Patent Publication Number: US-7719966-B2

Title: Network element architecture for deep packet inspection

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is related to the co-pending U.S. Patent Application, entitled AN APPLICATION AWARE TRAFFIC SHAPING SERVICE NODE POSITIONED BETWEEN THE ACCESS AND CORE NETWORKS, Ser. No. 11/106,163 filed on Apr. 13, 2005. 
     BACKGROUND 
     1. Field 
     Embodiments of the invention relate to the field of computer networking; and more specifically, to shaping data traffic in a computer network. 
     2. Background 
     A modern metro area network  100  is composed of two types of networks: a core network  102  and one of more access networks  106 . The core network  102  communicates data traffic from one or more service providers  104 A- 104 N in order to provide services to one or more subscribers  108 A- 108 M. Services supported by the core network  102  include, but are not limited to, (1) a branded service, such as a Voice over Internet Protocol (VoIP), from a branded service provider; (2) a licensed service, such as Video on Demand (VoD), through a licensed service provider and (3) traditional Internet access through an Internet Service Provider (ISP). 
     The core network supports a variety of protocols (Synchronous Optical Networking (SONET), Internet Protocol (IP), Packet over SONET (POS), Dense Wave Division Multiplexing (DWDM), OSPF, BGP, ISIS, etc.) using various types of equipment (core routers, SONET add-drop multiplexers (ADM), DWDM equipment, etc.). Furthermore, the core network communicates data traffic from the service providers  104 A- 104 N to access network(s)  106  across link(s)  112 . Link(s)  112  may be a single optical, copper or wireless link or may comprise several such optical, copper or wireless link(s). 
     On the other hand, the access network(s)  106  complements the core network  102  by aggregating the data traffic from the subscribers  108 A- 108 M. Access network(s)  106  may support data traffic to and from a variety of types of subscribers  108 A- 108 M, (e.g. residential; corporate, mobile, wireless, etc.). Although the access network(s)  106  may not comprise of each of the types of subscriber (residential, corporate, mobile, etc), access(s) network  106  will comprise at least one subscriber. Typically, access network(s)  106  supports thousands of subscribers  108 A- 108 M. Access network(s)  106  aggregates data traffic from the subscribers over link(s)  112  connecting to the core network  102 . Access networks support a variety of protocols (IP, Asynchronous Transfer Mode (ATM), Frame Relay, Ethernet, Digital Subscriber Line (DSL), Dynamic Host Configuration Protocol (DHCP), Point-to-Point Protocol (PPP), Point-to-Point Protocol over Ethernet (PPPoE), etc.) using various types of equipment (Edge router, Broadband Remote Access Servers (BRAS), Digital Subscriber Line Access Multiplexers (DSLAM), Switches, etc). The access network(s)  106  uses subscriber policy manager(s)  110  to set policies for individual ones and/or groups of subscribers. Policies stored in a subscriber policy manager(s)  110  allow subscribers access to different ones of the service providers  104 A-N. Examples of subscriber policies are bandwidth limitations, traffic flow characteristics, amount of data, allowable services, etc. 
     Before discussing subscriber policies and the effect on services, it is worth noting that data traffic is transmitted in data packets. A data packet (also known as a “packet”) is a block of user data with necessary address and administration information attached, usually in a packet header and/or footer that allows the data network to deliver the data packet to the correct destination. Examples of data packets include, but are not limited to, IP packets, ATM cells, Ethernet frames, SONET frames and Frame Relay packets. Data packets are transmitted in a flow at a transmission rate. The transmission rate is determined by the packet size and the transmission gap (or “inter-packet gap”) between each packet. In addition, the transmission rate of data packets is dependent on the capacity of the network connection and processor capability of the transmitting device. 
       FIG. 2  represents the Open Systems Interconnect (OSI) model of a layered protocol stack for transmitting data packets  200 . Each layer installs its own header in the data packet being transmitted to control the packet through the network. The physical layer (layer 1)  202  is used for the physical signaling. The next layer, data link layer (layer 2)  204 , enables transferring of data between network entities. The network layer (layer 3)  206  contains information for transferring variable length data packet between one or more networks. For example, IP addresses are contained in the network layer  206 , which allows network devices to route the data packet. Layer 4, the transport layer  208 , provides transparent data transfer between end users. The session layer (layer 5)  210 , provides the mechanism for managing the dialogue between end-user applications. The presentation layer (layer 6)  212  provides independence from difference in data representation (e.g. encryption, data encoding, etc.). The final layer is the application layer (layer 7)  212 . The layer contains the actual data used by the application sending or receiving the packet. While most protocol stacks do not exactly follow the OSI model, it is commonly used to describe networks. 
     Returning to  FIG. 1 , bandwidth sensitive services, such as VoIP or VoD, require a dedicated bandwidth over link(s)  112  to properly operate. However, because each access network  106  can support thousands of subscribers, link(s)  112  can get overloaded and not provide enough bandwidth for these bandwidth sensitive services. Subsequently, the quality of these services degrades or becomes interrupted altogether. One solution to this problem is to enforce a Quality of Service (QoS) from the core  102  and/or access  106  networks. QoS allocates different bandwidth rates to different types of data traffic. For example, QoS can be set up to allocate a bandwidth of 20 Mbps for VoIP service over link(s)  112 . In addition, QoS shapes the data traffic by re-transmitting the data traffic in a constant rate. However, for QoS to work properly, both the core and access networks must be set up to support the desired QoS policy. 
     Devices that solely perform QoS can be categorized, but not limited to, either traffic shapers or flow switches. A traffic shaper is a device that classifies a packet by deep packet inspection and transmits the packet based on pre-determined subscriber policies. Turning to  FIG. 2 , deep packet inspection examines the data contained in layers up to and including application layer  214  of each data packet  200  to determine what quality or service should be used for the packet. For example and by way of illustration, deep packet inspection matches the structure of the application layer data with potentially hundreds of known application data types. This allows a traffic shaper to finely tune the quality of service enforced. For example, a traffic shaper may identify control packets for an adaptable video conferencing protocol to configure the network for an optimal video conferencing rate. 
     Although existing traffic shapers are subscriber aware, these traffic shapers only enforce pre-determined subscriber policies. That is subscribers policies are set by the operator of the traffic shaper and do not change until the operator modifies the subscriber policies. This does not allow subscriber policies to change in real-time based on existing network conditions. Furthermore, existing traffic shapers cannot handle the high volume of data traffic that cross the core  102  and access  116  networks. 
     On the other hand, flow switches are network devices that transmit data packets in connected flows, instead of discrete packets. Flow switches operate on groups of similar packets to provide QoS for an application. However, flow switches have limited data traffic processing capability, are not subscriber aware, perform limited or no deep packet inspection, and cannot update subscriber policies in real-time. 
     BRIEF SUMMARY 
     A method and apparatus for an application aware traffic shaping service node architecture is described. One embodiment of the invention, the service node architecture includes a set of one or more line cards, a set of one or more processor cards and a full mesh communication infrastructure coupling the sets of line and processor cards. Each link coupling the sets of line and processor cards is of equal capacity. A line card includes a physical interface and a set of one or policy network processors, with the network processors performing deep packet inspection on incoming traffic and shaping outgoing traffic. Processors cards include a set of one or more policy generating processors. According to another embodiment of the invention, the service node generates a set of statistics based on the incoming traffic and continually updates, in real-time, traffic shaping policies based on the set of statistics. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention may be best understood by referring to the following description and accompanying drawings which illustrate such embodiments. The numbering scheme for the Figures included herein are such that the leading number for a given element in a Figure is associated with the number of the Figure. For example, core network  102  can be located in  FIG. 1 . However, element numbers are the same for those elements that are the same across different Figures. In the drawings: 
         FIG. 1  (Prior Art) is illustrates one embodiment of a metro area network configuration. 
