Avago’s Interesting Demos at OFC/NFOEC

As always, the top transceiver manufacturers were represented at OFC, but of the top three datacom transceiver providers, Avago Technologies stood out to me. They had two significant demonstrations:

1. Connecting a 40GBASE-SR4 Ethernet port using its QSFP+ to four standard 10GBASE-SR Ethernet ports with its SFP+ modules. On the surface, this seems pretty easy to do, until you realize that the specifications for the transmitters and receivers in these devices have are very different. The 10G devices could easily overpower the 40G receiver if it’s not designed to handle the higher power. Avago has solved this issue with its parts and hopes to be able to be interoperable with anyone’s transceivers in the near future.
2. A VCSEL-based 25G short-wavelength SFP+ working prototype. At first I was puzzled about this because I couldn’t figure out the application. Well, it turns out there really is none for the 25G part, yet, but showing that it could be done makes you realize that 32G Fibre Channel applications using the SFP+ may not be as far-fetched as we think. And, perhaps we can get a 100GBASE-SR4 (4x25G that isn't in the IEEE standard yet) solution soon.

Stay tuned for more on other developments announced or demonstrated at OFC/NFOEC.

SFP+ - The New Optical RJ45?

For those of you that have been in the industry for what seems to be 100 years, but is really about 25 years, you know that the one “connector” that hasn’t changed much is the RJ45. While there have been improvements by adding compensation for the error that was made way back when AT&T developed the wiring pattern (splitting the pair causing major crosstalk issues), the connector itself has remained intact. Contrastingly, optical connectors for datacom applications have changed several times – ST to SC to MT-RJ to LC. They have finally seemed to settle on the LC and perhaps on a transceiver form factor – the SFP+. The SFP was originally introduced at 1G, was used for 2G and 4G and with slight improvements has become the SFP+ and the dominant form factor now used for 10G. Well, it is in the process of getting some slight improvements again and promises to make it all the way to 32G. That’s six generations of data rates – pretty impressive. But how?

The INCITS T11.2 Committee's Fibre Channel Physical Layer – 5 (FC-PI-5) standard was ratified in September. It specifies 16G Fibre Channel. Meanwhile, the top transceiver manufacturers have been demonstrating pre-standard 16G SFP+ SW devices. But, wait a minute – short-wavelength VCSELs were supposed to be very unstable when trying to modulate them at data rates above 10G right? Well, it seems that at least Avago and Finisar have figured this out. New microcontrollers and adding at least one clock and data recovery (CDR) device in the module to help clean up the signals have proven to be keys. Both vendors believe it is possible to do this and not add too much cost to the modules. In fact, both also think that possibly by adding electronic dispersion compensation (EDC) they can push the SFP+ to 32G as well - which is the next step for Fibre Channel - hoping to stop at 20G and 25G to cover developments in Ethernet and InfiniBand.

And what about long wavelength devices? It has always been a challenge fitting the components needed to drive long distances into such a small package mainly because the lasers need to be cooled. But not anymore – Opnext has figured it out. In fact, it was showing its 10km 16G FC SFP+ devices long before any of the SW ones were out (March 2010). Of course, this isn't surprising considering Opnext has already figured out 100G long haul as well.

These developments are important to datacom optical networking for a few of reasons:  

1. They show that Fibre Channel is not dead.
2. The optical connector and form factor "wars" have seemed to subsided so transceiver manufacturers and optical components vendors can focus on cooperation instead of positioning.
3. They will impact the path other networking technologies are taking – Ethernet and InfiniBand are using parallel optics for speeds above 10G – will they switch back to serial?

Stay tuned for more on these points later.

 

SC10 and Optical Transcievers

It’s a beautiful time of year in New Orleans for the top supercomputing companies to show their wares. While I wouldn’t consider SC10 exactly the place to sell optical components, there were a few new developments there. SCinet – the network that is always built at the top HPC conference – boasted 100G Ethernet as well as OTu4. Alcatel-Lucent, Ciena, Cisco, Force10 and Juniper, among others donated equipment to build this network. Module vendors Avago Technologies, Finisar and Reflex Photonics contributed QSFP and CFP 40G and 100G devices to the cause.

