a smarter dwdm/otn layer in your network€¦ · 28/09/2015 · networks ∙ services ∙ people...

Networks ∙ Services ∙ People www.geant.org

Guy Roberts

Technology Exchange, Cleveland

Alien waves, packet aggregation and router bypass

A smarter DWDM/OTN layer in your network

7th October 2015

Transport Network Architect, GÉANT

Networks ∙ Services ∙ People www.geant.org 2

Contents

• Alien waves• Alien wave background

• Economic case for alien waves

• Field trial results

• Alien wave production services

• OTN Router bypass and packet aggregation


Alien WavesTheory and economics


Alien wave over DWDMScaling Fiber Capacity

Optical fiber

Tx

Tx

Tx

Rx

Rx

Rx

Transmitters Receivers

Combining and separating colors

Alien Wave provider – fibre, amplifiers and muxing

Alien Wave user – Txand Rx transponders

Amplifier

Demarcation between provider and user

• DWDM uses the 1525–1565 nm C band to make use of erbium doped fibre amplifiers (EDFAs)

• Approx. 80 waves per fibre on 50GHz ITU-T gridThe AW provider is selling spectrum on their DWDM transmission system


The economics traditional transmission services

• Cost structure for transmission layer:

• Fixed one-off costs – system design costs, installation fees

• Fixed annualized costs – common equipment depreciation, fibre

lease, equipment maintenance fee, power etc.

• Variable costs – transponders added on a per-service basis.

• For the first few services added, the fixed costs greatly exceeds the

variable costs.

• As new services are added the fixed costs per service falls.

• The break-even point occurs when revenues exceed the overall cost

of running the service


• Alien waves allow multiple providers to share one common fibre infrastructure

• This means that there will be more services on the fibre, and the fixed cost are shared across many

services, reducing the overall cost.

• The collaboration model agreed between Surfnet and GÉANT is for the fixed costs to be shared

equally between each of the providers using the common fibre infrastructure.

• In the case of Amsterdam to Hamburg this is Surfnet, Nordunet and GÉANT. In future this may also

include PSNC.

• Common costs are reduced by 2/3s compared to GÉANT only fibre.

• Solution also retains GMPLS control plane and ability to rapidly turn up new services.

• TeleGeography: “huge demand (for alien waves) from nontraditional operators”

Economics of alien waves


Economics of alien wavesActual costs for Ams-Ham

Annualized cost

over 3 years in

Euros

AW brings savings cf.

leased waves with only

3 x 100Gbps

1 x 100 2 x 100 3 x 100 4 x 100 5 x 100

GÉANT DF € 198,623 € 123,623 € 98,623 € 86,123 € 78,623

Leased Wavelengths € 65,000 € 65,000 € 65,000 € 65,000 € 65,000

Alien Waves € 98,623 € 73,623 € 65,290 € 61,123 € 58,623

€ 0

€ 50,000

€ 100,000

€ 150,000

€ 200,000

€ 250,000

Ams-Ham, Alien Waves cost per 100Gbps


Source: TeleGeography

Alien waves growth driven by content providers

Most of the growth has been

in content provider networks


Alien WaveField trial


Amsterdam – Hamburg fibreEliminating redundant fibre infrastructure

• R&E community has two parallel fibre systems between Amsterdam and Hamburg.

• Yellow cable is Surfnet.

• Green cable is GÉANT.

• Duplication of infrastructure dilutes utilization.

• Objective 1: remove one fibre system and share remaining fibre

• Objective 2: retain GMPLS control plane

• Solution: alien waves


Phase I

• Tested the technology and operational procedures.

• Objective was to understand if GÉANT can make use of SURFnet’s dark fibre to carry our DWDM trunks.

Fixed Filters

• Phase I used fixed filters to insert alien waves

• Convenient for fast trial, but does not scale well

• After successful competition of trail, the production solution will use ROADMs

• ROADMs allow waves to be remotely turned up and reduces inter-site fibres

11

Field TrialThe setup


AOLX-500

AOLM-500

AOLX-500

OTC OTC

DANTE Amsterdam

DANTEHamburg

DTN-X

AOLX-500

AOLX-500

SURFnetAmsterdam

6500 CPL6500 CPL

SURFnetHamburg

AOLM-500

Pair of loan AOLMs in the blue spectrum

(OCG 2)

Existing DANTE fibre

Switch Matrix

ATC ATC

N x amps

N x amps

SURFnet/Cienaline system

Pair of loan ATCs with OLA and OFM-4-D

Existing AOLX on OCG 7

AOLX-500

Switch Matrix

DTN-X

Field TrialConnectivity

Surfnet system operated in parallel with GÉANT production fibre for duration of trial


1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

-30 -25 -20 -15 -10

pre

-FEC

BER

channel Rx power (dBm)

AOLM-500-T4-1-C5 Hamburg Pre-FEC sensitiviy

Ham 1556.56nm

Ham 1554.94nm

• Receive sensitivity measured on two wavelengths in each direction

• Better than 10 dB receive margin in both directions – i.e power into Rx can fall by 10dB before errors are seen

