(12) United States Patent
`(10) Patent N0.:
`US 6,970,943 B1
`
`Subramanian et al.
`(45) Date of Patent:
`Nov. 29, 2005
`
`U5006970943B1
`
`(54) ROUTING ARCHITECTURE INCLUDINGA
`COMPUTE PLANE CONFIGURED FOR
`HIGH-SPEED PROCESSING OF PACKETS
`TO PROVIDE APPLICATION LAYER
`
`SUPPORT
`.
`,
`,
`.
`InVemorS Slva subr?maman> cam NC (US)>
`Tall-LaVlaIl,SunHYVa1€, CA(US)
`
`(75)
`
`.
`(73) ASSIgnee: Nortel Networks Limited, St. Laurent
`(CA)
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U S C 154a,) by 1028 days
`'
`'
`'
`
`'
`
`6,134,589 A * 10/2000 Hultgren ..................... 709/227
`6,151,633 A
`11/2000 Hurst et al.
`709/235
`
`........... 709/202
`6,157,941 A * 12/2000 Verkler et al.
`............. 370/235
`6,226,267 B1
`5/2001 Spinney et al.
`6,286,052 B1
`9/2001 McClOghrie et al.
`....... 709/238
`6 289 389 B1
`9/2001 Kikinis
`709/239
`6:424:621 B1
`7/2002 Ramaswamy et al.
`...... 370/230
`6,560,644 B1 *
`5/2003 Lautmann et al.
`.......... 709/223
`6,570,867 B1
`5/2003 Robinson et al.
`.....
`370/351
`
`8/2003 McCanne ................... 709/238
`6,611,872 B1 *
`6,611,874 B1 *
`8/2003 Denecheau et al.
`......... 709/239
`6,754,219 B1 *
`6/2004 Cain et al.
`.................. 370/401
`6,757,289 B1 *
`6/2004 Cain et a1.
`.................. 370/401
`6,785,704 B1 *
`8/2004 McCanne ................... 718/105
`6,792,461 B1 *
`9/2004 Hericourt .......
`709/225
`
`6,810,421 B1 * 10/2004 Ishizaki et al.
`709/226
`.................. 709/238
`6,810,427 B1 * 10/2004 Cain et al.
`
`(21) Appl. No.: 09/736,692
`
`(22)
`
`Filed:
`
`Dec. 13, 2000
`
`Related US. Application Data
`
`* cited by examiner
`
`Primary Examiner—Nabil El-Hady
`(74) Attorney, Agent, or Firm—Withrow & Terranova,
`PLLC
`
`(60)
`
`PrOViSional application No. 60/239,484, filed on Oct.
`11, 2000.
`
`(57)
`
`ABSTRACT
`
`7
`
`............................................. G06F 15/173
`Int. Cl.
`(51)
`...................... 709/238; 709/223; 709/225;
`(52) US. Cl.
`709/226; 709/227; 709/230; 709/232
`_
`(58) Fleld of Search ................................ 709/200, 202,
`709/223, 225, 226, 227,238,239, 230, 232
`
`(56)
`
`References Cited
`US. PATENT DOCUMENTS
`
`5:167:03 A
`5,377,327 A
`5’495’426 A
`5,854,899 A
`6,044,075 A
`6,078,953 A
`6,092,096 A *
`
`11/1992 Bryant 6t al~ ~~~~~~~~~~~~~~~ 709/235
`
`12/1994 Jain et al. ................ 709/235
`2/1996 wadaWSky et al’ """" 709/226
`12/1998 Callon et al.
`............... 709/238
`..... 370/351
`3/2000 Le Boudec et al.
`.
`
`............... 709/223
`6/2000 Vaid et a1.
`
`........................ 709/200
`7/2000 Lewis
`
`The present invention provides a routing architecture includ-
`mg a control plane, a compute plane, and a forward plane.
