On the horizon: 100 Gigabit Ethernet

The IEEE's latest project could significantly boost the speed of traffic delivery across the Internet. In November, the IEEE's 802.3 Higher Speed Study Group announced that it's working to create a 100Gbps Ethernet standard, which could be ready by 2010. The group is racing against time to accommodate the increasing demands of content creators and consumers around the world. Sandra Gittlen recently spoke with John D'Ambrosia, chairman of the study group and a scientist at Force10 Networks, about the impact of 100G Ethernet on technology users.

What is driving the need for 100G Ethernet?

There are many applications where you're seeing the need for 100G emerging. Some examples are Internet exchanges, carriers and high-performance computing. You're also seeing a need when you look at what's happening with personalized content, which includes video delivery such as YouTube, IPTV and HDTV. There's also video on demand. All of this together is driving the need for 100G Ethernet.

Consumers are also contributing to this. For instance, people have digital cameras that churn out large files that they want to share across the Internet. Content-generation capabilities are increasing rapidly at both the professional and consumer level. This is creating a basic ecosystem problem -- people are sharing content at a higher level, and all of that has to feed into today's pipes.

Is there enough bandwidth today to meet the needs of businesses, content providers and consumers?

You do have 10G Ethernet already, and if you use link aggregation -- which allows you to pool your 10G links to create a bigger pipe -- you can go higher. But bandwidth needs are quickly surpassing these bandwidth limits.

When we did an analysis to check the viability of a 100G Ethernet standard, we found that the top supercomputers could already use that much bandwidth today. However, these standards are not something you whip out in 18 months. Right now, we're trying to define what will be in the 100G project. That's a time-consuming process -- you have to create baseline proposals, develop the spec and get comments. We have to go through the document and make sure we got everything right. But, yes, we are hearing people say we need it now, even though a final spec is at least three to four years away.

Do you foresee a lot of prestandard technology on the market?

Some companies are already talking about 100G. I think the reality is that there are a lot of different technologies that are going to be needed to fully deploy 100G Ethernet. You'll need new optics, backplanes and chip technologies. 10G backplanes won't be sufficient, so you need to make a leap there.

In regard to 100G Ethernet prestandard, [IT managers] are very nervous about going with prestandard technology. They'll do it if they have to, but it will be hesitantly. And they will surely keep their eyes on what's happening in the standards bodies.

You mentioned that companies are using link aggregation to get to higher speeds today. Why is that a problem?

Link aggregation scales up to a limit, and then it becomes an issue. Depending on who you to talk to, you'll hear that two, four or eight links can be aggregated together before you have management and troubleshooting issues. Also, those cables take up precious real estate, and you have power and cooling considerations. Using up those ports for link aggregation also creates lost revenue opportunities, because any port that's tied up is not bringing in revenue. There are a lot of issues with scaling, too.

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YouTube is interesting -- it's experiencing 20 percent traffic growth per month and is constantly adding 10G links to support this growth. However, YouTube is not the only reason for 100G. The study group has had to prove that there is a need by addressing five criteria: broad market potential, compatibility, technical feasibility, economic feasibility and distinct identity. This has to be a unique and necessary solution.

A major part of this is broad market potential. You don't generate a spec for one customer that's out there. While YouTube is one of the content providers I talked about earlier in terms of applications and exploding bandwidth requirements, it is not the only one.

We are also considering the move to HDTV for many households.

Comcast charts the difference between standard traffic rates and high-definition traffic rates at 3.5Mbps vs. 19Mbps. If you look at the number of HDTVs being sold, that higher rate becomes critical to support.

Will the typical IT or data centre manager be affected by the move to 100G Ethernet?

People with large data centers will start to feel it if they don't feel it already. Applications will start driving bandwidth requirements of aggregated and individual links. One IT manager I know works in construction, and he told me how he could already use 100G today because of the reports his vertical application generates. Each report uses up about 30Mbps or 40Mbps of bandwidth. He's got a 60G pipe handling the load, but he worries that new platforms such as Vista might alter his requirements. He's already looking for workstations with 10G Ethernet links.

The medical industry is another example. The folks working on the Human Genome Mapping [Project] could use 100G to share information among university research groups. They already generate reams and reams of data. There are also MRIs -- the bandwidth requirements for these imaging machines are phenomenal. They can generate 500MB of data an hour. Think about the fact that the diagnostics being done for those images is now handled offshore in some cases. That's a lot of data to send back and forth.

And finally, there's disaster recovery and backup that needs to be dealt with within companies. All the data we're creating and consuming personally and professionally has to be stored and protected.

Gittlen is a freelance writer for Computerworld.com.

Why 100G?

The IEEE 802.3 Higher Speed Study Group considered various speeds for the next-generation Ethernet, but 100Gbit/sec. won approval as the best goal. For now.

The IEEE 802.3 Higher Speed Study Group considered various speeds for next-generation Ethernet, including 40Gbps, 80Gbps and 120Gbps, but none of them garnered enough backing. It was 100Gbps that achieved the required 75 percent vote. The group weighed the time and effort required to achieve a speed against how well it would meet the needs that will exist when it becomes available, says group Chairman John D'Ambrosia.

Products are expected in 2009 or 2010, but the cycle never ends. "This will never be the last Higher Speed Study Group," D'Ambrosia says. "We'll get this done, and eventually, there will be a push for another speed after this."