Thursday, March 23, 2017

An Ecosystem Forms to Drive 400G Forward

The next big step on the relentless march forward for Ethernet is 400 Gbit/s. This week's OFC in Los Angeles brought a flurry of activity around 400 Gbit/s and finally we are seeing efforts come together from across a broad ecosystem of module vendors, chip suppliers, test and measurement companies, network equipment suppliers, telecom companies and Internet content providers. As with previous generations, the 400 Gigabit Ethernet will appear in next-generation switches and routers used in high-density cloud data centres and in the core of carrier networks. Meanwhile, work continues on 200 Gbit/s as an interface speed for optical transport, especially in data centre interconnect (DCI) and metro networks, but the building momentum behind 400 Gbit/s seems likely to assure its place as the 'new 100 Gbit/s' as the common denominator for high-speed networks.

While there are always prototype implementations of any new technology years before a standard is ready, this time it looks as if legitimate 400 Gbit/s transceivers will hit the market this year, and switch designs capable of driving this bandwidth may soon follow. The recent Ethernet Switch - Data Centre 5-year forecast report from Dell'Oro predicts that cloud data centres will drive the transition toward 400 Gbit/s by 2019. However, it must first be shown that 400 Gbit/s works as specified, that multi-vendor interoperability is ensured, and that the famous Ethernet price curve is maintained.

Where the technology stands today

At this year's OFC, the first-generation of 400 Gigabit Ethernet pluggable transceiver modules, offered in the MSA based CFP8 form-factor, were shown. Some designs are sampling and some promise to do so soon. Testing tools for 400 Gbit/s developers are on the market and specification work has progressed and MSAs are being completed, while multi-vendor interoperability events are being held, and even the first carrier field trials are occurring.

In February, the Optical Internetworking Forum (OIF) approved an Implementation Agreement (IA) for an optical integrated polarisation multiplexed (PM) quadrature modulator for coherent applications with nominal symbol rates up to 64 Gbaud. The agreement supports the 16QAM modulation format for 400 Gbit/s applications.

In March, a new MSA group released a specification for a new quad small form factor pluggable double density (QSFP-DD), which is a next generation high-density, high-speed pluggable module with a QSFP28-compatible double-density interface. QSFP-DD pluggable modules can quadruple the bandwidth of networking equipment while remaining backwards compatible with existing QSFP form factors used across Ethernet, Fibre Channel and InfiniBand for 40 and 100 Gbit/s network applications. To have significant market impact, the 400 Gbit/s transceiver will need to plug into switches and routers that are 400 Gbit/s ready, and this requires switching silicon ready to support these rates.

AT&T has announced that it completed the first of a multi-phase trial testing 400 Gigabit Ethernet data speeds, using optical gear from Coriant to carry a true 400 Gigabit Ethernet service across a long-distance span of AT&T global backbone from New York to Washington. This demonstrated that AT&T's nationwide software-centric network is 400 Gbit/s-ready. A second phase of the trial will carry 400 Gigabit Ethernet on a single wavelength across its OpenROADM metro network. This phase is expected to use optical gear from Ciena. A third phase is expected to test the first instance of a 400 Gigabit Ethenet open router platform. The 'disaggregated router' platform uses merchant silicon and open source software and is expected to be another industry first.

In a post deadline paper at OFC, researchers at AT&T Labs described the trial, which encompassed an end-to-end 400 Gigabit Ethernet circuit, inclusive of 400 Gbit/s client cards with a CPF8 interface and dual-carrier 16QAM line-side. The trial demonstrated the feasibility of SDN-enabled creation, deletion and re-routing of the 400 Gbit/s service.

In addition, the Ethernet Alliance conducted a live 400 Gbit/s demo carrying traffic from its stand to four additional company booths on the show floor, namely Finisar, Xilinx, Broadcom and Viavi. All the connections were made with LR8 CFP8 transceivers over single mode fibre using 8 x 50 Gbit/s PAM4. Notably, three test equipment companies also participated - Ixia, Spirent and Viavi.