`The forward plane provides traditional forwarding of pack-
`ets to the next-hop address, along with any necessary header
`manipulation, whlle the control plane configures the forward
`plane and the compute plane for desired operation. The
`compute plane is configured for high-speed processing of
`packets to provide application level support,
`including
`manipulating application data in the payload of the packets
`during routing. The forward plane preferably implements
`forwarding rules using filters sufficient to forward a received
`packet to the next_h0p address, to the compute plane for
`a
`lication rocessin
`or to the control
`lane to facilitate
`p
`.g’
`pp
`COHHOI 0r configuramn'
`
`p
`
`37 Claims, 4 Drawing Sheets
`
`/10
`
`COMPUTE PLANE
`
`MEMORY
`42
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`B l
`A N
`FORWARD
`s B
`B I
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`52
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`CONTROL PLANE
`BACKPLANE
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`INTEngACE
`CONTROL
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`Q
`223
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`1
`
`ARISTA 1006
`
`1
`
`ARISTA 1006
`
`

`

`US. Patent
`
`Nov. 29, 2005
`
`Sheet 1 0f4
`
`US 6,970,943 B1
`
`/10
`
`CONTROL PLANE
`
`12
`
`16
`
`COMPUTE SERVICES
`18
`
`NETWORK SERVICES
`20
`
`COMPUTE API
`
`NETWORK API
`
`2
`
`a
`
`COMPUTE PLANE
`14
`
`FORWARD PLANE
`
`FIG. 1
`
`CONTROL PLANE
`
`1.2
`
`1‘1
`
`COMPUTE SERVICES
`
`NETWORK SERVICES
`
`g
`
`20
`
`COMPUTE API
`
`NETWORK API
`
`2
`
`21
`
`COMPUTE PLANE
`
`FORWARD PLANE
`16
`
`FO RWARDED
`PACKETS
`
`FIG. 2
`
`2
`
`

`

`US. Patent
`
`Nov. 29, 2005
`
`Sheet 2 0f4
`
`US 6,970,943 B1
`
`/-10
`
`CONTROL PLANE
`
`
`
`COMPUTE SERVICES
`
`NETWORK SERVICES
`
`1_8
`
`2_0
`
`COMPUTE API
`
`NETWORK API
`
`2_2
`
`2_4
`
`COMPUiAE PLANE
`
`FORWARD PLANE
`
`16
`
`PACKETS
`MANIPULATED BY
`COM PUTE PLANE
`
`FIG. 3
`
`CONTROL PLANE
`
`CONFIGURATION
`INSTRUCTIONS
`
`2
`
`_1_4
`
`COMPUTE8SERVICES
`
`NETWORK SERVICES
`
`20
`
`COMP2U2TE API
`
`NETWORK API
`2_4
`
`COMPUTE PLANE
`
`FORWARD PLANE
`
`PACKETS DIRECTED
`TO CONTROL PLANE
`
`FIG. 4
`
`3
`
`

`

`US. Patent
`
`Nov. 29, 2005
`
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`US 6,970,943 B1
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`Nov. 29, 2005
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`

`US 6,970,943 B1
`
`1
`ROUTING ARCHITECTURE INCLUDING A
`COMPUTE PLANE CONFIGURED FOR
`HIGH-SPEED PROCESSING OF PACKETS
`TO PROVIDE APPLICATION LAYER
`SUPPORT
`
`This application claims the benefit of provisional appli-
`cation No. 60/239,484, filed Oct. 11, 2000, entitled COM-
`PUTATION IN NETWORK DEVICES, and is related to
`application Ser. No. 09/736,678, filed Dec. 13, 2000, entitled
`DISTRIBUTED
`COMPUTATION
`IN
`NETWORK
`DEVICES and Ser. No. 09/736,674, filed Dec. 13, 2000,
`entitled SERVICE BASED ROUTING, the disclosures of
`which are incorporated herein by reference in their entirety.
`
`FIELD OF THE INVENTION
`
`The present invention relates to processing and routing
`packets in a network, and in particular, to providing high-
`speed, application level processing on the packets during
`routing.
`
`BACKGROUND OF THE INVENTION
`
`Existing routers have limited computation capacity and
`offer little or no application layer support during routing.
`These routers are typically divided into a control plane and
`a forward plane. The control plane is used for basic setup
`and control of the router. For example, the control plane is
`generally used to establish routing tables used by the for-
`ward plane. The forward plane receives packets, processes
`the packets based on the routing tables set up by the control
`plane, and delivers the packets to the next-hop address or the
`final destination, depending on the termination point for
`each packet.
