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data center bridging (802.1) (DCB)

Data centers have specific requirements for Ethernet. They need extremely low latency, the ability to prioritizetraffic and the flexibility to manage traffic instructions. As for storage traffic management, this has become much more important with the standardized Fibre Channel over Ethernet( FCoE). This ANSI standard requires Ethernet to provide lossless data transmission, Lossless Ethernet, similar to that of Fibre Channel networks.

Data center bridging requirements are being developed by the IEEE802.1working group, Data Center Bridging (DCB). The goal of this working group is to improve the 802.1 specification to meet the requirements of switches for modern data centers. This is because data center networks can only be flexibly expanded via the DCB functionality of the switches.

In the current version of Data Center Bridging, congestion is handled in large bridging domains with Priority Flow Control( PCF) and Enhanced Transmission Selection( ETS) with Deficit-Weighted Round Robin Queuing( DWRR). Four protocol techniques are implemented in the implementation of DCB functionality: that of Priority Flow Control( PFC), Congestion Notification( CN), Enhanced Transmission Selection (ETS), and Data Center Bridging Exchange ( DCBX). Extensive congestion is to be solved with the Quantized Congestion Notification( QCN) specified in the 802.1Q (au) standard; here, the bridges send a Congestion Notification Message( CNM) to the end host.

Informations:
Englisch: data center bridging (802.1) - DCB
Updated at: 04.01.2011
#Words: 207
Links: Ethernet, latency, traffic, arsenic (As), traffic management
Translations: DE
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