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RFC 6956

 
 
 

Forwarding and Control Element Separation (ForCES) Logical Function Block (LFB) Library

Part 4 of 5, p. 69 to 102
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6.  XML for LFB Library

<?xml version="1.0" encoding="UTF-8"?>
<LFBLibrary xmlns="urn:ietf:params:xml:ns:forces:lfbmodel:1.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     provides="BaseLFBLibrary">
   <load library="BaseTypeLibrary"/>
   <LFBClassDefs>
      <LFBClassDef LFBClassID="3">
         <name>EtherPHYCop</name>
         <synopsis>
           The EtherPHYCop LFB describes an Ethernet interface
           that limits the physical media to copper.
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort>
               <name>EtherPHYIn</name>
               <synopsis>
                 The input port of the EtherPHYCop LFB.  It expects any
                 type of Ethernet frame.
               </synopsis>
               <expectation>
                  <frameExpected>
                     <ref>EthernetAll</ref>
                  </frameExpected>
               </expectation>

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            </inputPort>
         </inputPorts>
         <outputPorts>
            <outputPort>
               <name>EtherPHYOut</name>
               <synopsis>
                 The output port of the EtherPHYCop LFB.  The output
                 packet has the same Ethernet frame type as the
                 input packet, associated with a metadata indicating
                 the ID of the physical port.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>EthernetAll</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>PHYPortID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component componentID="1" access="read-only">
               <name>PHYPortID</name>
               <synopsis>
                 The identification of the physical port
               </synopsis>
               <typeRef>uint32</typeRef>
            </component>
            <component componentID="2" access="read-write">
               <name>AdminStatus</name>
               <synopsis>
                 The port status administratively requested
               </synopsis>
               <typeRef>PortStatusType</typeRef>
               <defaultValue>2</defaultValue>
            </component>
            <component componentID="3" access="read-only">
               <name>OperStatus</name>
               <synopsis>
                 The port actual operational status
               </synopsis>
               <typeRef>PortStatusType</typeRef>
            </component>
            <component componentID="4" access="read-write">
               <name>AdminLinkSpeed</name>
               <synopsis>
                 The port link speed administratively requested

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               </synopsis>
               <typeRef>LANSpeedType</typeRef>
               <defaultValue>LAN_SPEED_AUTO</defaultValue>
            </component>
            <component componentID="5" access="read-only">
               <name>OperLinkSpeed</name>
               <synopsis>
                 The port actual operational link speed
               </synopsis>
               <typeRef>LANSpeedType</typeRef>
            </component>
            <component componentID="6" access="read-write">
               <name>AdminDuplexMode</name>
               <synopsis>
                 The port duplex mode administratively requested
               </synopsis>
               <typeRef>DuplexType</typeRef>
               <defaultValue>Auto</defaultValue>
            </component>
            <component componentID="7" access="read-only">
               <name>OperDuplexMode</name>
               <synopsis>
                 The port actual operational duplex mode
               </synopsis>
               <typeRef>DuplexType</typeRef>
            </component>
            <component componentID="8" access="read-only">
               <name>CarrierStatus</name>
               <synopsis>The carrier status of the port </synopsis>
               <typeRef>boolean</typeRef>
               <defaultValue>false</defaultValue>
            </component>
         </components>
         <capabilities>
            <capability componentID="30">
               <name>SupportedLinkSpeed</name>
               <synopsis>
                 A list of link speeds the port supports
               </synopsis>
               <array>
                  <typeRef>LANSpeedType</typeRef>
               </array>
            </capability>
            <capability componentID="31">
               <name>SupportedDuplexMode</name>
               <synopsis>
                 A list of duplex modes the port supports
               </synopsis>

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               <array>
                  <typeRef>DuplexType</typeRef>
               </array>
            </capability>
         </capabilities>
         <events baseID="60">
            <event eventID="1">
               <name>PHYPortStatusChanged</name>
               <synopsis>
                 An event reporting change on operational status of the
                 physical port.
               </synopsis>
               <eventTarget>
                  <eventField>OperStatus</eventField>
               </eventTarget>
               <eventChanged/>
               <eventReports>
                  <eventReport>
                     <eventField>OperStatus</eventField>
                  </eventReport>
               </eventReports>
            </event>
            <event eventID="2">
               <name>LinkSpeedChanged</name>
               <synopsis>
                 An event reporting change on operational link speed
                 of the physical port.
               </synopsis>
               <eventTarget>
                  <eventField>OperLinkSpeed</eventField>
               </eventTarget>
               <eventChanged/>
               <eventReports>
                  <eventReport>
                     <eventField>OperLinkSpeed</eventField>
                  </eventReport>
               </eventReports>
            </event>
            <event eventID="3">
               <name>DuplexModeChanged</name>
               <synopsis>
                 An event reporting change on operational duplex mode
                 of the physical port.
               </synopsis>
               <eventTarget>
                  <eventField>OperDuplexMode</eventField>
               </eventTarget>
               <eventChanged/>

