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Optical components

Startups Move 10-Gig to Copper

Yet another IEEE standard is born, this time for 10-Gbit/s over Category 5 copper wiring. Last week, the Institute of Electrical and Electronics Engineers Inc. (IEEE) gave the green light to a six-company coalition after a presentation from startup SolarFlare Communications Inc. during last week's meetings in Hawaii (see SolarFlare Holds 10GE Tutorial).

The "10-G Base T" study group hasn't set a timetable yet, but initial backers expect to complete the standard within the four-year window allotted by the IEEE. The group will be part of the 802.3 series of standards for Ethernet.

SolarFlare's pitch was backed by five other startups: Cicada Semiconductor Inc., Accelerant Networks Inc., Mysticom Ltd., Plato Labs, and Telicos. This clique won't necessarily be running the study group that the IEEE approved; those kinds of administrative details will be ironed out in the coming months.

"Our worst issue was the cynics," says Ahmet Tuncay, SolarFlare's founder and vice president of marketing. "Most people thought 10 Gbit/s could not be brought onto this type of cabling because it was beyond the Shannon wall" -- that is, beyond the theoretical limit of transmission speeds on a noisy channel.

SolarFlare's presentation -- which went into significant technical detail -- convinced the engineers in attendance that the feat was possible. "You just have to mitigate more of the capacity-reducing impairments like echo," Tuncay says.

The IEEE already addresses 10-Gbit/s Ethernet in its 802.3ae standard, but the new group's focus is on a deeper level. Specifically, they'll be discussing the electronics required to make 10-Gbit/s signals viable on existing copper wiring, as the noise levels on those cables can be enough to slow down or disrupt high-speed signals.

The goal is to make 10-Gbit/s Ethernet viable for the existing business environment without forcing companies to rewire their buildings with fiber.

"Unlike metro Ethernet, enterprise Ethernet has a legacy of working on installed cabling, and UTP [unshielded twisted pair] is the predominant flavor of cabling in these data centers," Tuncay says. "The real challenge of 10 Gbit/s in the enterprise has been to figure out how to make it run on this installed cabling."

It's worth noting that the six startups aren't in lockstep agreement on the standard. They all want to use technologies available today, such as pulse-amplitude modulation and adaptive equalization, but the specifics are up for grabs.

PAM, for example, is a way for electronic signals to carry more than one bit per pulse, but the startups disagree on which version of PAM should be used. With adaptive equalization -- the ability to compensate for the variations in signal quality -- it's a question of whether an analog or digital technique is best.

"These are the areas where the study group is going to spend some time," says Jim Tavacoli, vice president of marketing for Accelerant.

The study group's next step is to submit a Project Authorization Request to the IEEE. Once that's approved, the group becomes a "working group" and is officially on its way toward defining a standard.

— Craig Matsumoto, Senior Editor, Light Reading
www.lightreading.com

Want to know more? The big cheeses of the optical networking industry will be discussing 10-Gigabit Ethernet at LightSpeed Europe. Check it out at http://www.lightspeedeurope.com.



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MrLight 12/4/2012 | 9:13:12 PM
re: Startups Move 10-Gig to Copper next-gen-wisdom, yes it is an interesting concept, however the goal as stated :

"to make 10-Gbit/s Ethernet viable for the existing business environment without forcing companies to rewire their buildings with fiber."

would be an easier to sell if there was some historical market data on the re-use of Ethernet wiring that took place going from 10Base-T to 100Base-T or 100Base-T to 1000Base-T. Otherwise I can't judge if the goal is worthwhile or just hype.

I can defintely see the value of 10,000Base-T on a new CAT cabling category with an appropriate connector for short distance , say less than 100m.

A less critizable, but la ess-laudable goal would have been to have it be able to auto-sense between 1000Base-T and 10,000Base-T.

Also the startups may be under-estimating the effort involved here. This is not a trival effort, irregardless of their laudable goal of cable re-use, based on my experience trying to get 10Gbps electrical over backplanes. But hey, it will happen given enough resources.

For some of the difficulties they will be dealing with see "Nov 21, 2002: Proper Serdes Selection Solves Serial Backplane Design Woes" http://www.commsdesign.com/sto...
for some public information on this topic from PMC-Sierra.

This is also in keeping with recent work by the OIF Physical Link Layer (PLL) Working Group announcing "a new project aimed at defining a new electrical I/O specification for 5- and 10-Gbit signaling. According to the OIF, the working group will work on defining specs for short reach (up to 200 mm with one connector) and long reach (up to 1 meter with up to two connectors)". See "Nov 21, 2002: OIF specs address optical packaging, performance " http://www.commsdesign.com/sto...


MrLight :-) Fully supporting the 10,000Base-T effort since it will help with 10Gbps over the backplane.
sidepipes 12/4/2012 | 9:14:01 PM
re: Startups Move 10-Gig to Copper Half Inch, I agree with your concern over the cat 5 crimp conncector, especially with the inconsistent assembly and crimping practices by the discount or import cablers.

A parallel push for 10-Gig over copper (but not Cat5)is coming from the Cat6 cable vendors, whose cabling is spec'd and tested in the 250-300 Meg. range. Check out the TIA TR47 cabling group's efforts.

sidepipes

Obsolete 12/4/2012 | 9:19:23 PM
re: Startups Move 10-Gig to Copper Last week, the IEEE authorized the creation of a study group to look at this topic. The purpose of the study group is not to create the standard but rather to study whether or not the creation of such a standard is justified.

In doing so they need to prove: broad market potential, technical feasibility, economic feasibility, compatibility, and distinct identity. These are the 5 criteria that need to be investigated along with a PAR (project authorization request) by the study group. There are several presentation on the IEEE website beginning to address these issues.

