shown in Figure 6.7. The packet inspections nodes implement IP packet manipulation based on the results obtained from DPI elements and then using the traffic policies set in the given network. The DPI elements are typically deployed in the core network nodes (close to the net- work edges), which inspect the packets to determine their traffic types. With the DPI IP traffic monitoring and QoS control intervention QoS functions Deep packet (admission control, Bitpipes Inspection priority control, (DPI) queuing, etc.) Layer 3 (IP) and Layer 4 (TCP/ Layer 1 (physical)/Layer 2 UDP) end-to-end path (data-link) bitpipes - IP packets to MAC and physical layer - IP packet classification - Layer 2 (MAC layer) scheduling - Packet marking - Scheduling - Service differentiation - Layer 1/Layer 2 resources allocation - Buffering and scheduling on Layer 3 - Ethernet/WiFi Class of Service control IP - Internet protocol QoS - Quality of service MAC - Medium access control TCP - Transmission control protocol UDP - User datagram protocol Figure 6.7 General traffic management architecture. 6.6 QoS for Internet Access Service and Over-the-Top Data Services Service Service servers servers Edge router DPI node Core router QoS Policy and network control Edge router Access network Access network Access network gateway gateway network Data traffic DPI - Deep packet inspection Layer 3/ Layer 4 interventions IP - Internet protocol Layer 1/ Layer 2 pipe bitrates QoS - Quality of service Figure 6.8 DPI-based OTT traffic management. are inspected all headers and payload information in each IP packet. Association of the IP packets belonging to a particular flow can be provided by using the five-tuple (that includes five parameters: source and destination IP addresses, source and destination port numbers, and protocol being in use over the IP such as TCP, UDP, or IP in tunnel- ing cases). The positioning of DPI and its relation to other network elements are shown in Figure 6.8. The information collected from the DPI elements is further sent to th