1

Optical Coarse Packet Switched IP-over-WDM Network (OPSINET): Technologies and

Experiments

Presentation for WOCC’2004

Maria C. YuangDepartment of Computer Science and Information Engineering

National Chiao Tung UniversityMarch 8, 2004

2

Outline

Optical Networking- Introduction

A New Paradigm- Optical Coarse Packet Switching (OCPS)

OPSINET- An Overview

System and Network Technologies

Conclusions

3

Why Optical Networking?

A

AA

A

AA

A

IP Router

O/E/OGrooming

Switch

O/O/OSwitch

O/O/OSwitch

O/O/OSwitchFlexibility

Distance ULH

DWDM

SONET/SDH

All Optical Switching

Reliability

Economics

Capacity

NewServices

Ch 1

Ch 1

Ch n UNI

Source: Dr. N. Patel Talk on NGN2002Source: Dr. N. Patel Talk on NGN2002

4

Optical Networking Evolution

1st Generation 3rd Generation2nd Generation

Wavelength Transport

Wavelength Switching

Wavelength Routing/ Sharing

Optical TransmissionOEO SwitchingIP-over-ATM-over-SONET

Optical TransmissionOOO SwitchingCircuit Switc. IP-over-WDM

Optical TransmissionOOO SwitchingIP-over-WDM

– Optical Packet Switching– Optical Burst Switching– Optical Coarse Packet

Switching– Photonic Slot Routing

5

Optical Networking Evolution (cont.)

Optical Circuit Switching (OCS)

– Static utilization of WDM channels

– Good to support stream traffic

Optical Packet Switching (OPS)

– All optical: transport, processing, and buffering

– Fine-grained WDM channel allocation

– An ultimate solution for data-centric Internet

Current dilemma for OPS

– Lack of optical signaling processing and optical RAM

– Large switching overhead

Alternatives ?

6

OPS Alternatives

Optical Burst Switching (OBS)

– Supports per-burst (rather than per-packet) switching

– Focuses on out-of-band, one-way wavelength allocation

+ A control packet for each burst payload is first transmitted out-

of-band, allowing each switch to perform just-in-time

configuration before the burst arrives

+ Wavelength is reserved only for the duration of the burst

+ The burst payload follows its control packet immediately after a

predetermined offset time

OBS can be viewed as a more efficient variant of OCS

Our approach: Optical Coarse Packet Switching (OCPS)

7

A New Paradigm- OCPS

By “Coarse”

– Per-burst switching (rather than per-packet switching)

– Header is electronically processed while the payload remains in the

optical domain

By “Packet Switching”

– Header is in-band modulated with payload and sent via one λ

– Wavelengths are shared via wavelength converters

– Enforcement of traffic control and traffic engineering to maximize

wavelength-dimension statistical multiplexing gain

OCPS can be considered as a less stringent variant of OPS

Based on OCPS, we have constructed an IP-over-WDM network, called

OPSINET (Optical coarse Packet Switched IP-over-WDM Network)

8

Project at a Glance

Prof. W. Z. Chen

• Prof. Maria Yuang- Res. Assist. Prof.：2 - PhD：4- MS：4

• Prof. Winston Way- PhD：1- MS：1

Prof. S. L. Lee

Prof. J. H. Chen

NCTU/IEO

Engineers

NCTU/CSIE/Excel. Proj.

• Director Dr. S. C. Jeng- PhD researchers: 1 - MS researchers: 9

ITRI/CCL

Propose a new OCPS paradigmSupport 2.5 Gb/s with basic QoS

New Technologies– New optical switch architecture– New header/payload multiplexing– 10Gbps Burst Mode Receiver

Support 10 Gb/s with full-grown QoS

Phase- IOPSINET

Phase- IIOPSINET

Prof. Y. J. Chen

CSEE, Univ. of Maryland NTUST

ITRI/OES

NCTU/EE

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OPSINET: All-Optical Experimental Network

O-1O-2I-1I-2

O-3O-4I-3I-4

1G1G1G

1G

O-1O-2

L3SCL3SCEdgeEdgeRouterRouter

AWG Switch

FiberSwitch

I-2

I-3/I-4λSwitch

O-3/O-4Mac@1

Mac@2

λ1’

λ2’

