Abstract:
A system and method for locating Open System Interconnection (OSI) Layer 3 or higher devices at strategic locations throughout the network. The Layer 3 devices may have additional capabilities, such as wireless connections or other functionality that may benefit both the consumer and network provider. Layer 2 traffic is confined to smaller areas, allowing the main backbone of the network to handle more useful data traffic and less overhead traffic.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     a. Field of the Invention  
         [0002]     The present invention pertains generally to communication networks and specifically to network architectures with distributed intelligence.  
         [0003]     b. Description of the Background  
         [0004]     Cable television and digital subscriber line (DSL) networks are becoming prevalent for delivering data services to businesses and consumer homes. When each customer adds another device on the network, such as information appliances, laptop and desktop computers, television receivers, or other Internet capable devices, the network traffic increases dramatically.  
         [0005]     Widely used network architectures have a large central controller, such as a Cable Modem Termination System (CMTS) or Digital Subscriber Line Access Multiplexer (DSLAM) to connect many subscribers to the Internet. The network performance diminishes as the communications load across the distribution backbone increases due in part to protocol overhead, especially with connection establishment and connection maintenance.  
         [0006]     It would therefore be advantageous to provide a system and method for providing improved service to subscribers using a given distribution backbone. It would be further advantageous to provide such service without adding substantial complexity or cost to the network  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention overcomes the disadvantages and limitations of previous solutions by providing a system and method for locating high level protocol devices at various places within the network, including at the subscriber connection points. The devices may operate at the Open Systems Interconnection (OSI) layer 3 or higher and manage network traffic at the edge of the network.  
         [0008]     The devices may have additional capabilities, such as wireless connections or other functionality that may benefit both the consumer and network provider.  
         [0009]     An embodiment of the present invention may include a network comprising: a wide area network connection point device having a connection to the Internet; a distribution backbone connected to the wide area network connection point; a subscriber connection point adapted to maintaining a first table comprising the address of at least one downstream device located distally from the wide area network connection point, the first table being located in the subscriber connection point, the subscriber connection point being located off any subscriber&#39;s premises; and a subscriber receiver located within a subscriber&#39;s premises.  
         [0010]     Another embodiment of the present invention may include a multi-floor building comprising: a messaging distribution backbone spanning several floors; a wide area network connection point connected to the backbone; a plurality of subscriber connection points connected to the backbone, the subscriber connection points adapted to maintain a first table comprising the address of at least one downstream device located distally from the wide area network connection point, the first table being located in the subscriber connection point, the subscriber connection points being located off any subscriber&#39;s premises; and a subscriber receiver being located within a subscriber&#39;s premises.  
         [0011]     Yet another embodiment of the present invention may include a subscriber connection point comprising: a connection to a distribution backbone; at least one connection to a subscriber receiver; an address table; and a processor capable of determining a subscriber device address and storing the address in the address table; wherein the subscriber connection point is located off any subscriber&#39;s premises.  
         [0012]     Still another embodiment of the present invention may include a method of sending messages through a network comprising: connecting a wide area network connection point to the Internet; connecting the wide area network connection point to a distribution backbone; connecting a subscriber connection point to the distribution backbone at a point distal to the wide area network connection point, the subscriber connection point being located off any subscriber&#39;s premises; connecting a subscriber receiver to the subscriber connection point; connecting a subscriber device to the subscriber receiver; sending a query from the subscriber connection point to the subscriber device to determine an address for the subscriber device; sending the address for the subscriber device to the subscriber connection point; storing the address in a first address table located in the subscriber connection point; receiving a message for the subscriber device at the wide area network connection point; transmitting the message from the wide area network connection point to the subscriber connection point based on the address in the second address table; and transmitting the message from the subscriber connection point to the subscriber device based on the address in the first table.  
         [0013]     The advantages of the present invention are that lower level traffic is confined to smaller areas, allowing the main backbone of the network to handle more useful data traffic and less overhead traffic. Such a system increases the overall performance of the network. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     In the drawings,  
         [0015]      FIG. 1  is a diagrammatic illustration of an embodiment showing a network.  
