ops: optical packet switches

8/14/2019 OPS: Optical Packet Switches

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OPS: Optical Packet SwitchesOPS: Optical Packet Switches

Hiroaki Harai ([email protected])

National Institute of

Information and Communications TechnologySep 8, 2006

Optical Network Testbeds Workshop 3


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Sep 8, 2006 H. Harai (NICT) 2

Why do we Need OPS?Why do we Need OPS?

Internet Traffic in Japan: approx. 500 Gbps

Peta-bps backbone future: doubled per year 500 Tbps in 10 years

Electronic packet switch

Year 2004: Throughput 640Gbps (16x40 Gbps) Lightpath networks

Need fully meshed connections/ feasible?

Need complex traffic engineering

Important technology for bandwidth-assured applications

OPS networks

Provide extremely high-throughput

Much larger bandwidth for switching (> 40 Gbps)

O/E/O: 40Gbps 64 x 622 Mbps bus, SERDES

May need MPLS-like control (labels can be merged)

Important to ubiquitous society


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Optical Packet SwitchingOptical Packet Switching

Data-path is all-optical (No O/E/O) Switch, Buffer Increase data bandwidth

Label lookup (i.e. forwarding)

Electronic parallel processing? Optical processing

Optical

Electrical

payload

payload header

header

SchedulingAvoid packet collision

Priority control

SchedulingAvoid packet collision

Priority control

ForwardingDetermine output portfrom the routing table

ForwardingDetermine output portfrom the routing table

SwitchingSwitch the packet

to the appropriate port

SwitchingSwitch the packet

to the appropriate port

BufferingStore the packetsin appropriate time

BufferingStore the packetsin appropriate time

RoutingMake a routing table forforwarding procedure

RoutingMake a routing table forforwarding procedure

payload

payload header

header

Nx1 Buffer

Nx1 Buffer

Nx1 Buffer

Nx1 Buffer

Nx1 Buffer

Nx1 Buffer

Nx1 Buffer

Nx1 Buffer

1xNLabelSwitch

1xNLabelSwitch

1xNLabel

Switch

1xNLabel

Switch

1xNLabelSwitch

1xNLabelSwitch

1xNLabelSwitch

1xNLabelSwitch

payload

payloadpayload

payload

Electronicserial

Optical

payload

payload payload

payload


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What should be Solved for OPS?What should be Solved for OPS?

OPS Increasing number of ports of optical switchElectronic: 16x16, 40Gbps 640GbpsOptical: 128x128, 160Gbps 20.48 Tbps

25 Waves 500 Tbps Increasing speed of label lookup and buffer managementWire-speed operation

Increasing number of labels looked-up

Several thousands (New L2 possibility)More (L3 switching) Increasing buffer sizeAt least tens of fiber-delay-lines

Decreasing guard time between packets

Several nanoseconds OPS Monitor/Analyzer Bit error / Optical packet error

Under

developingin NICT


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OPS Prototype

Optical label lookup

Optical buffer

Electronic buffer management

Remaining Topics of This TalkRemaining Topics of This Talk


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NICTNICTss40Gbps40Gbps--based OPS Experimentbased OPS Experiment

N. Wada, H. Harai,F. Kubota, OFC2003 (no. FS7).


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OpticalOpticalCCode basedode basedUUltraltraFFastastLLabelabelPProcessingrocessing

Optical label has different modulation format with payload data

Optical label is physically distinguished from payload data

Optical hardware based label processing is available

Fully passive, ultra high-speed optical label processing

Payload data

Packet format

Header(label)

Replace to the optical code (label)


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Time Domain Optical Code ProcessingTime Domain Optical Code Processing----Measured Waveform at 8Measured Waveform at 8--chip, 200Gchips/schip, 200Gchips/s

Ref.) K. Kitayama,N. Wada, IEEEPhotonic Tech.Lett., vol. 11,

pp. 16891691,

Dec. 1999.

10ps/div.

10ps/div.

Auto-correlation

Cross-correlation


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Optical FiberOptical Fiber--DelayDelay--Line BufferLine Buffer

Different lengths of FDLs

Need at least tens of FDLs H. Furukawa, H. Harai, N. Wada,

N. Takezawa, K. Nashimoto, T.Miyazaki, A31-FDL Buffer

Based on Trees of 1x8 PLZTOptical Switches, to bepresented at ECOC 2006, no.Tu4.6.5, Sep 2006. Discard

0T

2T

3T

4T

(B-1)T

Buffer

Manager

Nx(B+1)

switch

11

22

33

Control signal

Optical packets

44

55

55

44

11

3322

22

11

3344

55


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Switch 1 out

Switch 2 out Time (2s/div)

Intensity(

a.u.)

Intensity

(a.u.)

Buffer 1 out

Buffer 2 out

Packet collision!!

Output port

Avoidance of collision

Buffer 1Buffer 1

Buffer 2Buffer 2

LN-SW LN-SW LN-SW

LN-SW LN-SW LN-SW

OutputOutputportport

LN-SW

LN-SWLN-SW

LN-SW

LN-SW

LN-SW

Single Switch

Double Switches

Time

(2s/div)

1

11 1

SchedulerScheduler

Noise

Optical FDL Buffering at 160GbpsOptical FDL Buffering at 160Gbps

Source: N. Wada (NICT)


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HighHigh--Performance Buffer ManagementPerformance Buffer Management

for Optical Fiberfor Optical Fiber--DelayDelay--Line BufferLine Buffer Establish practical-scale high-performance management for FDL buffer

(1) Develop buffer management by parallel and pipeline processing

For number of ports, time complexity of each processor is O(1)

Parallel expansion of sequential (i.e. round-robin) scheduling N-times higher throughput than sequential scheduling

(2) Confirm feasibility of support for 128x40Gbps packet switch by FPGA

8 times higher performance than ASIC based router (16x40Gbps)

IP packet granularity (64byte or more; 10 Gpps), variable length

(3) Prototyping 8-port buffer management system

8-port buffer management hardware

P q

P41

P42

P43

P44

P45

P46

P47

P48

l1

l2

l3

l4

l5

l6

l7

l8

1

2

3

4

5

6

7

8

Parallel and pipeline buffer management (N=8)

P35

P36

P37

P38

P23

P24

P25

P26

P27

P28

P12

P13

P14

P15

P16

P17

P18

cf) H. Harai and M. Murata, IEEE/ACMTransactions on Networking, Feb. 2006.


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Performance ComparisonPerformance Comparison

16000/port

2 Gpps **

125 Mpps/port**

40 Gbps

16

Electronic

Router

10 Gpps4 MppsScheduling

31/port2/portBuffer

10 Gpps (at40Gbps)

160 Gbps

2 *

NICTs Top Data

(As of Sep, 2006)2IN/OUT ports

160 GbpsBit rate

800 Mpps/portLabel processing

NICT OPS

Prototype

* Can scale with nanosecond optical switches** Estimated data: Assumption of wire rate processing of 40byte-packets


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ConclusionConclusion

We need high-throughput backbone network for ubiquitous society

OPS will provide extremely high-throughput

Switching bandwidth is not limited

Buffer size is increasing Electronic scheduling is fast

NICT has developed OPS but,

Need more advanced devices (e.g., ns-switch) and systems

Acknowledgment

N. Wada, H. Furukawa of Photonic Network Group in NICT forvaluable discussion, collaboration, and some slides in OPS

Thank you for your attentionThank you for your attention

ops: optical packet switches

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