Meanwhile, the Ethernet alliance was showing two demonstrations in its booth – a converged network running FCoE and RoCE over 40GigE and 100GigE. Nineteen different vendors participated in this demo that was run by the University of New Hampshire Interoperability Lab. Both CFPs and QSFPs were used in this demo.

Some of you may wonder why I would attend SC10. I keep my eye on the HPC market because it usually indicates where the broader data center market will be in a few years. And, in fact, even medium-sized businesses’ data centers with higher computational needs are starting to resemble small HPC centers with their server clusters using top-of-rack switching.

Most of the top optical transceiver vendors and even some of the smaller ones see this market as an opportunity as well. While InfiniBand still uses a lot of copper interconnects, for 40G and 120G, this is changing. QSFP was the standout for 40G IB displays and CXP AOCs were shown for 120G as well. Avago Technologies was the first to announce a CXP module at the show.

Some believe that the CXP will be short-lived because there is progress being made on 4x25 technologies – Luxtera announced its 25G receivers to go with its 25G transmitter that it announced earlier this year. But it will still be a few years before all of the components for 25G will be ready for system’s developers to spec in. Tyco Electronics had a demonstration at their booth showing it is possible to run 28G over eight inches of a PCB, but this was still a prototype. And Xilinx has announced a chip for 28G electrical transceivers that can be used with this board design. But, none of these devices are even being tested by equipment manufacturers yet and the CXP has already been adopted by a few. So I think the CXP may have more life in it than some people may think.

DARPAs Chip-to-Chip Optical Interconnects (C2OI) Program

The C2OI DARPA program is funding on-going optical components projects. Its end goal is to “demonstrate optical interconnections between multiple silicon chips that will enable data communications between chips to be as seamless as data communication within a chip.”

This program grew out of work initially done by Agilent (now Avago Technologies) under the DARPA Parallel Optical Network Interconnect (PONI) project. Agilent/Avago developed a 30 Gbps transmitter (2.5 Gbps/lane) that was eventually standardized as the SNAP-12.

IBM (with help from Avago) extended the work originally done by Agilent/Avago into inter-chip connections and in 2009 achieved optical interconnection with 16 parallel lanes of 10G. By early 2010, IBM was extending this work into board-to-board applications which resulted in the new Avago MicroPOD™ product that was specifically designed for IBM’s POWER7™ supercomputer.

While it was designed for HPC server interconnects, the MicroPOD could be used for on-board or chip-to-chip interconnects as well. As mentioned in previous posts, the devices use a newly designed miniature detachable connector from US CONEC called PRIZM™ LightTurn™. The system has separate transmitter and receiver modules that are connected through a 12-fiber ribbon. Each lane supports up to 12.5 Gbps. It uses 850nm VCSEL and PIN diode arrays. The embedded modules can be used for any board-level or I/O-level application by either using two PRIZM LightTurn connectors or one PRIZM LightTurn and one MPO.

While MicroPOD is targeted at high-density HPC environments, a natural expansion of its market reach would be into switches and routers in high-density Ethernet data center environments. While this may not happen in the next few years, for me it looks like it could be a more cost-effective solution than say a 40G serial one.

25G/40G VCSELs Driving Short-reach Optical Interconnects

Just a few years ago, laser designers were struggling with stability of their 10G VCSELs. But now, at least one, VI Systems GmbH, claims it will have production-ready 40G VCSELs within the next few years. The German start-up has developed two products it believes will take VCSELs beyond 10G applications - a directly-modulated (DM) device and an electro-optic modulated (EOM) DBR VCSEL. Both are short-wavelength (850nm) lasers.

In a recent press release, VI Systems explains that it “developed the VCSEL products at a wavelength of 850 nm along with a range of extremely fast integrated circuits based on the SiGe BiCMOS (silicon-germanium bipolar junction transistors in complementary metal-oxide-semiconductor) technology. The company uses a patent pending micro-assembly platform for the integration of the opto-electrical components and for alignment to a standard high performance multi-mode glass-based fiber.” The start-up has been presenting data supporting its claims of highly stable devices for more than a year now. It gets there by changing the laser active region material and structure to InAs quantum dot (QD).

