NETWORKING

  • 04/21/2015
    8:00 AM
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Ethernet Roadmap: A Raft Of New Speeds

The Ethernet Alliance's new roadmap charts out an ambitious path for the networking technology to meet increasing data center demands.

The Ethernet Alliance recently released its 2015 roadmap, which outlines Ethernet’s response to the ongoing desire for more bandwidth in data centers by adding new speeds for both in-rack and backbone connections. The roadmap calls for some eye-popping speeds in the future, but also charts out a plan for the low end of the market, representing an unprecedented level of activity for Ethernet.

The first new Ethernet speed is almost upon us. 25 GbE is designed to replace 10 GbE and 100 GbE will fit into the 40 GbE slot (both using quad-lane connections), basically by speeding up the individual link.  The first 25 GbE gear should hit late in 2015 with production volume in 2016.

25GbE will help the demand created by virtual systems and the huge data volume of the Internet of Things, but clearly we’ll be back to network bandwidth under-provisioning in just a couple of years, so the roadmap foresees another doubling of speed, to 50 GbE and 200 GbE in the 2018 to 2020 timeframe.

Even these speeds aren’t going to be enough, based on a broad look at the industry in a  2012 study by an an IEEE committee. Consequently, the roadmap has plans for a 400 GbE link using 50 GbE technology in an eight-lane configuration. Beyond 400 GbE, dates  start to get fuzzy -- “sometime after 2020” -- but doubling to 800 GbE will occur when true 100 GbE links are available. This technology will allow larger lane bundles, too, giving us a whopping 1 TbE or 1.6 TbE link with 10 or 16 lanes.

Of course, some of these high-performance levels will come at appropriately high prices, and within the basic roadmap we see a move to lower connection cost over time. The advent of single-lane 50 GbE will obsolete quad-lane 40 GbE, while the 2018 expected date seems to have made a 25 GbE dual-lane product unnecessary.

All of these products are aiming at the primarily fibre-based SFP and QSFP market, for primarily backbone or longer-haul connections. The venerable low-cost copper connection, which constitutes by far the bulk of connections, from servers to the top-of-rack switch, is  still going to be available in higher speeds at 25GBASE-T and 40GBASE-T, although using upgraded Cat 8 cabling. These links will handle 30 meters of connection, which is more than enough for in-rack connectivity.

The Ethernet roadmap also addresses the low end of the market. Driven by a need to upgrade wireless hub connections without expensive rewiring, we are going to see 2.5 GBE and 5 GbE connections using Cat 5e out to 100m.  This will support higher speed wireless hubs through to the end of the decade.

It’s been noted that the IEEE is planning more Ethernet standards in the next five years than its released in the last 40. This reflects the ingenuity and agility of the teams designing the core technologies involved, and presages further gains in the 2020s. There is even realistic talk of 10 TbE towards the end of the next decade.

Clearly, this rapid Ethernet evolution is needs-driven. The IO performance of flash-based storage, coupled with the horsepower of GPU and high-core-count CPUs is creating the need for a major boost in rates. The key question is affordability.  New cabling is just the start of the upgrade cost, and it makes more sense to make an upgrade part of a new installation. This begs the question of when motherboard chipsets will handle the new Ethernet speeds; Intel, AMD and ARM will have to deliver their own roadmaps to clarify that.

So many new standards could lead to quite a bit of confusion in the next few years. There are Ethernet subcategories which aren't road-mapped by the IEEE, including RDMA, converged Ethernet solutions and accelerators for protocols such as iSCSI and FCoE. These make the roadmap blurry, so that elements overlap each other;  creation of a clear plan for a data center will be challenging indeed.

One other impact of the intense emphasis on Ethernet is that other connection schemes will find their existence hard to justify. Fibre Channel and  InfiniBand may be casualties of the rapid change, while FCoE could find itself in an inescapable backwater. With Ethernet drives now available, even SAS and SATA may fall by the wayside in favor of a single, unified approach.

