Efficient 100G and 400G Data Center Optical Solutions Servers ToR Switches LEAF Switches SPINE...

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Efficient 100G and 400G Data Center Optical Solutions

ECOC 2017Market FocusRang-Chen (Ryan) Yu

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Examples of Hyper Scale Data Centers

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100+ DCs 87+ DCs

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Hyper Data Center Architecture Evolutions• Evolving from large mega data centers to inter-connected clusters of smaller

data centers within metro (<80Km)

• Closer to customers/End users

• Improved user experience

• Lower latency for mission critical app..

• Real estate, power cost/Op. flexibility

• Diversity for improved fault tolerance/disaster recovery

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Connectivity Requirements for Hyper Data Centers

Data Centers Interconnects (DCI) within Metro

• Reach: 70-80km

• Connection bandwidth: >4Tbps

• 100G DWDM 400G DWDM

Intra-Data Center

• Reach~300m to 2Km

• Connection bandwidth

• Server: 25G/50G 100G

• Switches: 100G 400G

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Servers

ToR Switches

LEAF Switches

SPINE Switches

Core Switches/Routers

Current 100G DC Optical Solutions

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“DR” Optics

• 100G PSM4

SR Optics

Active Optical Cable (AOC)

100G

Direct Attached Cable (DAC)

Or Active Optical Cable (AOC)

25G or 2x25G

“FR” Optics

• 100G CWDM4

LR Optics

• 100G LR4

Acronym Reach Fiber

SR <100m MMF

DR <500m SMF

FR <2Km SMF

LR <10km SMF

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Modulation Transition from NRZ to PAM4

• Current 100G solution based on 4x 25G NRZ Modulations

• Complex, and relative higher cost

100G PSM4

4x25G NRZ

100G CWDM4

4x25G NRZ

• To reduce cost and set foundation for efficient 400G

solutions, industry is driving adopting 100G with single

optical channel 50GB PAM4 modulation:

• 2x of Baud Rate

• 4 level modulation

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• Total 22 Companies

• Defines 100G FR, LR and 400G FR4, LR4 with 50GB-PAM4

• Eliminate inverse gearbox with SERDES progression

• Lay foundation for improved 400G, and higher speed

• Strong Benefits:

• Much reduced optics elements leads to lower cost

(4x2.5G)

(1x10G)

Historical 10G Deployments

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100G Optical Solutions Evolution

100G PSM4

4x25G NRZ500m

SMF

100G SR4

4x25G NRZ100m

MMF

100G LR4

4x25G NRZ10km

SMF

100G CWDM4

4x25G NRZ2km

SMF

100G DR

56GB-PAM4

100G FR

56GB-PAM4

100G LR

56GB-PAM4

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Servers

ToR Switches

LEAF Switches

SPINE Switches


New 100G DC Optical Solutions

“DR” Optics

• 100G DR

SR Optics


100G



25G or 2x25G

“FR” Optics

• 100G FR

LR Optics

• 100G LR

Acronym Reach Fiber

SR <100m MMF

DR <500m SMF

FR <2Km SMF

LR <10km SMF

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Servers

ToR Switches

LEAF Switches

SPINE Switches


Transition from 100G to 400G

“DR” Optics

100G 400G

SR Optics


100G 400G



25G/2x25G 50G/100G

“FR” Optics

100G 400G

LR Optics

100G 400G

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400G Optical Solutions Evolutions

400G LR4

50GB-PAM4

100G SR16

16x25G NRZ

100m

MMF

400G DR4

4x50GB-PAM4500m

SMF

400G SR8

25GB-PAM4

400G SR4.2

25GB-PAM4

400G FR8

8x25GB PAM42km

SMF

LWDM400G LR8

8x25GB PAM410km

SMF

LWDM

400G FR4

50GB-PAM4

CWDM

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Servers

ToR Switches

LEAF Switches

SPINE Switches


400G DC Optical Solutions

400G DR4 or

SR Optics


400G SR8



50G/100G

400G FR4

400G LR4

Acronym Reach Fiber

SR <100m MMF

DR <500m SMF

FR <2Km SMF

LR <10km SMF

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100G/400G DWDM DCI Solutions

2x25GB PAM4 QSFP28 1x50GB PAM4 QSFP28

Direct Detect

4x25G NRZ+MLSE

/or ODB CFP

400G

DP 16QAM

DCO

QSFP-DD, OSFP, COBO

TL

Coherent Detection

TL

100G

DP QPSK

ACO/DCO CFP2

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Direct Detection Coherent Detection

Modulation format NRZ, ODB, PAM4 DP QPSK, DP 16QAM

Distance Reach 100G up to 80km with DCM 100G up to 2000km

400G up to 600km

Power Dissipation Low power, ~4W @ 16nm

DSP

High power, >15W @ 16nm

DSP

Size/Density Small. 100G fit QSFP28 Large size, 100G CFP2

Cost Low. 200-300% higher cost

Direct use in DC

switch

Yes Need special dedicated

switch or transponders

Best use case DC campus, metro-edg DCI Metro core DCI, Long Haul




400G up to 600km


DSP


DSP


Cost Low. 200-300% higher cost

Direct use in

Layer2/3 switches

Yes Need special dedicated

switches or transponders




400G up to 600km


DSP


DSP


Cost Low. 3-4x higher cost




400G up to 600km


DSP


DSP

Size/Density Small form factor QSFP28 Larger size, 100G CFP2




400G up to 600km

Power Dissipation 100G PAM4 Low power,

~4W @ 16nm DSP

High power, 100G ~15W @

16nm DSP;



Distance Reach up to 80km with DCM 100G/400G >80Km without

DCM

50GB PAM4 vs. Coherent Optical Solutions


Modulation format 50GB PAM4 DP QPSK, DP 16QAM

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Pluggable Form Factors Supporting 400G Solutions

QSFP DD MSA:

• Backward compatible with QSFP-28

• Support 8x56G PAM4 Electrical Interface

• Allow 36x400G=14.4T for 1RU switch density

• Up to 12W power dissipation

CFP8 MSA:

• First Gen. 400G Router interface

• Unlikely for large scale data center Deployment

OSFP MSA:

• Support 8x56G PAM4 Electrical Interface

• Allow 32x400G=12.8T for 1RU switch density

• Up to 15W Power dissipation

Consortium for On-board Optics:

• Support up to 16x56G PAM4 Electrical interface

• Up to 17.5W, potentially

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Summary

• 100G data center optical solution transitioning from 4x25G to 1x100G with

56GB PAM4 technology

• Lower cost and future proof

• Efficient 400G solution emerging based on 4x56GB PAM4

• Good industry support with 100G Lambda MSA

• 56GB PAM4 DWDM as complementary DCI solution vs coherent

• A few plugable form factors emerging to support 400G

• QSFP-DD most promising for widest range of deployments

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Thank You!

Efficient 100G and 400G Data Center Optical Solutions Servers ToR Switches LEAF Switches SPINE...

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