Molex just purchased Luxtera’s AOC business completing the circle that all the other optical interconnect players started. During the telecom bust in the early 2000’s, Amphenol, FCI, Molex and Tyco Electronics all either de-emphasized their optical interconnect businesses or exited them all together. Now, they have all re-entered. Why?
While they are all working on more high-speed copper solutions like the one Tyco showed for 25G and beyond at SC10, I beleive they also see the writing on the wall. While they won’t admit it, I think they know that beyond 100G copper cable interconnects may have FINALLY reached the end of their useful life. At 40G and 100G, for example, there is still no twisted-pair solution and the direct-attach copper can only reach about 7m reliably.
It has been interesting watching the choices these traditional connector companies have made:
- Amphenol: It never exited the optical interconnect business, but left the transceiver products to Avago, Finisar, JDSU and others until recently. It has a stronghold on the short-reach copper direct-attach market so has inroads at customers for its AOCs and modules.
- FCI: Exited the optics business entirely for a few years but then started again from scratch and subsequently purchased MergeOptics in February 2010. MergeOptics is what was left of Infineon Technologies and still has strong technical abilities in short-reach products. It also has the building blocks to provide all-optical interconnects all the way from the chip (see my previous posts on MergeOptics). They can provide both AOCs and transceiver modules so have the ability to cover all high-speed markets in InfiniBand, Ethernet and Fibre Channel.
- Molex: Purchased Luxtera’s AOC business recently. So while FCI and Tyco are stressing short-wavelength technologies, Molex has turned to custom long-wavelength ones. Luxtera’s technology is based on 1490nm devices, which really doesn’t matter if you’re purchasing an AOC, but will matter if you want transceiver modules. According to company representatives, they will eventually get back into supplying transceiver modules, but there has been no evidence of this as of yet. Perhaps the possession of Luxtera AOCs will prompt this.
- Tyco Electronics: Tyco exited the transceiver business in the early 2000’s, but still had a very active fiber-optic interconnect business – especially for premise wiring (AMP NETCONNECT). It acquired Zarlink Semiconductor’s optical products group in May 2010. Zarlink is on the forefront of parallel-optics technology and was one of the first to introduce AOCs. It does not appear that Tyco intends to supply optical transceiver modules again.
I would never bet against copper re-inventing itself in order to meet the demands of future high-speed networks, but with optical 10G dominating the market currently and 40/100G optical products starting to emerge, it will be an uphill battle for copper solutions to gain traction. And beyond 100G, all bets are off. I’m thinking that these companies are reaching the same conclusions and that if they don’t add optical capabilities soon, they may render themselves obsolete within the next ten years or so. That's not to say that there won't be a vibrant businesses in both copper structured cabling and interconnects over the next ten years - there will be. But I think that R&D dollars will be better spent on optical interconnect technologies rather than trying to figure out how to run 25G signals using copper interconnects (including backplanes.) Or how to convince end-user customers in the US that a shielded structured cabling solution for 40G is better than a short-reach optical one because it will be cheaper - but at what cost to power, cooling and space?
What do you think? I'd love to hear your thoughts.
If you’ve read my previous posts on the subject, you know that polarity can be a tricky matter and it’s even more complicated when you try to choose it for your data center cabling. You really have to choose based on several factors:
- Patch cords – method A has two different patch cords that you have to stock, but the upside is that it’s pretty simple to follow where the signal is going and if you happen to be out of one type of patch cord, you can really take the one you have and just flip the fibers as a temporary fix until you can get the other patch cords. Of course this isn’t recommended, but if you’re in a bind and need to get up-and-running right away, it will work. With methods B and C you have the same patch cord on each end so no need to worry about this, but if you happen to have the wrong cassettes or backbone, nothing will work and you'll have to wait to get the correct ones.
- Cassettes and backbone cables – you need to make sure you buy all of one method of polarity or your system won’t work. If you’re concerned about supply, all three polarity methods are available from multiple vendors, but Method A is “preferred” by most.
- Upgradability – this is where it can get dicey. Typically your pre-terminated assemblies are running Gigabit applications today and a few may be running 10G. Any of the polarities will work at these data rates. But when you move to 40/100G, methods A and B have straight forward paths, while C does not. Also, you’ll want to make sure you use the highest grade of LOMF available, which is OM4 – this will give you the best chance of being able to reuse your backbones up to 125m. If you need something longer, you’ll need to go to SMF.
If you are thinking about installing pre-terminated cassette-based assemblies now for 10G with an upgrade path to 40 and 100G, you need to consider the polarity method you use. Unlike today's 2-fiber configurations, with one send and one receive, the standards for 40G and 100G Ethernet implementations use multiple parallel 10G connections that are multiplexed. While 40/100G equipment vendors will tell you that polarity is not an issue, care must be taken if you want to reuse this installed base.
40G will use four 10G fibers to send and four 10G fibers to receive, while 100G uses either four 25G fibers or ten 10G fibers in each direction. Because 40 and 100G will be using the MPO connector, if the polarity method is carefully chosen, you will be able to reuse your backbone cables. This is enabled by the fact that the IEEE took much care in specifying the system so that you can connect any transmit within a connection on one end of the channel to any receive on the other end.
