Transcript THE BIG PICTURE

Optical Networking
CS 294-3
2/5/2002
John Strand
AT&T Optical Networks Research Dept.
[email protected]
U. of California - Berkeley - EECS Dept.
[email protected]
The Views Expressed In This Talk Are The Author’s. They Do Not Necessarily Represent
The Views Of AT&T Or Any Other Corporation Or Individual.
John Strand
1/18/2002
1
Outline
• Transport - Traditional TDM Networks
• Optical Networking
• Optical Networking & IP
Concentrate On Intercity Networks
• Time Constraint
• Metro, Access Optical Networks More Complex, Less Mature
John Strand
1/18/2002
2
Layering
Possible Service
Architecture Layers
IP
Layers
"Service"
Prototype Apps
Context
Awareness
Services
Adaptation
Services
Wide-Area
Services
PM &
Monitoring
Transport
Layers
Application
DS1
DS3
Tranport
Network
Link
Physical
SONET- Path
Line
Section
Wavelength
Fiber
Cable
Conduit
ROW
John Strand
1/18/2002
3
Basic DS-1 Signal Format
193 Bits
F
Bit
Time
Slot
1
Time
Slot
2
1 bit
8 bits
8 bits
Time
Slot
3
8 bits
o o o o o o o o o o o
Time
Slot
23
8 bits
Time
Slot
24
8 bits
• Designed To Carry 24 Full Duplex 64 Kilobit/sec Voice Circuits (“DS-0’s”)
• Transmission Rate = 1.55 Megabits/Second (8000 frames/sec * 193 bits/frame)
• DS-1 Is A Protocol; T-1 Is A Specific AT&T Implementation Of This Protocol
For Local Networks
• This Is The Traditional Building Block For Transmission Networks In U.S.
John Strand
1/18/2002
4
What is SONET?
•
Synchronous Optical Network standard
SONET Interface
SONET
Network
Element
Digital
Tributaries
•
•
•
•
•
SONET
Network
Element
Digital
Tributaries
Defines a digital hierarchy of synchronous signals
Maps asynchronous signals (DS1, DS3) to synchronous format
Defines electrical and optical connections between equipment
Allows for interconnection of different vendors’ equipment
Provides overhead channels for interoffice Operations,
Administration, Maintenance, & Provisioning (OAM&P)
John Strand
1/18/2002
5
SONET Structure
PRS: Primary Source
ST2: Stratum 2
ST3: Stratum 3
Network Of
Synchronized
Clocks
Must Be
Synchronized
Byte-Interleaved Multiplexing
John Strand
1/18/2002
6
Digital Signal Hierarchies
Most Common Rates
DS-1
DS-3
(1.544 Mb/s)
(45 Mb/s)
1
28
Asynchronous
("Plesiochronous")
[Non-Standardized]
84
336
1344
5376
Capacity
(DS-1 Equiv)
VT1.5
STS-1
STS-3
STS-12
STS-48
STS-192
(1.7 Mb/s)
(52 Mb/s)
(156 Mb/s)
(622 Mb/s)
(2500 Mb/s)
(10000 Mb/s)
SONET
STM-1
STM-4
STM-16
STM-64
SDH
VC-11
VC-3
DS:
Digital Signal
SONET: Synchronous Optical NETwork (US)
SDH:
Synchronous Digital Hierarchy (ITU)
STS:
Synchronous Transport Signal
STM: Synchronous Transfer Mode
VC:
Virtual Container
VT:
Virtual Tributary
John Strand
1/18/2002
7
SONET Rates
Level
Optical
Designation
Bit Rate
(Mb/s)
STS-1
OC-1
51.840
STS-3
OC-3
155.520
STS-12
OC-12
622.080
STS-48
OC-48
2,488.320
STS-192
OC-192
9,953.280
STS-768
OC-768
39,813.120
STS
OC
= SYNCHRONOUS TRANSPORT SIGNAL
= OPTICAL CARRIER
(“..result of a direct optical converions of the STS after
synchronous scrambling” - ANSI)
EC (Not Shown) = ELECTRICAL CARRIER
John Strand
1/18/2002
8
SONET STS-1 Frame Structure
3
Bytes
87
Bytes
t
87 Columns
Ptr
t
T
O
H
3
Bytes
P
O
H
Synchronous
Payload
Envelope
(SPE)
9
Rows
P
O
H
F
I
x
e
d
S
t
u
f
f
SPE
F
I
x
e
d
S
t
u
f
f
87
Bytes
John Strand
1/18/2002
9
STS-N And STS-Nc
(N = 3, 12, 48, 192)
• STS-N
• Formed By Byte-Interleaving N STS-1 Signals
• 3N Columns of Transport Overhead
• Frame Aligned
• Redundant Fields Not Used - eg APS, Datacomm
• N Distinct Payloads (87N Bytes)
• NOT Frame Aligned
• N Columns Of Path Overhead - All Used
• 2N Columns Of Fixed Stuff Bytes
• 84N Columns Of Information
• STS-Nc
• 3N Columns of Transport Overhead
• Frame Aligned
• Redundant Fields Not Used - eg APS, Datacomm
• Single Payload
• 1 Column Of Path Overhead
• 3N - 1 Columns Of Fixed Stuff Bytes