         FIG. 2  (Prior Art) is a block diagram illustrating layers of the OSI protocol stack. 
         FIG. 3  illustrates an exemplary network configuration using a traffic shaping service node shaper in a metro area network according to one embodiment of the invention. 
         FIG. 4A  is a block diagram illustrating one embodiment of unshaped network data traffic flow originating from the core network according to one embodiment of the invention. 
         FIG. 4B  is a block diagram illustrating one embodiment of network data traffic flow shaped by the traffic shaping service node according to one embodiment of the invention. 
         FIG. 5A  is a block diagram illustrating one embodiment of unshaped network data traffic flow originating from subscribers. 
         FIG. 5B  is a block diagram illustrating one embodiment of unshaped network data traffic flow from subscribers aggregated by the access multiplexer and edge router according to one embodiment of the invention. 
         FIG. 5C  is a block diagram illustrating one embodiment of network data traffic flow from subscribers shaped by the traffic shaping service node. 
         FIG. 6  is an exemplary block diagram illustrating packet flow in the traffic shaping service node according to one embodiment of the invention. 
         FIG. 7  is an exemplary flow diagram for shaping data traffic according to one embodiment of the invention. 
         FIG. 8  is an exemplary flow diagram for deep packet inspection and classification according to one embodiment of the invention. 
         FIG. 9  is an exemplary flow diagram for updating statistics according to one embodiment of the invention. 
         FIG. 10  is an exemplary flow diagram for updating traffic policy in real-time according to one embodiment of the invention. 
         FIG. 11  is a block diagram illustrating of a traffic shaping service node according to one embodiment of the invention. 
         FIG. 12  is a block diagram illustrating a mesh backplane used in the traffic shaping service node according to one embodiment of the invention. 
         FIG. 13  is a block diagram illustrating communication between a line and multiple CPUs according to one embodiment of the invention. 
         FIG. 14  is a block diagram illustrating connections between line cards and processor card according to one embodiment of the invention. 
         FIG. 15  is a block diagram illustrating architecture of a line card according to one embodiment of the invention. 
         FIG. 16  is a block diagram illustrating architecture of a processor card according to one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, numerous specific details such as application subscriber data traffic flow, traffic policy, data packet, processor card, line card, deep packet inspection and interrelationships of system components are set forth in order to provide a more thorough understanding of the invention. It will be appreciated, however, by one skilled in the art that the invention may be practiced without such specific details. In other instances, control structures, gate level circuits and full software instruction sequences have not been shown in detail in order not to obscure the invention. Those of ordinary skill in the art, with the included descriptions, will be able to implement appropriate functionality without undue experimentation. 
     References in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. 
     In the following description and claims, the term “coupled,” along with its derivatives, is used. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. 
     A method and apparatus for an application traffic shaping service node positioned between the access and core networks is described. One embodiment of the invention enforces a per subscriber, per application traffic policy for network traffic between subscribers and service providers. According to another embodiment of the invention enforcement of the per subscriber, per application traffic policy comprises classifying the network traffic into application level subscriber flows, maintaining real-time statistics on the application level subscriber flows, updating, in real-time, the per subscriber, per application traffic policy based on the real-time statistics and shaping the application level subscriber flows as necessary to enforce the per subscriber, per application traffic policy. Yet another embodiment of the invention is a combined service node with integrated edge routing and traffic aggregator. 
     Furthermore, embodiments of the traffic shaping service node architecture are described. One architecture embodiment of the invention describes a high speed connection between a line card and a multiple CPU processor card. According to another architectural embodiment of the invention, a full mesh backplane connects a plurality of line and multiple CPU processor cards. According to another embodiment of the invention, the line card comprise a network processor, host CPU, protocol queue, statistics queue and physical interface. According to another embodiment of the invention, the processor card comprises multiple CPUs connected via a very high capacity low latency (VHCLL) bus connecting the multiple CPUs to the backplane. 
     Since each of the above embodiments is independent, different embodiments may implement different ones, different combinations, or all of the above aspects of the invention. For example, certain embodiments of the invention include a service node that enforces a per subscriber, per application traffic policy for network traffic between subscribers and service providers where the service node employs an architecture with a full mesh backplane between the plurality of line and processor cards. 
     Exemplary embodiments of the invention will now be described with reference to  FIGS. 3-16 . In particular, the operations of the flow diagrams in  FIGS. 6-10  will be described with reference to the exemplary embodiments of  FIGS. 3-5  and  11 - 16 . However, it should be understood that the operations of these flow diagrams can be performed by embodiments of the invention other than those discussed with reference to  FIGS. 6-10 , and that the embodiments discussed with reference to  FIGS. 6-10  can perform operations different than those discussed with reference to these flow diagrams. 
     Exemplary Traffic Shaping Service Node 
       FIG. 3  illustrates an exemplary network configuration using a traffic shaping service node  302  in a metro area network according to one embodiment of the invention. In  FIG. 3 , traffic shaping service node  302  is communicatively coupled between the core  102  and access  106  networks. While one embodiment is described or which the traffic shaping service node may shape traffic traveling in either direction, alternative embodiments may shape in only one direction (e.g., the service provider data traffic coming from the core network  102 . Traffic shaping, a form of QoS, is the process of regulating and smoothing the flow of network data traffic within a computer network. Restricting the bandwidth of the traffic flow is one way to regulate data traffic. There are a variety of ways to bring data traffic flow with a desired rate, including dropping or discarding data packets buffering received data packets and re-transmitting the data packets at the desired rate, combinations of these (e.g., buffering packets when there is space in the buffer and dropping packets when there is not), etc. Buffering the data traffic flow allows the traffic shaping service node to smooth the data traffic flow. Smoothing removes the bursts of data traffic and shapes the data traffic into a constant flow of data traffic. Smoothing is advantageous for applications that depend on a constant flow of data traffic. For example, video-based applications, such VoD or video conferencing, or real-time voice applications (VoIP) benefit from a constant flow of data traffic. An example of shaping service provider data traffic is further described in  FIGS. 4A and 4B . Shaping aggregated subscriber data traffic coming from the access network(s)  106  is further described in the  FIG. 5A-5C . Referring back to  FIG. 3 , the traffic shaping service node  302  uses the subscriber policies contained in subscriber policy manager(s)  110  for instruction on how to shape the data traffic from service providers  104 A- 104 N and/or subscribers  108 A- 108 M accordingly. 
       FIG. 4A  is a block diagram illustrating one embodiment of unshaped network data traffic flow originating from the core network.  FIG. 4A  is an embodiment coupling a core router  402  with a traffic shaping service node  406  via link  404 . Traffic shaping service node  406 , in turn, is coupled with edge router  410  via link  408 . In  FIG. 4A , by way of illustration, a core router  402  transmits several data packets over link  404  to the traffic shaping service node  406 . Typically, the core router  402  transmits millions of packets per second.  FIG. 4A  is a conceptual drawing representing that each packet typically includes some identification of the application used (e.g., an ID in the header, type of protocol used, etc.). As such, each packet illustrated in  FIG. 4  is labeled with the subscriber, the application used by the data packet, a number representing the ordered position of the data packet in a flow of similar packets. For example, data packet  412 , labeled “A- 1 . 1 ”, designates the packet is used by subscriber A, application  1  and is the first packet in a flow of packets used by subscriber A and application  1 . As another example, packet  438 , labeled “B- 3 . 3 ”, means the packet is for subscriber B, application  3  and is the third such packet in the flow for this application and subscriber. 
