This vendor-written tech primer has been edited by Network World to eliminate product promotion, but readers should note it will likely favor the submitter’s approach.
Hyperscale public cloud providers and social media giants have already made the jump to 40Gbps Ethernet for their server and storage connectivity for lower total cost of ownership (TCO) and operational efficiency, and now they are migrating to 50 and 100Gbps Ethernet.
Forward thinking enterprises are looking at these hyperscale giants and trying to understand how to achieve Webscale IT efficiencies on an enterprise scale IT budget. Rather than bolting from 10Gbps server connectivity straight to 100Gbps, many are considering 25Gbps as an affordable and less disruptive step that will still provide significant performance improvements.
So, the question is, are you ready for 25G? If not, how do you get ready?
There are four issues to consider when determining your readinenss for 25G:
1. Which Workloads Benefit from 25G?
Short answer: All of them. Businesses frequently say they don’t run high performance applications and therefore don’t need high speed networks. But this belief fails to take into account the key insight the Webscale folks have learned: High speed networks are not just about performance, they are about efficiency.
As more and more applications become converged, virtualized and distributed, the network is being utilized constantly. This is being further driven by the trend towards hyperconverged infrastructure, which combines compute, storage and virtualization into an integrated platform.
Hyperconverged solutions from Nutanix, Microsoft and VMware all utilize distributed, software-defined storage that relies on the network to move data. Furthermore, snapshots, backups and virtual machine migration is a regular occurrence to achieve load-balancing and high availability.
These ‘background’ tasks consume significant resources and frequently take applications offline or degrade performance while they occur. One solution is simply to over-provision everything; compute, storage and VM instances so that it is possible to provide adequate service level guarantees.
The alternative is to increase network speeds to minimize the impact of background tasks, enabling servers and storage resources to serve applications and users, rather than be consumed simply by moving data. The relationship between higher speed networks and infrastructure efficiency is a key insight that the hyperscale public cloud providers have embraced and has positioned them on the forefront of 25, 50 and 100Gbps network speed adoption.
2. What is the server, switch and storage infrastructure availability?
As of this month, there are 25G Ethernet solutions from all of the major switch and server vendors available. This is remarkable given that it was just over two years ago (in July of 2014) that the 25G Ethernet Consortium was formed. This initiative was created by a group of companies, including cloud giants Microsoft and Google, to define a specification that enabled interoperable 25G and 50Gbps Ethernet solutions. Since then, multiple suppliers have released silicon and system products that support the standard. Major server vendors including Dell, HPE and Lenovo are now offering 25G, 50G and 100Gbps Ethernet Adapters across a broad range of servers with both traditional stand-up PCI and mezzanine cards available. In addition, a broad range of switch vendors are supporting 25G, 50G and 100Gbps Ethernet speeds.
3. Is there a significant cost to upgrade to 25G?
Fortunately, even though they provide 2.5X more bandwidth, 25Gbps NICs and switches are not significantly more expensive than 10Gbps Ethernet solutions. Furthermore, they are fully backwards compatible and will auto-negotiate down to a slower rate when connected to 10Gbps equipment. This means that you don’t need to do a wholesale forklift upgrade to your data center. Instead, you can upgrade your data center network as part of a regular refresh cycle and still future proof your network with 25G capabilities.
So, if you need more switching ports you can simply secure 25G capable switches. Similarly, as new servers are brought on line, these can be equipped with 25G Ethernet adapters. Those parts of your network that are still running at 10Gbps won’t get the benefit of the faster 25Gbps capabilities, but there is no penalty and your network is future proofed. As more and more of the server, storage and switching infrastructure converts to 25G you will be able to recognize the performance and efficiency benefits of the faster network speeds. So, for just a small incremental cost, you can be ready for 25G and begin seeing the benefits of better compute and storage efficiency in your data center today.
4. Is my cable plant ready for 25G, 50G & 100G Ethernet?
One of the biggest costs and risks for any data center is installing cabling fiber plant. This often involves lifting up the floor panels or running cable in overhead channels. Not only is this labor intensive, but also extremely disruptive to data center operations and carries with it the potential for confusion and errors. For most data center operators the preference is to install fiber cabling just once and then leave it.
Fortunately, most 10Gbps data centers use Small Form Factor (SFP) optical transceivers and multimode or single mode fiber. For those considering a 25G upgrade, the good news is the fiber that has already been installed in the data center will work in the vast majority of cases. Single mode fiber (typically yellow) is the most flexible and supports distances of up to 2 kilometers or more. However, even if you have installed multimode fiber (typically orange) you should still be fine unless you are running distances of greater than 100 meters. This, however, is unusual for most deployments.
So, there is a high probability that you can reuse all of your existing fiber plant. You will only need to upgrade the optical transceivers and copper cables to support the faster 25Gbps speeds. Fortunately, the upgrade from 10G to 25G (or from 40G to 100G) avoids tearing out and laying new fiber, which is typically the most expensive, time consuming and the error-prone part of an upgrade.
What are you waiting for?
Now that you know the top four things to consider when making the jump to 25G, only one question remains: What are you waiting for? There are no roadblocks and 25G offers the opportunity to future-proof your data center.
Whether you want to upgrade your servers, switches or storage, you can choose gear that is 25G-ready. It will automatically downshift to operate seamlessly at 10G with the rest of your infrastructure. And, as you upgrade the data center infrastructure over time, you will begin to recognize a 2.5X performance gain with a minimal price delta. This will improve the performance and efficiency of every workload that you run and allow better utilization of expensive compute and storage resources. All of this means that it is really a no-brainer these days to make the move to 25G.
This story, "Four things to consider before upgrading your data center net to 25G" was originally published by Network World.