Boosting copper’s reach in the data centre

Marvell has unveiled a chip that enables copper cables to send 1.6 terabits-per-second (Tbps) of data between equipment in the data centre. 

Copper cabling, also referred to as direct attach copper, is the standard interconnect used to connect compute nodes in a server, and between servers when building larger computing systems. 

Venu Balasubramonian

Data centre operators prefer to use passive copper cables. A copper cable costs less than an optical cable, a critical consideration when tens of thousands may be used in a large data centre.

Compute servers using the latest processors and AI accelerator chips have increasing input-output (I/O) requirements. This is causing interface speeds between servers, and between servers and switches, to keep doubling—from 400 gigabits to 800 gigabits and soon 1.6Tbps.

Moreoever, with each speed hike, the copper cable’s reach shrinks. A copper cable sending 25 gigabits of data has a reache of 7m, but it is only 2m at 100Gbps and is only 1m at 200Gbps.

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Optical module trends: A conversation with Finisar

Finisar demonstrated recently a raft of new products that address emerging optical module developments. These include: 

• A compact coherent integrated tunable transmitter and receiver assembly 
• 400GBASE-FR8 and -LR8 QSFP-DD pluggable modules and a QSFP-DD active optical cable 
• A QSFP28 100-gigabit serial FR interface 
• 50-gigabit SFP56 SR and LR modules

Rafik Ward, Finisar’s general manager of optical interconnects, explains the technologies and their uses.

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The era of cloud-scale routeing

Nokia's FP4 p-chip. The multi-chip module shows five packages: the p-chip die surrounded by four memory stacks. Each stack has five memory die. The p-chip and memory stacks are interconnected using an interposer.

• Nokia has unveiled the FP4, a 2.4 terabit-per-second network processor that has 6x the throughput of its existing FP3. 
• The FP4 is a four-IC chipset implemented using 16nm CMOS FinFET technology. Two of the four devices in the chipset are multi-chip modules.
• The FP4 uses 56 gigabit-per-second serial-deserialiser (serdes) technology from Broadcom, implemented using PAM-4 modulation. It also supports terabit flows.
• Nokia announced IP edge and core router platforms that will use the FP4, the largest configuration being a 0.58 petabit switching capacity router. 

Much can happen in an internet minute. In that time, 4.1 million YouTube videos are viewed, compared to 2.8 million views a minute only last year. Meanwhile, new internet uses continue to emerge. Take voice-activated devices, for example. Amazon ships 50 of its Echo devices every minute, almost one a second.

Given all that happens each minute, predicting where the internet will be in a decade’s time is challenging. But that is the task Alcatel-Lucent’s (now Nokia’s) chip designers set themselves in 2011 after the launch of its FP3 network processor chipset that powers its IP-router platforms.

Six years on and its successor - the FP4 - has just been announced. The FP4 is the industry’s first multi-terabit network processor that will be the mainstay of Nokia’s IP router platforms for years to come.

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OFC 2014 product round-up - Final part

Part 2: Client-side technologies

The industry is moving at a clip to fill the void in 100 Gig IEEE standards for 100m to 2km links. Until now, the IEEE 10km 100GBASE-LR4 and the 10x10 MSA have been the interfaces used to address such spans.

But responding to data centre operators, optical players are busy developing less costly, mid-reach MSAs, as was evident at the OFC exhibition and conference, held in San Francisco in March. 

Meanwhile, existing IEEE 100 Gigabit standards are skipping to the most compact CFP4 and QSFP28 form factors. The -LR4 standard was first announced in a CFP in 2010, and moved to the CFP2, half the size of the CFP, in 2013. Now, several companies have detailed CFP4 -LR4 products, while Source Photonics has gone one better, announcing the standard in a QSFP28.

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Avago's latest optical engine targets active optical cables

Avago Technologies has unveiled its first family of active optical cables for use in the data centre and for high performance computing.

The company has developed an optical module for use in the active optical cables (AOCs). Known as the Atlas 75x, the optical engine reduces the power consumption and cost of the AOC to better compete with direct-attach copper cables. 

“Some 99 percent of [active optical cable] applications are 20m or less”

Sharon Hall, Avago

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Reflections 2011, Predictions 2012 - Part 2

Gazettabyte asked industry analysts, CEOs, executives and commentators to reflect on the last year and comment on developments they most anticipate for 2012. Here are the views of Verizon's Glenn Wellbrock, Professor Rod Tucker, Ciena's Joe Berthold, Opnext's Jon Anderson, NeoPhotonics' Tim Jenks and Vladimir Kozlov of LightCounting.

Glenn Wellbrock, Verizon's director of optical transport network architecture & design

The most significant accomplishment from an optical transport perspective for me was the introduction of 100 Gigabit into Verizon's domestic - US - network. 

"The key technology enabler in 2012 will be the flexible grid optical switching that can support data rates beyond 100 Gigabit"

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Next-gen 100 Gigabit short reach optics starts to take shape

The latest options for 100 Gigabit-per-second (Gbps) interfaces are beginning to take shape following a meeting of the IEEE 802.3 Next Generation 100Gb/s Optical Ethernet Study Group.  

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