     Furthermore,  FIG. 4A  illustrates application subscriber traffic flows. An application subscriber traffic flow is a flow of data packets that are particular to a unique combination of subscriber, application and instance of that application. For example, packets  412 - 416  are organized into an application subscriber traffic flow for subscriber A, application  1  (“packet flow A- 1  ). Similarly, packets  420 - 424  (packet flow “A- 3 ”),  426 - 432  (packet flow “B- 2 ”) and  434 - 442  (packet flow “B- 3 ”) are organized into different application subscriber traffic flows. Only four such flows are illustrated in  FIG. 4 . Typically, the traffic shaping service node  406  handles millions of application subscriber traffic flows at a time. 
     However, the packets in the flows on link  404  are illustrated to indicate they are mixed together in disorderly flows of packets. Disorderly means the packet flow is not a constant stream of packets within the flow. For example, in packet flow A- 1 , packet  412  (“A- 1 . 1 ”) is relatively far away from packet  414  (“A- 1 . 2 ”), whereas packet  414  is relatively close to packets  416  (“A- 1 . 3 ”) and  418  (“A- 1 . 4 ”). The wide varying gaps between the packets can cause dropped packets and failed services. For example, if the gap between the packets is too large, then bandwidth sensitive services such as VoIP or VoD will fail because the steady flow of video becomes disrupted. Conversely, if the packets are bunched too close together, then packets can be dropped because the rate of packets exceeds the bandwidth allocated to the subscriber or the capacity of the network. Dropped packets can severely disrupt video or real-time audio services. Packet flow A- 3  (packets  420 - 424 ), B- 2  (packets  426 - 432 ) and packet flow B- 3  (packets  434 - 442 ) are similarly disorderly arranged. 
       FIG. 4B  is a block diagram illustrating one embodiment of network data traffic flow shaped by the traffic shaping service node  406 . Similar to  FIG. 4A , core router  402  is linked to traffic shaping service node  406  via link  404 . Traffic shaping service node  406 , in turn, is connected with edge router  410  via link  408 . However in  FIG. 4B , the same flow of packets from  FIG. 4A  are now ordered into application subscriber traffic flows on link  408 . 
     In addition to organizing the data packets, the traffic shaping service node  406  applies the policies to the application subscriber traffic flows when transmitting the data packets.  FIG. 4B  illustrates the application of the policies to the four application subscriber traffic flows. Typically, the traffic shaping service node  406  shapes thousands of application subscriber traffic flows. One of the policies that may be applied to the traffic flows is to transmit each packet within a traffic flow at a certain transmission rate. For example, in  FIG. 4B , packets  412 - 418  in packet flow A- 1  are now transmitted at a regularly spaced interval. This is in contrast to  FIG. 4A , where packets  412 - 418  are in a disorderly flow. Packet flows A- 3  (packets  420 - 424 ), B- 2  (packets  426 - 432 ) and B- 3  (packets  434 - 442 ) are likewise transmitted in regularly spaced intervals. 
     It should be understood that different flows may transmit at different rates. In  FIG. 4B , the spacing of packets is used to conceptually illustrate this in that inter-packet gaps are different for each pair of packets in the data flow. For example, packets  412 - 418  in packet flow A- 1  are transmitted at a higher rate than packets  420 - 424  in packet flow A- 3  because the inter-packet gap for packet  412 - 418  is smaller than for packets  420 - 424 . Similarly, packets  426 - 432  in packet flow B- 2  have the smallest inter-packet gap of the four application traffic flows and transmits at the fastest rate. Finally, packets  434 - 442  in packet flow B- 3  are transmitted at a lower rate than packets  426 - 432  in packet flow B- 2 , although packet flow B- 3  transmits at a higher rate than packets  412 - 418  and  410 - 424 . 
     As illustrated in  FIG. 4B , traffic shaping service node  406  transmits different application subscriber traffic flows at different rates. The need for the different rates depends on the application and the subscriber policy. For example, web traffic typically does not require high transmission rate because generally, web page retrieval is not time sensitive. However, DVD-quality VoD requires a high data traffic rate to enable an interruption free viewing experience. Thus, different applications require different traffic rates for the packet data flows. Furthermore, each subscriber may have different policies. For example, subscriber A&#39;s policy allows web page retrieval at 1.0 megabits per second (Mbps), whereas subscriber B&#39;s policy allows web page retrieval at 5.0 Mbps. This idea is reflected in  FIG. 4B , where application traffic flows A- 3  and B- 3  transmit at different rate although the packets for each flow refer to the same application. 
       FIG. 5A  is a block diagram illustrating one embodiment of unshaped network data traffic flow originating from the access network. Links  516  and  518  are coupled with access multiplexer  508 . The access multiplexer  508  aggregates the data traffic from links  516  and  518 . Access multiplexer  508  is further coupled to edge router  506  by link  514 . Edge router  506  is in turn coupled to traffic shaping service node  504  through link  512 . Finally, traffic shaping service node  504  is coupled to core router  502  via link  510 . In  FIG. 5A , the data traffic from subscriber A is shown for application  1  (packets  520 - 526 ) and application  2  (packets  528 - 532 ) on link  516 . Similar to the data traffic illustrated in  FIG. 4A , the data traffic from subscriber A is mixed together in two disorderly flows. Similarly, data traffic from subscriber B is likewise is disordered for packets  534 - 538  and  540 - 544  on link  518 . 
       FIG. 5B  is a block diagram illustrating one embodiment of unshaped network data traffic flow from subscribers aggregated by the access multiplexer.  FIG. 5B  has a similar network configuration as  FIG. 5A . Core router is coupled to traffic shaping service node by link  510 . Link  512  couples traffic shaping service node  504  and edge router  506 . Furthermore, edge router  506  coupled to access multiplexer  508  via link  514 . Links  516  and  518  couple with access multiplexer  508 . 
     In  FIG. 5B , the access multiplexer receives the data packets  520 - 532  from link  516  and data packets  534 - 544  from link  518 . The access multiplexer  508  aggregates the subscriber data packets and transmits data packets  520 - 544  to the edge router along link  514 . The edge router receives data packets  520 - 544  and re-transmits data packets  520 - 544  to the traffic shaping service node on link  512 . In  FIG. 5B , the edge router transmits the subscriber data packets  520 - 544  in a disorderly flow because the packets are received in a disorderly fashion. 
       FIG. 5C  is a block diagram illustrating one embodiment of network data traffic flow from subscribers shaped by the traffic shaping service node.  FIG. 5C  has a similar network configuration as  FIG. 5A . Core router is coupled to traffic shaping service node by link  510 . Link  512  is coupled traffic shaping service node  504  and edge router  506 . Furthermore, edge router  506  is coupled to access multiplexer  508  via link  514 . Links  516  and  518  couple with access multiplexer  508 . 
     In  FIG. 5C , and similar to  FIG. 4B , the traffic shaping service node organizes the received data packets into application subscriber data flows (flow “A- 1 ” (packets  520 - 526 ), flow “A- 3 ” (packets  528 - 532 ) and flow “B- 2 ” (packets  534 - 538 )). Flow B- 3  (packets  540 - 544 ) is not transmitted because the policy for subscriber B does not allow subscriber B to use application  3 . For example, application  3  maybe a value-added service such as VoD. Instead of transmitting flow B- 3  (packets  540 - 544 ), traffic shaping service node  504  drops packets  540 - 544 . This action effectively disallows subscriber B from using application  3 . Thus, traffic shaping service node effectively blocks a connection between subscriber B and the application associated with flow B- 3 . In contrast, subscriber A&#39;s policy allows subscriber A to use application  3 . 