`The forward plane in existing routers is typically limited
`to packet delivery based on basic header analysis and
`manipulation. Application layer support, such as that requir-
`ing analysis or manipulation of the packet’s payload, is
`typically avoided. Those specially configured devices
`capable of providing application processing, such as fire-
`walls, are uniquely configured for the special application
`wherein the routing speeds for normal routing in the forward
`plane are significantly impacted or the control plane is
`uniquely adapted to handle such processing. In either case,
`basic routing capability of the forward plane is inhibited.
`Thus, traditional network routers typically do not provide
`application level processing, and routing devices providing
`such support are only used in limited applications.
`Given the general desire to distribute processing over a
`network, there is a need for efficient routing devices capable
`of providing application level processing without signifi-
`cantly impacting forwarding performance for the packets
`being processed at an application level or for those requiring
`only basic routing. There is a further need to provide a
`routing device that is readily configurable to provide various
`types of application support
`in any number of network
`environments.
`
`SUMMARY OF THE INVENTION
`
`invention provides a routing architecture
`The present
`including a control plane, a compute plane, and a forward
`plane. The forward plane provides traditional forwarding of
`packets to the next-hop address, along with any necessary
`header manipulation, while the control plane configures the
`forward plane and the compute plane for desired operation.
`
`10
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`2
`The compute plane is configured for high-speed processing
`of packets to provide application level support, including
`manipulating application data in the payload of the packets
`during routing.
`The forward plane preferably implements forwarding
`rules using filters sufficient to forward a received packet to
`the next-hop address, to the compute plane for application
`processing, or to the control plane to facilitate control or
`configuration. For those packets not sent to the compute
`plane or control plane, the forward plane will provide any
`necessary processing and forward the packets from an input
`port
`to an output port. Additionally,
`the forward plane
`receives packets from the control plane and the compute
`plane for forwarding after processing by the respective
`planes.
`Preferably, the compute plane is implemented using high-
`speed field programmable gate arrays (FPGAs), application
`specific integrated circuits (ASICs), digital signal processors
`(DSP), network processors, or a combination thereof suffi-
`cient to provide processing speeds that are close to forward-
`ing speeds of the forward plane. Further, the compute plane
`is preferably configurable by the control plane to provide
`various types of application processing. The compute plane
`may be configured to provide different types of application
`processing for different packets. The forward plane may be
`set to determine where to send the packets in the compute
`plane for processing, or the compute plane may determine
`how or where to process the packets upon receipt.
`With the present invention, the routing device is able to
`perform application level processing on packets without
`impacting forwarding performance. The invention separates
`the task of control from computation to avoid negatively
`impacting performance for either task. A new, high-speed
`computation plane is provided in the routing device to
`handle application level processing, while the forward plane
`provides basic forwarding. The routing abilities of the
`present invention may be provided in any number of net-
`work devices, including traditional routers and media gate-
`ways capable of routing packets over homogeneous or
`heterogeneous networks.
`Those skilled in the art will appreciate the scope of the
`present invention and realize additional aspects thereof after
`reading the following detailed description of the preferred
`embodiments in association with the accompanying drawing
`figures.
`
`BRIEF DESCRIPTION OF THE DRAWING
`FIGURES
`
`The accompanying drawing figures incorporated in and
`forming a part of the specification illustrate several aspects
`of the invention, and together with the description serve to
`explain the principles of the invention.
`FIG. 1 depicts a preferred architecture for a routing node
`constructed according to the present invention.
`FIG. 2 illustrates the forwarding path of packets pro-
`cessed within the forward plane of the architecture shown in
`FIG. 1.
`
`FIG. 3 illustrates the forwarding path of packets pro-
`cessed by the compute plane of the architecture shown in
`FIG. 1.
`
`FIG. 4 illustrates the forwarding path of packets directed
`to the control plane and the path of instructions for config-
`uring the compute plane and forward plane from the control
`plane according to a preferred embodiment of the present
`invention.
`
`6
`
`

`

`US 6,970,943 B1
`
`3
`FIG. 5 is a flow diagram outlining the basic flow for
`processing packets in the control plane, compute plane,
`and/or the forward plane according to a preferred embodi-
`ment of the present invention.