Other 400 Gbit/s announcements from OFC

Broadcom announced a comprehensive portfolio of N x 56 Gbit/s PAM4 PHY devices enabling 50, 100, 200 and 400 Gigabit Ethernet. The new 16 nm N x 56 Gbit/s PAM4 PHY enables low power PAM4 PHYs with high performance DSP-based equalisation to address both copper and optical cabling systems, including multi-mode fibre (MMF) and single-mode fibre (SMF). The PHYs are protocol agnostic to support various interconnect interfaces, including IEEE 802.3bs/cd 50/100/200/400 Gigabit Ethernet for backplane and copper cabling, CDAUI-8 chip-to-module and chip-to-chip, and OIF 56G-LR-PAM-4 for PCB and cabled backplanes.

Inphi introduced the Polaris 16 nm PAM4 DSP PHY ICs, which provide a full bi-directional interface with host ASICs that have 28 GBaud PAM4 and NRZ electrical interfaces and support bridging to 28 Gbaud PAM4 optics. The products also support retiming and gearbox functionality. The line-up includes: Polaris-400G, 8 x 56 Gbit/s PAM4, 16 x 28 Gbit/s NRZ gearbox for CFP8; and Polaris-400G (NG), 8 x 56 Gbit/s, 8 x 56 Gbit/s PAM4 retiming for OSFP/QSFP-DD.

Ixia, Cisco and Foxconn Interconnect Technology (FIT) demonstrated 400 Gigabit Ethernet traffic with QSFP-DD via PAM4 electrical lanes, and Lumentum showcased several 400 Gbit/s transceivers, including QSFP-DD FR4, DR4 and OSFP FR4. The QSFP-DD and OSFP transceivers comply with the recently announced QSFP-DD MSA and OSFP MSA, respectively. Lumentum was an early participant and contributor to both MSAs. The new transceivers use the company’s high-performance EML (electro-absorption modulator laser) technology.

MACOM announced a complete PAM4 technology chipset for 100 Gbit/s data rates over a single wavelength enabling single fibre and four-lane parallel fibre connectivity for 100, 200 and 400 Gigabit Ethernet applications. The chipset features a new TIA, transmit and receive clock and data recovery (CDR) devices and linear EML driver module.

In addition, NeoPhotonics demonstrated a pluggable coherent CFP2-ACO module for 400 Gbit/s over data centre interconnect and metro/regional distances. The ClearLight CFP2-ACO platform uses the company's high bandwidth Class 40 coherent receiver, capable of 64 Gbaud with 16QAM to 64QAM modulation.

Oclaro announced sampling of its 400 Gbit/s CFP8 transceiver for core routers/transport applications. The CFP8 leverages Oclaro's EML laser and receiver technology and is compliant with 400GBASE-LR8 optical and 400GAUI-16 electrical interface specifications under final standardisation by the IEEE 802.3bs task force. Oclaro expects commercial production in the second half of 2017.

Finally, Viavi Solutions showcased its ONT-600 400 Gbit/s test platform, which aims to accelerate 400G deployment, from the early stages of developing and validating CFP8 FR8/LR8 modules to fully comprehensive Ethernet performance needed for system level and service validation. The company said it has recently released several applications, including enhanced FEC testing, enabling validation of performance of 400 Gbit/s elements against IEEE P802.3 bs (draft) FEC. Viavi also announced new advanced error analysis applications: all types of errors including bursts, individual bit errors and slips are characterized to quickly establish the root cause.

Watch for bigger switching silicon

One further area to keep an eye on is the progression of terabit-class switching silicon. Broadcom dominates in switching silicon but several start-ups are looking at this next step function in Ethernet bandwidth as the ideal opportunity to make a market entrance.  One such upstart is San Jose-based Innovium, which has unveiled its 12.8 Tbit/s TERALYNX scalable Ethernet silicon for data centre switches. The design is powerful enough to deliver 128 ports of 100 Gigabit Ethernet, 64 ports of 200 Gigabit Ethernet or 32 ports of 400 Gigabit Ethernet in a single device. Innovium, in partnership with Inphi, has already produced a single switch chip-based reference design for a platform supporting 12.8 Tbit/s (128 x 100 Gigabit Ethernet) QSFP28 deployments. The reference design uses Innovium's 12.8Tbit/s TERALYNX Ethernet switch silicon and Inphi's PAM4 chipset. Versions with 400 Gbit/s ports should be just over the horizon.