• 87N - N/3 Columns Of Information
John Strand
1/18/2002
10
SONET/SDH Layering
Multiplexer
Or Other
PTE
CrossConnect
Regenerator
(derived clock)
CrossConnect
Multiplexer
Or Other
PTE
SONET
Path
SDH
Virtual Container (VC)
Line
Multiplex Section (MS)
Section
Regenerator Section
(RS)
Key Feature: Basis Of
• Fault Management & Restoration
• Maintenance
John Strand
1/18/2002
11
Service Survivability Objectives
Typical Commercial Networks
Restoration Time
Objectives (secs)
1000
100
10
1
0.1
0.01
Standard Leased Frame
Voice
Lines
Relay
IP
Services
New trends in IP services: supporting real-time application, e.g. voice and
video, & mission critical data
=> Require much faster restoration than traditional IP rerouting
John Strand
1/18/2002
12
Network Outage Analysis
Voice Services
Equipment
Failure
Route Failure
• Backhoe, Flood, Train
Wreck
• ~1/1000 km/year
John Strand
1/18/2002
13
Survivability 101
C
D
X
A
B
Y
Protection: Pre-Allocated
Survivability Requires:
Restoration: Dynamically Allocated
• Fault Detection
• Spare Inter-Office Capacity
• Switch Fabrics To Put Failed Facility On This Capacity
• Control Logic To Identify Fault & Reroute Failed Circuits
John Strand
1/18/2002
14
Effect Of Restoration Topology
Restoration Overbuild
(Protection Capacity/Service Capacity)
"Ring" Degree 2
Nodes
100%
50%
Degree 3
Nodes
"Mesh"
Degree N
Nodes
1/(N-1)
Degree = # Of Physically Diverse Routes
John Strand
1/18/2002
15
Ring Example
SONET: Bi-Directional Line-Switched Ring (BLSR)
SDH: Multiplex Section Shared Protection Ring (MS-SPRING)
S
S: Service
P: Protection
B
S
C
P
P
S
P
Different
Fibers But
Same Cable
A
D
P
P
S
S
P
F
E
Original Circuit
S
Protection Switch
John Strand
1/18/2002
16
Ring Example
SONET: Bi-Directional Line-Switched Ring (BLSR)
SDH: Multiplex Section Shared Protection Ring (MS-SPRING)
S
S: Service
P: Protection
B
S
C
P
P
S
P
Different
Fibers But
Same Cable
A
Standardization:
• Physical Layer &
Signaling Standardized
• Client State Information
Not Standardized
• OAM Not Standardized
D
P
P
S
S
P
F
X
S
E
Original Circuit
Protection Switch
John Strand
1/18/2002
17
Public Switched Telephone Network
(PSTN)
Central
Office
Toll Network
Central
Office
CO
CO
Customer
Premises
Equipment
(CPE)
Toll Connect Trunks
Inter-Toll Trunks
64 Kb/sec FDX Circuits
Switches: Terminate Trunks
Switch Individual Calls
John Strand
1/18/2002
18
Basic Service Types
Central
Office
CPE
PSTN
"POTS"
PBX
Switch
• ~ 100 Intercity
Switches*
Transport Network
Private Line (PL)
• Shared By Many
Services
• ~10x As Many Offices*
POTS: Plain Old Telephone Service
* ATT Network
John Strand
1/18/2002
19
Entering The Transport Network
64 kb/s
POTS
&
VG PL
1
O
O
O
O
24
O
O
1.5 Mb/s
D
S
1
45 - 622
Mb/s
1
o
D
S
3
o
o
o
1.5 Mb/s PL
45 - 2500 Mb/s PL
1Gb Ethernet
2.5 - 10
Gb/s
28
O
C
192
W
D
M
Backbone
Fiber
Network
1 - 10 Gb/s PL,
10 Gb WAN Ethernet *
10 Gb WAN Ethernet
• SONET Framed - 9.953 Gb/s
• Asynchronous
POTS: "Plain Old Telephone Service"
VG:
Voice Grade
PL:
Private Line
John Strand
1/18/2002
20
Service Routing
Service Layer
(e.g., POTS or PL)
Transport Layer
John Strand
1/18/2002
21
Outline
• Transport - Traditional TDM Networks
• Optical Networks
• Optical Networking & IP
John Strand
1/18/2002
22
Fiber Structure
Pure Glass Core
Lightpack Cable Design
8.3 micron*
Glass Cladding
Protects “core”
Serves as a “Light guide”
125 micron
Inner Polymer Coating
Outer Polymer Coating
Protection Layers
250 micron
Single Fiber
Typical Loss: 0.2 – 0.25 dB/km
Plus Connector Loss
* Single Mode Fiber; Multi-Mode Has A 50 Micron Core
John Strand
1/18/2002
23
Intercity Fiber Network
About 50,00 Route Miles Of Fiber Cable
John Strand
1/18/2002
24
Optical Amplifier/WDM Revolution
Frequency-registered
transmitters
Receivers
l1
R
All-Optical Amplification
Of Multi-Wavelength Signal!!!