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               <eventReports>
                  <eventReport>
                     <eventField>OperDuplexMode</eventField>
                  </eventReport>
               </eventReports>
            </event>
         </events>
      </LFBClassDef>
      <LFBClassDef LFBClassID="4">
         <name>EtherMACIn</name>
         <synopsis>
           EtherMACIn LFB describes an Ethernet port at MAC data link
           layer.  The LFB describes Ethernet processing functions
           of MAC address locality check, deciding if the Ethernet
           packets should be bridged, providing Ethernet-layer flow
           control, etc.
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort group="false">
               <name>EtherPktsIn</name>
               <synopsis>
                 The input port of the EtherMACIn LFB.  It expects any
                 type of Ethernet frame.
               </synopsis>
               <expectation>
                  <frameExpected>
                     <ref>EthernetAll</ref>
                  </frameExpected>
                  <metadataExpected>
                     <ref>PHYPortID</ref>
                  </metadataExpected>
               </expectation>
            </inputPort>
         </inputPorts>
         <outputPorts>
            <outputPort group="false">
               <name>NormalPathOut</name>
               <synopsis>
                 An output port in the EtherMACIn LFB.  It outputs
                 Ethernet packets to downstream LFBs for normal
                 processing like Ethernet packet classification and
                 other L3 IP-layer processing.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>EthernetAll</ref>
                  </frameProduced>

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                  <metadataProduced>
                     <ref>PHYPortID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
            <outputPort>
               <name>L2BridgingPathOut</name>
               <synopsis>
                 An output port in
                 the EtherMACIn LFB.  It outputs Ethernet packets
                 to downstream LFBs for layer 2 bridging processing.
                 The port is switched on or off by the
                 L2BridgingPathEnable flag in the LFB.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>EthernetAll</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>PHYPortID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component componentID="1" access="read-write">
               <name>AdminStatus</name>
               <synopsis>
                  The LFB status administratively requested, which has
                  the same data type with a port status.  Default is in
                  'Down' status.
               </synopsis>
               <typeRef>PortStatusType</typeRef>
               <defaultValue>2</defaultValue>
            </component>
            <component componentID="2" access="read-write">
               <name>LocalMACAddresses</name>
               <synopsis>
                 Local MAC address(es) of the Ethernet port the LFB
                 represents.
               </synopsis>
               <array>
                  <typeRef>IEEEMAC</typeRef>
               </array>
            </component>
            <component componentID="3" access="read-write">
               <name>L2BridgingPathEnable</name>
               <synopsis>

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                 A flag indicating if the LFB L2 BridgingPath output
                 port is enabled or not.  Default is not enabled.
               </synopsis>
               <typeRef>boolean</typeRef>
               <defaultValue>false</defaultValue>
            </component>
            <component componentID="4" access="read-write">
               <name>PromiscuousMode</name>
               <synopsis>
                 A flag indicating whether the LFB is in promiscuous
                 mode or not.  Default is not.
               </synopsis>
               <typeRef>boolean</typeRef>
               <defaultValue>false</defaultValue>
            </component>
            <component componentID="5" access="read-write">
               <name>TxFlowControl</name>
               <synopsis>
                 A flag indicating whether transmit flow control is
                 applied or not.  Default is not.
               </synopsis>
               <optional/>
               <typeRef>boolean</typeRef>
               <defaultValue>false</defaultValue>
            </component>
            <component componentID="6" access="read-write">
               <name>RxFlowControl</name>
               <synopsis>
                 A flag indicating whether receive flow control is
                 applied or not.  Default is not.
               </synopsis>
               <optional/>
               <typeRef>boolean</typeRef>
               <defaultValue>false</defaultValue>
            </component>
            <component componentID="7" access="read-reset">
               <name>MACInStats</name>
               <synopsis>
                 The statistics of the EtherMACIn LFB
               </synopsis>
               <optional/>
               <typeRef>MACInStatsType</typeRef>
            </component>
         </components>
      </LFBClassDef>
      <LFBClassDef LFBClassID="5">
         <name>EtherClassifier</name>
         <synopsis>

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           EtherClassifier LFB describes the process to decapsulate
           Ethernet packets and then classify them into various
           network-layer packets according to information in the
           Ethernet headers.  It is expected the LFB classifies packets
           by packet types like IPv4, IPv6, MPLS, ARP, ND, etc.
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort>
               <name>EtherPktsIn</name>
               <synopsis>
                 Input port of Ethernet packets.  PHYPortID metadata is
                 always expected while LogicalPortID metadata is
                 optionally expected to associate with every input
                 Ethernet packet.
               </synopsis>
               <expectation>
                  <frameExpected>
                     <ref>EthernetAll</ref>
                  </frameExpected>
                  <metadataExpected>
                     <ref>PHYPortID</ref>
                     <ref dependency="optional" defaultValue="0">
                  LogicalPortID</ref>
                  </metadataExpected>
               </expectation>
            </inputPort>
         </inputPorts>
         <outputPorts>
            <outputPort group="true">
               <name>ClassifyOut</name>
               <synopsis>
                 A group port for output of Ethernet classifying
                 results.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>Arbitrary</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>PHYPortID</ref>
                     <ref>SrcMAC</ref>
                     <ref>DstMAC</ref>
                     <ref>EtherType</ref>
                     <ref availability="conditional">VlanID</ref>
                     <ref availability="conditional">VlanPriority</ref>
                  </metadataProduced>
               </product>

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            </outputPort>
            <outputPort group="false">
               <name>ExceptionOut</name>
               <synopsis>
                 A singleton port for output of all Ethernet packets
                 that fail the classifying process.  An ExceptionID
                 metadata indicates the failure reason.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>Arbitrary</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>ExceptionID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component access="read-write" componentID="1">
               <name>EtherDispatchTable</name>
               <synopsis>
                 An EtherDispatchTable array component that is defined
                 in the LFB to dispatch every Ethernet packet to output
                 ports according to logical port ID assigned by the
                 VlanInputTable in the LFB and Ethernet type in the
                 Ethernet packet header.
               </synopsis>
               <typeRef>EtherDispatchTableType</typeRef>
            </component>
            <component access="read-write" componentID="2">
               <name>VlanInputTable</name>
               <synopsis>
                 A VlanInputTable array component that is defined in
                 the LFB to classify VLAN Ethernet packets.  Every input
                 packet is assigned with a new LogicalPortID according
                 to the packet's incoming port ID and VLAN ID.
               </synopsis>
               <typeRef>VlanInputTableType</typeRef>
            </component>
            <component access="read-reset" componentID="3">
               <name>EtherClassifyStats</name>
               <synopsis>
                 A table recording statistics on the Ethernet
                 classifying process in the LFB.
               </synopsis>
               <optional/>
               <typeRef>EtherClassifyStatsTableType</typeRef>