Not only is VI Systems working on innovative laser structures, it has also developed new electro-optic integration methods to further reduce the cost of these devices.

I’ve noted in previous posts how VCSELs are the key to low-cost optical networks in the data center. These new VCSELs and packaging methods would bring an even more cost-effective “serial” solution for 40/100G. They could also be used for very short-reach optical connections like for chip-to-chip, on-board or board-to-board. Perhaps these inventive products will rival Avago’s MicroPOD and Luxtera’s OptoPHY (also in previous posts). Based on the presentations that VI Systems has released, it sure appears that its management completely understand the needs of both the data center and optical interconnect markets so could very well give incumbents in the industry some competition.

Intel’s Light Peak OR USB 3.0?

After Intel’s Developer’s Forum last week, there is renewed interest in Light Peak. For those of you that don’t remember one of my first blog posts, Light Peak is an Intel-developed optical interconnect techonolgy that uses a new controller chip with LOMF and a 10G 850nm VCSEL-based module with a new optical interface connector that looks very similar to the one used in Avago Technologies MicroPOD transceiver. Light Peak is aimed at replacing all of your external connectors on your PC including USB, IEEE 1394, HDMI, DP, PCIe, etc. It is also targeted at other consumer electronic devices like smart phones and MP3 players.

Many in the industry think Light Peak is intended to replace USB 3.0 even before USB 3.0 is finished being standardized. I tend to disagree. USB 3.0 is a 5G data rate and to me, will bridge the gap between existing USB 2.0 (480 Mbps max) and the 10G that Light Peak can provide. Just because they are being developed at the same time, doesn’t mean they will make it to production simultaneously.

While Intel is now saying that 2011 will be the year for Light Peak to take off, I’m still skeptical. There may be some really high-end applications like video editing that may need this bandwidth, but your run-of-the-mill PC user isn’t going to want to pay the extra money for it when you probably won’t be able to actually detect the improvement. And, what might be more important – what kind of power consumption difference is there and how does this affect battery life?Or is this technology not meant for laptops?  I’m not sure these questions have been sufficiently answered yet.

AOCs (Part 2)

Summary of a few more AOC Implementations:

Avago Technologies had a late entry into the AOC market with its 10GBASE-CX4 replacement and QSFP+ products. But they have a rich history in parallel optics so have quickly come up to speed their products. While they may have been somewhat late to market, Avago has an existing customer base to peddle its wares to.

Finisar’s products include Quadwire and Cwire AOCs to address early adoption of 40G and 100G. Quadwire is Finisar’s mainstream product, both in terms of its use of the VCSEL arrays the company produces in volume at its Texas fab, and in terms of its use of the popular QSFP form factor.

The high end of the Finisar product line is designed to exploit anticipated interest in 100G Ethernet and 12-channel QDR InfiniBand. Cwire offers an aggregate data rate of 150 Gbps and a CXP interface. Not only does this represent the direction of high-end enterprise cluster design, but it allows Finisar to utilize the most integrated VCSEL arrays it manufactures. The 12-channel array also represents the most cost-effective per-laser manufacturing option, allowing Finisar to take advantage of its expertise in designing large VCSEL-arrays. The benefit in high channel count can also be seen in power dissipation. While the single serial channel of Laserwire dissipates 500mW per end, the 12-channel Cwire dissipates less than 3W per end – half the power dissipation per channel.

MergeOptics (now part of FCI) was born of the old Infineon which was once a powerhouse in the optical transceiver markets—both telecom and datacom. It emerged in 2006 with its SFP and then SFP+ products and is now one of the first entrants for 40G and 100G AOCs. Unlike most of its competitors, it is focused on 10G and above products so can bring them to market rather quickly. Its technology is being leveraged for InfiniBand and Ethernet applications.

Stay tuned for the next post for just a little more on AOCs.

Gigabit Transcievers

In our rush to want to discuss all the new technologies, it seems to me that analysts have forgotten that part of our job is to also point out ongoing trends in existing products. So while talking about Gigabit transceivers might not be as appealing as talking about Terabit Ethernet, it’s also a necessity – especially since, without these devices and the continuing revenue they produce, we wouldn’t have 40/100G or even 10G Ethernet. So what are the important points to make about Gigabit transceivers?

