1. IEEE 802.1 Inter Networking Shortest Path Bridging Security Audio/Video Bridging DCB (802.1) Task Group PFC 802.1Qbb ETS 802.1Qaz DCBX 802.1Qaz QCN 802.1Qau EVB 802.1Qbg BPE 802.1Qbh 802.1QBR DCB Protocol Tree I/O Consolidation & Network Convergence Physical/Virtual Server/Switch Interaction NOTE: QBR replaces Qbh Network Wide Congestion Management Builds on existing standards: 802.1P User Priorities & VLAN structure 802.1Q Forwarding & Queuing Functions 802.3X Flow Control 802.3bd MAC Control Frame for PFC amended 802.1AB LLDP

2. Physical Port Physical Port Physical Port Physical Port PFC – LOGICAL VIEW TX Queue 4 RX Buffer 4 TX Queue 5 RX Buffer 5 TX Queue 6 RX Buffer 6 TX Queue 7 RX Buffer 7 TX Queue 0 RX Buffer 0 TX Queue 1 RX Buffer 1 TX Queue 2 RX Buffer 2 TX Queue 3 RX Buffer 3 RX Buffer 4 TX Queue 4 RX Buffer 5 TX Queue 5 RX Buffer 6 TX Queue 6 RX Buffer 7 TX Queue 7 RX Buffer 0 TX Queue 0 RX Buffer 1 TX Queue 1 RX Buffer 2 TX Queue 2 RX Buffer 3 TX Queue 3 PFC OFF PFC ON PFC OFF PFC ON PFC OFF PFC ON PFC OFF PFC ON STOP drop pause Keeps sending

3. ETS – Logical View Physical 10GE Port Physical 10GE Port TX Queue 4 TX Queue 5 TX Queue 6 TX Queue 7 TX Queue 0 TX Queue 1 TX Queue 2 TX Queue 3 Class Group 1 Class Group 2 Class Group 3 Offered traffic Realized traffic T1 T2 T3 1 1 2 2 3 3 2 2 6 6 5 5 2 2 4 4 3 3 1 1 2 2 2 2 2 2 5 5 5 5 2 2 3 3 3 3 Unicast / Multicast User Group / Priority Class – apply ETS Physical Port Port 1Group 1012Group 23Group 34567

4. QCN – Before and After Lossless without QCN –Congestion spread Lossy without QCN –Congestion causes loss –TCP Congestion management CNA Using QCN with Lossless –Reduces congestion spread Using QCN with Lossy –Reduces packet loss CNA