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Opportunities and Challenges for Optical Burst- and Packet- switching-. S. J. Ben Yoo, Fei Xue, et al. Optical Switching and Communications Systems Lab University of California, Davis yoo@ece.ucdavis.edu. Progress in Optical Networks. Optical Packet Switching. Optical Burst Switching. - PowerPoint PPT Presentation
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OpportunitiesOpportunities and and ChallengesChallenges for for Optical Burst- andOptical Burst- and Packet- Packet- switching-switching-
OpportunitiesOpportunities and and ChallengesChallenges for for Optical Burst- andOptical Burst- and Packet- Packet- switching-switching-
S. J. Ben Yoo, Fei Xue, et al.Optical Switching and Communications Systems Lab
University of California, Davisyoo@ece.ucdavis.edu
2
Progress in Optical NetworksProgress in Optical Networks
Capacity
Function
Ring Mesh
Dynamic
Static
Optical Packet
Pt-to-PtSingle Channel
WDM
Optically Amplified
Optical Add/Drop
Topology
Optical Circuit Switching
Optical Burst Switching
Optical Packet Switching
Optical
Lab
el S
witchin
g
3
Optical Burst Switching Optical Burst Switching
4
Diff Serve OBS Performance
5
Throughput comparison OBS vs. OCS
Under the same network conditions, OBS networks can achieve 20%~30% more throughput than those in OCS networks.
6
Motivations for Optical Packet SwitchingMotivations for Optical Packet Switching
• Data-centric + High-Bandwidth Packet + Optical• Sub-wavelength granularity• Cost-effective service delivery and flexibility• Avoid electrical RAM and O/E/O bottleneck
– DRAM getting faster only by 7%/year– O/E/O conversion consumes power and space
• Scalability for future bandwidth growths• Use optical parallelism for simpler switching fabric• From ATM/SONET to IP/WDM paradigm
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Next Generation Network Overview
Wireline O-CDMA LAN
LegacyMAN
Free Space and Wireline O-CDMA LAN
Optical Core Network
Edgerouter
EdgerouterOLS
routers
OLSswitches
Star Coupler
MAN
Star Coupler
MANEdge router
LegacyLAN
OLSswitches
SENSORNetworks
8
fiberdelay
DE
MU
X
NC&M
SwitchingFabric
Label Processing Module-TI(LP-TI)
Lab
el P
roce
ssin
g
Mo
du
les-
CI
(LP
-CI)
CI CICI
OLE OLR OLEOLR OLE OLR
IP Router ATM Client Machine
UNAS
labelreader Switch Controller
w/ ForwardingLook-up Table
OL
S
Ed
ge
Ro
ute
r
9
BufferMemoryM
AC
controller
• Buffer, Schedule, and Forward• Electronic RAM--Diverse Functions • Contention Resolution, Queuing, etc in Time
BufferMemoryM
AC
BufferMemoryM
AC
BufferMemoryM
AC
BufferMemory
BufferMemoryBuffer
Memory MA
C
BufferMemory
BufferMemoryBuffer
Memory MA
C
BufferMemory
BufferMemoryBuffer
Memory MA
C
BufferMemory
BufferMemoryBuffer
Memory MA
C
Conventional Electronic Packet SwitchesConventional Electronic Packet Switches
SPACE
TIME
10
Optical Switch Fabric used in UCDavis OLS core RoutersOptical Switch Fabric used in UCDavis OLS core Routers
Rapid Tuning (~ 1 nsec) of T_WC to achieve switching in
Wavelength, Time, Space domainsScalable to 42 Petabit/sec capacity32*(2562x2562) connectivity
T_WC
T_WC
T_WC
T_WC
F_WC
F_WC
F_WC
F_WC
switch control
Tunable Wavelength Converters
-router(AWGR)
controller
TIME
WAVELENGTH
SPACE
Fixed Wavelength Converters
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Contention Resolution AlgorithmContention Resolution Algorithm
packet arrives
contention ?
cont. res.?
time cont. res.?
space cont. res.?
Send to Edge Router for cont. res. or drop
yes
no
no
no
forward
no
yes
yes
yes
•S. Yao, S. J. B. Yoo, and B. Mukherjee, “A comparison study between slotted and unslotted all-optical packet-switched network with priority-based routing,” OFC 2001, #TuK2
•S. Yao, S. J. B. Yoo, B. Mukherjee, S. Dixit, “Hybrid contention resolution for an optical packet-switched network with self-similar IP traffic,” APOC 2001 #4585-04.
