The Ethernet Alliance recently completed another round of interoperability testing at one of its interoperability plugfests. The alliance is a community of Ethernet end users, system and component vendors, industry experts and university and government professionals focused on standards-based Ethernet, and supports activities that span from incubation of new Ethernet technologies to interoperability demonstrations, certification and education.
The latest event – the Data Center Bridging (DCB) plugfest – focused on testing of DCB technologies per the IEEE 802.1Qxx standards and the various network topologies and interconnect technologies that leverage those standards, and included such vendors as CommScope, Dell, Emulex, Extreme Networks, Intel, and others. It was held at the University of New Hampshire InterOperability Laboratory (UNH-IOL) in late October.
I’ve written about the Ethernet Alliance’s interest in Data Center Bridging, which in effect is the consolidation of the group of disparate networks most organizations have running through their data centers into a single, cohesive network. Or more succinctly, it is data center consolidation. As Ethernet champions, the alliance members definitely want to see Ethernet become the foundation for true converged data center networks capable of supporting all three types of data center networks—storage area networks (SANs), local area networks (LANs) and Inter-process Communication Networks (IPC)—and their unique requirements.
Of course, Ethernet has its limitations (don’t all networking fabrics?). For example, there are issues in distinguishing between types or classes of traffic in the technology’s existing Quality of Service (QoS) mechanisms. That limitation means data center managers must either over provision network bandwidth for peak loads, accept customer complaints during these periods, or manage traffic prioritization at the source side by limiting the amount of non-priority traffic entering the network.
At the latest plugfest, the alliance says a number of industry-firsts were achieved during the event, a few of which take aim at the aforementioned limitation. For example, the participants established that Enhanced Transmission Selection (ETS) bandwidth provisioning overrules other transmission queue managements in DCB-enabled networks. ETS provides the capability to group each type of data flow, such as storage or networking, and assigns an identification number to each of the traffic class groups. The value of this new feature lies in the ability to manage bandwidth on the Ethernet link by allocating portions (percentages) of the available bandwidth to each of the groups. Bandwidth allocation allows traffic from the different groups to receive their target service rate (such as 8 Gbps for storage and 2 Gbps for LAN). Bandwidth allocation provides quality of service to applications.
Another first, the organization reports, was the construction and demonstration of an end-to-end DCB network via the IEEE 802.1Q standard Data Center Bridging Exchange (DCBX), a discovery and initialization protocol that discovers the resources connected to the DCB cloud and establishes its limits. The plugfest also included monitoring of the IEEE 802.1Qbb Priority Flow Control (PFC) behaviors, the part of the standard aimed at establishing priorities for flow control based to enable control over individual data flows on shared lossless links.
The Ethernet Alliance says the latest plugfest sets the stage for implementation. In a prepared statement, Joy Jiang of JDSU, chair of the DCB Plugfest, said, “DCB is enabling the convergence of traditional Ethernet and storage traffic on one, lossless Ethernet cable. This interoperability testing confirms that the standards are complete and we have products that create an eco-system of solutions that are ready to be deployed."