     While in embodiments illustrated in  FIGS. 4A-B  and  5 A-C shape and block traffic in one direction, alternate embodiments may shape and/or block traffic in both directions (e.g. shaping traffic coming from and/or going to access networks, blocking connections between subscribers and service providers, etc.) and/or combination thereof (e.g., shape traffic in one direction and block connections in the other direction, shape traffic in both directions, block connections in both directions and shape traffic in one direction, etc.). In addition, as previously described, shaping includes dropping of packets. While embodiments of the invention shape in one and/or both directions (e.g. towards the core and/or towards the subscribers), embodiments which do not shape in a given direction may be implemented to drop packets in that direction (e.g. rate limiting). 
       FIG. 6  is an exemplary block diagram illustrating one direction of packet flow in the traffic shaping service node  600  according to one embodiment of the invention.  FIG. 6  illustrates an exemplary embodiment of a conceptual traffic shaping service node used to shape traffic described in  FIGS. 4 and 5 . Although  FIG. 6  illustrates a flow of data traffic from core router  622  to edge router  624 , alternative embodiments of traffic shaping service node  600  can additionally or alternatively shape data traffic from edge router  624  to core router  622 . While in one embodiment, the traffic shaping service node  600  is non-routing, alternate embodiments may include some switching or routing capability (e.g., some simple switching or static routing to support coupling to multiple core and/or edge routers; full edge routing functionality so that flow forwarding decision are made based on dynamic rules to support coupling to multiple core routers and/or directly to devices of the access network typically coupled to edge routers, etc.). In  FIG. 6 , line cards  610 - 614  receive data packets from core router  622  over links  626 - 630 .  FIG. 6  shows by way of illustration, three ingress line cards and three egress line cards. This is only an example for illustration and other embodiments may have more or less ingress or egress line cards. Alternatively, a single line card can function as both an ingress and egress line card. By way of illustration, line cards  610 - 614  process the packets by forwarding packets through packet flow  602  to line cards  616 - 620 . In addition to forwarding packets to line cards  616 - 620 , line cards  610 - 614  generate statistics  606  based on the received packets. Statistics generated may be based on total amount of data traffic, the individual application subscriber data flows, subscriber traffic, etc. In addition, statistics may include duplicates of the received packets. The statistics  606  are forwarded to the traffic policy shaper engine  604 . The traffic shaping service node policy engine  604  processes the statistics along with subscriber policies from subscriber policy manager and updates the traffic shaping policies used by line cards  618 - 620 . The traffic shaping service node policy engine  604  sends the updated traffic shaping policies  608  to line cards  616 - 620 . Line cards  616 - 620  use the updated traffic policies  608  in transmitting packets from packet flow  602  to edge router  624 . 
     Different embodiments use different triggers to update policies. For example, while there are embodiments that use control protocol data triggers and statistical triggers, alternate embodiments may use less, more and/or different triggers. In one embodiment, receiving line cards  610 - 614  recognize control protocol data for a traffic flow and policy engine  604  updates traffic policies  608  in order to support optimal transmission of the data portion of the traffic flow. For example and by way of illustration, VoIP service initiates VoIP calls by exchanging control protocol between sender and receiving nodes. Once the VoIP call is initiated, VoIP service transmits data representing the actual VoIP call. In this example, line cards  610 - 614  identify the VoIP control protocols and policy engine  604  updates traffic policies  608  for VoIP data traffic flow transmission. Line cards  616 - 620  use the updated policy  608  to optimally transmit the data of the VoIP traffic flow. 
     Regardless of the triggers used, different embodiments install policy updates at different times with respect to the packets that caused the trigger. For example and by way of illustration, if traffic shaping service node  600  receives a video traffic flow on line card  610 , line card  610  generates statistics for that video traffic flow. Traffic shaping service node policy engine  604  processes the statistics for this traffic flow, recognizing that this traffic flow requires a certain bandwidth for the video. Policy engine  604  updates the policies for transmitting line card  620  uses to transmit the video traffic flow at the certain bandwidth. Policy engine  604  updates the policy in real-time on line card  620  before line card  620  transmits the video traffic flow. Alternatively, policy engine  604  updates line card  620  after line  620  starts transmitting the video traffic flow. This later model would typically be applied when an associated session control protocol is involved. These protocols are transactional in nature, and can be intercepted before a media stream begins flowing. In both cases, once a media stream flows, the traffic shaping service node  600  typically does not block or cause latency, and shaping policies will be applied either before the flow begins, or as shortly after the flow is detected. 
     While in one embodiment, packets received on one line card (e.g. line card  610 ) trigger an updated traffic policy installation on another line card (e.g. line card  620 ), alternate embodiments may include packets received on one line card that trigger an updated traffic policy installation on that same line card. For example and by way of illustration, control protocol data to initiate a VoD session flows from the subscriber in the access network to a VoD system through the core network. Line card  620  receives the VoD control protocol data, which triggers an update for the VoD media flow (e.g. video stream) to line card  620  that transmit the VoD media flow. 
     While  FIG. 6  illustrates one direction of flow ( 602 ,  606 , &amp;  608 ), it should be understood that other embodiments may support flow in the reverse (e.g., using different line cards or the same line cards) or simultaneous flow in both directions (e.g., using the same line cards or different line cards). By way of particular example, in one embodiment of the invention line cards  616 - 620  receive packets from edge router  624 , generate statistics and forward the statistics to traffic shaping service node policy engine  604 . The traffic shaping service node policy engine  604  generates updated traffic shaping policies to line cards  610 - 614 . Line cards  610 - 614  use the updated traffic shaping policies when transmitting the packets to the core router. Furthermore, while in one embodiment, line cards  610 - 614  receives statistical and control protocol data triggers (representing traffic flow from core router  622  to edge router  624 ), alternate embodiments have other line cards receiving such triggers (e.g., line cards  616 - 620 ), or combinations thereof (e.g., receiving triggers at line cards  610 - 614  and  616 - 620 , etc.). 
     In addition, while  FIG. 6  illustrates statistics generation, policy updates and traffic flow, it should be understood that other embodiments may support statistics generation and policy updates in conjunction with traffic shaping/connection blocking as illustrated in  FIGS. 4A-B  and  5 A-C (e.g. may receive a control packet from subscriber, decide whether to block corresponding connection, and if not block the connection, shape a related traffic flow from the core; may receive a control packet from subscriber, decide whether to block corresponding connection, and if not block the connection, shape a related traffic flow from the subscriber; may shape traffic in one direction, but block connections in both directions; based on control protocol data/statistical triggering events, shape in the same, opposite or both directions; etc.; and/or combinations thereof). 
     In addition to this traffic shaping mode, a further embodiment of traffic shaping service node  604 , has another mode called the passthrough mode. In passthrough mode, traffic shaping service node does no shaping, it just passes the traffic through. That is the packets are transmitted in the same fashion as they are received. The passthrough mode may be used for a variety of reasons, including failures, when traffic shaping service node is overloaded, trouble shooting the network, etc. While traffic shaping service node  602  may apply passthrough mode to traffic flowing in either or both directions it supports, it will be described with reference to one direction. An example of passthrough mode for data flowing between the core ( 502 ) and edge ( 506 ) router may be illustrated by referring to  FIGS. 5B and 5C . In  FIG. 5C , the traffic shaping service node  504  transmits packets  520 - 544  in the same disorderly flow as received in  FIG. 5B , instead of transmitting the packets  520 - 544  in the orderly flow as illustrated in  FIG. 5C . Similarly, an example of passthrough mode for data traffic traveling from the edge router  410  to the core router  402  may be illustrated by referring to  FIGS. 4A and 4B . Instead of shaping packets  412 - 442 , the traffic shaping service node  406  transmits packets  412 - 442  in the same disorderly flow as received in  FIG. 4B . 