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            </component>
         </components>
       </LFBClassDef>
      <LFBClassDef LFBClassID="6">
         <name>EtherEncap</name>
         <synopsis>
           The EtherEncap LFB abstracts the process of encapsulating
           Ethernet headers onto received packets.  The encapsulation
           is based on passed metadata.
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort group="false">
               <name>EncapIn</name>
               <synopsis>
                 An input port receiving IPv4 and/or IPv6 packets for
                 encapsulation.  A MediaEncapInfoIndex metadata is
                 expected, and a VLAN priority metadata is optionally
                 expected with every input packet.
               </synopsis>
               <expectation>
               <frameExpected>
                  <ref>IPv4</ref>
                  <ref>IPv6</ref>
               </frameExpected>
               <metadataExpected>
                  <ref>MediaEncapInfoIndex</ref>
                  <ref dependency="optional" defaultValue="0">
                  VlanPriority</ref>
               </metadataExpected>
               </expectation>
            </inputPort>
         </inputPorts>
         <outputPorts>
            <outputPort group="false">
               <name>SuccessOut</name>
               <synopsis>
                 An output port for packets that have found Ethernet
                 L2 information and have been successfully encapsulated
                 into an Ethernet packet.  An L2PortID metadata is
                 produced for every output packet.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv4</ref>
                     <ref>IPv6</ref>
                  </frameProduced>
                  <metadataProduced>

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                     <ref>L2PortID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
            <outputPort group="false">
               <name>ExceptionOut</name>
               <synopsis>
                 An output port for packets that fail encapsulation
                 in the LFB.  An ExceptionID metadata indicates failure
                 reason.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv4</ref>
                     <ref>IPv6</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>ExceptionID</ref>
                     <ref>MediaEncapInfoIndex</ref>
                     <ref availability="conditional">VlanPriority</ref>
                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component componentID="1" access="read-write">
               <name>EncapTable</name>
               <synopsis>
                 An array table for Ethernet encapsulation information
                 lookup.  Each row of the array contains destination MAC
                 address, source MAC address, VLAN ID, and output
                 logical L2 port ID.
               </synopsis>
               <typeRef>EncapTableType</typeRef>
            </component>
         </components>
      </LFBClassDef>
      <LFBClassDef LFBClassID="7">
         <name>EtherMACOut</name>
         <synopsis>
           EtherMACOut LFB abstracts an Ethernet port at MAC data link
           layer.  It specifically describes Ethernet packet process
           for output to physical port.  A downstream LFB is usually
           an Ethernet physical LFB like EtherPHYCop LFB.  Note that
           Ethernet output functions are closely related to Ethernet
           input functions; therefore, some components defined in this
           LFB are aliases of EtherMACIn LFB components.
         </synopsis>

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         <version>1.0</version>
         <inputPorts>
            <inputPort group="false">
               <name>EtherPktsIn</name>
               <synopsis>
                 The input port of the EtherMACOut LFB.  It expects
                 any type of Ethernet frame.
               </synopsis>
               <expectation>
                  <frameExpected>
                     <ref>EthernetAll</ref>
                  </frameExpected>
                  <metadataExpected>
                     <ref>PHYPortID</ref>
                  </metadataExpected>
               </expectation>
            </inputPort>
         </inputPorts>
         <outputPorts>
            <outputPort group="false">
               <name>EtherPktsOut</name>
               <synopsis>
                 A port to output all Ethernet packets, each with a
                 metadata indicating the ID of the physical port
                 that the packet is to go through.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>EthernetAll</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>PHYPortID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component componentID="1" access="read-write">
               <name>AdminStatus</name>
               <synopsis>
                 The LFB status administratively requested, which has
                 the same data type with a port status.  The
                 component is defined as an alias of AdminStatus
                 component in EtherMACIn LFB.
               </synopsis>
               <alias>PortStatusType</alias>
            </component>
            <component componentID="2" access="read-write">

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               <name>MTU</name>
               <synopsis>Maximum transmission unit (MTU) </synopsis>
               <typeRef>uint32</typeRef>
            </component>
            <component componentID="3" access="read-write">
               <name>TxFlowControl</name>
               <synopsis>
                 A flag indicating whether transmit flow control is
                 applied, defined as an alias of TxFlowControl
                 component in EtherMACIn LFB.
               </synopsis>
               <optional/>
               <alias>boolean</alias>
            </component>
            <component componentID="4" access="read-write">
               <name>RxFlowControl</name>
               <synopsis>
                 A flag indicating whether receive flow control is
                 applied, defined as an alias of RxFlowControl
                 component in EtherMACIn LFB.
               </synopsis>
               <optional/>
               <alias>boolean</alias>
            </component>
            <component componentID="5" access="read-reset">
               <name>MACOutStats</name>
               <synopsis>
                 The statistics of the EtherMACOut LFB
               </synopsis>
               <optional/>
               <typeRef>MACOutStatsType</typeRef>
            </component>
         </components>
      </LFBClassDef>
      <LFBClassDef LFBClassID="8">
         <name>IPv4Validator</name>
         <synopsis>
          This LFB performs IPv4 validation according to RFC 1812 and
          its updates.  The IPv4 packet will be output to the
          corresponding LFB port, indicating whether the packet is
          unicast or multicast or whether an exception has occurred
          or the validation failed.
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort>
               <name>ValidatePktsIn</name>
               <synopsis>