1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

-30 -25 -20 -15 -10p

re-F

EC B

ERChannel Rx power (dBm)

AOLM-500-T4-1-C5 Amsterdam re-FEC sensitiviy

Ams 1556.56nm

Ams 1554.94nm

Field TrialTest results – excellent receive margin


1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-7 -6 -5 -4 -3 -2 -1 0

Pre-FEC BER @ AMS vs insertion loss at input to Ciena mux @ HAM

1556.56nm 1554.94nm

1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

-3.5 -3 -2.5 -2 -1.5 -1 -0.5 0

pre-FEC BER vs insertion loss at point of insertion of alien wave into fibre

1556.56 1554.94

• Power injection is reduced at two points:• Where the AW signal is injected into the fibre

• Where the AW signal is injected into the Ciena equipment

• In both cases the reduction in power did not result in a significant change in the pre-FEC BER.

• Demonstrates that system is stable under power level changes.

Field TrialTest results – robust to input power variation


Infinera pre-FEC Q out of range alarm

Infinera Loss of Frame alarm

Alarms and notification aid debugging: four types signal deterioration can be distinguished

1. If there is a loss of fidelity of the signal, this can be detected using pre-FEC threshold crossing notification

2. If the alien wave becomes so degraded that the Q-factor drops below 10, Infinera will raise a pre-FEC Q out of range alarm

3. A cut in the SURFnet fibre results in a Loss of Frame (LOF) alarm, some signal from the optical amplifiers leaks through, so there will not be a Loss of Signal (LOS) alarm.

4. If the local patching between GÉANT and SURFnet sites is broken, then a Loss of Signal (LOS) alarm is raised.

Field TrialTest results – Infinera alarms allow debugging of alien wave


Alien WavesNext steps


Production Alien WaveFlexible solution uses ROADM technology

• These positive field trial results mean that GÉANT will go ahead and work with SURFnet to a solution that scales up to 5 x 100G of alien waves from Amsterdam to Hamburg.

• The production solution will use ROADMs for a more scalable solution.

• The addition of Wavelength Selective Switches (WSS) on the drop side of the SURFnet ROADMs adds support for colourless add-drop.

• This means that the multiplexed set of 10 x 50Gbps waves from the Infinera Photonic Integrated Circuit (PIC) can be injected straight into the Ciena ROADM without the need for fixed mux/demux.

• Reduces the number of optical patch cords between GÉANT and SURFnet racks.


OTM

DTN-X

AOLX-500

Ciena6500 CPL

AOLX-500

Up to 10 waves of 50Gbps each on single fibre pair

Switch Matrix

GÉANT Amsterdam PoP SURFnet Amsterdam PoP

TrueWavereduced slopefibre

OTC

AOLX-500

AOLX interleaving

WSSWSS

OCG-7

WSS for Directional Independent

Access (DIA) line side

Production Alien WaveConnectivity

The use of a wavelength selective switch (WSS) on the access ports allows each wavelength to be individually turned up and adjusted


OTN & PXMFlexible capacity management


PXM in DTN-XPacket Aware OTN Core

Port Consolidation Transport Efficiency Stat-Mux

• Reduce router ports/fiber• Improve router efficiency• Aggregate packet flows

• Right-size transport• Build ODUflex as needed• Efficient optical protection

• Multiple flows combined• Traffic profiles per flow• Comprehensive QoS & TM

100GbEN x 10GbE

N x 10GbE

N x 10GbE

Packet Aware OTN Core

PXM: 200G Ethernet switch on a blade

Pt2pt ELINE or multipoint ELAN services.Built over OTN circuits


• Current IP architecture mirrors the underlying optical fibre links

• As a result IP trunks chain through all routers

HU

CH DE CZ

ATIT SK

HRSI

Fibrelayer

Routinglayer

Old Eastern ringIP trunks follow fibre

100G

40G100G

100G 100G

100G

40G

20G20G

20G

Router interfaces are filled upwith transit traffic


• OTN allows flexible and rapid reallocation network services

• PXM cards allow multiple services to terminate on a single DTN-X 100G port

• Allows for fine-grained allocation of GÉANT trunks

• Express links saves on high cost router interfaces

• Trunk capacity can be rapidly adjusted without the need to change routers interfaces

New eastern ring IPIP trunks follow traffic not fibre

HU

CH DE CZ

ATIT SK

HRSI

Transmission layer

Routinglayer

50G

100G 50G

50G

50G 50G

40G

50G

10G

10G10G

10G10G

FR

50G

Trunks follow traffic rather than fibre


Summary

• GÉANT’s first production alien wave has been commissioned on the Amsterdam-

Hamburg section.

• Good stable operation with no bit errors. Operational model is well understood.

• The next AW system is planed to be from Hamburg to the Polish border.

• We have re-designed the IP trunks on the Eastern ring to make use of packet aggregation

cards and router bypass.


Thank you and any questions


24

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a smarter dwdm/otn layer in your network€¦ · 28/09/2015 · networks ∙ services ∙ people...

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