         [0016]      FIG. 2  is a diagrammatic illustration of an embodiment showing a subscriber connection point.  
         [0017]      FIG. 3  is a diagrammatic illustration of an embodiment showing a network having address tables.  
         [0018]      FIG. 4  is a diagrammatic illustration of an embodiment showing message transfers between the subscriber connection point and the subscriber device.  
         [0019]      FIG. 5  is a diagrammatic illustration of an embodiment showing a message receipt from the internet.  
         [0020]      FIG. 6  is a diagrammatic illustration of an embodiment showing a multistory building having a wireless network service.  
         [0021]      FIG. 7  is a plan diagram of an embodiment showing a subscriber connection point with sector directed antennas. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]     While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims. Like reference numbers signify the elements throughout the description of the figures. It will also be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there is no intervening elements present.  
         [0023]     The present invention may be embodied as devices, systems, methods, and/or computer program products. Accordingly, the present invention may be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.) Furthermore, the present invention may take the form of a computer program product on a computer-usable or computer-readable storage medium having computer-usable or computer-readable program code embodied in the medium for use by or in connection with an instruction execution system. In the context of this document, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.  
         [0024]     The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a random access memory (RAM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read only memory (CD-ROM), and a digital versatile disk read only memory (DVD-ROM). Note that the computer-usable or computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, of otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.  
         [0025]      FIG. 1  illustrates an embodiment  100  of the present invention showing a network. The internet connection point  102  is connected to the internet  104  and the distribution backbone  106 . Attached to the distribution backbone  106  are subscriber connection points  108  and  110 .  
         [0026]     Subscriber connection point  108  is connected to subscriber receiver/hub  112  and subscriber receiver  114 . Subscriber receiver/hub  112  is attached to devices  116  and  118  as well as hub  120 , which is in turn connected to devices  122  and  124 . Subscriber receiver  114  is connected to device  126 .  
         [0027]     Subscriber connection point  110  has a wireless connection  128  to subscriber receiver  130 . Subscriber receiver  130  is connected to hub  132 , which is connected to devices  134 ,  136 , and  138 .  
         [0028]     The subscriber connection points  108  and  110  may reduce the traffic on the distribution backbone  106  by minimizing much of the lower level communication traffic from the various devices. The subscriber connection point  108  and  110  may various functionality such as network address translation (NAT), proxy services, IP masquerading, routing, other high level interfaces, and/or information management interfaces. The higher level interfaces at the subscriber connection points  108  and  110  have a number of useful functions, including reducing network traffic. These functions include allocating addresses, buffering or storing cached data remotely, handing various address resolving protocols, and signaling at remote locations throughout the network.  
         [0029]     The subscriber connection points  108  and  110  may connect to a single subscriber or may connect to several subscribers. For example, subscriber connection point  108  may connect two different subscribers to the network while subscriber connection point  110  may connect only one subscriber. In some embodiments using a wireless connection, a single subscriber connection point may connect to many subscribers, perhaps hundreds simultaneously.  
         [0030]     The internet connection point  102  and the distribution backbone  106  may be any type of network. For example, the distribution backbone  106  may be a fiber optic, wired, or wireless network. An example of a typical network may include a hybrid fiber/coax cable television network wherein the internet connection point is a Cable Modem Termination System (CMTS). Another example may be a twisted pair distribution backbone connected to a Digital Subscriber Line Access Multiplexer (DSLAM) interface to the internet. In some embodiments, the distribution backbone  106  may include wireless connections between the internet connection point  102  and the subscriber connection points  108  and  110 . Various network configurations may be possible while keeping within the spirit and intent of the present invention.  
         [0031]     The subscriber receivers  112 ,  114 , and  130  may include hardware and software that establishes a connection with a subscriber connection point. In some embodiments, the connection may be established using authentication and verification routines that may include user identification and password, hardware addresses, subscriber account verification, or other security or account verification mechanisms. In some embodiments, the connection verification routine may allow a new subscriber to establish a connection.  
