336/udp
Instant Service Chat


proshare-mc-1
1673/tcp
Intel Proshare Multicast


proshare-mc-1
1673/udp
Intel Proshare Multicast


kazaa
1214/tcp
KAZAA


kazaa
1214/udp
KAZAA


msgsrvr
8787/tcp
Message Server


msgsrvr
8787/udp
Message Server


messageservice
2311/tcp
Message Service


messageservice
2311/udp
Message Service


opsmgr
1270/tcp
Microsoft Operations Manager


opsmgr
1270/udp
Microsoft Operations Manager


wins
1512/tcp
Microsoft's Windows Internet




Name Service


wins
1512/udp
Microsoft's Windows Internet




Name Service


msfw-control
3847/tcp
MS Firewall Control


msfw-control
3847/udp
MS Firewall Control


mdns
5353/tcp
Multicast DNS


mdns
5353/udp
Multicast DNS


adapt-sna
1365/tcp
Network Software Associates


adapt-sna
1365/udp
Network Software Associates


ddi-tcp-1
8888/tcp
NewsEDGE server TCP 1


ddi-udp-1
8888/udp
NewsEDGE server UDP 1


nimgtw
48003/tcp 
Nimbus Gateway


nimgtw
48003/udp 
Nimbus Gateway


netware-csp
1366/tcp
Novell NetWare Comm Service


netware-csp
1366/udp
Novell NetWare Comm Service


x500ms
5757/tcp
OpenMail X.500 Directory


x500ms
5757/udp
OpenMail X.500 Directory


pdp
1675/tcp
Pacific Data Products


pdp
1675/udp
Pacific Data Products


pc-mta-addrmap
2246/tcp
PacketCable MTA Addr Map


pc-mta-addrmap
2246/udp
PacketCable MTA Addr Map


passwrd-policy
1333/tcp
Password Policy


passwrd-policy
1333/udp
Password Policy


pcanywheredata
5631/tcp
pcANYWHEREdata


pcanywheredata
5631/udp
pcANYWHEREdata


pcanywherestat
5632/tcp
pcANYWHEREstat


pcanywherestat
5632/udp
pcANYWHEREstat


pktcable-cops
2126/tcp
PktCable-COPS


pktcable-cops
2126/udp
PktCable-COPS


pptp
1723/tcp
Peer-to-peer tunneling protocol


pptp
1723/udp
Peer-to-peer tunneling protocol


radio-bc
1596/udp
radio-be


radio-sm
1596/tcp
radio-sm


swa-1
9023/tcp
Secure Web Access - 1


swa-1
9023/udp
Secure Web Access - 1


sep
2089/tcp
Security Encapsulation Protocol -




SEP


sep
2089/udp
Security Encapsulation Protocol -




SEP


shockwave2
1257/tcp
Shockwave 2


shockwave2
1257/udp
Shockwave 2


snap
4752/tcp
Simple Network Audio Protocol


snap
4752/udp
Simple Network Audio Protocol


stvp
3158/tcp
SmashTV Protocol


stvp
3158/udp
SmashTV Protocol


sun-lm
7588/tcp
Sun License Manager


sun-lm
7588/udp
Sun License Manager


tivoconnect
2190/tcp
TiVoConnect Beacon


tivoconnect
2190/udp
TiVoConnect Beacon









Data filtering can be implemented based upon application layer 507 protocol identifier. CBB subscribers can decide to allow, deny or restrict data packets according to its identifier. For example, a subscriber may determine they desire to exclude Internet data associated with Distributed Mail Service Protocol (DNSP), Internet Relay Chat Protoco (IRC), Network News Transfer Protocol (NNTP), Internet Mail Access Protocol (IMAP), Post Office Protocol (POP, POP2, POP3), Peer-to-peer tunneling protocol (PPTP), etc.
Data transfer filtering on port numbers will normally use the well known port assignments of Table 2 (in the range of 1-1023) in order to filter categories or types of data traffic. Registered port numbers may also be filtered in order to prevent accidental entry into undesired Internet sites (e.g. upstream data packets) or to prevent non-subscribers from accessing data using an internal port number (e.g. downstream data packets). For example, a home network may be using port 2099 for print routing. By filtering data packets using port 2099, the printing will be secure from external print requests.
Filtering data transfer based upon protocol identifiers and IP addresses are forms of “packet filtering”. An example of a subscriber choices using packet filtering is: 1) Allow all outgoing TCP connections; 2) Allow incoming SMTP and DNS to external mail server; and 3) Block all other traffic.
Basic packet filters make decisions about whether to forward a packet based on information found at the IP or TCP/UDP layers. However, such packet filters handle each packet individually. They do not keep track of TCP sessions. As a result, spoofed packets may go undetected. Spoof packets may, for example, come in through Internet-CMTS interface, pretending to be part of an existing session by setting the ACK flag in the TCP header. Packet filters are configured to allow or block traffic according to source and destination IP addresses, source and destination ports, and type of protocol (TCP, UDP, ICMP, and so on).
An improvement over a basic packet filter is the “stateful packet filter.” Stateful packet filtering is a method that restricts data transfers based upon the origin of the data packet. In the case of TCP packets, stateful packet filtering detects embedded state information. The first packet of a new connection has its SYN flag set and its ACK flag cleared. Such first packets are used as initiation packets. Packets not having this flag structure are subsequent packets, since they represent data that occurs later in the TCP stream.