l2
l3
R
WDM
Mux
OA
OA
WDM
DeMux
R
40 - 120 km
(80 km typically)
lN
Up to 10,000 km
(600 km in 2001 basic commercial products)
WDM: Wavelength Division Multiplex
OA: Optical Amplifier
R
John Strand
1/18/2002
25
John Strand
1/18/2002
A. Willner
26
Optical Amplifier/WDM Revolution
Conventional Transmission - 20 Gb/s
40km
40km
40km
40km
40km
40km
40km
40km
40km
1310
1310
1310
1310
1310
1310
1310
1310
LTE
LTE
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
LTE
LTE
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
LTE
LTE
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
LTE
DS3
LTE
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
LTE
LTE
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
LTE
LTE
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
LTE
LTE
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
LTE
DS3
LTE
RPTR
RPTR
RPTR
RPTR
RPTR
RPTR
RPTR
RPTR
1310
1310
1310
1310
1310
1310
1310
1310
LTE
LTE
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
LTE
LTE
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
RPTR
1310
LTE
LTE
RPTR
RPTR
RPTR
RPTR
RPTR
RPTR
RPTR
RPTR
1310
1310
1310
1310
1310
1310
1310
1310
LTE
LTE
RPTR
RPTR
RPTR
RPTR
RPTR
RPTR
RPTR
RPTR
OC-48
OC-48
OC-48
OC-48
OC-48
OC-48
DS3
OC-48
OC3/12
OC-48
DS3
120 km
120 km
OA
12 fibers
120 km
OA
1 fiber; 36 regenerators 1 optical amplifier
In Each Direction:
• 12IsFibers
Economic Advantage
Distance Dependent
• Intercity: Compelling
• 36 Regenerators
• Metro:
WDM: Wavelength Division Multiplex
OA: Optical Amplifier
OC-48
OC-48
DS3
OC-48
OC3/12
OC-48
OC-48
OC-48
OC-48
OC-48
Depends On Dark Fiber Availability
John Strand
1/18/2002
27
Single Fiber Capacity
Gb/s
5120
1280
Moore's
Law
320
80
20
1996
1998
2000
2002
2004
Bandwidth
Capacity = (Bandwidth/ l) * (Bits / l)
Source: K. Coffman & A. Odlyzko, “Internet Growth: Is There A Moore’s Law For Data Traffic?” (research.att.com/~amo)
John Strand
1/18/2002
28
Single Fiber Capacity
Bandwidth
S++
S+
S
C
L
Fiber loss
1300
1400
1525 1565 1600
John Strand
1/18/2002
29
Single Fiber Capacity
Bandwidth/l - C Band
4 THz
(THz)
199.0
196.0
195.0
194.0
193.0
192.0
l (nm)
1505
1510
~ 125 GHz/nm
50 GHz Spacing
(For OC48)
1530
1535
1540
1545
1550
1555
1560
1565
C-Band
(80 l) x (2.5 GHz/l) = 200 GHz
x2
100 GHz Spacing
(For OC192)
(40 l) x (10 GHz/l) = 400 GHz
John Strand
1/18/2002
30
Transport Layer Model
“Packet”
1/0 DCS
“Packet”
“Packet”
“Packet”
4E
1/0 DCS
1/0 DCS
4E
LA
1/0 DCS
4E
4E
CHCG
Service
Layers
DS1
(1.5 Mb/s)
ATM/IP
ATM/IP
ATM/IP
ATM/IP
Core ATM/IP
Layers
DACS III
LA
3/1 DCS
DACS III
DS3
(45 Mb/s)
LA
PHNX
ADM
ADM
HardWired
LA
OTS
OTS
OTS
OTS
OTS
PHNX
CHCG
Wavelength Path
Crossconnect
OTS
(OTS: Optical Transport
CHCG
System)
CHCG
PHNX
SONET ADM
Layer
ADM
Proprietary
(20-400 Gb/s)
LA
CHCG
3/3 DCS
Layer (DACS III)
ADM
ADM
ADM
OC48+
(2.5+ Gb/s)
ADM
3/1 DCS
3/1 DCS
Layer
CHCG
DACS III
DACS III
3/1 DCS
LA 3/1 DCS
DS3
(45 Mb/s)
Fiber Conduit/
Sheath
Wavelength Mux Section
Crossconnect
Media
Layer
John Strand
1/18/2002
31
Optical Cross-Connect (OXC)
Alternatives
Line Rate
Line Rate
(Proprietary)
(Proprietary)
OC48
OC192
OC48
OC192
D
W
D