OFS Carries 200G over 4,500 km with TeraWave Fiber

OFS, a designer, manufacturer and supplier of fibre optic network products and solutions, announced it is showcasing the capacity and un-regenerated reach of Nokia's 1830 Photonic Service Switch (PSS) C+L-band DWDM system over OFS TeraWave ULL fibre, enabling reduced cost-per-bit of transport across the ultra-long haul distances between hyper-scale data centres.

TeraWave ULL fibre is claimed to offer the largest available effective area for a terrestrial fibre, thereby allowing improved suppression of non-linear penalties that limit the reach of high capacity, coherent modulation formats. The company also claims that the cost-per-bit of fully lighting a TeraWave ULL fibre can be up to 50% less than that of a G.652 fibre through avoiding the need for regeneration.

The Nokia 1830 PSS networking platform is designed to support ultra-long haul performance at 200 Gbit/s using the 8QAM modulation format, and extended metro/DCI reach with high spectral efficiency. The OFS TeraWave ULL ITU-T G.654.E fibre is designed to reduce amplifier noise leveraging low nominal loss of 0.168 dB/km and to minimise non-linear distortion via its large effective area of 125 microns squared.

OFS noted that the waveguide of TeraWave ULL fibre was designed to minimise both micro- and macro-bending losses in the L-band to enable enhanced terrestrial cable performance and superior splice performance.

For extended reach metro/DCI applications, the TeraWave ULL fibre can support 400 Gbit/s capacity over up to 300 km with 100 km spans without the need for Raman amplification when used with the Nokia 1830 platform. When combined with a hybrid Raman-EDFA amplifier, the fibre can support up to 200 Gbit/s transport over distances of up to 4,500 km un-regenerated with 100 km spans.

Commenting on the demonstration, Robert Lingle, Jr., director, market and technology strategy at OFS, said, "Traffic is growing inside the networks of cloud content providers at CAGRs up to 50%, while the distance between web-scale data centres can be over 4,000 km in Europe and North America… as practical and fundamental limits make it more difficult to increase spectral efficiency in the future, C+L-band transmission (can)… double the capacity per fibre if the fibre and cable are designed for L-band wavelengths".

http://www.ofsoptics.com/index.html

Nokia and Facebook Test Trans-Atlantic Optimization

Nokia and Facebook announced they have collaborated on field trials of new optical digital signal processing technologies over a 5,500 km trans-Atlantic link between New York and Ireland.

To help address increasing demand for capacity on subsea fibre networks, Nokia and Facebook tested Nokia Bell Labs' new probabilistic constellation shaping (PCS) technology. The companies stated that the trial achieved an increase of almost 2.5x in capacity compared with the stated transmission capacity of the system, demonstrating the feasibility of using the technology across a real-world optical network.

PCS, a field of research at Nokia Bell Labs, is an advanced technique that utilises 'shaped' QAM formats to flexibly adjust transmission capacity to close to the physical limits, the Shannon limit, of a given fibre-optic link. Believed to be a first-of-its-kind experiment conducted on an installed submarine link, the test was conceived and planned by Facebook,

Nokia noted that PCS is based on 64QAM and, combined with digital nonlinearity compensation and low-linewidth lasers, enabled a claimed record spectral efficiency of 7.46 b/s/Hz, indicating the potential to upgrade this cable to 32 Tbit/s per fibre in the future. The test also included round-trip submarine transmission over 11,000 km using 'shaped' 64QAM with spectral efficiency of 5.68 b/s/Hz.

During the trial transmission tests based on the commercially available Nokia Photonic Service Engine 2 (PSE-2) validated the transmission of 8QAM wavelengths running at 200 Gbit/s and 16QAM wavelengths running at 250 Gbit/s, which is believed to be a first for trans-Atlantic transmission. The 200 Gbit/s 8QAM wavelengths supported a spectral efficiency of 4 b/s/Hz while also exhibiting sufficient performance margin for commercial operation.