λ2

λ1

λ1 λ2

λSwitchL3SCL3SC

CoreCoreSwitchSwitch

FFSCSC

λλSSCC

λλSSCC

L2SCL2SCBridgeBridge

L3SCL3SCEdgeEdgeRouterRouter

λ1

λ1

λ2

1G1G1G

1G

λ1

λ1’ λ1

’

λ2’

λ2’

λ2’

L2SCL2SCBridgeSmartbitsSmartbits Bridge

Legend:L2SC: Layer 2 Switch CapableL3SC: Layer 3 Switch CapableλSC: λ- Switch CapableFSC: Fiber Switch Capable

L3SCL3SCEdgeEdgeRouter I-1Router

10

OPSINET- Phase I

Ingress and Egress Edge routersOptical Label Switched Routers (OLSRs)Fiber/Lambda Switches

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Ingress Edge Router Architecture

(Multimode)

Traffic

Generator

SmartBitsIXP1200 NP

(ψ,τ)-Sched./

Shaper

Header+

PayloadGeneration

FPGA

PayloadGenerator

HeaderGenerator

G-EthernetController

1G (GE)

µ-ProcessorInterrupt

Configuration

λ1

ON/OFF

(Multimode)

(Multimode)

(Multimode)

(Multimode)

Legend:: Optical Line: Electronic Line

Label Update PC Linux

Digital Comm.Network

Traffic Engineering

OSPF RSVP-TE LMPRoutingSignalingControl Channel Mgmt

Routing and Wavelength Assignment,Constraint Based Routing,

Call Admission ControlGMPLSControlPlane

OpticalGating

8B/10BEncoder

Fixed OpticalLD

Header/Payload

SCM

32

8 λ2

Mux

1G

1G

1G

λ1, λ2

1G

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Optical Label Switched Router Architecture

F4

F3

F2

F1

OpticalFilter(FFP)

FTLS

FPGA

λ1

λ2

λ3

λ4

Cyclic

Frequency

(CF)

AWG

F1

F2

F3

F4

λ3

λ1

λ4

λ2

D

E

M

U

XEPDL

Burst Mode Receiver

O/E LimitingAmp.

TH Stb.(1R)

DigitalSplitter

CAM

LabelSwapping

Burst-ModeCDR

(3R)

µ-processor

QoSProcessing

Clock

HeaderPayload

(1R)

Tuning Signal

Legends:: Optical Line: Electronic Line

Header/PayloadSynchronizer(SCM-based)

COMBINER

Header Generator

Payload Regenerator

Label UpdatePC Linux

GMPLSControlPlane

Digital Comm.Network

Traffic Engineering

OSPF RSVP-TE LMPRoutingSignalingControl Channel Mgmt

Routing and Wavelength Assignment,Constraint Based Routing,

Call Admission Control

F1

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System and Network Technologies

Label multiplexing and swapping

Traffic control at edge routers

Traffic control at core switch routers: λ contention resolution

Traffic engineering: Optical Tunnel Allocation

Optical switch architecture with partial λ-sharing and limited

optical buffers

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Label Multiplexing and Swapping

Existing Method: Sub-Carrier Multiplexing (SCM)

– Payload and label are carried at different frequencies

– Payload is carried at low band

– Label is carried around 7.9 GHz

– Advantage: Simple

– Disadvantage: Fail to support 10Gbps payload transport

Our Innovative Method: Superimposed ASK-based Label

Multiplexing and Swapping

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All optical label swapping technique -Superimposed ASK label

FixedFiberdelayline

Limitingamp.

LPFt

LPFr

AMmodulator

AMmodulator

Label swapping

Coreswitchcontroller

LPFt

New Header

1 0 1 1 0 1 0 0 1 High speedpayload data

Label bitstream:

Eye diagram ofTransmitted signal

After header eraser Received Headerwaveform

10GbpsPayload

100MbpsHeader

CWlaser MZM MZM

8B10Bcoder

OpticalTransmitter

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Traffic Control at Edge: (ψ,τ)-Scheduler/Shaper

For a (ψ,τ)-Scheduler/ShaperK

– It is a scheduler for packets of different delay classes– It is a shaper for bursts of the same loss class

Legend:Fd,y : Packet flow of destination/loss class d and of delay class y;OLSP : Optical Label Switched Path;TLS : Tunable Laser Source;

Pack

et C

lass

ifier …Packets

(delay class 1)

