ops: optical packet switches - 123seminarsonly.com€¦ · sep 8, 2006 h. harai (nict) 3 optical...

OPS: Optical Packet SwitchesOPS: Optical Packet Switches

Hiroaki Harai ([email protected])National Institute of

Information and Communications TechnologySep 8, 2006Optical Network Testbeds Workshop 3

Sep 8, 2006 H. Harai (NICT) 2

Why do we Need OPS?Why do we Need OPS?Internet Traffic in Japan: approx. 500 GbpsPeta-bps backbone future: doubled per year 500 Tbps in 10 yearsElectronic packet switch

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

Need fully meshed connections/ feasible?Need complex traffic engineeringImportant technology for bandwidth-assured applications

OPS networksProvide 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


Optical Packet SwitchingOptical Packet SwitchingData-path is all-optical (No O/E/O)

Switch, BufferIncrease data bandwidth

Label lookup (i.e. forwarding)Electronic parallel processing?Optical processing

Optical

Electrical

payloadpayload headerheader

SchedulingAvoid packet collision

Priority control

SchedulingAvoid packet collision

Priority control

ForwardingDetermine output port from the routing table

ForwardingDetermine output port from the routing table

SwitchingSwitch the packet

to the appropriate port

SwitchingSwitch the packet

to the appropriate portBuffering

Store the packetsin appropriate time

BufferingStore the packetsin appropriate time

Routing Make a routing table for forwarding procedure

Routing Make a routing table for forwarding procedure

payloadpayload headerheader

Nx1 BufferNx1 Buffer




1xN LabelSwitch

1xN LabelSwitch

1xN LabelSwitch

1xN LabelSwitch

1xN LabelSwitch

1xN LabelSwitch

1xN LabelSwitch

1xN LabelSwitch

payloadpayload payloadpayload

Electronicserial

Optical

payloadpayload payloadpayload


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 TbpsIncreasing speed of label lookup and buffer management

Wire-speed operationIncreasing 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 packetsSeveral nanoseconds

OPS Monitor/AnalyzerBit error / Optical packet error

Under developing in NICT


OPS PrototypeOptical label lookupOptical bufferElectronic buffer management

Remaining Topics of This TalkRemaining Topics of This Talk


NICTNICT’’ss 40Gbps40Gbps--based OPS Experimentbased OPS ExperimentN. Wada, H. Harai, F. Kubota, OFC 2003 (no. FS7).


Optical Optical CCode based ode based UUltra ltra FFast ast LLabel abel PProcessingrocessing

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)


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, IEEE Photonic Tech. Lett., vol. 11, pp. 1689—1691, Dec. 1999.

10ps/div.

10ps/div.Auto-correlation

Cross-correlation


Optical FiberOptical Fiber--DelayDelay--Line BufferLine Buffer

Different lengths of FDLs

Need at least tens of FDLsH. Furukawa, H. Harai, N. Wada, N. Takezawa, K. Nashimoto, T. Miyazaki, ”A 31-FDL BufferBased on Trees of 1x8 PLZT Optical Switches,” to be presented at ECOC 2006, no. Tu4.6.5, Sep 2006. Discard

0T2T3T4T

(B-1)T

BufferManager

Nx(B+1)switch

11

2233

Control signal

Optical packets

44

55

55

44

11

3322

2211

3344

55

Switch 1 out

Switch 2 out Time (2µs/div)

Inte

nsity

(a.u

.)In

tens

ity (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

Output Output portport

LN-SW

LN-SWLN-SW

LN-SW

LN-SW

LN-SW

Single Switch

Double Switches

Time (2µs/div)

1

1 1 1

SchedulerScheduler

Noise

Optical FDL Buffering at 160GbpsOptical FDL Buffering at 160Gbps

Source: N. Wada (NICT)


HighHigh--Performance Buffer Management Performance 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/ACM Transactions on Networking, Feb. 2006.


Performance ComparisonPerformance Comparison

16000/port

2 Gpps **

125 Mpps/port **

40 Gbps16

Electronic Router

10 Gpps4 MppsScheduling

31/port2/portBuffer

10 Gpps (at 40Gbps)

160 Gbps2 *

NICT’s Top Data(As of Sep, 2006)

2IN/OUT ports160 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


ConclusionConclusionWe need high-throughput backbone network for ubiquitous societyOPS will provide extremely high-throughput

Switching bandwidth is not limitedBuffer size is increasingElectronic scheduling is fast

NICT has developed OPS but,Need more advanced devices (e.g., ns-switch) and systems

AcknowledgmentN. Wada, H. Furukawa of Photonic Network Group in NICT for valuable discussion, collaboration, and some slides in OPS

Thank you for your attentionThank you for your attention

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