Download Optical Label Switch Router

The Transparent Optical
Network
An Optical Illusion?
Richard S. Wolff
Telcordia Technologies
[email protected]
973-829-4537
An SAIC Company
Key Contributors
Telcordia:
-Paul Toliver
-Matt Goodman
-Janet Jackel
-George Clapp
-Stu Wagner
-Ron Skoog
-Haim Kobrinski
-Robert Runser
-Ann Von Lehmen
-Joel Gannett
-Brian Meagher
Collaborators
-GK Chang, Georgia Tech
-Ben Yoo, UC Davis
-Dan Blumenthal, UC Santa Barbara
RSW - 2
Outline of Talk
 Some background on optical networking
 Optical packet switching
 Multi-layer optical network architectures
 Where do we go from here?
RSW - 3
Growth of the Internet
Number of hosts, in millions
75% growth in the number of hosts over the last 12 months
Source: www.netsizer.com
RSW - 4
Evolution of Optical Networking
Optical Provisioning, Reconfiguration, and Switching Strategies
Network Efficiency
True Convergence of
IP and Optical Layer
Static
Highly Dynamic
Optical Label
Switching
Dynamic
Reconfigurable
Optical Networks
Addresses carrier needs*:
Reconfigurable
• Bandwidth utilization
Optical Networks
• Provisioning time
Point-to-Point
Optical Transport
Past
• Scalability
Inflexible reconfigurability
High Management Complexity
Present
Future
*RHK Carrier Survey
RSW - 5
IP and Optical Routing
IP over Re-configurable WDM Packet Routing Strategies:
(a) IP/Client Layer, (b) MPlS/Integrated Layer, and (c) OLS/Transport
Layer
IP
IP
IP
IP
IP
IP
(a)
WDM
WDM
WDM
WDM
WDM
IP
IP
IP
IP
IP
IP
(b)
WDM
WDM
WDM
WDM
WDM
IP
IP
(c)
WDM
IP
IP
WDM
WDM
WDM
IP
IP
IP
WDM
RSW - 6
Key Enabling OLS Technology
 Packet payload and in-band OLS label are decoupled through the
use of subcarrier multiplexing technology
 The simplified packet processing hardware results in significant cost
savings for core network interfaces
High Bit Rate
Optical Packet
Low Bit Rate
Subcarrier Label
Label and Packet
Forwarded
Fiber
NRZ Packet
Payload Subcarrier
Optical Label
Optical Header
Extraction Unit
Label Extracted
for Processing
Only low cost
electronics
required to
process the label
in parallel
Frequency
to Forwarding
Engine
RSW - 7
Optical-Label Switch Node Design
Fiber Delay
Line
Header
Sub-carrier
Processor
Receiver
Forward Engine
Switch
Control
Logic
Sub-carrier
Receiver
Header
Processor
Forward Engine
LiNbO3
Optical Switch
RSW - 8
Optical Label Switch RouterNC&M
Schematics
Interoperable
with existing
network elements
G
bE
S
PO
O
C
-X
Beta Client Specified Interface
N l’s Optical Header
Extraction
per fiber
Outgoing
Optical
Traffic
OLS
Switch Fabric
N labels
Switch Drivers
Forwarding engine
l
ro
t
on e
C lan
p
NC&M
Incoming
Optical
Traffic
Routing protocols
RSW - 9
Optical Label Switch Router–Physical
Layout
OLS system processor
GbE NIC
Optical header generator
OLS transmitter
OLS receiver
Edge
node
Running OLS Server....
128.96.80.230
Craft
interface
O LS S witch C ontrolPlane
M
Workstation
2
3
1
K
Video
4
Optical header receivers
O LS Receiverarray
Core
node
1
2
3
Optical switch fabric &
packet forwarding engine
4
TranportInterface
1
CH. 2
CH. 1
2
3
4
CH. 3
CH. 4
FiberAmplifiers
1
2
3
4
Client/transport interface
Optical amplification,
wavelength conversion
RSW - 10
Optical Switch Fabric and Forwarding
Engine
LiNbO3
switch array
LiNbO3
switch driver
Packet
Forwarding
engine
Network
control
processor
Optical switch
ribbon output
Optical switch
ribbon input
RSW - 11
Switch Fabric Testing: Optical Rise & Fall
Time
Optical rise & fall time: ~3 ns
Dead time:
~6 ns
Total packet guard time: <10 ns
Optical output (A.U.)
1.0
0.8
0.6
0.4
0.2
0.0
0
2
4
6
8
10
12
14
16
18
20
Time (ns)
RSW - 12
Optical Label Switching NGI Testbed
Laboratory
Host 1
1
4
Tx Rx
NC&M Interface
Host 4
Tx Rx
Switch node
Host 3
Host 2
2
Tx Rx
Terminal
3
NC&M
Edge
Routers
Tx Rx
RSW - 13
Areas for Research: Label Swapping
and Wavelength Conversion
 Wide tunable semiconductor lasers
– Tuning range: 40nm
– Frequency accuracy: <10GHz
– Accessing speed: < 10ns
 Wavelength converter
– Any wavelength to a fixed wavelength
– Any wavelength to any wavelength
– Efficient fiber couple with expanded beam technologies
 Subcarrier Label Swapping
– Optical notch filter in combination with single side band SCM
tramsimitter (Improved tracking mechanism) by NCTU
– Semiconductor optical amplifier (SOA) based optical label
eraser as a low-pass filter by UCSB
RSW - 14
Area for Research: Optical Switch
Fabric Technologies
 LiNbO3 Waveguide Switch (Lucent, EOspace, Lynx)
–
–
–
–
PDL, < 1dB
High crosstalk rejection, >35 dB
Fast switching, 5 ns
Medium dimension, 16 x 16
 SOA Optical Switch (Alcatel, NEC, Kamelian)
–
–
–
–
Fast Switching, 1 ns
Provide optical dump
Optical multicast
Small dimension with PIC technology, 4 x 4
 3-D Optical MEMs (Lucent, Calient, Nortel)
– Low insertion loss
– Large dimension, 256 x 256
– Switching speed, currently 10 ms
RSW - 15
Areas for Research: Network Issues
 Critical Issue : Absence of Optical Buffer
Memory
 Lack of Precision Optical Synchronization
 Contention of packets at the switching nodes
 Possible Solutions :
–
–
–
–
Wavelength Conversion
Deflection Routing
Wavelength Flooding
Deflection Flooding
RSW - 16
Optical-Label Switching for Packet Routing
Signal
Source
Optical-label
switching
IP/WDM Node
Signal
Destination
• Priority
• Wavelength interchange
• Alternate path
RSW - 17
Simulation of OLS Packet Dropping
OLS Drop Rates for Various Wavelength Counts
1.00E-010.05
0.15
0.25
0.35
0.45 0.55
0.65
0.75
0.85
0.95
drop rate
1.00E-03
8:OLS
16:OLS
32:OLS
64:OLS
128:OLS
1.00E-05
1.00E-07
1.00E-09
1.00E-11
1.00E-13
utilization
RSW - 18
The Multi-layer Transparent Optical
Network
Objective:
To provide a scalable multi-granular photonic layer
infrastructure with the ability to provide intelligent dynamic
access into optical bandwidth from packet to pipe.
the optical layer IS the convergence layer…