• The market for Gigabit Ethernet transceivers (copper and optical) is expected to be about $2.5-billion in 2010 according to CIR, but it is also supposed to start declining in 2011 when more 10GigE will take its place.
• Pricing for a 1000BASE-SX SFP module is now at about $20 for OEMs. End users still pay Cisco or Brocade or their agents about 8x that much (more about this later).
• Low pricing makes it difficult on profit margins so transceiver vendors hope to make it up in volume.
• While SFP is certainly the preferred form factor, there is still a decent amount of GBIC modules being sold.
• SFP direct-attach copper cable assemblies have become an option for top-of-rack switches to servers instead of using UTP Category patch or fiber cabling, although the majority of implementations today are still UTP patch cords, mainly because the connections within the rack are still 100M with the uplink being Gigabit Ethernet of the 1000BASE-SX variety.
• While 10/100/1000 ports are the norm for desktop and laptop computers, most of these devices are still connected back through standard Category 5e or 6 cabling to 100M switch ports in the telecom room.
• Gigabit Fibre Channel business is pretty much non-existent now. It was quickly replaced by 2G and has progressed through 4G and 8G is expected to become the volume application this year. Look for more on Fibre Channel in future posts.
• Avago Technologies and Finisar top the list of vendors for 1000BASE-SR devices. JDSU has all but disappeared from the scene, mainly because they have de-emphasized this business in favor of their telecom products. In fact, rumor has it that JDSU is shopping its datacom transceiver business and has been for some time.

A note on JDSU: It appears that the optical components giant has taken the technology that was developed at IBM, E2O and Picolight and thrown it away. Picolight was once a leader in parallel optics and, along with E2O, long-wavelength VCSELs. IBM pioneered v-groove technology and the oxide layer that enabled the next leap in speed and improved reliability for 850nm VCSELs. All of these technologies look like they are destined to die a slow, painful death after being acquired by JDSU. The company’s attention is clearly focused on its tunable technology and telecom applications, which is where, of course, it started. JDSU has never had a good reputation for assimilating acquisitions, so none of this should be a surprise. I was optimistic when JDSU bought these companies thinking that now these emerging technologies would be supported by a larger pocketbook. What is the reasoning for JDSU deemphasizing the technologies it acquired? Is it trying to get rid of short-reach competition in hopes that all optical networking would move towards long-wavelength devices? This would have been naïve; the likes of Finisar, Avago, MergeOptics and others would still be supporting 850nm optics and there remains a healthy market for them in enterprise networks and data centers—albeit a very competitive one as stated above.

 

Optical Engines

I was reviewing some research I recently conducted for the Optical Interconnect report I wrote for CIR and realized that I hadn’t yet “blogged” about what I would consider some exciting new product directions that many optical components suppliers are taking. We’ve been talking about optical integration for many years and some companies, like Infinera, have actually implemented it into their real-world products. But there are more cases of this than ever before and I think we’re on the brink of some true industry breakthroughs using what many have deemed “optical engines.”

Here is a summary of the component companies and their associated optical engine products:

• BinOptics – it uses its InP PICs to build "custom integrated microphotonics solutions" for its customers
• ColorChip – its silicon photonics is at the center of its 40G QSFP modules
• Lightwire – its Opto-electronic Application Specific Integrated Subsystem (OASIS) promises low power and higher density
• MergeOptics/FCI – OptoPack is at the center of its 10G and above transceiver designs
• Reflex Photonics – LightAble is the building block for its transceiver modules
• Santur – DFB/waveguide architecture has promise for not only tunable lasers, but many different optical interconnects

So what’s the big deal? In the past, optical integration was a science project looking for an application. Now, these companies are leveraging their research to create products such as QSFP modules or tunable transceivers that are selling today. So even though you could make these transceivers tiny, they package them in standard form factors in order to develop a revenue stream in hopes that the technology can truly be used for miniature devices in the near future. Pretty smart business plan I think – especially since we’ve already seen a glimpse of the miniaturization products with Avago’s MicroPOD, Intel’s Light Peak and Luxtera’s OptoPhy, which can also be considered optical engines. And, which are supposedly on the cusp of true adoption into active equipment.

