GloRTs and VEPA — The New Virtualization Standard
The IEEE is defining an important new specification for the cloud data center that defines how to connect multiple virtual machines to a data center bridging (DCB) fabric through a single high bandwidth port. An earlier proposal by the PCI-SIG for single root complex IO virtualization (SR-IOV) has not gained much traction in the industry. Although Cisco has released the Nexus 1000 as a virtualized bridge within the blade server rack, it is in effect a proprietary solution that forces the use of Cisco equipment throughout the data center if unified management software and network policies are desired. This can be an expensive and limiting solution.
A new proposal called Virtual Ethernet Port Aggregator (VEPA) is being developed by the IEEE, as described in this article from Network World. This standard moves the virtualization function from the blade servers into the DCB fabric. Many companies are attracted to this proposal because the management and network policies can be easily applied to both the physical and virtual fabrics using a single software stack running on an Ethernet bridge. With the Cisco proposal, part of the fabric is inside the blade server system, which of course, Cisco wants to supply as well. It looks like Cisco has now acquiesced, and will join the VEPA standards effort.
FocalPoint switches have several features to support the VEPA standard. A key feature is the use of Global Resource Tags (GloRTs), which can be used to identify the locations of thousands of virtual machines connected to the FocalPoint fabric. Translation between VEPA tags and GloRTs at the ingress and egress of the fabric using a Q-in-Q type approach allows easy address translation across blade server domains while maintaining support for all other DCB traffic such as FCoE. This highly scalable solution can be achieved while maintaining the low cut-through latency pioneered by Fulcrum.
For more details on DCB and CEE support in FocalPoint, download this PDF whitepaper.
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