     Different embodiments of the invention may use different techniques to implement passthrough mode (e.g. ignoring the traffic shaping policies on line cards  616 - 620 , although the traffic policies exist on line cards  616 - 620 ; deleting thru traffic policies from line cards  616 - 620 , so no traffic policies exist on the line cards  616 - 620 ; etc.) 
     The traffic shaping service node is inserted at a point in the network where the traffic crosses between the core and access networks. This is advantageous because the traffic shaping service node is in a position to shape traffic associated with services destined for subscribers and apply traffic shaping policies for traffic from subscribers targeted to service providers. An example would be voice or video services offered by a provider for subscribers. A traffic shaping service node situated between the core and access networks allows a traffic shaping service node to shape all the voice and/or video traffic going to or coming from the subscriber. Because voice and video services are bandwidth sensitive and because a network can only handle up to a fixed number of instances of voice and/or video sessions, a traffic shaping service node can guarantee optimal performance for the voice and/or video services for all subscribers. A traffic shaping service node not positioned between core and access network cannot shape all the traffic crossing the core and access networks. 
     Alternatively, the traffic shaping service node is positioned in the core network and includes routing functionality. For example, the traffic shaping service node can shape and route traffic related to VoD service. 
     Equivalently, a further embodiment of the traffic shaping service node can be positioned to shape and route traffic from a single or group of subscribers. This traffic shaping service node position may be used for a subscriber (or group of subscribers) that has a great volume or variety of data traffic (e.g. a large corporate subscriber). 
       FIG. 7  is an exemplary flow diagram for shaping traffic according to one embodiment of the invention. In  FIG. 7 , the method  700  receives data packets at block  702 . At block  704 , method  700  determines if there are any data packets available for processing. If not, method  700  waits to receive data packets at block  702 . Otherwise, method  700  performs deep packet inspection and classification on the received packets at block  706 . Deep packet inspection and classification is further described in  FIG. 8 , below. At block  708 , method  700  takes the results of the deep packet inspection and updates the statistics. Updating of statistics is further described in  FIG. 9 , below. At block  710 , method  700  uses the statistics and subscribers policies, and updates in real-time the traffic policies used by the line card(s). Real-time updating of the traffic policies is described in  FIG. 10 , below. Based on the updated traffic policies, the method  700  determines if any of the packets received are dropped at block  712 . For those packets being dropped, method  700  drops those packets and returns to block  702  in order to receive (and process) additional data packets. For those packets not being dropped, at block  712 , method  700  transmits those data packets according to the updated traffic policies and returns to block  704 . 
     Different embodiments may implement passthrough mode in a variety of ways. In one embodiment of passthrough mode, method  700  executes block  704 , but does not perform deep packet inspection and classification. Instead, method  700  jumps down to block  714  to determine transmit. In an alternate embodiment of passthrough mode, method  700  performs deep packet inspection and classification (block  706 ), but forgoes updating the statistics (block  708 ) and proceeds directly to block  712  to either drop or transmit the packet. In yet another alternate embodiment of passthrough mode, method  700  updates statistics (block  708 ), and then proceeds directly to block  714  instead of updating the traffic policy in real-time (block  710 ). In still another alternative embodiment, method  700  performs blocks  706 - 712 , but when transmitting the data packet in block  714 , method  700  transmits without using the traffic policies. 
     The traffic shaping service node  600  illustrated in  FIG. 6  may implement one embodiment of method  700 . Line cards  610 - 620  receives data packets as described in block  702 . Although  FIG. 6  illustrates line cards  616 - 620  transmitting data packets, another embodiment has line cards  616 - 620  receiving data packets. Furthermore, line cards  610 - 620  determine if there are additional data packets to be received as described in block  704 . In addition, line cards perform deep packet inspection and classification as described in block  706 . An alternate embodiment has the traffic shaping service node policy engine  604  performing deep packet inspection (block  706 ). In a still further embodiment, parts of the deep packet inspection method (block  706 ) are performed on both line cards  610 - 620  and the traffic shaping service node policy engine  604 . 
     As illustrated in  FIG. 6 , statistics are generated by line card  610 - 614  and processed by the traffic shaping service node policy engine  604 . Although line cards  616 - 620  are illustrated as not generating statistics  606 , line cards  616 - 620  can similarly generate statistics  606  based on the packets received on line cards  616 - 620 . Thus, both line cards  610 - 620  and traffic shaping service node policy engine  604  update the statistics as described in block  708 . Similarly, both line cards  610 - 620  and traffic shaping service node policy engine  604  update the traffic policy in real-time as described in block  710 . In this embodiment, the traffic shaping service node policy engine updates the current traffic policy and sends the updated traffic policies to line cards  610 - 620 . Although line cards  610 - 614  are illustrated as not receiving the updated traffic shaping policies  608 , an alternate embodiment of block  710  has line cards  610 - 614  receiving the updated traffic policies  608  from the traffic shaping service node policy engine  604 . 
     Finally, based on the updated traffic policies  608 , line cards  610 - 620  determine whether to drop (block  712 ) or transmit the packet according to the traffic shaping policies (block  714 ). Although line cards  610 - 614  are not illustrated in  FIG. 6  as transmitting the packets, an alternate embodiment of  FIG. 6  has line cards  610 - 614  transmitting packet according to traffic shaping policies  608 . 
       FIG. 8  is an exemplary flow diagram for deep packet inspection and classification (“deep packet inspection method”  706 ) according to one embodiment of the invention. Thus,  FIG. 8  illustrates an example of what deep packet inspection and classification can be implemented to accomplish. Of course, alternative embodiments of the invention could implement the deep packet inspection method to do more, less and/or different types of operations. 
     In block  802 , the deep packet inspection method  706  determines if the packet is associated with a subscriber. Different embodiments of the method  706  may use one or more ways to associate packets with a subscriber. For example, identifying the subscriber may be accomplished by associating the source (and possibly destination) address contained in the packet with the subscriber. For a packet based on the OSI model ( FIG. 2 ), the source or destination address is determined by interrogating the network layer header  206  of the packet. As another example, the subscriber may be associated with a circuit identified in the data link layer ( 204 ) of the packet (e.g., circuit information could be in Asynchronous Transfer Mode (ATM) circuits, using virtual path identification (VPI) and/or virtual circuit information (VCI) identifiers; circuit information may be a PPPoE identifier, such as an subscriber and a domain name, etc.). As another example, subscriber information may be contained in the application layer  214 . Still further methods may be employed to identify the subscriber from the data packet depending on the nature of the packet. 
     If the packet is associated with a subscriber, at block  804 , the subscriber associated with the packet is identified. Otherwise, the method  706  skips deep packet inspection and proceeds to block  708 . 
     Returning to  FIG. 8 , from block  804 , control passes to block  806 . In block  806 , deep packet inspection method  706  identifies the application associated with the packet. Block  806  can be implanted any number of ways (or combinations thereof), including those currently known and/or those future developed. By way of illustration, and not by limitation, several will be described. For example, the deep packet inspection method may examine the application layer  214  of the packet. Specifically, the method examines the structure of the data stored in the application layer  214  to determine which application sent or uses this packet. For example, a packet containing several frames of video could indicate the packet is for a VoD application. As another example, deep packet inspection method  706  may interrogate the transport layer header  208  to determine the source or destination port of the packet. Many applications use a well-known port to send or receive the packet. For example, a packet with a source or destination port of  80  is usually associated with web page retrieval. As another example, the deep packet inspection may determine if the source and/or destination address is associated with a particular application. For example, the packet may be associated with a well-known application server located in the core network. 
     From block  806 , control passes to block  808 . At block  808 , deep packet inspection method  706  determines if the packet contains control protocol data in the application layer  214 . An application control protocol is a protocol used to control network functions of an application. For example, Session Initiation Protocol (SIP) is used to set up VoIP calls and video conferencing. If the data packet contains control protocol data, the deep inspection method identifies the control protocol at block  810 . 
