 Updated for matching packets. The OpenFlow specification defines a variety of timers. Counters Examples include the number of received bytes and packets per port, per flow table, and per flow-table entry; number of dropped packets; and duration of a flow. Instructions Actions to be taken if a match occurs. Timeouts Maximum amount of idle time before a flow is expired by the switch. Opaque data value chosen by the controller. May be used by the controller to filter flow Cookie statistics, flow modification, and flow deletion; not used when processing packets. VLAN ID and VLAN User Priority: Fields in the IEEE 802.1Q Virtual LAN header. IPv4 or IPv6 DS and ECN: Differentiated Services and Explicit Congestion Notification fields. Stream Control Transmission Protocol (SCTP) Source and Destination Ports: Exact match or wildcard value. Internet Control Message Protocol (ICMP) Type and Code Fields: Exact match or wildcard value. Address Resolution Protocol (ARP) Opcode: Exact match in Ether-net Type field. Source and Target IPv4 Addresses in Address Resolution Protocol (ARP) Payload: Can be an exact address, a bit masked value, a subnet mask value, or a wildcard value. IPv6 Flow Label: Exact match or wildcard. ICMPv6 Type and Code Fields: Exact match or wildcard value. IPv6 Neighbor Discovery Target Address: In an IPv6 Neighbor Discovery message. IPv6 Neighbor Discovery Source and Target Addresses: Link-layer address options in an IPv6 Neighbor Discovery message. Multiprotocol Label Switching (MPLS) Label Value, Traffic Class, and Bottom of Stack (BoS): Fields in the top label of an MPLS label stack (Ravi Tomar, Hitesh Kumar, Ankur Dumka, Abhineet Anand, (2015)). Flow-Table Pipeline A switch may include more than one flow tables. If there is more than one flow table, they are organized as a pipeline as shown in Figure 5, with the tables labeled with increasing numbers starting with 0. Downloaded 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 Quality of Service in SDN Technology Figure 5. Pac