Nokia and Facebook stated that the results of the trial will be presented in a post-deadline paper at the OFC 2017.

http://www.nokia.com

Finisar Shows 400, 200 and 100G Pluggables

Finisar, a major supplier of subsystems and components for fibre optic communications, announced multiple optics product and technology demonstrations at OFC, including new 400 Gbit/s CFP8 FR8 and LR8 transceiver, 200 Gbit/s QSFP56 FR4 and LR4 transceiver and a 100 Gbit/s QSFP28 eSR4 extended reach transceiver modules.

The company will also demonstrate its new Flexgrid single low-profile wavelength selective switch (WSS) for next generation ROADM subsystems during the OFC event.

400 Gbit/s CFP8 FR8 and LR8 transceivers

Finisar will hold multiple demonstrations of its MSA-compliant 400 Gbit/s CFP8 transceiver, enabled by 50 Gbit/s PAM4 technology. The CFP8 module family includes an FR8 version supporting 2 km reach and an LR8 version for 10 km reach, both operating over single mode fibre. The modules are designed for applications in router-to-router and router-to-transport client interfaces.

At OFC, optical cables will link a number of booths to create a network of systems and test equipment platforms to demonstrate error-free live traffic transmission at 400 Gbit/s using working Finisar CFP8 modules.

200 Gbit/s QSFP56 LR4 transceiver

Finisar's new 200 Gbit/s QSFP56 optical module is an evolution of the four lane QSFP+ form factor designed for hyperscale data centre and high performance computing (HPC) environments. The 200 Gbit/s QSFP56 family initially includes an FR4 version for 2 km and an LR4 version for 10 km reach over single mode fibre. The module utilises 4 x 50 Gbit/s PAM4 electrical and optical interfaces and is designed to work with next generation of switching silicon to enable 6.4 Tbit/s in a 1 RU configuration.

The demonstration at OFC will feature an LR4 module designed for 10 km reach as per the IEEE 200GBASE-LR4 standard.

100 Gbit/s QSFP28 eSR4 transceiver

Finisar's latest 100 Gbit/s QSFP28 extended SR4 (eSR4) module offers long reach over multimode fibre (MMF) and targets enterprises and large data centre applications. Finisar noted that IEEE 100GBASE-SR4 species 70 metres over OM3 fibre or 100 metres over OM4 fibre; the new QSFP28 eSR4 module enables 300 metres over OM3 fibre and 400 metres over OM4 fibre to address typical 10 and 40 Gbit/s applications.

The extended reach capability allows data centres and enterprises with installed multimode fibre to use existing fibre plant to upgrade to 100 Gbit/s. The product employs parallel optics and can interoperate in a fan-out configuration with four of Finisar's 25 Gbit/s SFP28 eSR transceivers. A demonstration will show two Finisar 100 Gbit/s QSFP28 eSR4 transceivers connected over 300 metres of OM3 fibre, with traffic generated and measured by an Anritsu MT1100A network master flex.

Flexgrid single low profile WSS

The new single low profile WSS, designed for single-slot ROADM line cards, expands Finisar's portfolio of WSS based on its Flexgrid and LCoS technology. The ITU Flexible Grid-compliant device enables dynamic deployment of bandwidth at 6.25 GHz spectral width and intra-channel attenuation control to enhance performance over an optical link.

The WSS is offered in configurations from 1 x 2 to 1 x 9 and supports next generation express and colourless/directionless add/drop architectures. The OFC demonstration will feature a 1 x 9 WSS configured to switch a mix of transceiver and ASE inputs to a common output port.

http://www.finisar.com

Oclaro Announces 1 Tbit/s Dual Wavelength PM-QMZ External Modulator

Oclaro announced that it has expanded its lithium niobate (LiNbO3) portfolio with a dual wavelength PM-QMZ external modulator for data rates up to 1 Tbit/s and that at OFC it is hosting an interoperability demonstration showcasing a 100 Gbit/s ER4-Lite QSFP28 and CFP2 over 40 km single-mode optical fibre (SMF).