     In either case, deep inspection method  706  determines the instance of the application at block  812 . An instance of an application means the number of concurrent application session flowing through the traffic shaping service node. A session is defined as a lasting connection between a user and a peer, where a peer can be a client or a server. A session may be maintained in different levels (e.g., a session may be maintained at the transport layer (for example, Transmission Control Protocol (TCP)) ( FIG. 2 ,  206 ), a session may be maintained by a higher-level program using a method defined in the data packet being exchanged, etc.). In one embodiment of the deep packet inspection method  706 , concurrent application sessions are derived from the application subscriber traffic flows currently moving through the traffic shaping service node. For example, the traffic shaping service node could determine the number of concurrent VoD sessions passing through the traffic shaping service node at any given instance in time. In another embodiment, the number of concurrent application sessions is determined from the application subscriber flows that are currently flowing through the traffic shaping service node or have flowed within a specified time window. This embodiment is used when an application has natural gaps in the data traffic flow, for example, pauses of silence in a VoIP call. 
     From block  812 , control passes to block  814 . At block  814 , the deep packet inspection method classifies the packet based on the subscriber, application, instance of application and whether the packet contains control protocol data. The classification of each packet is used to organize the packets into application subscriber traffic flows and in determining what traffic policy is used when transmitting the packet. From block  814 , control passes to block  708 . 
       FIG. 9  is an exemplary flow diagram for updating statistics (“statistics method”  710 ) according to one embodiment of the invention. Thus,  FIG. 9  illustrates an example of updating statistics from  FIG. 7 , block  708 . Of course, alternative embodiments of the invention could implement the traffic policy method to do more, less and/or different types of operations. 
     At block  902 , the statistics method updates global long terms statistics. These statistics are, but not limited to, the overall packets sent or received by the subscriber. For example, the statistics method may keep track of the total number of packets sent and received by the subscriber. In addition, the statistics method may keep track of the total number of bytes sent and received by the subscriber. Furthermore, the statistics method may collect the total number of packets and bytes sent or received by the traffic shaping service node. From block  902 , control passes to block  904 . 
     At block  904 , the statistics method  708  updates the long-term application specific subscriber statistics. In one embodiment of the invention, these statistics are the number of bytes and packets sent or received on a per application, per subscriber basis. For example, the statistics method  708  may separately track the number of bytes and packets sent for web, VoIP and VoD traffic. These statistics may be used for billing purposes and/or updating traffic policy. From block  904 , control passes to block  906 . 
     At block  906 , the statistics method  708  determines the sliding window used for short-term statistics. The statistics method  708  uses the window to calculate statistics based on given time period. For example, statistics method may calculate a subscriber&#39;s overall bandwidth and application traffic flow bandwidth over a one-minute period. From block  906 , control passes to block  908 . 
     The statistics method  708  updates overall subscriber short-term (block  908 ) and application specific subscriber data rates (block  910 ). For example, for a given moment in time, the subscriber&#39;s overall data rate is 5.0 Mbps, where 3.0 Mbps is for VoD, 128 kbps for two VoIP calls and the rest for web downloads. From block  910 , control passes to block  710 . 
       FIG. 10  is an exemplary flow diagram for updating traffic policy (“traffic policy method”  712 ) in real-time according to one embodiment of the invention. Thus,  FIG. 10  illustrates an example of updating traffic policy in real-time from  FIG. 7 , block  710 . Of course, alternative embodiments of the invention could implement the traffic policy method to do more, less and/or different types of operations. 
     At block  1002 , the traffic policy method retrieves the subscriber policy. In one embodiment, the subscriber policy is stored locally. In another embodiment, the subscriber policy is stored remotely and the traffic policy retrieves the remotely stored subscriber policy. For example, the subscriber policy is stored in a Remote Authentication Dial In User Service (RADIUS) database. From block  1002 , control passes to block  1004 . 
     At block  1004 , the traffic policy method retrieves statistics from entities generating or storing the statistics. In one embodiment, as illustrated in  FIG. 6 , the statistics are retrieved from line cards  610 - 620 . Although  FIG. 6  does not illustrate line cards  616 - 620  generating statistics, line cards  616 - 620  can generate the statistics as well. The retrieved statistics may be subscriber specific, global statistics or both. Returning to  FIG. 10 , from block  1004 , control passes to block  1006 . 
     At block  1006 , the traffic policy method retrieves the current network condition. The network condition is a snapshot of the amount of traffic flowing through the traffic shaping service node. In one embodiment, the network condition is stored with the overall statistics. In addition, network statistics may be stored on a, but not limited to, per port, per circuit, per individual host address, and/or per subnetwork address basis (e.g., IP address with a network or prefix). From block  1006 , control passes to block  1008 . 
     At block  1008 , the traffic policy method retrieves the number of application instances flowing through the box. In one embodiment, the number of application instances is the number of applications presently flowing through the traffic shaping service node. In another embodiment, the number of application instances is determined over a window of time. From block  1008 , control passes to block  1010 . 
     At block  1010 , the traffic policy method retrieves the current short-term subscriber data rate. In one embodiment the data rate is the overall subscriber data rate. In another embodiment, the data rate comprises application specific subscriber data rates. From block  1012 , control passes to block  712 . 
     Using current subscriber policy, the statistics, current network condition and the subscriber&#39;s data rate, the traffic policy method updates the subscriber policy at block  1012 . Referring back to  FIG. 6  and its associated description, subscriber&#39;s policy are one of the traffic policies sent to line cards  616 - 620  from traffic shaping service node policy engine  604 . A subscriber policy may consist of, but is not limited to (a) an overall rate limit on the subscriber&#39;s traffic, (b) permanently changing bandwidth limits for a particular application, (c) temporarily increasing or decreasing bandwidth limits for a particular application or (d) restricting or allowing instantaneous bandwidth based on a long-term data packet throughput. 
       FIG. 11  is a block diagram illustrating a different representation of a traffic shaping service node  1100  according to one embodiment of the invention. Traffic shaping service node  1100  communicates with the core and access networks via core network communications module(s)  1102  (e.g., line cards) and access network communications module(s)  1118  (e.g., on the line cards), respectively. Data packets received on communications module(s)  1102  and  1118  are inspected and classified through deep packet inspection by packet classifying module  1104 . One embodiment of the packet classifying module  1104  resides in the line cards, whereas another embodiment of the packet classifying module  1104  resides in the traffic shaping policy engine. Alternatively, functionality of the packet classifying module can be divided among one or more line cards and/or the traffic shaping policy engine. Results of the deep packet inspection from packet classifying module  1104  are fed into statistics module  1106 . Statistics module  1106  generates statistics on, but not limited to, overall network traffic, subscriber traffic, and application traffic. Similar to the packet classifying module  1104 , the statistics module can reside on the line card, the traffic shaping policy engine, or combinations of the line and/or the traffic shaping policy engine. Policy module  1108  uses results from the statistics module  1106  and updates both subscriber and overall traffic policies. In an exemplary embodiment, policy module  1108  resides in the processor card. Updated traffic policies are fed to traffic monitor module  1110 . 
     Data packets from packet classifying module are forwarded to traffic forwarding and shaping module  1110 . Traffic forwarding and shaping module  1110  forwards data packets using the updated traffic policies to either core network  1102  or access network  1118  communications module(s), depending on the destination of data packet. In an exemplary embodiment, traffic forward and shaping module  1110  resides in a line card. 