`FIG. 6 is a block schematic of a preferred configuration of
`a routing node according to the present invention.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`
`The present invention provides for a routing node having
`a separate processing plane for application layer support
`during routing. The application layer support may include
`any type of processing or network service on packet content.
`In addition to forward and control planes, the routing node
`includes a separate compute plane for processing packets
`according to specific applications during routing. The for-
`ward plane provides traditional forwarding, along with any
`necessary header manipulation, while the control plane
`preferably configures the forward plane and the compute
`plane as desired. Upon reading the following description in
`light of the accompanying drawing figures, those skilled in
`the art will understand the concepts of the invention and will
`recognize applications of these concepts not particularly
`addressed herein. It should be understood that these con-
`
`cepts and applications fall within the scope of this disclosure
`and the accompanying claims.
`The embodiments set forth below represent the necessary
`information to enable those skilled in the art to practice the
`invention and illustrate the best mode of practicing the
`invention. With reference to FIG. 1, a routing node is
`illustrated and generally referenced as 10. The routing node
`10 is divided into three primary processing planes; a control
`plane 12, a compute plane 14, and a forward plane 16.
`Preferably, all incoming packets are received by the forward
`plane 16 through various ports interacting with a network,
`such as a packet-switched network. The forward plane 16 is
`configured to analyze each of the incoming packets and
`determine where to send each packet. In general, the incom-
`ing packets need to be forwarded on toward their final
`destination, to the control plane 12, or to the compute plane
`14.
`
`Depending on the extent or nature of any necessary
`manipulation of the packet, the packet may be processed by
`the forward plane 16 and forwarded to the next-hop routing
`node or final destination. Preferably, any packet processing
`provided by the forward plane 16 is limited to manipulating
`information in one or more headers of the packet as neces-
`sary in traditional routing. As depicted in FIG. 2, packets
`requiring only traditional routing are maintained in the
`forward plane 16 for processing and immediately forwarded
`to the next-hop routing node or destination.
`Packets entering the forward plane 16 that require appli-
`cation level processing, which may entail manipulation of
`the packet’s payload, are directed to the compute plane 14
`by the forward plane 16. As depicted in FIG. 3, these packets
`are passed through the forward plane 16 to the compute
`plane 14 for processing and then sent back to the forward
`plane 16, which will forward the processed packet to the
`next-hop routing node or final destination.
`Although additional detail is provided below, the compute
`plane 14 provides application level processing, and any
`necessary payload manipulation required by such process-
`ing. During processing by the compute plane 14, the payload
`may be reviewed, removed, modified, and repacked as
`directed by any number of applications. The routing node 10
`
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`4
`preferably supports programming and unique configuration
`of the compute plane 14 and the forward plane 16.
`Any number of applications may be supported through the
`compute plane 14. For example, Internet Protocol (IP)
`security and secure socket layer (SSL) applications may be
`implemented in a routing node 10 using the compute plane
`14. Various types of multimedia applications are made
`possible, alone or in combination with other applications.
`Further, incorporating a high-speed compute plane 14 for
`application specific packet processing enables streaming
`applications and minimizes or eliminates the need for buff-
`ering. The compute plane 14 is capable of implementing
`virtually any type of application, ranging from carrying out
`mathematical operations on payloads to implementing com-
`pression and encryption algorithms. The compute plane 14
`may also help facilitate high-speed firewalls acting as a
`single point of entry or distributed to provide multiple points
`of entry. Typically, the compute plane 14 operates on layer
`four and higher protocols that are typically application
`related.
`
`In addition to traditional forwarding of incoming packets
`and directing packets to the compute plane 14 for process-
`ing, the forward plane 16 may direct selected incoming
`packets to the control plane 12 for basic communications
`with the routing node 10 as shown in FIG. 4. In essence, the
`control plane 12 provides overall control and configuration
`for the routing node 10, and in particular, for the compute
`plane 14 and the forward plane 16. This control may range
`from running diagnostics to setting configurations for the
`compute plane 14 and the forward plane 16. These settings
`may dictate the type of processing to carry out on the
`incoming packets and which plane handles the processing.