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                 Input port for data packets to be validated
               </synopsis>
               <expectation>
                  <frameExpected>
                     <ref>Arbitrary</ref>
                  </frameExpected>
               </expectation>
            </inputPort>
         </inputPorts>
         <outputPorts>
            <outputPort>
               <name>IPv4UnicastOut</name>
               <synopsis>
                 Output port for validated IPv4 unicast packets
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv4Unicast</ref>
                  </frameProduced>
               </product>
            </outputPort>
            <outputPort>
               <name>IPv4MulticastOut</name>
               <synopsis>
                 Output port for validated IPv4 multicast packets
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv4Multicast</ref>
                  </frameProduced>
               </product>
            </outputPort>
            <outputPort>
               <name>ExceptionOut</name>
               <synopsis>
                 Output port for all packets with exceptional cases
                 when validating.  An ExceptionID metadata indicates
                 the exception case type.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv4</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>ExceptionID</ref>
                  </metadataProduced>
               </product>
            </outputPort>

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            <outputPort>
               <name>FailOut</name>
               <synopsis>
                 Output port for packets that failed validating
                 process.  A ValidateErrorID metadata indicates the
                 error type or failure reason.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv4</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>ValidateErrorID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component access="read-write" componentID="1">
               <name>IPv4ValidatorStats</name>
               <synopsis>
                 The statistics information for validating process in
                 the LFB.
               </synopsis>
               <optional/>
               <typeRef>IPv4ValidatorStatsType</typeRef>
            </component>
         </components>
       </LFBClassDef>
      <LFBClassDef LFBClassID="9">
         <name>IPv6Validator</name>
         <synopsis>
           This LFB performs IPv6 validation according to RFC 2460 and
           its updates.  Then, the IPv6 packet will be output to the
           corresponding port, indicating whether the packet is
           unicast or multicast or whether an exception has occurred
           or the validation failed.
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort>
               <name>ValidatePktsIn</name>
               <synopsis>
                 Input port for data packets to be validated
               </synopsis>
               <expectation>
                  <frameExpected>
                     <ref>Arbitrary</ref>

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                  </frameExpected>
               </expectation>
            </inputPort>
         </inputPorts>
         <outputPorts>
            <outputPort>
               <name>IPv6UnicastOut</name>
               <synopsis>
                 Output port for validated IPv6 unicast packets
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv6Unicast</ref>
                  </frameProduced>
               </product>
            </outputPort>
            <outputPort>
               <name>IPv6MulticastOut</name>
               <synopsis>
                 Output port for validated IPv6 multicast packets
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv6Multicast</ref>
                  </frameProduced>
               </product>
            </outputPort>
            <outputPort>
               <name>ExceptionOut</name>
               <synopsis>
                 Output port for packets with exceptional cases when
                 validating.  An ExceptionID metadata indicates the
                 exception case type.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv6</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>ExceptionID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
            <outputPort>
               <name>FailOut</name>
               <synopsis>
                 Output port for packets failed validating process.
                 A ValidateErrorID metadata indicates the error type

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                 or failure reason.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv6</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>ValidateErrorID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component access="read-write" componentID="1">
               <name>IPv6ValidatorStats</name>
               <synopsis>
                 The statistics information for validating process in
                 the LFB.
               </synopsis>
               <optional/>
               <typeRef>IPv6ValidatorStatsType</typeRef>
            </component>
         </components>
       </LFBClassDef>
      <LFBClassDef LFBClassID="10">
         <name>IPv4UcastLPM</name>
         <synopsis>
           The IPv4UcastLPM LFB abstracts the IPv4 unicast Longest
           Prefix Match (LPM) process.  This LFB supports
           implementing equal-cost multipath (ECMP) routing and
           reverse path forwarding (RPF).
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort group="false">
               <name>PktsIn</name>
               <synopsis>
                 A port for input of packets to be processed.
                 IPv4 unicast packets are expected.
               </synopsis>
               <expectation>
               <frameExpected>
                  <ref>IPv4Unicast</ref>
               </frameExpected>
               </expectation>
            </inputPort>
         </inputPorts>
         <outputPorts>

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            <outputPort group="false">
               <name>NormalOut</name>
               <synopsis>
                 An output port to output IPv4 unicast packets that
                 successfully passed the LPM lookup.  A HopSelector
                 metadata is produced to associate every output packet
                 for downstream LFB to do next-hop action.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv4Unicast</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>HopSelector</ref>
                  </metadataProduced>
               </product>
            </outputPort>
            <outputPort group="false">
               <name>ECMPOut</name>
               <synopsis>
                 The port to output packets needing further ECMP
                 processing.  A downstream ECMP processing LFB is
                 usually followed to the port.  If ECMP is not
                 required, no downstream LFB may be connected to
                 the port.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv4Unicast</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>HopSelector</ref>
                  </metadataProduced>
               </product>
            </outputPort>
            <outputPort group="false">
               <name>ExceptionOut</name>
               <synopsis>
                 The port to output all packets with exceptional cases
                 happened during LPM process.  An ExceptionID metadata
                 is associated to indicate what caused the exception.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv4Unicast</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>ExceptionID</ref>