Those selecting fiber to support 10G now and 40G in the near future need to understand what will be involved in transitioning and repurposing their cable plant. In order to upgrade using method A, you can replace the cassettes with MPO-to-MPO patch panels and MPO-to-MPO patch cords and it will enable flexibility to address moves, adds and changes as well as promoting proper installation best practices. The polarity flip will need to be accomplished in either an A-to-A patch cord or possibly with a key up/key down patch panel.
Method B multimode backbone cables can also readily support 40G applications. For a structured cabling approach, method B will still use a patch panel and patch cords, though as with current method B, both patch cords could be A-to-B configuration. While Method C backbones could be used, they are not recommended for 40G as completing the channel involves complex patch cord configurations.
It appears that 100G will use either the 12-fiber (4x25G) or the 24-fiber (10x10G) MPO connector. With transmits in the top row and receives in the bottom row, the connection will still be best made using a standardized structured cabling approach as described above.
There are many suppliers of pre-terminated optical assemblies including Belden, Berk-Tek, a Nexans Company, CommScope, Corning, Panduit, Siemon, Tyco Electronics NetConnect as well as many smaller shops that give quick-turn assemblies like Cxtec CablExpress and Compulink.
The last of my summary of AOC Implementations:
Reflex Photonics has gained an early customer base in InfiniBand and PCI Express extender applications with its SNAP 12 products, and is using the existing customer base to increase awareness of InterBoard products for data center customers. In developing InterBoard, Reflex Photonics moved into coarser channel implementations to meet industry AOC standards. The four-channel cables terminate in an array of 850nm VCSELs that use QSFP connectors suitable for both InfiniBand DDR and 40G Ethernet. What is also interesting about Reflex’s InterBoard is that it contains its optical engine technology, LightAble.
Zarlink (now part of Tyco) began its ZLynx product line with a CX4 interconnect, but quickly added QSFP as the module was standardized. Zarlink is unique in anticipating possible customer interest in dissimilar terminations by offering CX4-to-QSFP cables. Zarlink product developers say they will take the same attitude as CXP applications emerge. While most AOCs will use identical termination on both ends of the cable, the company will explore customer demand for hybrid connectors. Before it was acquired by Tyco, Zarlink was working on 40G implementations that were expected to be released this year. No announcements have been made as of yet, though. Tyco had its own QSFP AOC, namely the Paralight. It remains to be seen how Tyco will merge these product lines.
The first implementations of 40G Ethernet have indeed materialized as AOCs, but are expected to transition into actual optical modules as soon as transceiver manufacturers are ready with their products. What is nice for the end user is that if they want to implement 40G today, they can with AOCs and the same ports will then accept optical modules later if needed. InfiniBand AOC products are expected to stay as AOCs and not transition into optical modules, mainly because most of these connections are less than 30m so are easier to pull through pathways and spaces.
According to CIR, the market for AOCs is expected to be about $180 million (a rather small market for so many entrants) this year, most of which will be for data centers. However, by 2013, it is expected to grow to more than $1-billion – a steep climb and one that will need a lot of suppliers if it is actually going to happen.
With the advent of top-or-rack (ToR) switching and SFP+ direct attach copper cables, more data centers are able to quickly implement cost-effective 10G and beyond connections. ToR designs are currently one of two configurations:
- GigE Category cabling (CAT5e, 6, or 6A) connection to each server with a 10G SFP+ or XFP uplink to either an EoR switch or back to a switch in the main distribution area (MDA)
- SFP direct attach cabling connection to each server with a 10G SFP+ or XFP uplink to either an EoR switch or back to a switch in the MDA
Either way, SFP and SFP+ modules and cable assemblies are starting to see huge inroads where Category cabling used to be the norm. Consequently, structured cabling companies have taken their shot at offering the copper variants of these devices. Panduit was one of the first that offered an SFP direct-attach cable for the data center, but Siemon quickly followed suit and surpassed Panduit by offering both the copper and optical versions of the assemblies as well as the parallel optics QSFP+ AOC. Others rumored of working on entering into this market are Belden and CommScope. This really marks a shift in philosophy for these companies who traditionally have stayed away from what they considered “interconnect” products. There are a couple of notable exceptions in Tyco Electronics and Molex that have both types of products, however.
So what makes these companies believe they can compete with the likes of Amphenol Interconnect, Molex and Tyco Electronics? Well, it might not be the fact that they think they can compete, but that they see some erosion of their patch cord businesses and view this as the only way to make sure the “interconnect” companies don’t get into certain customers. So, protecting their customer base by offering products they won’t necessarily make any money on – because, after all, many of them are actually private-labeled from the very companies they are trying to oust. Smart or risky? Smart, I think, because it seems to me that the future of the data center will be in short-reach copper and mid-range fiber in the form of laser-optimized multi-mode fiber (LOMF).