`Returning now to FIG. 1, the routing node 10 may support
`various services, which are groups of code or objects that
`implement specific functionality. Preferably, these services
`use Java code and may be divided into compute services 18
`related to the compute plane 14, and network services 20
`related to the operation of the forward plane 16. Each of
`these services cooperates with the corresponding compute
`plane 14 and forward plane 16 via a compute application
`program interface (API) 22 and network API 24, respec-
`tively. Since the services are preferably Java compatible, the
`compute API 22 and network API 24 may specify interfaces
`for Java applications to control the respective compute plane
`14 and forward plane 16.
`Preferably, the network API 24 can be used to instruct the
`forward plane 16 to alter packet processing through the
`installation of hardware or software filters that facilitate
`
`forwarding rules. These filters execute actions specified by
`a defined filter policy. Typically, these filters can be based on
`combinations of fields in the machine address, IP address,
`and transport headers. The filters may also be configured to
`trigger on a payload as well. The filter policy can define
`where the matching packets are delivered and can also be
`used to alter the packet content as noted above.
`Typical packet delivery options include discarding match-
`ing packets and diverting matching packets to the control
`plane 12 or compute plane 14 based on the filter policy. With
`the present invention, a high-speed compute plane 14 is
`provided to handle such processing. Additionally, packets
`may be “copied” to the control or compute planes 12, 14 or
`may be mirrored to a selected interface. Packets may also be
`identified as being part of high-priority flow; these packets
`can be placed in a high-priority queue and delivered accord-
`ingly. As noted, the filter policy can also cause packet and
`header content to be selectively altered for most of these
`operations. The particular plane handling the processing is
`
`7
`
`

`

`US 6,970,943 B1
`
`5
`capable of re-computing IP header check sums at high
`speeds when and if the IP header or payload is changed.
`In the present invention, all control plane computations,
`such as installing new routing tables or parsing a new
`Internet Control Message Protocol (ICMP) message type,
`are easily accommodated through the network API 24.
`Through the network API 24, the forward plane 16 may
`provide a number of services. The applications are typically
`contained within the forward plane 16 and will not require
`additional processing by the compute plane 14 for traditional
`operation. The following list of services is merely exemplary
`and is not intended to limit the scope of the present inven-
`tion.
`
`A filtering firewall may be implemented that allows or
`denies packets to traverse specified interfaces depending on
`whether the packet header matches a given bit map. An
`application specific firewall may be implemented that
`dynamically changes the firewall rules according to the
`application. For example, a file transfer protocol (FTP)
`gateway that dynamically changes the firewall rules to allow
`FTP data connections to a trusted host can be implemented.
`Security functions like stopping Transmission Control Pro-
`tocol (TCP) segments with no or all bits set can also be
`dynamically programmed.
`Dynamic Real-Time Transfer Protocol (RTP) flow iden-
`tification is possible. RTP over User Datagram Protocol
`(UDP) flows, which are often not well known, are identified
`by a UDP port number. Mechanisms can be implemented to
`identify RTP flows based on the UDP port number. For
`example, control protocol messages, such as those used in
`Session Initiation Protocol (SIP), Real Time Streaming
`Protocol (RTSP), and H.323, can be intercepted and parsed
`for their RTP port numbers. Various differential services may
`be provided. For example, the forward plane 16 may be
`configured as a differential service classifier by properly
`programming the filters or forwarding rules. Since the
`forward plane 16 may change selected bits and IP header at
`line speed, the routing node 10 can be used to implement
`ingress/egress marker capabilities for differential services.
`Reliable multi-casts are also made possible with proper
`forwarding rules.
`In addition to being able to copy certain packets for
`inspection by the control plane 12, the forward plane 16 may
`be used to divert acknowledgements from multi-cast ses-
`sions to the control plane 12. For example, the forward plane
`16 can send one copy of the acknowledgment to the control
`plane 12 and suppress duplicate acknowledgements. Addi-
`tionally, a token bucket system may be arranged where a
`configurable buffer is implemented with a specified packet
`draining rate. Differential service shapers and assorted
`RSVP policies can be implemented as well. RSVP is a
`resource reservation setup protocol for the Internet. Its major
`features include: (1) the use of “soft state” in the routers, (2)
`receiver-controlled reservation requests, (3) flexible control
`over sharing of reservations and forwarding of subfiows, and
`(4) the use of IP multicast for data distribution. For addi-
`tional information regarding RSVP, please see the Internet
`Engineering Task Force’s RFCs 2205 through 2210, which
`are incorporated herein by reference in their entirety.