• S. Yao, B. Mukherjee, S. J. Ben Yoo, and S. Dixit, “All-optical Packet-switching for Metropolitan Area Networks: Opportunities and Challanges,” IEEE Comm. Magazine, vol.39, p.142-8 (2001)
•S. J. B. Yoo, Y. Bansal, Z. Pan, J. Cao, V. K. Tsui, S. K. H. Fong, Y. Zhang, J. Taylor, H. J. Lee, M. Jeon, V. Akella, K. Okamoto, S. Kamei, “Optical-Label Switching based Packet Routing System with Contention Resolution Capabilities in Wavelength, Time, and Space Domains,” OFC 2002, paper #WO2 (2002).
12
OLS Core and Edge Routers
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Optical Packet Assembly Mechanism
• Assemble a larger optical packet from IP packets based on destination and QoS
• The creation of an optical packet:– Reach the Maximum Payload Size (MPS)– Expiration of Assembly Time-out Period (T)
MPS
14
Optical Packet Assembly Mechanism
MPS
• Assemble a larger optical packet from IP packets based on destination and QoS
• The creation of an optical packet:– Reach the Maximum Payload Size (MPS)– Expiration of Assembly Time-out Period (T)
15
Optical Packet Assembly Mechanism
MPS
• Assemble a larger optical packet from IP packets based on destination and QoS
• The creation of an optical packet:– Reach the Maximum Payload Size (MPS)– Expiration of Assembly Time-out Period (T)
16
Optical Packet Assembly Mechanism
MPS
• Assemble a larger optical packet from IP packets based on destination and QoS
• The creation of an optical packet:– Reach the Maximum Payload Size (MPS)– Expiration of Assembly Time-out Period (T)
17
Optical Packet Assembly Mechanism
MPS
• Assemble a larger optical packet from IP packets based on destination and QoS
• The creation of an optical packet:– Reach the Maximum Payload Size (MPS)– Expiration of Assembly Time-out Period (T)
18
Optical Packet Assembly Mechanism
MPS
• Assemble a larger optical packet from IP packets based on destination and QoS
• The creation of an optical packet:– Reach the Maximum Payload Size (MPS)– Expiration of Assembly Time-out Period (T)
19
Traffic Shaping at the Edge RoutersPacket length distribution at the Client and at the Core
client transport
20
Packet-loss rates for networks with various number of
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IP Client-to-IP Client with Cascaded Operation of OLSRsIP Client-to-IP Client with Cascaded Operation of OLSRs
IP Client Network
Optical Label Switching Network
Core Router
Edge RouterPOS
Payload
Label
PO
S
IP Client Network
Edge Router
Core Router
Core Router
Payl
oad
Labe
l
Payload
Label
Physical Layer Interface
Encapsulation
Label processing Unit
Data bus traffic controller
Data Bus
SONET
PPP
Physical Layer Interface
Data bus traffic controller
AO
LS
Interface
PO
S In
terface
Ingress Path
Egress Path
Edge Router
L1P1
L3P3
L1, L2P1, P2
L2P2
P1,P2, P3
P1, P2, P3L1, L2, L3
P1
22
Possible Network Evolution ScenarioPossible Network Evolution Scenario
Electronic ATM Network
Electronic IP Network
LAN
Electronic IP Network
LAN
23
Electronic MPLS
Network
Electronic IP Network
LAN
Electronic IP Network
LAN
Possible Network Evolution ScenarioPossible Network Evolution Scenario
24
Electronic MPLS Network
Electronic MPLS Network
MPLambdaS Network
LAN LAN
Possible Network Evolution ScenarioPossible Network Evolution Scenario
25
Electronic MPLS Network
Electronic MPLS Network
Optical Label Switched Network
LAN LAN
Possible Network Evolution ScenarioPossible Network Evolution Scenario
26
Optical Label Switched Network
Electronic MPLS Network
LAN
Electronic MPLS Network
LAN
MPS Network
Electronic MPLS Network
Electronic MPLS Network
LAN
Possible Network Evolution ScenarioPossible Network Evolution Scenario
GMPLS II
27
• Optics provides capacity, packet switching provides flexibility and fine granularity• Optical Label Switching Provides interoperability in Packet, Burst, and Circuit switching • Unified contention resolution in wavelength, time, and space domain.• Edge router function critical in performance enhancement and traffic shaping• Seamless network evolution from today’s circuit-switching to tomorrow’s burst- and packet- switching
SummarySummary
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