     Control module  1112  configures and controls packet classifying module  1104 , statistics module  1106 , policy module  1108 , traffic monitor module  1110 , communications modules  1102  and  1118 , reporting module  1114  and alarm module  1116 . In one embodiment, control module  1112  comprises a graphical user interface (GUI) used to configure and control the other modules. Alternatively, control module  1112  is a command-line interface or simple network management protocol (SNMP) agent. In an exemplary embodiment, control module  1110  resides in a processor card. 
     Reporting module  1114  generates system reports based on the traffic flow through the traffic shaping service node  1100 . In an exemplary embodiment, reporting module  1114  resides in a processor card. Finally, the alarm module  1116  generates and sends alarms alerting operators to problems with the traffic shaping service node  1100 . In an exemplary embodiment, alarm module  1116  resides in a processor card. 
     Exemplary Traffic Shaping Service Node Architecture 
       FIGS. 2-11  detail a traffic shaping service node used to shape network data traffic between a core and access network. A hardware architecture embodiment of the traffic shaping service node, as illustrated in  FIGS. 2-11 , requires sufficient hardware resource to inspect, classify, shape and transmit the potentially millions of packets per second flowing between the core and access networks. Conceivably, one embodiment of the traffic shaping service node may be as simple as a device comprising of a central processing unit (CPU) and two network interfaces. However, this embodiment requires a very large amount of processing power in one CPU to inspect, classify, shape and transmit millions of packets per second. This capability is currently beyond state of the art for CPUs, whether general purpose CPU or CPUs specialized for network processing. An embodiment of the traffic shaping service node comprising multiple CPUs would be better able to handle the high flow of network data traffic between the core and access networks. Furthermore, the traffic shaping service node should comprise of more than two network interfaces so as to handle one core network communicating with multiple access networks and have multiple network connections between the traffic shaping service node and a single core or access network. 
       FIGS. 12-16  illustrate exemplary network device architectures that may be used for a variety of purposes, including but not limited to, a traffic shaping service node as previously described. Thus, while for exemplary network device architectures described with reference to  FIGS. 12-16  are described with reference to a traffic shaping service node, it should be understood that these architectures are independent as part of the invention. 
       FIG. 12  is a block diagram illustrating a mesh backplane used in the traffic shaping service node according to one embodiment of the invention. In  FIG. 12 , a number of processor cards  1204 - 1210  are communicatively coupled to line cards  1212 - 1230  through a mesh of  10  Gbps backplane links coupling each processor card-processor card, line card-line card and processor card-line card pair with an aggregate bandwidth of 230 Gbps. A 10 Gbps connection between each pair of cards allows a large volume of data traffic and communication between the processor and line cards. The data traffic flowing between each pair of line cards and each pair of processor-line cards is illustrated in  FIG. 13 , below. In addition to processor card-line card connectivity, processor card-processor card connections enable the coordination of high speed communications between compute resources. In addition, it allows for different ratios of processor cards to line cards since each slot is connected to every other slot. For example and by way of illustration, data traffic flows between the processor cards can be, but not limited to, statistics data, policy provisioning, routing information, etc. 
     Furthermore, the use of a mesh backplane as illustrated in  FIG. 12 , allows for a failover mode in the traffic shaping service node. For example, in one embodiment, consider a scenario where data packets are flowing from line card  1212  to line card  1214  while processor card  1206  updates line card  1214  with traffic policies. If line card  1214  should fail, the system can automatically switch the flow of data packets from line card  1212  to line card  1216  and update the traffic policies from  1206  to line card  1216 . This allows for different configurations in which the number of line cards use the number of processor cards can be adjusted to meet application requirements. In addition, in another embodiment, mesh backplane  1202  allows for failover of a processor card. For example and by way of illustration, in this embodiment, functionality and state of processor  1206  is running on backup processor  1208 . This means that processor card  1208  is ready to take over in the event processor card  1206  fails. If processor card  1206  fails, processor card  1208  assumed processing formerly performed by processor card  1206 . 
     An alternative embodiment of the traffic shaping service node can use a backplane that is not a mesh backplane. For example, line cards  1212 - 1230  and processor cards  1204 - 1210  may communicate via a bus architecture, where each card  1204 - 1230  connects to a single high-throughput bus. Alternatively, traffic shaping service node can use any high speed backplane configuration known in the art (e.g. dual-star, etc.) and/or developed in the future. 
       FIG. 13  is a block diagram of an architecture  1300  illustrating communication between a line card and multiple processors according to one embodiment of the invention. In  FIG. 13 , a line card  1302  is communicatively coupled to multiple processors  1304  via a 10 Gbps connection. Alternate embodiments may have slower or faster speed connections. As the line card  1302  receives the data packet on an ingress port  1310 , line card  1302  processes the data packets by sending a high bandwidth of statistics  1306  to the multiple processors  1304 . In addition, the line card  1302  sends received data packets to either the back plane  1314  to get to another line card  1316  for transmission or transmits the packets out one of the egress ports. 
     Furthermore, in  FIG. 13 , the multiple processors  1304  process the high bandwidth of statistics  1306 . In one embodiment, the multiple processors  1304  are contained in one processor card. In an alternate embodiment, the multiple processors are contained in multiple processor cards. After processing the statistics the multiple processors  1304  send continuous feedback  1308  to the line card  1302 . In one embodiment, the continuous feedback  1308  updates traffic policies for the network condition as a whole and not particular to a subscriber. For example, the multiple CPUs  1304  determine that the amount of data traffic flowing to the access network is higher than the access network can handle. In this embodiment, the traffic policy scales back all data traffic headed for the access network. In another embodiment, the continuous feedback updates traffic policy for all subscribers. An example of this type of traffic policy update would be if a new service is added or modified that results in new bandwidth for the service. For example, a service provider adds a new VoD service requiring 3.5 Mbps for each VoD session (i.e. each VoD application subscriber traffic flow). The multiple processors  1304  push down the traffic policy via the continuous feedback  1308  for the VoD service to the line card  1302 . 
     In a still further embodiment, the continuous feedback  1308  updates traffic policy for one subscriber. In one embodiment of the updated traffic policy, a subscriber&#39;s traffic is at too high a rate to comply with the subscriber&#39;s monthly data packet throughput. Thus, the updated traffic policy dials down nonessential data traffic (e.g. web traffic, file transfer, etc.) to a rate that would be better in line with the subscriber&#39;s monthly data packet throughput. In example above, the continuous feedback  1308  is used to update the traffic policy in real-time. By the multiple processors  1304  continually updating the line card  1302  with latest traffic policies on a per subscriber, per application or network-wide basis, line card  1302  gives greater control over the data traffic currently flowing through the network. 
     An advantage of architecture  1300  is that there is a large amount of processing power compared with the communication throughput. For example, if comparing one exemplary line and processor card as described in  FIGS. 15 and 16 , (and using the Broadcom 1480 CPU as an exemplary CPU that has an 12,000 millions of instructions per second (MIPS) rating) there are up to 48,000 MIPS per 10 Gpbs of communications throughput. Another metric is the number of MIPS per 1 Gbps network throughput available in architecture  1300 . In one embodiment, assuming two processors cards supporting ten line cards, architecture  1300  has 96,000 Dhrystone MIPS for 100 Gbps of network throughput, or 960 Dhrystone MIPS per 1 Gbps. This high amount of processing power enables architecture  1300  to process a high amount of statistics. Furthermore, architecture  1300  is built to withstand a “packet storm” state. A packet storm is a high volume of packets, statistics or other information being processed within a network device. Usually, a packet storm is a volume of packets, statistics or information that is too great for a network device and results in a shutdown or degradation of performance of the network device. However, architecture  1300  is designed to handle this high volume through the use of a high level of processing power coupled with a high speed mesh backplane. 