When the CMTS receives an Initiation packet as a downstream packet, an outside user is trying to make a connection from the Internet into the CPE network. Under stateful packet filtering, normally such packets are filtered out. Data transfer is restricted by eliminating these packets that do not originate from within the CPE terminal means. For example, downstream initiation packets can be dropped and logged.
When the CMTS receives an initiation packet as an upstream packet, an inside user is trying to make a connection from the CPE network to the Internet. Assuming that the packet contents are otherwise acceptable, the CMTS will allow the connection and create a cache entry that includes connection information such as IP addresses, TCP ports, sequence numbers, etc.
Subsequent packets received by the CMTS have their packet connection information extracted and compared to the cache. A packet is only allowed to pass through if it corresponds to a valid connection (that is, if it is a response to a connection which originated on the CPE network).
Some data packets do not lend themselves to stateful packet filtering as previously described. For example, UDP and ICMP do not contain connection information. Similarly some data packets conforming to upper layers of the OSI Reference model use multiple network connections simultaneously. As used herein “hybrid stateful packet filtering” comprises stateful packet filtering with additional functionality to address these situations.
For example, hybrid stateful packet filtering may handle UDP packets in the following fashion. The filter creates an entry in a connection database when the first UDP packet is transmitted. A UDP packet from a less secure network (a response) will only be accepted if a corresponding entry is found in the connection table.
Another example uses hybrid stateful packet filtering with file transfer protocol (FTP). FTP is different than UDP in that the server a user connects to on port 21 will initiate a data connection back on port 20 when a file download is requested. If the filtering agent does not store information about the FTP control connection during initial connection, it will not allow the data connection back in (via port 20). Similar techniques are needed for many of the newer multimedia protocols such as RealAudio and NetMeeting.
Hybrid stateful packet filtering software is commercially available from companies such as SonicWall, Cisco and Check Point. Such software is under the control of a network administrator or a DOC carrier in charge of the hardware upon which the software operates. In contrast, the present invention uses hybrid stateful packet filtering under the control of the cable subscriber but operating in hardware under the control of the DOC carrier.
In addition to packet filtering, application level 407 filtering is suitable with use of the present invention. Application filters evaluate data packets for valid data at application layer 407 before allowing a connection. The CMTS gateway agent examines all data packets at the application layer and stores connection state and sequencing information. For example, security items such as subscriber password and service requests that appear in the application layer data can be validated by the CMTS gateway agent.
Another important example of application level filtering is universal resource locator (URL) filtering. A URL is the address of a file (resource) accessible on the Internet. The complete URL contains the name of the protocol required to access the resource, a domain name that identifies a specific computer on the Internet, and a hierarchical description of a file location on the computer.
URLs are used instead of IP addresses when accessing Internet data sources. For example, a popular URL is http://www.uspto.gov and designates the home page of the US Patent and Trademark Internet website. URLs are more convenient to use than an IP address such as 12.92.116.135. Further, URLS are often referenced to dynamically assigned IP addresses.
For purposes of URL filtering, normally only the domain name is needed. Due to the large number of URLs that exist, it is convenient to group URLs into categories. FIG. 10 illustrates an exemplary selection screen that allows a data cable subscriber to select URL categories to allow or block. When a URL category is blocked, data packets to or from Internet locations with domain names identified as belonging to that category are blocked.
Preferred URL filtering utilizes a URL database of domain names that are sorted by category. The URL database may be manually updated or automatically updated. Preferably the URL database is automatically updated. Automatic updates may be provided by a subscription service that tracks domain name entries by category. Such subscription services are available from N2H2, Inc. SurfControl, SurfWatch, CyberPatrol, LittleBrother, and the like.
