The Ethernet traffic mix-up
Ethernet communications convergence conumdrum
Duncan Hughes - Pre-Sales Engineering Manager at Brocade
When and how far to converge the Ethernet (IP) and Fibre Channel (FC) traffic—or not to converge—is a decision that should be made in the context of the unique requirements of each organisation. In the short term, organisations can phase-in network convergence and reduce complexity while still supporting virtualisation and cloud computing services. But how?
For data centres that can take advantage of the converged LAN/SAN environment, there are solutions available in the market that provide end-to-end FCOE (Fibre Channel over Ethernet) capabilities (using the IEEE DCB protocol), enabling traditional IP and storage traffic to exist on the same network. This converged design allows for a truly lossless communication within the Ethernet or storage fabric taking advantage of the Priority-based Flow Control (PFC) and Enhanced Transmission Selection capabilities defined within DCB to sustain critical network traffic including FCoE. The architecture provides shared storage access and connectivity for servers over a high-performance, multi-pathing, reliable, resilient, and lossless converged fabric. As a result, storage traffic is protected whilst 10 Gbps connections maximised.
Virtual machine environments rely heavily on shared storage platforms. The FC storage fabric (SAN) has been an industry standard for more than a decade and its tried and trusted capabilities will continue to be the solution of choice for a large number of organisations for the foreseeable future. However, Ethernet Fabrics present an alternative. With the inherent lossless nature of an Ethernet fabric FCoE becomes a reality whilst the benefits of a fabric solution can also bring enhancements to ISCI and NFS storage alternatives with significant cost benefits.
Ethernet fabrics are implemented at Layer 2, flattening the network, and allowing it to scale beyond the boundaries associated with traditional Ethernet, and, at the same time, reducing capital and operating costs. Like storage fabrics before them, Ethernet fabrics are self-aggregating, scale efficiently, and are lossless and deterministic.
With the inherent lossless nature of an Ethernet fabric FCoE becomes a reality
In Ethernet fabrics, all switches are aware of all end-devices so virtual machine mobility does not require manual reconfiguration of the network. Finally, the fabric is extensible between data centres via core routers and Ethernet tunnels in the IP network. Virtual machines with their applications can now move across a server cluster “stretched” between private and public cloud data centres.
Cluster traffic runs through the Ethernet tunnel whilst storage traffic can also be tunnelled over IP using the industry-standard Fibre Channel over IP (FCIP) protocol so that application data can be quickly replicated between public and private cloud data centres.
Duncan Hughes is a pre-sales Engineering Manager at Brocade, joining when Brocade acquired Foundry Networks, where he was also a systems engineering manager, having previously been at Anite Networks.
Our third expert is analyst Tony Lock who believes that new processes and procedures could be a wise investment when converging Fibre Channel onto Ethernet.
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