• 802.1Qau — Congestion Notification
• Data Center Bridging Exchange (DCBx) protocol
NOTE:
Dell Networking OS supports only the PFC, ETS, and DCBx features in data center bridging.
Priority-Based Flow Control
In a data center network, priority-based flow control (PFC) manages large bursts of one traffic type in
multiprotocol links so that it does not affect other traffic types and no frames are lost due to congestion.
When PFC detects congestion on a queue for a specified priority, it sends a pause frame for the 802.1p
priority traffic to the transmitting device. In this way, PFC ensures that PFC-enabled priority traffic is not
dropped by the switch.
PFC enhances the existing 802.3x pause and 802.1p priority capabilities to enable flow control based on
802.1p priorities (classes of service). Instead of stopping all traffic on a link (as performed by the traditional
Ethernet pause mechanism), PFC pauses traffic on a link according to the 802.1p priority set on a traffic type.
You can create lossless flows for storage and server traffic while allowing for loss in case of LAN traffic
congestion on the same physical interface.
The following illustration shows how PFC handles traffic congestion by pausing the transmission of incoming
traffic with dot1p priority 4.
Figure 32. Illustration of Traffic Congestion
The system supports loading two DCB_Config files:
• FCoE converged traffic with priority 3.
• iSCSI storage traffic with priority 4.
In the Dell Networking OS, PFC is implemented as follows:
• PFC is supported on specified 802.1p priority traffic (dot1p 0 to 7) and is configured per interface.
However, only two lossless queues are supported on an interface: one for Fibre Channel over Ethernet
(FCoE) converged traffic and one for Internet Small Computer System Interface (iSCSI) storage traffic.
Configure the same lossless queues on all ports.
• PFC supports buffering to receive data that continues to arrive on an interface while the remote system
reacts to the PFC operation.
Data Center Bridging (DCB)
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Содержание S4048T
Страница 1: ...Dell Configuration Guide for the S4048T ON System 9 10 0 1 ...
Страница 98: ... saveenv 7 Reload the system uBoot mode reset Management 98 ...
Страница 113: ...Total CFM Pkts 10303 CCM Pkts 0 LBM Pkts 0 LTM Pkts 3 LBR Pkts 0 LTR Pkts 0 802 1ag 113 ...
Страница 411: ...mode transit no disable Force10 Resilient Ring Protocol FRRP 411 ...
Страница 590: ...Figure 67 Inspecting the LAG Configuration Link Aggregation Control Protocol LACP 590 ...
Страница 591: ...Figure 68 Inspecting Configuration of LAG 10 on ALPHA Link Aggregation Control Protocol LACP 591 ...
Страница 594: ...Figure 70 Inspecting a LAG Port on BRAVO Using the show interface Command Link Aggregation Control Protocol LACP 594 ...
Страница 595: ...Figure 71 Inspecting LAG 10 Using the show interfaces port channel Command Link Aggregation Control Protocol LACP 595 ...
Страница 646: ...Figure 87 Configuring Interfaces for MSDP Multicast Source Discovery Protocol MSDP 646 ...
Страница 647: ...Figure 88 Configuring OSPF and BGP for MSDP Multicast Source Discovery Protocol MSDP 647 ...
Страница 648: ...Figure 89 Configuring PIM in Multiple Routing Domains Multicast Source Discovery Protocol MSDP 648 ...
Страница 653: ...Figure 91 MSDP Default Peer Scenario 2 Multicast Source Discovery Protocol MSDP 653 ...
Страница 654: ...Figure 92 MSDP Default Peer Scenario 3 Multicast Source Discovery Protocol MSDP 654 ...
Страница 955: ...Figure 119 Single and Double Tag First byte TPID Match Service Provider Bridging 955 ...
Страница 1179: ...Figure 147 Create Hypervisor Figure 148 Edit Hypervisor Figure 149 Create Transport Connector Virtual Extensible LAN VXLAN 1179 ...