Multi-granularity
Multi-protocol capable
Multi-format/bit-rate support
Multi-domain support: wireless & wireline
Multi-vendor, multi-technology interoperability
designed in
RSW - 19
Vision of a Multi-layer Optical
Network
Optical
packet/burst
granularity
Wavelength
granularity
Waveband
granularity
Fiber
granularity
RSW - 20
Multi-layer Optical Network Requirements
Optical
granularity
level
Typical
bandwidth
requirements
Typical switch
reconfiguration time
requirements
Optical packet
10 Mb/s-10Gb/s
10 ns-10 ms
Optical burst
1Gb/s-10Gb/s
1 ms-100 ms
Wavelength
2.5 Gb/s-40Gb/s
10 ms-500 ms
Waveband
10 Gb/s-640Gb/s
100 ms-10 s
Fiber
80Gb/s-6.4Tb/s
1 s-100 s
RSW - 21
Edge-to-Edge Flows:
Transparency selected to meet application
requirements
IP
OPS

band
Fiber
IP
OPS

band
Fiber
IP
OPS

band
Fiber
IP
OPS

band
Fiber
IP
OPS

band
Fiber
IP
OPS

band
Fiber
IP
OPS

band
Fiber
IP
OPS

band
Fiber
IP
OPS

band
Fiber
IP
OPS

band
Fiber
…
…
…
…
• = wavelength
RSW - 22
ATDNet: An Experimental Transparent
Optical Network
LTS
DARPA
NASA
West
Ring
East
Ring
DISA
MEMS OXC
LiNbO3 WSXC
DIA
LiNbO3 OADM
NRL
OEO OADM
EDFA
WDM fiber
Client l
RSW - 23
Optical WDM Wavebanding Approaches
Contiguous
wavebands
l
Interleaved
wavebands
l
l
Arbitrary
reconfigurable
wavebands
RSW - 24
Experimental Demonstration of
Wavebanding
ATDNet West Ring
25 GHz
Add
200 GHz
passband
Drop
Waveband
RSW - 25
Optical Burst Transmission Exeriment
Amplitude (mW)
ATDNet, LTS-NRL-LTS
15% Duty Cycle
170 msec period
26 msec burst
50
60
70
Amplitude (mW)
40
80
90
100
70% Duty Cycle
170 msec period
120 msec burst
40
50
60
70
80
90
100
Time (msec)
RSW - 26
Monitoring in Transparent Networks
OE boundaries within service provider administrative domains
may completely disappear
Routers &
Switches
Optical
Performance MonitoringADMs
(OPM)
ADMs &
&
DCS
DCS
required
OADMs
& PXCs
O/E/O
EDFA
Path
Customer
Line
Specified
Service
Regenerator Regenerator
OADMs
& PXCs
O/E/O
EDFA
Line
Path
Line
Section
Section
Section
Section
Section
Optical
Optical
Optical
Optical
Optical
CPE
Administrative Boundary
Routers &
Switches
Customer
Line
Specified
Service
Section
Optical
CPE
RSW - 27
What is Needed - Areas for Research
 Architecture
– Dynamic network reconfiguration in response to changing
traffic demands
 Enabling Technologies
– Multi-granular, high performance, scalable optical switch
fabrics
– Wavelength agility and conversion
– Optical packet switching technologies from switches to
receivers
 Network Management
– Unified management of multi-granularity transport and
switching
– Policy management of configurations, services, security
– Favorable compromise combining peer-to-peer and
centralized management
– Automated traffic engineering and connection management
RSW - 28
The Transparent Optical Network
Will packets and fiber optics converge?
?
Fiber Optics
Packet Networks
RSW - 29