@startuml

label _ [

  {{
    title RADIUS workflow for lease allocation in the DHCPv4 server
    :Packet Received;
    :Subnet Selection;
    start
    partition "**subnet4_select** callout" {
      :Retrieve reservation from host cache for the current host and subnet.;
      if (Reservation found?) then (yes)
        if (Reservation for a different subnet?) then (yes)
          :Reselect the subnet to the one from the reservation.;
        else (no)
        endif
        :Retrieve reservation from host cache again in case the subnet was reselected.;
        if (Reservation with cached attributes?) then (yes)
          :Use cached attributes from the reservation.;
          stop
        else (no)
        endif
      else (no)
      endif
      :Send Access-Request.;
      if (Response) then (Access-Accept)
        if (Framed-IP-Address attribute present?) then (yes)
          :Reselect subnet to match a subnet the contains the IP address.;
        else (no)
        endif
        if (Framed-IP-Pool attribute present?) then (yes)
          :Reselect subnet to match a subnet guarded by the client class.;
          :Assign packet to client class represented by the value of Framed-IP-Pool.;
        else (no)
        endif
        :Populate the host cache with the reselected subnet ID and the potential class guard or IP address returned from the RADIUS server.;
      else (Access-Reject)
        stop
      endif
      stop
    }
    partition "**lease4_select**, **lease4_renew**, **lease4_release**, **lease4_decline**, **lease4_expire** callouts"
      :Send Accounting-Request asynchronously.;
    }
  }}

  {{
    title RADIUS workflow for lease allocation in the DHCPv6 server
    :Packet Received;
    :Subnet Selection;
    start
    partition "**subnet6_select** callout" {
      :Retrieve reservation from host cache for the current host and subnet.;
      if (Reservation found?) then (yes)
        if (Reservation for a different subnet?) then (yes)
          :Reselect the subnet to the one from the reservation.;
        else (no)
        endif
        :Retrieve reservation from host cache again in case the subnet was reselected.;
        if (Reservation with cached attributes?) then (yes)
          :Use cached attributes from the reservation.;
          stop
        else (no)
        endif
      else (no)
      endif
      :Send Access-Request.;
      if (Response) then (Access-Accept)
        if (Framed-IPv6-Address attribute present?) then (yes)
          :Reselect subnet to match a subnet the contains the IP address.;
        else (no)
        endif
        if (Framed-IP-Pool attribute present?) then (yes)
          :Reselect subnet to match a subnet guarded by the client class.;
          :Assign packet to client class represented by the value of Framed-IP-Pool.;
        else (no)
        endif
        :Populate the host cache with the reselected subnet ID and the potential class guard or IP address returned from the RADIUS server.;
      else (Access-Reject)
        stop
      endif
      stop
    }
    partition "**lease6_select**, **lease6_renew**, **lease6_rebind**, **lease6_release**, **lease6_decline**, **lease6_expire** callouts"
      :Send Accounting-Request asynchronously.;
    }
  }}

]

@enduml