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                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component componentID="1" access="read-write">
               <name>IPv4PrefixTable</name>
               <synopsis>
                 A table for IPv4 Longest Prefix Match(LPM).  The
                 destination IPv4 address of every input packet is
                 used as a search key to look up the table to find
                 out a next-hop selector.
               </synopsis>
               <typeRef>IPv4PrefixTableType</typeRef>
            </component>
            <component componentID="2" access="read-reset">
               <name>IPv4UcastLPMStats</name>
               <synopsis>
                 The statistics information for the IPv4 unicast LPM
                 process in the LFB.
               </synopsis>
               <optional/>
               <typeRef>IPv4UcastLPMStatsType</typeRef>
            </component>
         </components>
      </LFBClassDef>
      <LFBClassDef LFBClassID="11">
         <name>IPv6UcastLPM</name>
         <synopsis>
           The IPv6UcastLPM LFB abstracts the IPv6 unicast Longest
           Prefix Match (LPM) process.  This LFB supports
           implementing equal-cost multipath (ECMP) routing and
           reverse path forwarding (RPF).
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort group="false">
               <name>PktsIn</name>
               <synopsis>
                 A port for input of packets to be processed.
                 IPv6 unicast packets are expected.
               </synopsis>
               <expectation>
               <frameExpected>
                  <ref>IPv6Unicast</ref>
               </frameExpected>
               </expectation>
            </inputPort>

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         </inputPorts>
         <outputPorts>
            <outputPort group="false">
               <name>NormalOut</name>
               <synopsis>
                 An output port to output IPv6 unicast packets that
                 successfully passed the LPM lookup.  A HopSelector
                 metadata is produced to associate every output packet
                 for downstream LFB to do next-hop action.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv6Unicast</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>HopSelector</ref>
                  </metadataProduced>
               </product>
            </outputPort>
            <outputPort group="false">
               <name>ECMPOut</name>
               <synopsis>
                 The port to output packets needing further ECMP
                 processing.  A downstream ECMP processing LFB is
                 usually followed to the port.  If ECMP is not
                 required, no downstream LFB may be connected to
                 the port.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv6Unicast</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>HopSelector</ref>
                  </metadataProduced>
               </product>
            </outputPort>
            <outputPort group="false">
               <name>ExceptionOut</name>
               <synopsis>
                 The port to output all packets with exceptional cases
                 happened during LPM process.  An ExceptionID metadata
                 is associated to indicate what caused the exception.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv6Unicast</ref>
                  </frameProduced>

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                  <metadataProduced>
                     <ref>ExceptionID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component componentID="1" access="read-write">
               <name>IPv6PrefixTable</name>
               <synopsis>
                 A table for IPv6 Longest Prefix Match (LPM).  The
                 destination IPv6 address of every input packet is
                 used as a search key to look up the table to find
                 out a next-hop selector.
               </synopsis>
               <typeRef>IPv6PrefixTableType</typeRef>
            </component>
            <component componentID="2" access="read-reset">
               <name>IPv6UcastLPMStats</name>
               <synopsis>
                The statistics information for the IPv6 unicast LPM
                process in the LFB.
               </synopsis>
               <optional/>
               <typeRef>IPv6UcastLPMStatsType</typeRef>
            </component>
         </components>
      </LFBClassDef>
      <LFBClassDef LFBClassID="12">
         <name>IPv4NextHop</name>
         <synopsis>
           The IPv4NextHop LFB abstracts the process of next-hop
           information application to IPv4 packets.  It receives an
           IPv4 packet with an associated next-hop identifier
           (HopSelector) and uses the identifier as a table index
           to look up a next-hop table to find an appropriate output
           port.  The data processing also involves the forwarding
           TTL decrement and IP checksum recalculation.
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort group="false">
               <name>PktsIn</name>
               <synopsis>
                 A port for input of unicast IPv4 packets, along with
                 a HopSelector metadata.
               </synopsis>
               <expectation>

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               <frameExpected>
                  <ref>IPv4Unicast</ref>
               </frameExpected>
               <metadataExpected>
                  <ref>HopSelector</ref>
               </metadataExpected>
               </expectation>
            </inputPort>
         </inputPorts>
         <outputPorts>
            <outputPort group="true">
               <name>SuccessOut</name>
               <synopsis>
                 The group port for output of packets that
                 successfully found next-hop information.  Some
                 metadata are associated with every packet.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv4Unicast</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>L3PortID</ref>
                     <ref>NextHopIPv4Addr</ref>
                     <ref availability="conditional">
                     MediaEncapInfoIndex</ref>
                  </metadataProduced>
               </product>
            </outputPort>
            <outputPort group="false">
               <name>ExceptionOut</name>
               <synopsis>
                 The output port for packets with exceptional or
                 failure cases.  An ExceptionID metadata indicates
                 what caused the case.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv4Unicast</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>ExceptionID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component componentID="1">

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               <name>IPv4NextHopTable</name>
               <synopsis>
                 The IPv4NextHopTable component.  A
                 HopSelector is used to match the table index
                 to find out a row that contains the next-hop
                 information result.
               </synopsis>
               <typeRef>IPv4NextHopTableType</typeRef>
            </component>
         </components>
      </LFBClassDef>
      <LFBClassDef LFBClassID="13">
         <name>IPv6NextHop</name>
         <synopsis>
           The LFB abstracts the process of next-hop information
           application to IPv6 packets.  It receives an IPv6 packet
           with an associated next-hop identifier (HopSelector) and
           uses the identifier as a table index to look up a next-hop
           table to find an appropriate output port.
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort group="false">
               <name>PktsIn</name>
               <synopsis>
                 A port for input of unicast IPv6 packets, along with
                 a HopSelector metadata.
                </synopsis>
               <expectation>
               <frameExpected>
                  <ref>IPv6Unicast</ref>
               </frameExpected>
               <metadataExpected>
                  <ref>HopSelector</ref>
               </metadataExpected>
               </expectation>
            </inputPort>
         </inputPorts>
         <outputPorts>
            <outputPort group="true">
               <name>SuccessOut</name>
               <synopsis>
                 The group port for output of packets that successfully
                 found next-hop information.  Some metadata are
                 associated with every packet.
                </synopsis>
               <product>
                  <frameProduced>