Network administration has never had so many opportunities to solve problems and so many challenges in identifying the correct path forward. On the whole, this is a very positive trend for the IT industry, but not a free lunch!


Comments

Ethernet subcategories

Jim, with regards to the Ethernet subcategories that aren't included in the roadmap, how much of a problem do you see this becoming? Are there any efforts to address it?

 

Re: Ethernet subcategories

I suspect the market will determine the raodmap much more than it has in the past. WE used to see dogmatic 10 performance between generations. This is certainly no longer the case. The pressure for 25GbE has opened things up.

The result will be that if enough companies want a configuration to be added, it will eventually get there. If not, it will likely still end up in the market. I expect there to be more flavors of Ethernet coming soon.

Re: Ethernet subcategories

@Jim  I agree too many changes will cause confusion.   What is going to happen to the de facto standard of 1G or 10G ?  Or is this not the typical setup in datacenters ?

Re: Ethernet Roadmap: A Raft Of New Speeds

You're right; The Ethernet Alliance is certainly not a name we hear everyday (at least, not compared to their cousins, The WiFi Alliance) when it comes to defining new standards and being at the forefront of where networking is headed. This is refreshing in that it seems like a very far-reaching plan, if a little lacking in specifics; It still seems like they're relying on individual vendors to fill in a lot of the gaps. "The Ethernet Alliance will award the first company that produces a 100GbE SFP+ with the Holy Grail of the 100GbE SFP+." I had to do a little extra reading to figure this out, but apparently, yes, there is a physical grail they will give to someone who publicly demonstrates 100GbE Housed in 1.5W SFP+ with CAUI at a major conference. Who knew?

Certainly, Ethernet has already proven itself in terms of being an enduring technology, but it's amazing if you stop to think that it actually may be growing in popularity. As for whether SATA really has something to worry about, I'd remain a little skeptical, but the fact that it's even on the table says something about where things are going. Maybe with our hardware moving towards greater and greater convergence, it shouldn't be so surprising that our connectivity is doing the same. Meanwhile, all this new horsepower is going to power infinite varieties of applications flung across the four corners of the globe - even if internet connectivity for an IoT device is wireless and slow, the speeds on the backend, in the datacenter, may need to be that much quicker to keep everything running smoothly.

Re: Ethernet Roadmap: A Raft Of New Speeds

" .....all this new horsepower is going to power infinite varieties of applications flung across the four corners of the globe - even if internet connectivity for an IoT device is wireless and slow, the speeds on the backend, in the datacenter, may need to be that much quicker to keep everything running smoothly."

 

@Zerox203   Thanks for this explanation.  I was struggling to understand just why these changes were needed, now it makes sense.

Re: Ethernet Roadmap: A Raft Of New Speeds

I guess important factor here is Ethernet packets have no time-to-live field and this can cause problems in the presence of a switching loop, other than this we talk of priortizing the packet this field becomes even more important.

Re: Ethernet Roadmap: A Raft Of New Speeds

I recently found an update which says, MEF has now approved the next phase of the MEF Ethernet Interconnect Points (EIP) project to standardize guidelines for current and future Ethernet Carriers around the globe. Although did noy found much on same but headlines explains that EIP project will provide rapid feedback from prototyping to help the project participants agree on a common approach to interconnecting by using MEF specifications.

Source: LightReading.

Re: Ethernet Roadmap: A Raft Of New Speeds

@viringh211    Thanks for the information, that certainly helps to understand the scope of transmission we are dealing with.

Re: Ethernet Roadmap: A Raft Of New Speeds

Another important success will be Ethernet geared for cars, I am curious to find progressive updates and glitches if any.

Re: Ethernet Roadmap: A Raft Of New Speeds

@aditshar1    Excellent point, it is all about the packet(s). 

Segmenting Network transmission Rationale

" The advent of single-lane 50 GbE will obsolete quad-lane 40 GbE,...."

 

I have always been skeptical about quad-lane transmission.  Was this used often ? By whom ? Mobile providers ? And since single-lane 50Gbe is replacing it, why not dual-lane ?