 

Other 10GigE Transceiver Markets – ER, LX4 and LRM

Some of you may have noticed that in my last post I neglected to talk about three other 10-Gigabit Ethernet variants – LX4, LRM and ER. That’s because the content was already long enough and I wanted to focus on the volume data center applications. Now, I’ll discuss the others.

10GBASE-ER runs over SMF at 1550nm for up to 40km. While there are a few service providers that might choose to do this, the vast majority of them choose WDM through the OTN instead. There may be some private networks that have need for this variant as well which is what prompted the IEEE include it in the standard. These transceivers are priced out of typical budgets for the average enterprise at over $4000.

10GBASE-LX4 was originally introduced to address installed base of FDDI-grade (not laser-optimized) MMF, but can also be used with higher-grades of LOMF as well as SMF. It uses CWDM to send four wavelengths (thus the X4) between 1269.0 to 1355.9nm running at data rates of 2.5 Gbps each. LX4 modules are available in both X2 and XENPAK form factors and from at least a couple of sources such as Emcore and Hitachi Cable. As you can imagine, because these devices have four lasers and four detectors with their associated electronics, they cost appreciably more than either the SR or LR transceivers. The module alone retails for about $2000, which means that the per port cost would probably around $2500. But, you most likely wouldn’t fill your switch with these modules of course; you would only use them as needed where you wanted to re-use existing installed fiber.

In response to the high priced LX4, 10GBASE-LRM variant was developed. It was enabled by chip companies such as Clariphy and Scintera with some new technology, electronic dispersion compensation (EDC), that could push 10G serial to longer distances on MMF. It took a while to develop the standard and the consequence was that LX4 really took much of the market it was intended for. However, once products were released and supported by the top-tier transceiver manufacturers (Avago, Finisar, Opnext), it has really taken much of the business away from LX4. LRM modules are now available in SFP+ packages as well, which clearly indicates the vendors think there will be an ongoing market for them.

One note of caution – if you intend to use either the LX4 or the LRM modules, you need to make sure that both ends of your channel have them, otherwise it won’t work.

Datacom Transceiver Vendors Transitioning into New Businesses

Have you noticed that it seems like all of the top datacom transceiver suppliers are transitioning their businesses? I’ve already talked about Avago’s new venture with its MicroPOD technology. They seemed to have supplanted Finisar as the technology leader in the space. Finisar has expanded its offerings into more telecom markets and JDSU is all but gone from the scene and focusing more on telecom again.

Finisar seems to be enjoying what may well be short-term success with its Laserwire offering. Since it is a non-standards based solution, it is difficult to believe it will become a mainstream one. While Finisar is offering other AOCs—C.wire (CXP-based) and Quadwire (QSFP-based), it does not seem to be participating in what seems to be a chip-to-chip optical interconnection revolution like Avago and Luxtera are (see previous posts for details) . Finisar used to be the technology leader in the optical transceiver space, it has veered off-course from that strength in preference for market diversification instead—now covering telecom and HPC standards-based solutions as an alternative. But perhaps this is the right move for Finisar, since it has not seemed to hurt its revenue position at all.

JDSU seems to be absent from the short-reach module market. It appears that the optical components giant has taken the technology that was developed at IBM, E2O and Picolight and thrown it away. Picolight was once a leader in parallel optics and, along with E2O, long-wavelength VCSELs. IBM pioneered v-groove technology and the oxide layer that enabled the next leap in speed and improved reliability for 850nm VCSELs. All of these technologies look like they are destined to die a slow, painful death after being acquired by JDSU. The company’s attention is clearly focused on its tunable technology and telecom applications, which is where, of course, it started. JDSU has never had a good reputation for assimilating acquisitions, so none of this should be a surprise. I was optimistic when JDSU bought these companies thinking that now these emerging technologies would be supported by a larger pocketbook. What was the reasoning for JDSU deemphasizing the technologies it acquired? Was it trying to get rid of short-reach competition in hopes that all optical networking would move towards long-wavelength devices? This would have been naïve; the likes of Finisar, Avago, MergeOptics and others would still be supporting 850nm optics and there remains a healthy market for them in enterprise networks and data centers—albeit a very competitive one.