         [0032]     The subscriber receivers  112 ,  114 , and  130  may be many different kinds of connections. In some embodiments, a subscriber receiver may be a network interface card (NIC) wired to the subscriber connection point via an Ethernet cable, or they may be modems of various types such as cable modems, DSL modems, or optoelectrical modems using compatible cabling. In other embodiments, the subscriber receiver may be a wireless receiver such as those compatible with the various IEEE 802 wireless protocols, various ultra-wideband protocols, or other wireless communications systems.  
         [0033]     The subscriber connection points  108  and  110  may be located outside of a subscriber&#39;s premise. For example, a subscriber connection point may be located on a utility pole or in a utility pedestal. In some embodiments, the location of the subscriber connection point may be on a subscriber&#39;s property, but within an easement or right of way of the network provider. For example, a cable television distribution network or phone distribution network may mount a subscriber connection point on the exterior of a subscriber&#39;s house but may be owned, installed, serviced, and accessed only by the service provider. In such a manner, an individual subscriber would have little ability to access the subscriber connection point.  
         [0034]     In a public wireless embodiment, a subscriber connection point may located on an antenna pole, in a coffeeshop, airport lounge, or other public facility. A subscriber may access the network through the antenna. In such an embodiment, and for the purposes of this application, the subscriber&#39;s premise may be defined to include, but is not limited to the subscriber&#39;s mobile electronic devices directly under the subscriber&#39;s control, whether it is a laptop computer, mobile phone, personal digital assistant, subscriber receiver, or any other device in communication with the antenna. A device outside the subscriber&#39;s premise includes, but is not limited to, those devices outside of the normal access of the subscriber, such as a connection box owned by a network services provider mounted on a subscriber&#39;s dwelling, a utility pedestal or utility pole mounted connection point, an antenna mounted in a public accessible area, or any other area generally considered to be owned, maintained, or controlled by a network service provider.  
         [0035]     The subscriber receiver hub  112  may incorporate a hub or switch functionality into the subscriber receiver. Such a device may allow multiple devices, such as computers, internet appliances, telephony devices, or other devices to use the connection to the internet. In other embodiments, the subscriber receiver  130  may include only a single connection which may then be connected to a hub  132  for distribution to several devices  134 ,  136 , and  138 .  
         [0036]      FIG. 2  is a block diagram illustration of an embodiment  200  showing a subscriber connection point. The subscriber connection point  202  is connected to upstream  204  and downstream  206  network connections. A duplex filter  208  separates the incoming connection into an upstream path  210  and downstream path  212 . A second duplex filter  214  combines the signals for the downstream connection  206 .  
         [0037]     The upstream path  210  is connected to a transmit interface  216 . Similarly, the downstream path  212  is connected to a receive interface  218 . Both the transmit interface  216  and receive interface  218  are connected to the processor  220 . The processor  220  is connected to subscriber interfaces  222  and  224 . The processor  220  is further connected to a hardware access table  226  and a routing table  228 .  
         [0038]     The subscriber connection point  202  is an embodiment that may be used in a linear broadband network, such as a cable television network. In such a system, one band of the network may be allocated for downstream communications and another band for upstream communications. In the present embodiment, the high frequency bands are used for downstream communication and the lower frequency bands are used for upstream communications.  
         [0039]     The processor  220  maintains and uses the hardware address table  226  to keep track of the various devices that may be connected to the subscriber interfaces  222  and  224 . The processor  220  may periodically send queries to all of the devices attached to subscriber interfaces  222  and  224  requesting their hardware addresses. The hardware addresses may be the media access control (MAC) address or Internet Protocol (IP) address of the various devices or some other identifier.  
         [0040]     Additionally, the routing table  228  may include addresses of devices located along the upstream  204  or downstream  206  connections to the subscriber connection point  202 . The routing table  228  may contain addresses for messages that are to be sent to computers or devices on the internet or located along upstream or downstream connections.  
         [0041]     The transmit interface  216  and receive interface  218  may perform various functions associated with transmitting and receiving messages, respectively. These tasks may include handshaking and low level communications, queuing the messages, and any processing of the messages. The transmit interface  216  and receive interface  218  may be embodied in a combination of software, firmware, microcode, field programmable gate arrays, hardware, or other technologies.  