Is it a necessary solution? I'm not sure I can make that decision yet. But I'll at least give the study group the chance to try to convince me.
horse of a different color 12/4/2012 | 9:19:26 PM
re: Startups Move 10-Gig to Copper Obsolete...

Again, who cares? This is great fodder for the scientists and engineers about the technical feasibility of doing 10G. It doesn't address why it should be done. Yes, technically it's the next step up, but at some point it doesn't make sense. Why try to make a technology work over a questionable media type when there is already one that works, and is not much more cost. Fiber is relatively cheap these days, and has none of the limitations of copper.

Why bother? If it's long distnces that need to be covered, there is no choice. It's Fiber only. If it's short distances, such as co-lo apps., the difference in costs of the media for short cables is pretty insignificant.

I don't see a reason why it's needed...unless there are some engineers and scientists who need to justify their jobs in a very tight job market.

Horse
Obsolete 12/4/2012 | 9:19:29 PM
re: Startups Move 10-Gig to Copper The tutorial mentioned in the article is contained here:

http://www.ieee802.org/3/tutor...

optobozo 12/4/2012 | 9:19:30 PM
re: Startups Move 10-Gig to Copper I'm at a loss as to what problem 10G copper addresses. If the distance limitations are so great, what's wrong with an ubiquitous technology such as optical transport? I doubt that 10G transmission rates would really be achieved. Perhaps greater than 1Gb/s, but an order of magnitude more? I doubt it.

If you have to pull any new transport medium, pull fiber. I think the some of the ethernet camp is getting confused over the line rate vs. the stack that runs over it. Even if 10Gb/s is achieved, what would be the corresponding improvements and cost reductions in alternate technologies (mainly optical).

At best, I see this as a band-aid transport medium that is used to justify not upgrading your plant until you can decide on a fiber architecture. "The goal is to make 10-Gbit/s Ethernet viable for the existing business environment without forcing companies to rewire their buildings with fiber." as the article states.

To me, it is similar to what the Narads of the world are to MSOs until the FTTx and regulatory arguements are settled after the next presidential election. The true benefit of the exercise might be just better overall transmission techniques over noisy mediums (which isn't a bad thing).

my 2-ó
metroman 12/4/2012 | 9:19:32 PM
re: Startups Move 10-Gig to Copper Horse has it in a nutshell!

You will not replace existing fiber installations just because you "can" do it with Copper.

So the question is; Where is the copper today that could use this?

Cat 5/6 in the enterprise workplace would cause more problems than it solves. In the enterprise the topologies are built in a "client-server" methodology, mainly because of the use of structured cabling. This means that the point of congestion that would need to be eased is at the Server. If a server was built that could be affordable to an enterprise and deliver real 10Gig over a copper NIC card via some king of next gen bus then you "might" have a product.

The market for this will be very small.

I think that research institutes and cluster computing based systems may benefit. I also think that in Server Farms there may be a benefit as a next gen Fiber Channel or for access to shared DR facilities.

Thinking about this technology as way of delivering carrier bandwidth, home capacity or enterprise LAN bandwitch is never likely to happen. Fiber will rule here.

In confined spaces where high capacity is required in short distances at low cost (compared to optical components) it has a place.

Metroman
marquishorse 12/4/2012 | 9:19:34 PM
re: Startups Move 10-Gig to Copper The Cat 5 twist pair can use for 10G transmit,the advantage of fiber will not be shown.So the most of fiber manufacturers will do when they heard the information?I think they will be dispointed and some new little company will be back to share the communication market.
lightmaster 12/4/2012 | 9:19:53 PM
re: Startups Move 10-Gig to Copper There appears to be some confusion in the discussion on the target application, comparing current local loop (DSL, etc.) limitations with enterprise.

The local loop (from the CO to you house or business) is typically up to 10,000 feet, goes through multiple punchdown blocks, etc. The LAN switches sit in a wiring closet that is typically 50-150 feet from a workstation or server. Fewer punchdowns, and those can be re-configured fairly easily for specific lines that will be used for higher speed. Fiber or more substantial cabling is often used between closets.

This is somewhat analagous to the difference between dial modems, which must pass through voice switches, and DSL, which is terminated immediately after the local loop.

The "impossibility" of running high speeds on unshielded twisted pair in the 50-100m range has been argued historically at 1 megabit, 2 megabits, 4 megabits (original token ring), 10 megabits (10bT), 16 megabits, 100 megabits, and Gigabit. One engineer at IBM pushing the 4 meg standard got so frustrated with the critics that he put together a demo of 4M token ring running over barbed wire to make his point.

Same thing can be said about optical transmission speeds, DWDM channel spacing, etc.

Same thing regarding the "theoretical" limit of modem speed at 28.8K.

I am sure the engineers will figure it out, perhaps with severe distance limitations. The real question is whether there is a need. If you build it, will they come??? ... And oh, by the way, in volumes and at pricing sufficient to make it profitable.
Half-Inch Stud 12/4/2012 | 9:19:56 PM
re: Startups Move 10-Gig to Copper CAT5 cable and 10gig daterate transfer sounds foolish. First hurdle is the deficient crimp connector. I'm not gullible.

Outcard: Guess I could read the article to see the 10g x 4 is really a intent on wordsmith spin of 2.5G x 4 somehow...when faced with REAL-LIFE deployment. I'm not gullible. Not even at 2.5g per twistpair...

Notwithstanding Balanced Line is good theory, and well-applied in Ham radio antenna feeds...for low Nyquist RF. Let's radiate.

Possible hero efforts get flat-lined when faced with the reality of deployment.

Half-Inch Stud
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