New PM-QMZ modulator

The new dual wavelength PM-QMZ modulator joins Oclaro's established high-bandwidth single carrier PM-QMZ (polarisation multiplexed quad parallel Mach-Zehnder) modulator line that was launched in 2015 and has been tested in labs and R&D centres operating at symbol rates up to 64 Gbaud and with different modulation formats up to 128QAM.

Oclaro's dual wavelength PM-QMZ LiNbO3 external modulator is designed to support data rates up to 1 Tbit/s utilising two wavelengths 'packed' into a single gold box. The modulator is a high electro-optic bandwidth PM-QMZ device that integrates into a hermetic package two PM-QMZ sets, each featuring an input beam splitter, four parallel Mach-Zehnder modulators configured for I-Q modulation, a polarisation combiner and monitor photodiodes for power and bias control.

Key features of the new product include: 3 dB electro-optic bandwidth exceeding 28 GHz; smooth optical response up to 45 GHz, enabling symbol rates up to 45 Gbaud; extinction ratio above 25 dB for complex modulation formats; insertion loss below 12 dB; and support for L-Band operation.

Interoperability demonstration

The demonstration of 100 Gbit/s ER4-Lite QSFP28 and CFP2 over 40 km single-mode fibre (SMF) is designed to show how ER4-Lite solutions can deliver the low power and low cost required to enable 100 Gbit/s in the access and core networks where longer reach is required.

Oclaro noted that as 100 Gbit/s technology is deployed in metro and access networks, operators require 100 Gbit/s client interfaces able to provide 40 km reach without the use of amplifiers. The new ER4-Lite specification is designed to enable cost-effective 100 Gbit/s 40 km pluggable solutions in compact QSFP28 transceivers with FEC and APD-based receivers.

The new Oclaro QSFP28 ER4-Lite device, which complements the existing CFP2 product, leverages the company's proven 28 Gbit/s EML as used in its CFPx and QSFP28 LR4 product families. The ER4-Lite QSFP28, which is currently sampling, can support 100 Gigabit Ethernet and OTU4 applications with up to 40 km reach with FEC, or 30 km without FEC, and is interoperable with existing ER4 solutions up to 30 km.

Oclaro noted that QSFP28 has been standardised by ITU-T as G.959.1 4L1-9D1F and is being standardised by the newly established 4-Wavelength WDM MSA group.

http://www.oclaro.com

Fujitsu Intros Access-agnostic Virtual Access Network for SMBs

Fujitsu Network Communications has introduced its Virtual Access Network (VAN) solution, designed to address the cost and time barriers for small-to-medium business (SMB) service deployment by eliminating the need for purpose-built routing devices and manual provisioning and allowing the use of any access technology to deliver services, and will showcase the solution at OFC 2017.

Fujitsu noted that SD-WAN and access services can be cost-prohibitive for SMB customers, thereby resulting in an underserved market. Fujitsu's new VAN solution is designed to enable delivery of SMB services more cost-effectively by removing the need for operators to deploy CPE routing devices requiring manual, on site provisioning. VAN also provides a single solution that can be used to deliver virtualised products using multiple access technologies.

The VAN solution helps to minimise service delivery time and costs leveraging features including centralised compute resources. By virtualising and centralising network functions, the solution both improves performance and makes services easier to manage.

Fujitsu's VAN solution comprises a services gateway unit, a low-cost whitebox that can support services over any access medium, a plan and provision tool that allows zero-touch plug-and-play provisioning, and a virtual private service VNF that serves to replace traditional routers.

The complete solution is designed to help operators: deploy new services without the need for manual provisioning; deliver seamless access regardless of underlying technology, whether fibre, copper, HFC, WiFi or LTE; reduce the cost of service delivery; and enable the delivery of competitively priced services to end customers.

Corning and Kaiam Demo CoPPhI

Kaiam, a privately-held developer of hybrid photonic integrated circuit (PIC) technology, and Corning announced they are showcasing an optical engine and single-mode fibre interface connector designed to be co-packaged with a 12.8 Tbit/s switch chip at the 2017 OFC in Los Angeles.