F1,N (ψ,τ)-Scheduler/Shaper1 (OLSP 1)Bursts

F1,1 …

TLS

Fk,N (ψ,τ)-Scheduler/Shaperk (OLSP k)Bursts

Fk,1 …

TLS

FM,N (ψ,τ)-Scheduler/ShaperM (OLSP M)Bursts

FM,1 …

TLS

…

……Packets

(delay class N)

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(ψ,τ)-Scheduler: Concept

FCFS-based burstification

(ψ,τ)-Scheduler (ψ = 6, τ = ∞)

A4A3C4B8C3A2B7A1C2B6 B5C1B4B3B2B1

Burst

A4

A3A2A1C1B2B1A4C2B4B3C3B6B5C4B8B7

Burst

A4

Window

Window size (W) = 6; wA : wB : wC = 3 : 2 : 1;

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(ψ,τ)-Scheduler: Delay Guarantee

1

10

100

0.9 0.92 0.94 0.96 0.98Load

Mean Burstification Delay

QBC-F1QBC-F2QBC-F3QBC-F4FCFS

ψ =25τ =10

wF1:wF2:wF3:wF4 = 10:6:5:4

Offeredservice

Amount of serviceStepwise Service curve

0Timeminθ

G

2G

3G

4G

I I I I

Legend:G : Bandwidth granularity;I : Incremental Interval;

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(ψ,τ)-Shaper: Concept

Departure Process contains burst inter-departure time (T) and burst

size (S) distribution

Packet Arrival

Burst Departure Burst k-1 Burst k Burst k+1

Time

T

T=0S…

…

BurstDeparture

Burst Generation

Reach ψ ?

τExpire?-

Y

Y

First Packet

+

PacketArrival

τActivated

Non-empty Queue

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Effectiveness of (ψ,τ)-Shaper (ψ=25)

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

0.8 0.81 0.82 0.83 0.84 0.85 0.86 0.87 0.88 0.89 0.9

Packet loss probability

Load

W =50ψ = 25τ = 80

Binomial + ShaperMMBP (b=3) + Shaper

MMBP (b=5) + ShaperMMBP (b=7) + Shaper

MMBP (b=3) Binomial

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Performance Comparison: OCPS and OBS

1.E-07

1.E-06

1.E-05

1.E-04

0.8 0.82 0.84 0.86 0.88 0.9 0.92 0.94 0.96 0.98

Pack

et lo

ss p

roba

bilit

y

Load

W =10B=5Class H- OCPS

Class H- OBS(2,1,0)Class H- OBS(2,1,0)Class H- OBS(2,1,0)

ψH=ψM=ψL=25, δ =48µs

1.E-07

1.E-06

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

0.8 0.82 0.84 0.86 0.88 0.9 0.92 0.94 0.96 0.98

Pack

et lo

ss p

roba

bilit

y

Load

W =10B=5Class H- OCPS

Class H- OBS(2,1,0)

Class M Class L

Class H- OBS(2,1,0)Class H- OBS(2,1,0)

ψH=ψM=ψL=25, δ =9.6µs

1.E-07

1.E-06

1.E-05

1.E-04

0.8 0.82 0.84 0.86 0.88 0.9 0.92 0.94 0.96 0.98

Pack

et lo

ss p

roba

bilit

y

Load

W =10B=5Class H- OCPS

Class H- OBS(2,1,0)

ψH=ψM=ψL=100, δ =48µs

1.E-07

1.E-06

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00

0.8 0.82 0.84 0.86 0.88 0.9 0.92 0.94 0.96 0.98

Pack

et lo

ss p

roba

bilit

y

Load

W =10B=5Class H- OCPS

Class H- OBS(2,1,0)

Class M Class L

Class H- OBS(2,1,0)Class H- OBS(2,1,0)

ψH=ψM=ψL=100, δ =9.6µs

1.E-03

1.E-02

1.E-01

1.E+00

Class M Class L

1.E-03

1.E-02

1.E-01

1.E+00

Class H- OBS(2,1,0) Class MClass L

Class H- OBS(2,1,0)

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Conclusions

OCPS is a relaxed OPS paradigm by exploiting coarse

switching granularity (burst vs packet)

OCPS is a viable paradigm making all-optical networks a cost-

effective reality within three to five years

OCPS can be applied to metro core networks

– Mesh topology: wavelength contention resolution

– Ring/Bus topology: Medium Access Control