As is seen during implementation of the present invention, using of URL databases often leads to desirable URLs being blocked, contrary to data cable subscriber wishes. In response for this need, exception lists are maintained by the DOC carrier for each subscriber account. This feature allows a category of URLs to be allowed or blocked except for URLs noted in allowance exception and disallowance exception lists.
Instead of performing URL filtering by comparing domain names to a database of categories (along with exception lists), an algorithm based content filtering may be performed. Internet documents are scanned for content that meets a particular undesirability criteria and then all data from the related URL is blocked. An example of this method is disclosed in U.S. Pat. No. 6,266,664 to Russell-Fall et al. and commercially available from RuleSpace, Inc. for implementation in subscriber controlled hardware. Preferably, exception lists are also employed with algorithm based filtering as overrides for each subscriber account.
Application level 407 filtering is useful for allowing or blocking peer-to-peer (P2P), instant messaging, and personal information data transfers. P2P networks make use of customer computing platforms to provide virtual servers. The virtual servers act as data repositories that can be easily accessed from non-local terminal means. One popular use of P2P networks is for freely shared file repositories. Popular for these repositories are sharing of music or video programs, including MP3 formatted digital music files.
P2P networks rely upon the virtual server application programs that permit and support file sharing from the external network to a local network connected computing platform. Popular virtual server application programs include KaZaa, Grokster, Morpheus, Gnucleus, BearShare, iMesh, LimeWire, eDonkey, BadBlue, WinMX, AudioGalaxy, Blubster, Filetopia, Net Brillant, Phex, Shareaza, Splooge, Swapper, Swaptor, Wippit and the like.
Many of the P2P networks further encourage users to provide file sharing by including an embedded “participation level.” For example, KaZaa users with higher participation levels receive and download files on a faster basis than users with lower participation. The application assigns user participation levels by determining the amount of megabytes of files external users have accessed. As a result, a KaZaa user sharing 10 megabytes will have a lower participation level than a user sharing 10 gigabytes. Furthermore, many P2P users while generally aware of how much data they have downloaded to their computer, they may not be aware of how many public users are connecting to their system transferring files as well.
A more limited use of P2P networks is in webcasting. Although a webcaster could broadcast messages to all receiving customers, such an arrangement would result in the webcaster absorbing all bandwidth charges. Instead the webcaster will use P2P networks, taking advantage of “free” bandwidth provided by cable network customers. Some webcasters have announced saving 60-75% of bandwidth charges by using P2P networks.
Many Internet service providers (ISPs) offer instant messenger applications that transmit messages to identified destinations within a short time period. Instant messenger applications are offered by Microsoft Network (MSN IM), Yahoo (Yahoo Messenger), Road Runner (RR Messenger), America Online (AOL IM), ICQ Messenger, Jabber Messenger and the like. Typical bandwidth usage for instant messaging is modest. However, users may have strong desire to reserve bandwidth for instant messaging on a high priority basis.
Preventing the transmission of personal information is often a high priority with cable data network subscribers. For example an application layer filter may block all data packets containing the telephone number, social security number, drivers' license, credit card number of the subscriber and subscriber's location. In the alternative, such information may be blocked for all but a subscriber with administrator login privileges.
An emerging cable data network use is PacketCableTM. The PacketCableTM initiative is sponsored by CableLabs® (a non-profit research and development consortium) and is intended for delivering real-time multimedia services over two-way cable networks. PacketCableTM networks use Internet protocol (IP) technology to enable a wide range of multimedia services, such as IP telephony (VoIP), multimedia conferencing, interactive gaming, and general multimedia applications.
By applying data transfer filters, the present invention also accommodates PacketCableTM. For example, unwanted gaming, conferencing and voice communications can be blocked or allowed on either a global (category) or specific basis.
Some preferred embodiments of the data gateway agent of the present invention provide consumption based billing subscribers additional ways to limit data transfer, and in turn, data transfer charges. The data gateway agent may incorporate data consumption triggers. Such triggers are used to automatically take action upon reaching a value of total data transfer. For example, the gateway agent may automatically block additional data traffic in order to limit consumption charges. The agent may also notify the subscriber that data traffic has reached or is approaching levels at which surcharges will begin.
