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Data center bridging. Data center bridging (DCB) refers to a set of enhancements to Ethernet local area networks for use in data center environments. Specifically, DCB goals are, for selected traffic, to eliminate loss due to queue overflow (sometimes called lossless Ethernet) and to be able to allocate bandwidth on links. Essentially, DCB enables, to some extent, the treatment of different priorities as if they were different pipes. The primary motivation was the sensitivity of Fibre Channel over Ethernet to frame loss. The higher level goal is to use a single set of Ethernet physical devices or adapters for computers to talk to a Storage Area Network, Local Area network and InfiniBand fabric.[1] Ethernet is the primary network protocol in data centers for computer-to-computer communications. One area of evolution for Ethernet is to add extensions to the existing protocol suite to provide reliability without requiring the complexity of TCP.

Terminology[edit] IEEE Task Group[edit] Other groups[edit] FCoE. Nexus 5000. Yesterday, Cisco announced the Nexus 5000 series of data center switches. The 5000, along with the Nexus 7000, brings high density 10GIG access to the data center. I did a quick review of 5000 and made some quick notes. It is a wire-rate, low latency (3.2 micro seconds), layer-2 only switch for data centers. It runs NX-OS, just like the 7000, but is missing a few key NX-OS features, like Virtual Device Containers. I am very upset the 5000 does not have VDCs. I think they are a key virtualization feature for data center network design. The 5000 has a loss-less cross-bar switching fabric provided by only two ASICs. Currently, the only 5000 model is the 5020 which provides up to 56 10GIG ports. 40 of the 10GIG ports are fixed on the chassis.

I think the biggest benefit the 5000 will provide is a unified connection to the servers with FCoE. The 5000 would provide us a single 10GIG FCoE connection to each server over which both IP and SAN traffic would flow. NX-OS's Best Feature: Virtual Device Contexts (VDCs) | NetworkWo. When I wrote about the Cisco Nexus 7000 NX-OS a few weeks back, I mentioned the pinnacle of new features in NX-OS was Virtual Device Contexts (VDCs) . This is a feature I could've used a lot in the past during network design and is a long-time coming. VDCs take a single physical switch and create many, unique virtual devices (switches), just as VMware does for servers. Each VDC is analogous to a virtual machine in VMware . NX-OS runs a single kernel and infrastructure layer to control the hardware and provide basic services. Each VDC is its own switch. Processes in each VDC are separate and run in their own protected memory space. VDCs offer several direct benefits: A completely separate partition between different groups or organizations (if you network requires this separation) while using only a single switch.

VDCs can be created for development, testing, stage, and production on the same switch. Network testing and training can occur in a separate VDC. . - 128,000 MAC addresses. The DC3....err....Nexus 7000 brings some exciting hardware to th. Even though I professed my dislike for the new name, the Cisco Nexus 7000 does have some very interesting new hardware features. First, the concept of a unified fabric inside the data center has the ability to finally merge many DC network topologies and technologies.

While it's not ready yet, the Nexus series will have FCoE for SAN connectivity, collapsing FC into the Ethernet network. However, I have to hold off judgement to see if this is a true differentiator since FCoE is not ready. It would be nice to have Fiber Channel SAN cards in the Nexus, truly creating a unified fabric (I couldn't find anything saying Cisco was working on that). Second, we all love bandwidth, and the Nexus 7000 brings it. 230 Gbps In per slot +230 Gbps Out per slot ---- 460 Gbps x 16 slots for cards in an 18-slot chassis ---- 7360 Gbps (7.3 Tbps) x 2 Future speed enhancements ---- ~15000 Gbps (15 Tbps) HOL blocking is now gone.

Finally, there's Ethernet inside the Nexus 7000.