         [0042]      FIG. 3  is a diagrammatic illustration of an embodiment  300  showing a network having address tables. The internet connection point  302  is connected to the internet  304  and subscriber connection points  306  and  308  through backbone  310 . The subscriber connection point  306  comprises a processor  312  that is connected to address table  314  and subscriber interfaces  316  and  318 , which are in turn connected to subscriber devices  320  and  322 , respectively. Similarly, subscriber connection point  308  comprises processor  324  that is connected to address table  326  and subscriber interfaces  328  and  330 . Subscriber interfaces  328  and  330  are connected to subscriber devices  332  and  334 , respectively. Internet connection point  302  comprises a processor  336  that is connected to address table  338 .  
         [0043]     The address tables  314  and  326  located within the subscriber connection points  306  and  308 , respectively, may be used to eliminate routine traffic over the backbone  310 . The subscriber connection points  306  and  308  may act as managers of local area networks (LANs) that comprise the downstream devices. The address tables  314  and  326  may be used in several different methods. Before explaining the methods, it is necessary to review some concepts of the OSI reference model in common use today.  
         [0044]     In the OSI reference model, layer 1 refers to the physical layer and the activities required to communicate over a physical medium. These activities vary for the specific medium and protocol, and may include low level handshaking, acknowledging, checking parity, and other physical actions required to transmit data.  
         [0045]     Layer 2 refers to the data link layer and handles to movement of data across the physical layer. Layer 2 contains the media access control (MAC) addresses and logical link control (LLC). Examples of layer 2 include Ethernet and point to point protocol (PPP).  
         [0046]     Layer 3 is the network layer and handles the routing of data packets across the network. An example of layer 3 is the Internet Protocol (IP). Layer 3 activities relate to the movement of messages across a network. Each message may contain the IP addresses of the sender and recipient of the message, and the message is passed from one computer to the next until the message reaches its destination.  
         [0047]     Layer 4 is the transport layer and coordinates the messages being sent on layer 3. For example, a long data transmission may be broken into small messages. These messages may be transmitted independently and may arrive at the destination in a different order than intended. The layer 4 activities are concerned with placing the messages in the proper order to create the long data transmission. Examples of layer 4 are transmission control protocol (TCP) and user datagram protocol (UDP).  
         [0048]     Layer 5 is the session layer and establishes a conversation between two computers. A session may be used for a single transmission or may be used for an extended conversation until one of the hosts terminate the session. In some embodiments, a computer may have a specific port dedicated to a specific type of communication. For example, port or session  80  is often dedicated to hyper text transfer protocol (HTTP) communications.  
         [0049]     Layer 6 is the presentation layer and ensures that the data is in the proper form. Layer 6 activities may include checks for data formats, compatibility with the host operating system, encapsulation of the data in appropriate envelopes, or other activities. An examples of a layer 6 device is the HTTP daemon which may receive an HTTP document, check the multipurpose internet mail extension (MIME) header, and launch the appropriate application.  
         [0050]     Layer 7 is the application layer and provides services to the application program to ensure an effective communication. Such services include making sure the other party is identified and ready to communicate, authenticate the sender and recipient, ensures agreement on data error recovery, and determining protocol and data syntax rules. Such services are generally the high level set-up services for the application or interactive user.  
         [0051]     In various embodiments of the present invention, the address tables  314  and  326  may be used to store several types of address information.  
         [0052]     In a layer 3 embodiment of a subscriber connection point, the address tables  314  and  326  may contain the MAC addresses of the subscriber devices. In such an embodiment, the processors  312  and  324  may send periodic queries to the subscriber devices to determine the MAC addresses of the subscriber devices. In many embodiments, such queries may be performed at different intervals, from a fraction of a second to several seconds, to many minutes. Such queries are confined between the processor and the downstream devices and may not be transmitted across the backbone  310 . In some embodiments, the process of querying, determining the addresses, and storing the addresses in an address table is known as address resolution protocol (ARP), which is but one embodiment of an address resolving method portion of the present invention.  