Preferred embodiments of the gateway agent also allow data traffic to be limited to particular periods of time. Time based data blocking is even more preferably combined with other types of data filtering. For example, a parent may wish to restrict instant messaging and online gaming to one hour per day while allowing unlimited access to educational Internet websites.
FIG. 6 through FIG. 11 illustrate how embodiments of the present invention interact with a typical CBB subscriber. These illustrations are provided as examples only and are not to be considered limiting. Features may be combined, eliminated or added to in order to adapt to particular CBB subscriber needs. Common to all embodiments is the use of DOC carrier equipment and devices providing data transfer filtering under the direction of a CBB subscriber. By placing control for data traffic with the subscriber, much greater consumer acceptance of consumption based billing is attained.
FIG. 6 illustrates how CBB subscribers configure the data gateway agent for their respective account. CBB subscriber requests account information 601. The data gateway agent checks settings for the account number to see if all subscribers are allowed to see account settings 610. If only a subscriber must have administrator privilege to view the settings, an appropriate login screen is displayed 611. Existing consumption based billing counts are then displayed 615.
The cable modem's MAC address is compared to the one registered for the account 620 and if it does not match the session terminates 650. In a variation, the IP address of the terminal means must also match that registered as the subscriber with administrator privilege. The subscriber is next taken to login process 621 where a password or other identifying method is used to verify that the subscriber has administrator privilege over the account. After login, current account values are displayed 630 and the subscriber may request to change settings 640 or exit 650.
A number of data transfer setting menus 640 are displayed and the subscriber with administrator privilege makes changes. Upon leaving the menus, changed values are stored 645 by the data gateway agent for use in data transfer filtering.
Subscriber administrator login is illustrated in FIG. 6 in order to increase security and further limit data transfer in accordance with subscriber desires. However, subscribers may also configure their account to permit changes from any terminal means connected to the subscribers' cable modem. In this case, administrator login steps are bypassed and the flowchart instead relies upon identification of the cable modem (e.g. from the MAC address).
Preferably, the transmission of subscriber login and data transfer settings to the data transfer gateway agent uses secured data transmissions, as is known in the art. For example, subscriber selections may use 40 bit or 128 bit encryption during transmission of data settings.
FIG. 7A and FIG. 7B flowsheets illustrate how the data gateway agent responds upon detecting a data transfer rule violation 701. Comparing data packets against data transfer settings a violation is detected 701. Automatically a notification message is transmitted to the subscriber 710 and optionally logged 702. When logged, it is desirable to also log information permitting tracking of the source of the violation and other relevant diagnostic information.
Data violations are initially separated into upstream data and downstream data 715. The subscriber is asked to allow data being sent 720 or received 730. If the data is not allowed, the data packets are discarded and the notification process ends 750.
In FIG. 7A, when subscribers choose to allow the data causing a rule violation they first login with administrator privilege 740, proceed to data transfer settings menus 640, enter appropriate changes, then save and activate the new settings 645.
It has been found that subscribers may be unable to determine which data transfer setting is involved in a given rule violation. The flowsheet of FIG. 7B addresses this difficulty. Once the subscriber has requested the allowance of data causing the rule violation (720 or 730) and entered identification of administrator privilege 740, the data gateway agent then proceeds to automatically adjust the data transfer settings to permit such data 745. Changes to settings are then saved and activated 645.
The flowsheets of FIG. 7A and FIG. 7B begin with the data gateway agent detecting a rule violation 701 and allow for dynamically changing data transfer settings (640 or 745). Another situation may arise in which a subscriber either receives unwanted data (e.g. pop-up ad, Spam, data filter settings wrong, etc.) or arrives at a URL website they want to restrict access to in the future. The flowsheets of FIG. 8A and FIG. 8B accommodate such possibilities beginning with the subscriber identifying unwanted data 801.