`The various functions provided by the forward plane 16
`listed above relate to analyzing incoming packets, manipu-
`lating packet headers,
`if necessary, and forwarding the
`packets to the next-hop or destination at high speeds.
`The present invention supplements these abilities with
`high-speed, preferably line rate, processing capabilities at an
`application level. As noted, the compute plane 14 is prefer-
`ably used to manipulate packet data or payloads beyond
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`layer three or four protocols that provide application layer
`support. Thus, instead of analyzing or modifying the header
`on a packet, data analysis and manipulation associated with
`application layers in the packet is possible in the compute
`plane 14.
`Importantly, the compute plane 14 provides application
`support efficiently and at high speeds without impacting the
`traditional routing speeds of the forward plane 16. Further,
`the application layer processing is provided at much faster
`speeds in the compute plane 14 than would be possible in the
`control plane 12. In addition to increased routing speeds and
`efficiency for application support,
`the compute plane 14
`allows significant configuration of routing nodes 10 to
`facilitate any number of applications or combinations
`thereof.
`
`Overall interaction between the control plane 12, compute
`plane 14, and forward plane 16 is outlined in the flow
`diagram of FIG. 5. Notably, the preferred processing for
`each of the three planes is illustrated. The process begins
`(block 100) with the forward plane 16 receiving all incom-
`ing packets regardless of whether the packets are intended
`for the routing node directly or simply sent to the routing
`node for routing. When a packet is received (block 102), the
`forward plane 16 will filter the packet based on the forward-
`ing rules (block 104).
`In general, the forwarding rules will dictate whether the
`packet is forwarded to the control plane 12, compute plane
`14, or sent to the next-hop or destination after processing by
`the forward plane 16 (step 106). As discussed above, packets
`directed to the routing node 10, such as those used for
`diagnostics or to set configurations, are directed to the
`control plane 12. Packets requiring application level pro-
`cessing are sent to the compute plane 14. Packets for which
`the forward plane 16 can handle all processing are simply
`processed in the forward plane 16 and forwarded to the
`next-hop or destination. Typically, packets processed by the
`compute plane 14 and forward plane 16 are those requiring
`routing.
`Assuming that the packet is one capable of being handled
`solely by the forward plane 16,
`the packet is processed
`accordingly in the forward plane 16 (block 108) and for-
`warded to the next-hop or destination (block 110). As noted,
`packet processing in the forward plane 16 is typically
`limited to header analysis and manipulation.
`If the packet received by the forward plane 16 is deter-
`mined to be one directed to the control plane 12 based on the
`forwarding rules (block 106), the packet is received by the
`control plane 12 (block 112) and processed by the control
`plane 12 accordingly (block 114). As noted, packets
`intended for the control plane 12 may facilitate diagnostic or
`control
`instructions for the compute plane 14, such as
`instructions to set particular configurations for the compute
`or forward planes 14, 16. For example, the compute plane 14
`may receive information for establishing the forwarding
`rules for the forward plane 16 as well as configure the
`particular processing carried out by the compute plane 14 or
`the forward plane 16.
`When the control plane 12 needs to respond to commu-
`nications or deliver instructions to another network device,
`the control plane 12 will prepare a suitable packet or
`response for sending to a select destination (block 116).
`Preferably, the packet or packets associated with an outgoing
`communication from the control plane 12 are sent to the
`forward plane 16 wherein the packet or packets are for-
`warded to the next-hop or destination (block 110).
`If the packet received by the forward plane 16 from the
`network is one requiring application level support and the
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`forwarding rules direct the packet to the compute plane 14
`(block 106), the packet is routed to the compute plane 14
`accordingly. As described in further detail below, the for-
`warding rules may dictate where to send the packet within
`the compute plane 14 or how the packet will be processed
`once it is received by the compute plane 14. In general, the
`compute plane 14 receives the packet (block 118) and
`processes the packet as dictated by the application (block
`120). As noted, preferably the application data or payload is
`processed in the compute plane 14.