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                     <ref>IPv6Unicast</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>L3PortID</ref>
                     <ref>NextHopIPv6Addr</ref>
                     <ref availability="conditional">
                     MediaEncapInfoIndex</ref>
                  </metadataProduced>
               </product>
            </outputPort>
            <outputPort group="false">
               <name>ExceptionOut</name>
               <synopsis>
                 The output port for packets with exceptional or
                 failure cases.  An ExceptionID metadata indicates
                 what caused the case.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>IPv6Unicast</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>ExceptionID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component componentID="1">
               <name>IPv6NextHopTable</name>
               <synopsis>
                 The IPv6NextHopTable component.  A HopSelector is
                 used to match the table index to find out a row that
                 contains the next-hop information result.
               </synopsis>
               <typeRef>IPv6NextHopTableType</typeRef>
            </component>
         </components>
      </LFBClassDef>
      <LFBClassDef LFBClassID="14">
         <name>RedirectIn</name>
         <synopsis>
           The RedirectIn LFB abstracts the process for the ForCES CE to
           inject data packets into the ForCES FE LFBs.
         </synopsis>
         <version>1.0</version>
         <outputPorts>
            <outputPort group="true">

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               <name>PktsOut</name>
               <synopsis>
                 The output port of RedirectIn LFB, which is defined as
                 a group port type.  From the LFB topology's point of
                 view, the RedirectIn LFB acts as a source point for
                 data packets coming from CE; therefore, the LFB is
                 defined with a singleton output port (and no input
                 port).
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>Arbitrary</ref>
                  </frameProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component componentID="1">
               <name>NumPacketsReceived</name>
               <synopsis>
                 Number of packets received from CE.
               </synopsis>
               <optional/>
               <typeRef>uint64</typeRef>
            </component>
         </components>
      </LFBClassDef>
      <LFBClassDef LFBClassID="15">
         <name>RedirectOut</name>
         <synopsis>
           The RedirectOut LFB abstracts the process for LFBs in a
           ForCES FE to deliver data packets to the ForCES CE.
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort group="false">
               <name>PktsIn</name>
               <synopsis>
                 The input port for the RedirectOut LFB.  From the LFB
                 topology's point of view, the RedirectOut LFB acts as
                 a sink point for data packets going to the CE;
                 therefore, RedirectOut LFB is defined with a
                 singleton input port (and no output port).
               </synopsis>
               <expectation>
                  <frameExpected>
                     <ref>Arbitrary</ref>
                  </frameExpected>

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               </expectation>
            </inputPort>
         </inputPorts>
         <components>
            <component componentID="1">
               <name>NumPacketsSent</name>
               <synopsis>
                 Number of packets sent to CE.
               </synopsis>
               <optional/>
               <typeRef>uint64</typeRef>
            </component>
         </components>
      </LFBClassDef>
      <LFBClassDef LFBClassID="16">
         <name>BasicMetadataDispatch</name>
         <synopsis>
           The BasicMetadataDispatch LFB is defined to abstract the
           process by which packets are dispatched to various output
           paths based on associated metadata value.  Current
           version of the LFB only allows the metadata value to be
           a 32-bit integer.
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort>
               <name>PktsIn</name>
               <synopsis>
                 The packet input port for dispatching.  Every input
                 packet should be associated with a metadata that will
                 be used by the LFB to do the dispatch.
               </synopsis>
               <expectation>
                  <frameExpected>
                     <ref>Arbitrary</ref>
                  </frameExpected>
                  <metadataExpected>
                     <ref>Arbitrary</ref>
                  </metadataExpected>
               </expectation>
            </inputPort>
         </inputPorts>
         <outputPorts>
            <outputPort group="true">
               <name>PktsOut</name>
               <synopsis>
                 The group output port that outputs dispatching
                 results.  A packet with its associated metadata

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                 having found an OutputIndex by successfully looking
                 up the dispatch table will be output to the group
                 port instance with the corresponding index.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>Arbitrary</ref>
                  </frameProduced>
               </product>
            </outputPort>
            <outputPort group="false">
               <name>ExceptionOut</name>
               <synopsis>
                 The output port that outputs packets that failed
                 to process.  An ExceptionID metadata indicates what
                 caused the exception.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>Arbitrary</ref>
                  </frameProduced>
                  <metadataProduced>
                     <ref>ExceptionID</ref>
                  </metadataProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component access="read-write" componentID="1">
               <name>MetadataID</name>
               <synopsis>
                 The ID of the metadata to be
                 used for dispatching packets.
               </synopsis>
               <typeRef>uint32</typeRef>
            </component>
            <component access="read-write" componentID="2">
               <name>MetadataDispatchTable</name>
               <synopsis>
                 The MetadataDispatchTable component, which contains
                 entries of a metadata value and an output index,
                 specifying that a packet with the metadata value must
                 go out from the instance with the output index of the
                 LFB group output port.
               </synopsis>
               <typeRef>MetadataDispatchTableType</typeRef>
            </component>
         </components>

