data center interconnect and the optical...

1

John Reynolds

Data Center Interconnect and

The Optical Layer

© 2016 Xtera Communications, Inc. Proprietary & Confidential 2

• Industry Trends – Growth

– Traffic Variability

• Disaggregation and Open Line Systems

• Subsea and Terrestrial Convergence

Agenda


• Typical 500,000 sq/ft web-scale DC requires ~8,000 100G WAN ports (Ovum)

• Workloads are driven by Application and Time of Day events

• Variability of transport traffic is increasing as is the range between the largest and smallest flows

• Transport Networks must become more agile

– Provide higher-bandwidth

services

– Turn up services faster

– Lower cost

Growth of DCI and its effects on Transport Networks

Global DCI traffic growth

3.1

3.8

4.7

5.8

7.1

8.6

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

2013 2014 2015 2016 2017 2018

Ze

tta

byte

s p

er

ye

ar

Source: Cisco Global Cloud Index, 2013–2018


Nature of IP Traffic….highly variable

Examples: Database Mirroring, VM Migrations, “elephant flows”….

5

Evolution of the Optical Layer and

Open Line Systems


Industry Direction

• Data Center industry has been pushing and deploying “Open” systems for years

– Separation of Control and Data planes (I.E. SDN) Open management

interfaces

– Software control and network programmability

– White box switches

– Focus is now turning to the WAN space

• Transport DCI

• Large Data Center operators are beginning to push for this model already

– E.G. Telecom Infra Project (TIP) – Facebook / Intel

Open Systems


• Modeled after the Open Compute Project (OCP) created by Facebook for the data center and server industry…

• Introduction of Open Packet DWDM model – Routers

– Transponders

– Open Line System

Telecom Infra Project (TIP)

“The Telecom Infra Project (TIP) is an engineering focused initiative driven by

operators, infrastructure providers, system integrators, and other technology companies that

aim to reimagine the traditional approach to building and deploying telecom network

infrastructure”


What is an Open Line System?

• OLS implies integrated management of both the Line System and Terminal equipment via an open Northbound Interfaces (NBI) and under SDN control • E.G. Netconf/Yang

Vendor A Terminals

Vendor B Line System

SDN Controller ”Orchestrator / Hypervisor / etc.”

NBI NBI

• Much more than just alien waves….


IP and Optical Transport

• Unified network orchestration tightly couples IP traffic demands and variability to Transport resources for more effective utilization • Time of day events • Route or latency sensitive workloads

Vendor A Terminals

Vendor B Line System

SDN Controller ”Orchestrator / Hypervisor / etc.”

NBI NBI

NBI

Routers


• Best of breed philosophy – Separates development lifecycle of Transponder vs Line System technologies

– No longer coupled, advancements can be introduced to the network faster

• Line System – Capacity

– Reach

• Transponder – Best transmission format for application

– Power/Capacity/Rack metric

Disaggregation


• Current C-Band technologies won’t be able to satisfy the bandwidth demands coming from the data center.

Maximizing Capacity

EDFA 36nm

Raman 61nm

Raman+ 100nm

Line System

Data Center/CO Nearly 3x the usable spectrum of EDFA

Xtera Raman Amplification…..not just for reach!

…but for increased the usable spectrum


Open Line System for Flexibility of Transport

MUX / DEMUX 50Ghz 37Ghz

Coupler Amplifier EDFA

EDFA (C+L) EDFA+RAMAN

All RAMAN

Advance Modulation 100G+

Spectrum Sharing (multi-vendor)

Direct Detection PAM-4

Switch/Router Coherent Detection

100G

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Terrestrial and Subsea Convergence


• Technology has converged dramatically over the past few years… FEC, coherent, modulation format...

• Optical transmission is fundamentally the same. Actually, tranmission is easier over a wet fiber plant:

– Uniform fiber type/vintage

– Uniform span length

– Zero optical connector loss

Are Terrestrial and Submarine Fundamentally Different?


What does this convergence mean?

• Elimination of back to back systems at landing station….reduced cost

• Common Platforms – Unified practices for engineering, maintenance, and support

– Common spares

Terrestrial and Subsea Convergence

POP/DC

LTE

SLTE

LTE

SLTE

LTE

LTE

POP/DC Cable Landing Station Cable Landing Station

Terrestrial Submarine Terrestrial


One example implementation

Terrestrial Submarine Terrestrial

POP/DC

PFE/LME

LTE

LTE

POP/DC Cable Landing Station Cable Landing Station

• Glass through for POP to POP connection

ROADM ROADM

PFE/LME

• But more than that…. Unified Global Network Management / Enablement of new SDN Services


Principle of Open System Gateway

• Separate supply of Terminal, PFE, Cable & Repeaters

• Independent fiber pair Monitoring and Control

• Can use any terminal equipment with suitable performance (SLTE or LTE)

• Separation of development lifecycles..

Open System for Subsea

LME

PFE NMS

3rd party

Terminal

OSG


• Optical Layer must evolve to keep pace with DCI traffic demands and changing patterns

• Open Line Systems enable change – Providing maximum spectral density and bandwidth headroom

– Separation of development lifecycles…speeds up delivery of technology

advances to the network

• Convergence of terrestrial and subsea is happening now… – Network boundaries and silo’s can be eliminated.

– DCI, LH, Subsea…...who cares?.....its all one network

Summary


Thank you

data center interconnect and the optical...

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