         [0053]     A layer 3 embodiment may operate as a hub or switch device within the network.  
         [0054]     In another layer 3 embodiment of a subscriber connection point, the address tables  314  and  326  may contain the IP addresses of the subscriber device. Such an embodiment may also store the MAC addresses of the subscriber devices in the address tables  314  and  326 .  
         [0055]     In a layer 4 embodiment of a subscriber connection point, the address tables  314  and  326  may contain the IP addresses of the subscriber device and additionally perform various transport layer functions, such as TCP or UDP functions.  
         [0056]     In a layer 5 embodiment of a subscriber connection point, the address tables  314  and  326  may contain a session or port identification. In such an embodiment, IP addresses and/or MAC addresses of downstream devices may be also stored in the address tables  314  and  326 .  
         [0057]     A layer 5 embodiment may include IP masquerading or network address translation (NAT), which is a process by which all communications from the internet are addressed to the IP address of the subscriber connection point. The communications are relayed to the appropriate subscriber device based on a predetermined session established between the subscriber connection point and the subscriber device. Some NAT embodiments may be one-to-many embodiments where a single address for the subscriber connection point is used to translate for many subscriber devices. Other NAT embodiments may be one-to-one embodiments where each subscriber device has its own IP address.  
         [0058]     In some embodiments, the internet connection point&#39;s address table  338  may contain some or all of the information contained in the subscriber connection point&#39;s address tables  312  and  326 . For example, if the IP addresses are uniquely assigned to the subscriber devices, those IP addresses will be maintained within the address tables of the appropriate subscriber connection points. The contents of the address tables  314  and  326  may be periodically transmitted to the internet connection point  302  for updating the address table  338 . In this manner, messages that are received at the internet connection point  302  may be compared to the address table  338  to determine if a message should be transmitted to a subscriber connection point.  
         [0059]     In other embodiments, the subscriber connection point  306  may comprise a proxy server, and may include such features as caching, firewalling, or other proxy features.  
         [0060]      FIG. 4  is a diagrammatic illustration of an embodiment  400  of message transfers between the subscriber connection point and the subscriber device. The subscriber connection point  306  is connected to an internet connection point  302  by backbone  310 . The internet connection point  302  has a connection to the internet  302 . The internet connection point  302  comprises a processor  336  and address table  338 .  
         [0061]     The subscriber connection point processor  312  sends a request for addresses  406  to a subscriber interface  316 , which passes through the subscriber receiver  402  to reach the device  404 . The device  404  replies with its address  408  through the receiver  402  and subscriber interface  316  to reach the processor  312 . The processor  312  stores the address  410  into the address table  314 .  
         [0062]     In the embodiment  400 , any address or identifier may be transmitted from the device  404  and stored in the address table  314 . Various embodiments may use different addresses or identifiers for the device  404  while keeping within the spirit and intent of the present invention. The embodiment  400  may include transmissions in compliance with an address resolution method.  
         [0063]      FIG. 5  is a diagrammatic illustration of an embodiment  500  of a message receipt from the internet. The subscriber connection point  306  is connected to an internet connection point  302  by backbone  310 . The internet connection point  302  has a connection to the internet  302 . The internet connection point  302  comprises a processor  336  and address table  338 .  
         [0064]     A message  502  is sent from the internet to the internet connection point  304 . The message  502  may contain an address for the destination device  404 . After receiving the message  502 , the processor  336  may send a query  504  to the address table  338  to return an address  506 . Based on the address  506 , the message  508  is transmitted to the subscriber connection point  306 . The processor  312  sends a query  510  to the address table  314 , which returns an address  512 . The processor  312 , using the address  512 , transmits the message  514  to the subscriber interface  316 , through the subscriber receiver  402 , and to the device  404 .  
         [0065]     Because the subscriber connection point  306  maintains the address table  314  comprising the addresses of downstream devices, much of the communication across the network backbone is reduced. Much of the repetitious querying of devices on the local network is confined between the subscriber connection point and the subscriber devices. This overhead traffic, which would otherwise burden the network backbone, is restricted to a local area. Since the network is less burdened with overhead traffic, more subscribers may connect to the network with comparable service than if the subscriber connection points did not handle such overhead traffic.  