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       </LFBClassDef>
      <LFBClassDef LFBClassID="17">
         <name>GenericScheduler</name>
         <synopsis>
           This is a preliminary generic scheduler LFB abstracting
           a simple scheduling process, which may be used as a
           basic LFB to construct a more complex scheduler LFB.
         </synopsis>
         <version>1.0</version>
         <inputPorts>
            <inputPort group="true">
               <name>PktsIn</name>
               <synopsis>
                 The group input port of the LFB.  Inside the LFB,
                 each instance of the group port is connected to
                 a queue marked with a queue ID, whose value is
                 index of the port instance.
               </synopsis>
               <expectation>
                  <frameExpected>
                     <ref>Arbitrary</ref>
                  </frameExpected>
               </expectation>
            </inputPort>
         </inputPorts>
         <outputPorts>
            <outputPort>
               <name>PktsOut</name>
               <synopsis>
                 The output port of the LFB.  Scheduled packets are
                 output from the port.
               </synopsis>
               <product>
                  <frameProduced>
                     <ref>Arbitrary</ref>
                  </frameProduced>
               </product>
            </outputPort>
         </outputPorts>
         <components>
            <component access="read-write" componentID="1">
               <name>SchedulingDiscipline</name>
               <synopsis>
                 The SchedulingDiscipline component, which is for the
                 CE to specify a scheduling discipline to the LFB.
               </synopsis>
               <typeRef>SchdDisciplineType</typeRef>
               <defaultValue>1</defaultValue>

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            </component>
            <component access="read-only" componentID="2">
               <name>QueueStats</name>
               <synopsis>
                 The QueueStats component, which is defined to allow
                 the CE to query every queue statistics in the
                 scheduler.
               </synopsis>
               <optional/>
               <typeRef>QueueStatsTableType</typeRef>
            </component>
         </components>
         <capabilities>
            <capability componentID="30">
               <name>QueueLenLimit</name>
               <synopsis>
                 The QueueLenLimit capability, which specifies
                 maximum length of each queue.  The length unit is in
                 bytes.
               </synopsis>
               <typeRef>uint32</typeRef>
            </capability>
         </capabilities>
       </LFBClassDef>
   </LFBClassDefs>
</LFBLibrary>

7.  LFB Class Use Cases

   This section demonstrates examples on how the LFB classes defined by
   the base LFB library in Section 6 can be applied to achieve some
   typical router functions.  The functions demonstrated are:

   o  IPv4 forwarding

   o  ARP processing

   It is assumed the LFB topology on the FE described has already been
   established by the CE and maps to the use cases illustrated in this
   section.

   The use cases demonstrated in this section are mere examples and by
   no means should be treated as the only way one would construct router
   functionality from LFBs; based on the capability of the FE(s), a CE
   should be able to express different NE applications.

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7.1.  IPv4 Forwarding

   Figure 2 shows the typical LFB processing path for an IPv4 unicast
   forwarding case with Ethernet media interfaces by use of the base LFB
   classes.  Note that in the figure, to focus on the IP forwarding
   function, some inputs or outputs of LFBs that are not related to the
   IPv4 forwarding function are not shown.  For example, an
   EtherClassifier LFB normally has two output ports: a "ClassifyOut"
   group output port and an "ExceptionOut" singleton output port, with
   the group port containing various port instances according to various
   classified packet types (Section 5.1.3).  In this figure, only the
   IPv4 and IPv6 packet output port instances are shown for displaying
   the mere IPv4 forwarding processing function.

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   +-----+                +------+
   |     |                |      |
   |     |<---------------|Ether |<----------------------------+
   |     |                |MACOut|                             |
   |     |                |      |                             |
   |Ether|                +------+                             |
   |PHY  |                                                     |
   |Cop  |            +---+                                    |
   |#1   |  +-----+   |   |----->IPv6 Packets                  |
   |     |  |     |   |   |                                    |
   |     |  |Ether|   |   | IPv4 Packets                       |
   |     |->|MACIn|-->|   |-+  +----+                          |
   +-----+  |     |   |   | |  |    |---> Multicast Packets    |
            +-----+   +---+ |  |    |        +-----+  +---+    |
                      Ether +->|    |------->|     |  |   |    |
      .           Classifier|  |    |Unicast |IPv4 |  |   |    |
      .                     |  |    |Packets |Ucast|->|   |--+ |
      .                     |  +----+        |LPM  |  |   |  | |
                      +---+ |   IPv4         +-----+  +---+  | |
            +-----+   |   | |   Validator              IPv4  | |
            |     |   |   | |                         NextHop| |
   +-----+  |Ether|   |   |-+ IPv4 Packets                   | |
   |     |->|MACIn|-->|   |                                  | |
   |     |  |     |   |   |----->IPv6 Packets                | |
   |Ether|  +-----+   +---+                                  | |
   |PHY  |           Ether               +----+              | |
   |Cop  |           Classifier          |    |   +-------+  | |
   |#n   |                +------+       |    |   |Ether  |  | |
   |     |                |      |       |    |<--|Encap  |<-+ |
   |     |                |      |<------|    |   |       |    |
   |     |<---------------|Ether |    ...|    |   +-------+    |
   |     |                |MACOut|   +---|    |                |
   |     |                |      |   |   +----+                |
   +-----+                +------+   | BasicMetadataDispatch   |
                                     +----------->-------------+

                Figure 2:  LFB Use Case for IPv4 Forwarding

   In the LFB use case, a number of EtherPHYCop LFB (Section 5.1.1)
   instances are used to describe physical-layer functions of the ports.
   PHYPortID metadata is generated by the EtherPHYCop LFB and is used by
   all the subsequent downstream LFBs.  An EtherMACIn LFB
   (Section 5.1.2), which describes the MAC-layer processing, follows
   every EtherPHYCop LFB.  The EtherMACIn LFB may do a locality check of
   MAC addresses if the CE configures the appropriate EtherMACIn LFB
   component.

