We’ve talked here before in ReadWriteWeb about the so-called “carrier cloud” concept being developed by Alcatel-Lucent. Think about the level of interconnectivity your enterprise data center would need to present voice and multimedia data to customers at carrier speed, while at the same time transferred to a cloud platform that’s scalable and easily provisioned.
Last week, A-L (the successor to Bell Laboratories) announced its first 64-port 10-gigabit Ethernet (10GbE), or 6-port 40GbE switch, essentially the first switch of this genre manufactured specifically to support cloud-style data center configurations. The news comes on the heels of an independent analysis released Monday of the OmniSwitch 10K, the company’s 10GbE switch released just last April – an analysis which (PDF available here) may have dropped jaws to the floor.
Lippis Enterprises, which tests all manners of networking equipment, put OmniSwitch 10K through a battery of tests to gauge its relative performance characteristics for variable workloads. Usually with a test like this you’d find some variance. As it turns out, there wasn’t any.
With packet frame sizes ranging from 64 bytes to 9,216 bytes, simulated traffic over network layers 2 and 3 pumped out 100% of throughput across the board. In congestion tests, forwarding rates – which for other switches may be observed to decline as congestion increases – stayed perfectly consistent at 80% for each frame size. Imagine an open-wheel race car (which I do every May, believe me) that delivers exactly the same performance no matter how much you open the throttle.
One reason for this may be a curious… shall we say, phenomenon of cloud-based switching. Typical switches that are susceptible to latency fall victim to a kind of congestion called head-of-line blocking (HOL blocking). Although Internet switching is designed to allow for packets in a stream to be received out-of-order, and reassembled in order at the receiving end, switches have a tendency to back up newer packets behind an older one if latency is forcing the older one to wait its turn in line to be forwarded. Until the older packets are forwarded, the newer ones wait and get older. In some switches, the phenomenon results in an exponential clogging.
With OmniSwitch 10K, it doesn’t happen at all, at least, not in Lippis’ experiments.
“The OmniSwitch did not use HOL blocking which means that as the 10GbE port on the OmniSwitch became congested, it did not impact the performance of other ports,” the Lippis Report reads. “There was no back pressure detected, and the Ixia test gear did not receive flow control frames” (meaning, there was no evidence that the testing gear had transferred any diagnostic or mediation instructions that would normally be sent in case of congestion).
The grand prize for all this was zero packet loss: “The OmniSwitch 10K performed well under cloud simulation conditions by delivering 100% aggregated throughput while processing a large combination of east-west and north-south traffic flows. Zero packet loss was observed as its latency stayed under 28?s.”
In a blog post today, Lippis Report Publisher Nick Lippis reached this conclusion: “From server connections to ToR [top-of-rack] to core switching plus storage enablement and virtualization aware software 10GbE is recommended as the fabric for cloud networking environments. We recommend that IT business leaders take full advantage of server I/O at 10Gbps bandwidth and low latency as it will provide the highest performance and greatest data center design options moving forward… With ToR and core switch latencies in the 500 ns to 2 microsecond range, the industry’s 10GbE switches possess the raw performance and capacity to support storage enablement, albeit this area is evolving.”
Unlike the OmniSwitch 10K (above), the forthcoming OmniSwitch 6900 (right) will be a 1U rackmount model, which can be positioned top-of-rack or as a core/aggregation switch. “This will lay the groundwork for enterprises to enjoy the same quality of experience with cloud services,” reads last week’s statement from Alcatel-Lucent, “as with applications deployed in their own data centers.”
CORRECTION: This article was updated with corrected data supplied by Alcatel-Lucent, particularly with respect to the OmniSwitch 6900 40GbE switch.
DISCLOSURE: Alcatel-Lucent is a ReadWriteWeb sponsor.