The subscriber sends a message to the data gateway agent indicating unwanted data has been received or a particular Internet website should be blocked 805. Optionally, the message may be logged 806 and the subscriber's account credited for unwanted data transmissions 807. The type of data, either upstream or downstream is determined 810. The subscriber is invited to verify that future data transfers will be blocked from a source 830 or to a destination 840. If the subscriber does not confirm, the data transfer agent ignores the request and ends this subroutine 850.
Subscriber accounts may be configured to limit who can direct blocking of data or to allow all users to initiate blocking. If all users are allowed to block (or if only one user), then optional subscriber administrator login 840 is unnecessary. Otherwise, an administrator identification step is completed 840. For example, the subscriber administrator may be required to identify their self with password, known secret, biometric information etc.
The data gateway agent of FIG. 8A then displays data transfer setting menus 640. After entry, any setting changes are stored and activated 645. The data gateway agent of FIG. 8B does not require subscriber entry. Instead, the gateway agent determines what changes are required to block the unwanted data traffic identified in step 801; automatically enter the changes 845; and then store and activate the required changes 645.
FIG. 9 through FIG. 12 present examples of menus for data transfer settings. FIG. 9 allows the selection of data filtering selections available to a subscriber. Corresponding to each selection is an associated exception table or detail menu that may be accessed using various subscriber inputs. For example, the keyboard combination Control-D may be programmed to access details of a given selection. Another method is to use drop down menus associated to a mouse “right-click” entry.
Exception lists permit the subscriber to set a general data filter and then allow known exceptions. For example, a subscriber could block data using hybrid stateful inspection and then permit as an exception downloaded webcasts from a reference website.
Detail menus augment the general settings menu. FIG. 10 is an example of URL filtering categories. The menu of FIG. 10 can first be used to select allowed Internet URL categories when accessed from FIG. 9 selection “URL Filtering-allow by category.” FIG. 10 menu can later be used to select blocked URL categories when accessed from “URL Filtering—deny by category.” In the alternative, FIG. 10 can include a block and deny selection adjacent to each URL category.
When FIG. 9 is used to select URL filtering by algorithm category, the subscriber makes individual selections on the detail menu of FIG. 11. From FIG. 11, URL allow exception lists and URL deny exception lists are accessed.
FIG. 12 allows entries for a consumption based billing subscriber desiring to limit data transfers by time. FIG. 12 includes general selections for weekday and weekend Internet use. In addition, a number of special time periods are allowed to be defined. The data gateway agent will first determine if the current time is within a special time period and permit or deny data transfers based upon the special entry. Next the gateway agent determines if the current time is a weekday (Monday through Friday) or a weekend (Saturday or Sunday).
Additional sophistication can be added to FIG. 12. For example, selections may be added for recognizing and entering holidays that are to be treated as weekends. Also, time control settings can be combined with other data filtering options so that different protocols of data can be blocked or allowed during different time segments.
As disclosed above, the present invention gives cable network subscribers control over data transfers for which they are responsible in a consumption based billing cable network. As subscribers are only responsible for desired data transfers, subscriber acceptance of consumption based billing is enhanced. Further, subscribers save the expense of maintaining additional anti-virus or anti-Spam software agents, with attendant computational overheads. Further, as undesired data transfers are eliminated, DOC carriers benefit by reducing cable network loading.
Although the present invention has been illustrated in terms of specific embodiments, various ways of accomplishing the enumerated steps are possible in accordance with the teachings described herein. For example, the present invention may incorporate the ability to filter specific Internet addresses based upon subscriber history, DOC carrier flags or externally maintained databases of Internet addresses categorized by data content. Additionally, the claims should not be read as limited to the described order of steps unless stated to that effect. Included in the invention are all embodiments that come within the scope, spirit and equivalents thereto of the following claims:

## Claims

1. A system for providing data filtering from a cable modem termination system (CMTS) in a cable data network consisting essentially of:
the CMTS, wherein the CMTS comprises a packet counter, wherein the packet counter determines a number of packets sent to a subscriber device from the CMTS (herein, “downstream packets”) and a number of packets originating from the subscriber device and sent to the CMTS (herein, “upstream packets”), and a data gateway agent;
a datastore accessible to the data gateway agent for storing a data transfer rule selected by a subscriber, wherein the selected data transfer rule comprises filtering criteria selected by the subscriber, and
wherein the data gateway agent comprises instructions that cause the CMTS to:
receive a packet prior to receipt of the packet by the packet counter;
access the data transfer rule stored in the datastore;
use the filtering criteria to determine whether the packet violates the data transfer rule;
forward the packet to the packet counter for counting when the packet does not violate the data transfer rule; and

apply a corrective measure to the packet when the packet violates the data transfer rule.

2. The system of claim 1, wherein the filtering criteria comprise packet payload criteria and the instruction to use the filtering criteria to determine whether the packet violates the data transfer rule comprises determining whether the packet comprises the packet payload criteria.

3. The system of claim 2, wherein the packet is an upstream packet and the packet payload criteria are selected from the group consisting of subscriber personal information, a telephone number, a social security number, a driver's license number, a credit card number, and location information.

4. The system of claim 1, wherein the filtering criteria further comprise a recurring time period and wherein the instruction to use the filtering criteria to determine whether the packet violates the data transfer rule comprises determining whether the packet is received during the recurring time period and comprises the packet payload criteria.

5. The system of claim 1, wherein the filtering criteria comprise protocol type criteria and wherein the instruction to use the filtering criteria to determine whether the packet violates the data transfer rule comprises determining whether the packet that is received at the CMTS uses a particular protocol.

6. The system of claim 1, wherein the filtering criteria comprise protocol criteria and the instruction to use the filtering criteria to determine whether the packet violates the data transfer comprises determining whether the packet received at the CMTS uses a particular protocol.

7. The system of claim 1, wherein the gateway agent further comprises instructions that cause the CMTS to:
receive an upstream packet;
create an entry in a connection database, wherein the entry in the connection database comprises an upstream packet identifier that identifies the upstream packet as originating from the subscriber device; and
receive a downstream packet, wherein the filtering criteria comprises the upstream packet identifier, and wherein the instruction to use the filtering criteria to determine whether the packet violates the data transfer rule comprises determining whether the downstream packet comprises the upstream packet identifier.

8. The system of claim 1, wherein the CMTS further comprises a billing agent and wherein the billing agent is configured to receive a subscriber count trigger and to transmit a count message to the subscriber comprising a current packet count upon the receipt of the subscriber count trigger.

9. The system of claim 8, wherein the subscriber count trigger is selected from the group consisting of an end of billing cycle, a receipt of a subscriber count request message, a subscriber count exceeding a subscriber selected trigger amount, and a subscriber count exceeding data over a cable carrier selected trigger amount.

10. The system of claim 8 wherein the billing agent is further configured to automatically transmit an electronic message identifying current subscriber data transfer counts to the subscriber upon the occurrence of the subscriber count trigger.