`In particular, the compute plane 14 is configured to carry
`out select functions to facilitate application level processing,
`which results in data or payload manipulation (block 120).
`The processing may require restructuring or re-packetizing
`the data or payload information depending on the particular
`application. Certain applications may simply process indi-
`vidual packets wherein other applications may require vari-
`ous types of data or payload reconstruction. For example,
`information in one packet may be used to create multiple
`new packets, or the information in multiple packets may be
`used to create a single packet. Regardless of the processing,
`the packets processed or provided by the compute plane 14
`are sent to the forward plane 16 (block 122) for forwarding
`to the next-hop routing device or destination. As such, the
`forward plane 16 will receive packets from the compute
`plane 14 and forward the packet to the next-hop or desti-
`nation (block 110).
`A block diagram of a preferred configuration of the
`switching node 10 is depicted in FIG. 6. Preferably, each of
`the control plane 12, compute plane 14 and forward plane 16
`includes dedicated processing capability and is in commu-
`nication with the other planes through a switching backplane
`26. As such, the control plane 12 will include a control
`processor 28 associated with a backplane interface 30
`coupled to the switching backplane 26 and will include
`sufficient memory 32 for storing the necessary instructions
`and data for operation.
`The compute plane 14 includes a backplane interface 34
`in communication with one or more high-speed compute
`processors (CP) 36. These compute processors 36 will
`include or be able to carry out select processes, rules or
`functions 38. Further, the compute processors 36 may stand
`alone or be controlled in part by a host processor 40.
`Preferably, the host processor 40 is associated with sufficient
`memory 42 for storing the necessary data and instructions
`for operation. The host processor 40 may also be associated
`with a library module 44, which may store various types of
`compute processor functions used to configure the function
`or rules 38 of the compute processors 36. The speed of the
`host processor 40 is not as critical as insuring that
`the
`compute processors 36 are capable of high-speed process-
`mg.
`the
`to maximize the processing speeds,
`In an effort
`compute processors 36 may be implemented using field
`programmable gate arrays (FPGAs); application specific
`integrated circuits (ASICs); digital signal processing (DSP)
`components; network processors; or a combination thereof.
`Preferably, each compute processor 36 will include a pro-
`cessor and an FPGA or ASIC cooperating to maximize
`processing throughput. The processor facilitates configura-
`tion of the cooperating FPGA or ASIC, while the FPGA or
`ASIC processes the packets. Notably, the compute processor
`36 is a generic name for any one or combination of hard-
`ware, firmware or software capable of providing the high-
`speed application processing required in the compute plane
`14. Those skilled in the art will appreciate the numerous
`techniques available to provide high-speed processing.
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`The compute processor 36 is configured to carry out select
`functions or rules 38 at or close to wire-line speeds on the
`selected packets directed to the compute plane 14 from the
`forward plane 16. Importantly, the compute processors 36
`may provide a combination of functions for varying appli-
`cations or may be configured wherein each compute pro-
`cessor 36 carries out a dedicated function or rule 38. In the
`
`latter case, different compute processors 36 may facilitate
`different processing based on the function or rules 38. As
`such, the packets sent to the compute plane 14 from the
`forward plane 16 are directed to a select compute processor
`36 capable of handling the application associated with the
`given packet.
`The forward plane 16 includes a backplane interface 46
`for communicating with the switching backplane 26. The
`backplane interface 46 of the forward plane 16 is associated
`with a forward processor 48 capable of implementing select
`forwarding rules 50 that facilitate packet filtering and deliv-
`ery to the control plane 12, compute plane 14, and the
`next-hop or destination. The forward processor 48 provides
`the typical routing processing and functions in traditional
`fashion for those packets that do not require the application
`processing of the compute plane 14. The forward processor
`48 is also associated with a network interface 52, which is
`coupled to the packet-switched network for receiving and
`sending packets.
`The network interface 52 may be any type of network
`interface, including a 10 Base T, 100 Base T, or gigabit
`Ethernet interface. As depicted, given the necessary volume
`of traffic handled by the routing node 10, the forward plane
`16 may be provided on multiple cards, all of which interface
`with the switching backplane 26. These cards may include
`their own forward processors 48 and network interfaces 52.
`Further,
`the compute plane 14