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   Ethernet packets out of the EtherMACIn LFB are sent to an
   EtherClassifier LFB (Section 5.1.3) to be decapsulated and classified
   into network-layer types like IPv4, IPv6, ARP, etc.  In the example
   use case, every physical Ethernet interface is associated with one
   Classifier instance; although not illustrated, it is also feasible
   that all physical interfaces are associated with only one Ethernet
   Classifier instance.

   EtherClassifier uses the PHYPortID metadata, the Ethernet type of the
   input packet, and VlanID (if present in the input Ethernet packets)
   to decide the packet network-layer type and the LFB output port to
   the downstream LFB.  The EtherClassifier LFB also assigns a new
   logical port ID metadata to the packet for later use.  The
   EtherClassifier may also generate some new metadata for every packet,
   like EtherType, SrcMAC, DstMAC, LogicPortID, etc., for consumption by
   downstream LFBs.

   If a packet is classified as an IPv4 packet, it is sent downstream to
   an IPv4Validator LFB (Section 5.2.1) to validate the IPv4 packet.  In
   the validator LFB, IPv4 packets are validated and are additionally
   classified into either IPv4 unicast packets or multicast packets.
   IPv4 unicast packets are sent to downstream to the IPv4UcastLPM LFB
   (Section 5.3.1).

   The IPv4UcastLPM LFB is where the longest prefix match decision is
   made, and a next-hop selection is selected.  The next-hop ID metadata
   is generated by the IPv4UcastLPM LFB to be consumed downstream by the
   IPv4NextHop LFB (Section 5.3.2).

   The IPv4NextHop LFB uses the next-hop ID metadata to derive where the
   packet is to go next and the media encapsulation type for the port,
   etc.  The IPv4NextHop LFB generates the L3PortID metadata used to
   identify a next-hop output physical/logical port.  In the example use
   case, the next-hop output port is an Ethernet type; as a result, the
   packet and its L3 port ID metadata are sent downstream to an
   EtherEncap LFB (Section 5.1.4).

   The EtherEncap LFB encapsulates the incoming packet into an Ethernet
   frame.  A BasicMetadataDispatch LFB (Section 5.5.1) follows the
   EtherEncap LFB.  The BasicMetadataDispatch LFB is where packets are
   finally dispatched to different output physical/logical ports based
   on the L3PortID metadata sent to the LFB.

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7.2.  ARP Processing

   Figure 3 shows the processing path for the Address Resolution
   Protocol (ARP) in the case the CE implements the ARP processing
   function.  By no means is this the only way ARP processing could be
   achieved; as an example, ARP processing could happen at the FE, but
   that discussion is out of the scope of this use case.

          +---+                             +---+
          |   | ARP packets                 |   |
          |   |-------------->---------+--->|   | To CE
    ...-->|   | .                      |    |   |
          |   | .                      |    +---+
          |   | .                      |   RedirectOut
          +---+                        ^
          Ether     EtherEncap         | IPv4 packets lack
        Classifier   +---+             | address resolution information
                     |   |             |
       Packets need  |   |--------->---+
        ...--------->|   |
     L2 Encapsulation|   |
          +---+      |   |                     +------+
          |   |  +-->|   |--+   +---+          |Ether |
          |   |  |   +---+  |   |   |--------->|MACOut|-->...
   From CE|   |--+          +-->|   | .        +------+
          |   |ARP Packets      |   | .
          |   |from CE          |   | .        +------+
          |   |                 |   |--------> |Ether |-->...
          +---+                 +---+          |MACOut|
       RedirectIn            BasicMetadata     +------+
                             Dispatch

                      Figure 3: LFB Use Case for ARP

   There are two ways ARP processing could be triggered in the CE as
   illustrated in Figure 3:

   o  ARP packets arriving from outside of the NE.

   o  IPV4 packets failing to resolve within the FE.

   ARP packets from network interfaces are filtered out by
   EtherClassifier LFB.  The classified ARP packets and associated
   metadata are then sent downstream to the RedirectOut LFB
   (Section 5.4.2) to be transported to CE.

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   The EtherEncap LFB, as described in Section 5.1.4, receives packets
   that need Ethernet L2 encapsulating.  When the EtherEncap LFB fails
   to find the necessary L2 Ethernet information with which to
   encapsulate the packet, it outputs the packet to its ExceptionOut LFB
   port.  Downstream to EtherEncap LFB's ExceptionOut LFB port is the
   RedirectOut LFB, which transports the packet to the CE (see
   Section 5.1.4 on EtherEncap LFB for details).

   To achieve its goal, the CE needs to generate ARP request and
   response packets and send them to external (to the NE) networks.  ARP
   request and response packets from the CE are redirected to an FE via
   a RedirectIn LFB (Section 5.4.1).

   As was the case with forwarded IPv4 packets, outgoing ARP packets are
   also encapsulated to Ethernet format by the EtherEncap LFB, and then
   dispatched to different interfaces via a BasicMetadataDispatch LFB.
   The BasicMetadataDispatch LFB dispatches the packets according to the
   L3PortID metadata included in every ARP packet sent from CE.



(page 102 continued on part 5)

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