BROCADE IP PRIMER

Data Center Bridging (DCB)3IntroductionData networking and storage networking technologies have evolved on parallelbut separate paths. Ethernet has emerged as the technology of choice forenterprise data networks, while Fibre Channel (FC) became the dominantchoice for enterprise shared Storage Area Networks (SANs). Ethernet and FibreChannel continue to evolve achieving higher speeds and adding new features.Anyone you ask is bound to have an opinion about Ethernet vs. Fibre Channeland they’ll probably all be right to some extent!Most large organizations invested in both technologies for data center needs:Ethernet for front-end Local Area Networks (LANs) linking users to enterpriseservers and Fibre Channel for back-end SAN links between server and storage.These days, server virtualization requires powerful CPUs and servers, placinghigher demands on server networking and storage I/O interconnects. Maintainingseparate data and storage networks also adds to the complexity ofmanaging and maintaining data centers. As enterprises embrace virtualizationand multiple applications are consolidated onto a smaller number of powerfulservers, the next step involves simplifying server I/O links by converging thedata and storage networks onto a common shared transport. New industrystandards are needed to enable the convergence of data and storage networkinginterconnects and manage the behavior of diverse converged traffic flowssharing 10 GbE links.The new transport of storage traffic over Ethernet had to be enhanced to handlestorage traffic. New features have been added to Ethernet to improve itsability to transport storage traffic in a reliable and predictable lossless manner.A new flow control mechanism allows 10 GbE links to handle multipletraffic flows and deal with flow control and congestion problems of each flowseparately. A new mechanism enables management of the various traffic flowsto deliver a quality of service to applications that need higher priority. Effortsto enhance Ethernet making it lossless, more reliable, and predictable are carriedout by IEEE under the framework of Data Center Bridging, or DCB. Thefollowing diagram shows the possible protocols that may be converged onto ashared lossless 10 GbE link.Brocade IP Primer 75