     Furthermore, an exemplary embodiment of architecture  1300  is specialized for traffic shaping and not routing. In this embodiment, packet routing decision are made by devices other than architecture  1300 , thus allowing for a highly specialized device than can handle the high volume of packets, statistics and other information. Alternative embodiments of architecture  1300  add routing decisions to architecture  1300 . 
       FIG. 14  is a block diagram illustrating an architecture  1400  of line and processor cards including processor-line card connections, according to one embodiment of the invention.  FIG. 14  illustrates architectural detail represented by  FIG. 13 . The architecture  1400  presented shows processor cards  1402 - 1406  connected to line cards  1438  and  1440  through a 10 Gbps backplane mesh  1466 . As illustrated in  FIG. 12 , every card connects to every other card with a 10 Gbps connection. Alternate embodiments may have faster or slower speed connections. Although only three processor cards  1402 - 1406  and two line cards  1438  and  1440  are illustrated, the architecture  1400  presented can scale to any number of processor and line cards. Furthermore, the architecture  1400  presented can accommodate any mix of processor and line cards, although an optimal mix is two or three line cards for every one processor card. An exemplary embodiment of architecture  1400  has four processor cards and ten line cards. 
     In  FIG. 14 , processor card  1402  comprises multiple CPUs  1408 - 1412  connected to shelf processor communication connector  1416  through a VHCLL bus  1414 . In one embodiment, processor card  1402  has four CPUs, although other embodiments can have more or less CPUs. The VHCLL bus  1414  on processor card  1402  provides a relatively high speed connection (e.g., 20 Gbps) between the backplane and the CPUs. This allows the CPUs to process and communicate at a full 10 Gbps bandwidth of data with both line cards  1438 - 1440  and processor cards  1404 - 1408  concurrently. Processor cards  1404  and  1406  have similar architecture to processor card  1402 . 
     The line card  1430  illustrated in  FIG. 14  further comprises line card communication connection  1442  to the backplane mesh  1466 . Network processor  1446  and host CPU  1444  connect to the line card communication connection as well as protocol queue  1452  and statistics  1450  queue. Physical interface  1448  connects with network processor  1448 . In one embodiment, the physical interface  1448  is an optical port and may be one of OC-192, OC-48, fiber-based GigE, fiber-based 10 GigE etc. In another embodiment, the physical interface is an electrical port, such as a copper-based GigE or 10/100 Ethernet port. In still a further embodiment, the physical interface is a wireless transceiver and may be radio transceiver based on protocols 802.11a, 802.11b/g and 802.16 (WiMAX). Alternatively, the wireless physical interface  1448  could be infrared port. In the three embodiments mentioned, the physical interface  1448  can comprise of one or more of optical, electrical or wireless ports. In an exemplary embodiment, physical interface  1448  comprises one OC-192, four OC48, one 10 GigE or ten GigE ports. Line card  1440  has the same architecture as line card  1438 . 
     In  FIG. 14 , line card  1438  receives data packets through the physical interface  1448 . The network processor  1446  processes the packets by deep packet inspection. The network processor  1446  passes the packet on to the line card communication connection  1442 . Furthermore, network processor provides the results of the deep packet inspection to the statistics queue  1450  and protocol queue  1452 . Statistics queue  1450  and protocol queue  1452  each feed their respective data to the line card communication connection  1442 . The line card communication connection  1442  puts the statistics and protocol data onto the backplane mesh  1466  in order for the data to be forwarded to one of the processor line cards  1402 - 1406 . Processor cards  1402 - 1406  process the statistics and protocol data. 
     In addition, the line card communications connection  1442  puts the data packet on to the backplane mesh and forwards the data packet to line card  1440 . However, it is understood line card communications connection  1442  can possibly forward packets to any other line card present in the traffic shaping service node. In an exemplary embodiment with ten line cards, line card communications connection  1442  can forward data packets to any one of the other nine line cards. Line card  1440  receives the data packet at line card communication connection  1454 . In addition, the line card communication receives feedback from processor cards  1402 - 1406  as updated network traffic policies. The Host CPU  1456  process the received network traffic policies and updates the network traffic policies used by network processor  1458 . Network processor  1458  transmits the received data packet through physical interface  1460 . 
       FIG. 15  is a block diagram illustrating architecture of a line card  1500  according to one embodiment of the invention. In  FIG. 15 , the line card  1500  comprises a physical interface  1502  connected to the network processor  1506  via a Systems Packet Interface level 4-phase 2 (SPI 4.2) connection  1516 . In an exemplary embodiment, physical interface  1502  comprises one OC-192, four OC-48, one 10 GigE or ten GigE ports, although physical interface  1502  is not limited to such ports. In one embodiment, network processor  1506  is an EZChip NP2 network processor. In another embodiment, network processor may be EZChip NP1C or another similar network processor. The host CPU  1508  connects to the physical interface  1502  via a peripheral component interface (PCI)  1518 . Network processor  1506  has memory  1504  associated with the network processor  1506 . The network processor  1506  connects to the fabric interface via data and control connections. First, a data connection between the network processor  1506  and the fabric interface  1512  is made through a common switch interface (CSIX) over a low voltage differential signaling (LVDS) connection  1524 . Secondly, a control connection between the network processor  1506  and the fabric interface  1512  is made through a field programmable gate array (FPGA)  1510 . The connection between the network processor  1506  and the FPGA  1510  is through a CSIX (N×2G) connection. The FPGA  1510  connects to the control port of the fabric interface  1512 . The FPGA also connects to the Host CPU  1508  over a GigE interface. Of course, alternative embodiments use different architectures for line card  1500 . 
       FIG. 16  is a block diagram illustrating architecture of a processor card  1600  according to one embodiment of the invention. In  FIG. 16 , by way of illustration, processor card  1600  comprises four processors (Processor  1602 - 1608 ). Processor card may contain more or less processors, depending on the computing resources of each processor. Processors can be one of, but not limited to, AMD OPTERON, TRANSMETA EFFICEON, Broadcom 1280 MIPS, Broadcom 1480 MIPS, and MPC 8540 (RAPIDIO). Each processor has a memory port and a VHCLL port. The memory port connects each processor to the dedicated processor cache  1618 - 1624 . Furthermore, each processor has its own dedicated memory  1610 - 1616 . The VHCLL port from processors  1604  and  1608  connect to the processor card FPGA  1626 . The FPGA  1626  connects to the fabric interface  1628 , which in turn connects to the switch fabric  1630 . Of course, alternative embodiments use different architectures for processor card  1600 . 
     This implementation of the application aware traffic shaping service node is an example, and not by way of limitation. Thus, network elements having other architectural configurations can incorporate embodiments of the invention. Examples of other network elements that could incorporate embodiments of the invention could have multiple forwarding cards or have a single line card incorporating the functionality of both the forwarding and the controlling. Moreover, a network element having the forwarding functionality distributed across the traffic cards could incorporate embodiments of the invention. 
     The traffic as well as the line cards, and processor cards included in the different network elements include memories, processors and/or Application Specific Integrated Circuits (ASICs). Such memory includes a machine-readable medium on which is stored a set of instructions (i.e., software) embodying any one, or all, of the methodologies described herein. Software can reside, completely or at least partially, within this memory and/or within the processor and/or ASICs. For the purposes of this specification, the term “machine-readable medium” shall be taken to include any mechanism that provides (i.e., stores and/or transmits) information in a form readable by a machine (e.g., a computer). For example, a machine-readable medium includes read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.); etc. 
     Alternative Embodiments 
     For example, while the flow diagrams in the figures show a particular order of operations performed by certain embodiments of the invention, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.) 
     While the invention has been described in terms of several embodiments, those skilled in the art will recognize that the invention is not limited to the embodiments described, can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative instead of limiting.