The companies stated that by converting high-speed signals to optical within the switch package, the high-density engine based on co-packaged photonic interconnect (CoPPhI) technology can potentially enable up to a halving in chip interconnect power consumption.

Kaiam noted that prior to CoPPhI, the sub-micron alignment tolerances required in single-mode optical packaging presented a barrier to creating practical co-packaged single-mode optical interconnect solutions, while the reduced power consumption provided by CoPPhI-enabled switches can address a key impediment to data centre growth.

At OFC, the demonstration by Corning and Kaiam features a prototype connector, with the optics capable of delivering 1.6 Tbit/s from four fibres at 400 Gbit/s per fibre, or lambda (4 λ), extendable to 8 λ. The demonstration interoperates at 25 Gbit/s per λ with a standard CWDM4 transceiver.

It was noted that multiple CoPPhI engines can be co-packaged in close proximity to the four sides of a switch ASIC to support over 12 Tbit/s of optical connectivity. Single-mode fibres interface to the engine via a low-profile connector compatible with electronic packaging and assembly processes, including solder reflow.

With the 12.8 Tbit/s switch IC generation, the companies stated that the power required to drive signals over a PCB between the switch IC and the optical module will equal the power required for the switching function. By shrinking the optics and pushing the electrical-optical conversion point close to the switch IC, the required line drive power can be minimised.

Separately, Kaiam announced that it plans to acquire the manufacturing facilities of Compound Photonics (CP) in Newton Aycliffe in the UK through a transaction hat includes investment by CP into Kaiam to develop the facility. Subject to final approvals, the agreement is expected to close in the second quarter.

The manufacturing space acquired through the deal will enable expansion of Kaiam's datacom transceiver manufacturing capacity and also includes a cleanroom for processing of III-V devices, including pHEMTs, HBTs, photodetectors and lasers. Kaiam noted that the new facility will advance its strategy of vertical integration.

Previously, Kaiam acquired Gemfire, its strategic PLC supplier, in 2013 and currently operates an 8 inch silica-on-silicon line for the fabrication of integrated optical components in Gemfire's Livingston facility in Scotland. It also operates 40 and 100 Gbit/s optical packaging lines at the facility that are nearing capacity due to rising demand.

The new facility in Newton Aycliffe and its wafer-fab will allow Kaiam to expand its silica-on-silicon and transceiver manufacturing and in the future enable it to add integrated InP photonic integrated circuits (PICs) for advanced transceivers.

Regarding the joint solution with Corning, Rob Kalman, Kaiam VP of marketing, said, "On-board optics such as COBO allow the industry to explore post-pluggable usage models but still require power-hungry electrical interfaces… Kaiam is working on the part of the problem that eliminates this power while also addressing the cost and density needs of hyperscale data centre customers".

Nistica unveils FLEXBOX grid-flexible, disaggregated ROADM

Nistica, a Fujikura subsidiary and supplier agile optical networking solutions, has unveiled FLEXBOX, a disaggregated ROADM node designed for next-generation software defined networks (SDN), and plans to work with existing system vendor customers to deliver the product to carriers and webscale end customers.

Offered in single rack unit (1 RU) form-factors, Nistica's products are designed to enable broadcast-and-select and route-and-select architectures by integrating its grid-flexible single and dual C-band and L-band wavelength selective switches (WSS).

For the new solution, Nistica has leveraged gain-controlled optical amplification derived from its expertise in ROADM blade optical signal control loops that is incorporated with the WSS technology to enable an automated optical layer for carriers seeking hands-free operation via software control.

Nistica is introducing a customised black-box model whereby OEMs can specify optical layer differentiators, as well as tailor the software layer to offer advanced optical capabilities to end customers. Based on standardised SDN support of NetConf and RestConf network management interfaces through Yang models, FLEXBOX is designed to be compatible with emerging standards within collaborative platforms such as OpenROADM and Telecom Infrastructure Project (TIP).

Nistica is demonstrating the functionality of the FLEXBOX solution at OFC 2017 in Los Angeles.

See also