11. The system of claim 2, wherein the cable network is a hybrid fiber coaxial cable network.

12. A method for providing data filtering from a cable modem termination system (CMTS) in a cable data network, wherein the CMTS comprises a packet counter, wherein the packet counter determines a number of packets sent to a subscriber device from the CMTS (herein, “downstream packets”) and a number of packets originating from the subscriber device and sent to the CMTS (herein, “upstream packets”), and a data gateway agent, the method consisting essentially of:
receiving a packet prior to receipt of the packet by the packet counter;
accessing a data transfer rule selected by a subscriber stored in a datastore accessible to the data gateway agent, wherein the selected data transfer rule comprises filtering criteria selected by the subscriber, and
using the filtering criteria to determine whether the packet violates the data transfer rule;
forwarding the packet to the packet counter for counting when the packet does not violate the data transfer rule; and
applying a corrective measure to the packet violates the data transfer rule.

13. The method of claim 12, wherein the filtering criteria comprise payload criteria and wherein using the filtering criteria to determine whether the packet violates the data transfer rule comprises using the filtering criteria to determine whether the packet comprises the packet payload criteria.

14. The method of claim 13, wherein the packet is an upstream packet and the payload criteria are selected from the group consisting of subscriber personal information, a telephone number, a social security number, a driver's license number, a credit card number, and location information.

15. The method of claim 12, wherein the filtering criteria further comprise a recurring time period and wherein using the filtering criteria to determine whether the packet violates the data transfer rule comprises using the filtering criteria to determine whether the packet is received during the recurring time period and comprises the packet payload criteria.

16. The method of claim 12, wherein the filtering criteria comprise packet protocol criteria and wherein using the filtering criteria to determine whether the packet violates the data transfer rule comprises using the filtering criteria to determine whether the packet that is received at the CMTS uses a particular protocol.

17. The method of claim 12, wherein the filtering criteria comprise protocol criteria and wherein using the filtering criteria to determine whether the packet violates the data transfer rule comprises using the filtering criteria to determine whether the packet received at the CMTS uses a particular protocol.

18. The method of claim 12 further comprising:
receiving an upstream packet;
creating an entry into a connection database, wherein the entry in the connection database comprises an upstream packet identifier that identifies the upstream packet as originating from the subscriber device; and
receiving a downstream packet, and
wherein the filtering criteria comprise the upstream packet identifier, and wherein using the filtering criteria to determine whether the packet violates the data transfer rule comprises using the filtering criteria to determine whether the downstream packet comprises the upstream packet identifier.

19. The method of claim 12, wherein the CMTS further comprises a billing agent and wherein the method further comprises configuring the billing agent to receive a subscriber count trigger and to transmit a count message to the subscriber comprising a current packet count upon the receipt of the subscriber count trigger.

20. The method of claim 19, wherein the subscriber count trigger is selected from the group consisting of an end of billing cycle, a receipt of a subscriber count request message, a subscriber count exceeding a subscriber selected trigger amount, and a subscriber count exceeding data over a cable carrier selected trigger amount.

21. The method of claim 19 further comprising configuring the billing agent to automatically transmit an electronic message identifying current subscriber data transfer counts to the subscriber upon the occurrence of the subscriber count trigger.

22. The method of claim 12, wherein the cable network is a hybrid fiber coaxial cable network.

23. The method of claim 12 further comprising:
sending the subscriber device a notification message when the packet violates the data transfer rule, wherein the notification message comprises a request for selection of an option from the group consisting of an option to allow the packet to be sent or received and an option to not allow the packet to be sent or received;
receiving a response from the subscriber device comprising the selected option;
discarding the packet when the selected option is to not allow the packet to be sent or received; and
forwarding the packet to the packet counter for counting when the selected option is to allow the packet to be sent or received.

24. The system of claim 1, wherein the gateway agent further comprises instructions that cause the CMTS to:
send the subscriber device a notification message when the packet violates the data transfer rule, wherein the notification message comprises a request for selection of an option from the group consisting of an option to allow the packet to be sent or received and an option to not allow the packet to be sent or received;
receive a response from the subscriber device comprising the selected option;
discard the packet when the selected option is to not allow the packet to be sent or received; and
forward the packet to the packet counter for counting when the selected option is to allow the packet to be sent or received.