According to JDSU, it is focusing on the LH and ULH versions of 40G and 100G first because it does not see the value in the CXP module for short-reach applications. For short-reach, it is focusing on QSFP+ modules, but development of these will take longer. The company claims it is not de-emphasizing its 850nm technology, but just focusing elsewhere first. I’m not so sure. Rumor has it, and I tend to believe that JDSU is looking for buyers for its short-wavelength business.

Luxtera’s Contribution to a Push for All-Optical Networks

Yesterday I wrote about Avago’s new miniaturized transmitters and receivers so today I’d like to introduce you to a similar product from Luxtera. Well known for its CMOS photonics technology, Luxtera actually introduced its OptoPHY transceivers first – in late 2009.

Luxtera took a different approach to its new high-density, optical interconnect solution. It is a transceiver module and is based on LW (1490nm) optics. Just like Avago’s devices, the transceivers use 12-fiber ribbon cables provided by Luxtera, but that’s really were the similarities end. The entire 10G–per-lane module only uses about 800mW compared to Avago's 3W, and they are true transceivers as opposed to separate transmitters and receivers. Luxtera is shipping its device to customers, but have not announced which ones yet.

In addition to the projected low cost for these devices, what should also be noted is that all of the solutions mentioned in the last three entries – Intel’s Light Peak; Avago’s MicroPOD and Luxtera’s OptoPHY – have moved away from the pluggable module product theme to board-mounted devices. This in and of itself may not seem significant until you think about why there were pluggable products to begin with. The original intent was to give OEMs and end users flexibility in design so they could use an electrical, SW optical or LW optical device in a port depending on what length of cable needed to be supported. You could also grow as you needed to – so only populate those ports required at the time of installation and add others when necessary. The need for this flexibility has seemed to have waned in recent years in favor of density, lower cost and lower power consumption. The majority of pluggable ports are now optical ones, so why not just move back to board-mounted products that can achieve the miniaturization, price points and lower power consumption?

Optical Interconnects for All-Optical Networking May be Closer to Reality than You Think

On-board interconnects have for some time just been handled with copper traces, but with data rates now reaching beyond 10G, this is ripe for change. In fact, it is already changing; evidenced by the big splash IBM and Avago Technologies made at this year's OFC/NFOEC conference. The computer giant and transceiver manufacturer teamed to develop what they are calling "the fastest, most energy-efficient embedded interconnect technology of its kind."

Deemed the MicroPOD™, Avago developed it for IBM's next generation supercomputer, POWER7™. While it was designed for HPC server interconnects, it could be used for on-board or chip-to-chip interconnects as well. The devices use a newly designed miniature detachable connector from US CONEC called PRIZM™ LightTurn™. The system has separate transmitter and receiver modules that are connected through a 12-fiber ribbon. Each lane supports up to 12.5 Gbps. It uses 850nm VCSEL and PIN diode arrays. The embedded modules can be used for any board-level or I/O-level application by either using two PRIZM LightTurn connectors or one PRIZM LightTurn and one MPO.

While these modules are currently for the HPC market, Avago designed something very similar for Intel and its Light Peak interconnect system (see previous post for details) for what some are calling “optical USB.” MicroPOD is targeted at high-density environments so a natural extension of its market reach would be into switches and routers. The market for such devices probably will not become huge in the next few years, but it is exciting to see that companies in this space have started to spend R&D dollars again and that there are at least a few customers willing to employ the technology right out of the gate. Of course, it must be noted that this project was partially funded by DARPA.

But this technology MUST be too expensive for the typical piece of network equipment right? Not so, says Avago, because the manufacturing process is 100-percent automated and with Avago's vertical integration, the prices (at volume) may actually be able to rival those of today's transceivers. I’ll hold judgment until Avago proves it can win more than one big customer, however, I think MicroPOD holds the promise to change the paradigm for on-board, board-to-board and even network-element-to-network-element optical interconnects.