         [0066]     The subscriber connection point  306  may be owned and controlled by the same company that owns the network backbone. In some embodiments, a single subscriber connection point  306  may connect to several different subscribers, each having one or more devices. When the subscriber connection point is owned and controlled by the same company as the network backbone, the network service provider may optimize the functions of the subscriber connection point  306  to provide optimum service.  
         [0067]     For example, the subscriber connection point  306  may invoke an address resolving method on a frequent basis, such as every few seconds, but similar queries from the internet connection point  304  to the various subscriber connection points may be performed much less frequently. In some embodiments, the address resolving method queries from the internet connection point  304  may be performed on a manually requested basis so that the address table  338  may be updated on command when changes are made to a downstream subscriber connection point.  
         [0068]     In some embodiments, the subscriber connection point  306  may transmit the addresses contained in the address table  314  to the internet connection point  304  only when the data in the address table  314  has changed. For example, during normal operation, the internet connection point address table  338  may contain IP or other addresses of each downstream subscriber connection point and may contain IP or other addresses of all or some of the downstream subscriber devices. If a subscriber device were brought online and have an IP or other address, the normal address resolving method queries similar to those shown in  FIG. 4  would detect the device and update the address table  314 . When the address table  314  was updated, the processor  312  may be capable of sending a message to the internet connection point  304  so that the address table  338  may be updated.  
         [0069]      FIG. 6  is a diagrammatic illustration of an embodiment  600  showing a multistory building having a wireless network service. The multistory building  602  is connected to a wide area network (WAN)  604  through subscriber connection points  606  and  608 . The antennas  610  are located on different floors of the building  602  and each have a focused antenna beam  612 .  
         [0070]     The antennas  610  may be designed and mounted so that the antenna beams  612  cover a portion of the building. In some embodiments, the antennas  610  may be adapted to cover a single floor of the building. For example, a single floor may have several apartments, condominiums, or hotel rooms. In such an example, each unit may be serviced by the antenna mounted on that floor. In other embodiments, antennas may be adapted to serve two or more floors of a building.  
         [0071]     The embodiment  600  may allow a service provider to offer internet, telephony, cable television, or other communications to several subscribers with a minimum of installation cost. Each subscriber connection point  606  may serve several floors of a building and enable access to many subscribers. A subscriber may use a wireless receiver to communicate to the appropriate subscriber connection point. In some embodiments, IEEE 802.11 standards may be used for the wireless transmissions while in other embodiments, specialized protocols may be used.  
         [0072]     In some embodiments, the WAN connection  604  may be a connection to the internet or may be a connection to a network such as a hybrid fiber/coax cable television network or other type of connection. In some embodiments, the multistory building  602  may be a single building on a business campus and the WAN connection  604  may be a connection to the company&#39;s wide area network.  
         [0073]      FIG. 7  illustrates a plan diagram of an embodiment  700  showing a subscriber connection point with sector directed antennas. The subscriber connection point  702  is connected to an antenna system  704  that broadcasts in several distinct sectors  706 ,  708 , and  710 .  
         [0074]     The antenna system  704  may comprise one or more antennas that have a focused coverage area. Several such areas may be useful when many subscribers attempt to access the subscriber connection point  702 , since the subscribers may be separated into separate sectors.  
         [0075]     The embodiment  700  may be particularly useful when deployed in an area such as a store, park, airport, stadium, or other venue where many subscribers may wish to communicate with the subscriber connection point  702 . Because the subscriber connection point  702  may handle much of the functionality such as address resolving requests, IP masquerading, network address translations, proxy services, and other functions, such data need not travel over the network backbone and use other resources for such purposes. By distributing various functionality downstream from the headend equipment, such as a CMTS or DSLAM, more data and more subscribers can be serviced with the same network backbone.  
         [0076]     The foregoing description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and other modifications and variations may be possible in light of the above teachings. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and various modifications as are suited to the particular use contemplated. It is intended that the appended claims be construed to include other alternative embodiments of the invention except insofar as limited by the prior art.