M
Wavelength
Multiplex
Section
(WMS)
CrossConnect
ADM’s
D
W
D
M
Wavelength
Path
CrossConnect
SDCS
Other
Service
Equipment
D
W
D
M
• More Bits Per Port
• Multivendor & Restoration Issues
WIXC
Would Go Here
• Fewer Bits Per Port
• Compatible With Opaque Architecture
• Better For Restoration
Could Have Either Optical Or Electrical Fabric
John Strand
1/18/2002
32
Office Architecture Impact
Optical Cross-Connect (Wavelength Path Cross-Connect)
Service Layers
Service Layers
OXC
• Adds An Additional Cost
• Operationally Essential In Larger Offices & Offices With High Churn
• Allows Software Controlled Provisioning
John Strand
1/18/2002
33
Opaque Wavelength Path Crossconnect
Optical transport system
(1.55 mm)
Standard
cross-office optics
(1.3 mm)
Optical transport system
(1.55 mm)
Add ports
...
= node-bypass
...
...
(Optical or
Electronic
Transparency
Interior)
Fibers
Out
...
...
...
Fibers
In
Wavelength Path
Crossconnect
...
...
...
...
l-Mux
Drop ports
John Strand
1/18/2002
34
Opaque Wavelength Path Crossconnect
(Electrical Fabric)
Power,
Cooling
Line
Modules
Optical
Modules
640 Gbps,
To 48 Tbps
Processor
Module
Timing
Module
Transparent
Switch Modules
(STS-1 Granularity)
Processor
Module
John Strand
1/18/2002
35
Fixed l Lasers in Optical Switches
Today’s
switches are
surrounded
with OEO –>
DWDM
Fixed
Wavelength
MUX
D
W
D
M
D
E
M
U
X
LR SR
Rx Tx
Rx
LR Tx
SR Rx
Tx
Rx
Tx
Rx
Tx
SR Rx
LR Tx
Rx
Tx
MUX
DWDM
Rx
Tx
70% of system
cost
SR LR
Rx Tx
Rx
Tx
Rx
Tx
Fixed
Wavelength
M
U
X
DWDM
Fixed wavelength
transponders are
required for each
input and output
fiber
John Strand
1/18/2002
36
An Early MEMS Device
Free-Space Micromachined Optical Switch (FS-MOS)
Switch Time < 1 ms
8x8 is 1 cm x 1 cm
Opportunities To Extend To
Significantly Larger Arrays
On A Single Substrate
Measured Switching Times
Under 1 ms (500ms)
3-D MEMS (2 degrees of
Freedom) seems to be the
Currently preferred architecture
Micro
lens
Si substrate
Free-rotating
switch-mirror array
Silicon
substrate
Input fibers
Switch reconfigured by actuating selected micromirrors
L. Y. Lin, E. L. Goldstein, and R. W. Tkach, “Free-space micromachined optical switches with
sub-millisecond switching time for large-scale optical crossconnects,” IEEE Photonics
Technology Letters, April 1998, pp. 525-528.
John Strand
1/18/2002
37
An 8 x 8 Switch
Chip size: 1 cm x 1 cm
Source: L-Y. Lin
John Strand
1/18/2002
38
Contained Domain of Transparency
TDRs
TDRs
TDRs
Optical Domain Circuit Switch
Issues:
•Transmission Engineering Concerns Especially For Non-Tree Topologies
• Fault Detection & Localization
• Without Wavelength Conversion Becomes Separate Single-l Networks
John Strand
1/18/2002
39
OTS System Length
ADM
o
o
o
ADM
D
W
D
M
Optical Transport System (OTS)
80 km
80 km
OA
80 km
OA
80 km
OA
80 km 80 km
80 km
OA
OA
OA
560 Km
D
W
D
M
ADM
o
o
o
ADM
“7 x 25 dB Spacing”
• Key Variables:
• Distance Between OA's
• Number of Spans
John Strand
1/18/2002
40
Domains Of Transparency
Transponder Costs In Traditional Systems
Transponder
Optical
Amplifier
Mux/Demux
Fiber (Installed)
l Utilization (%) 50
# Spans (80 km) 3
100
3
50
7
100
7
John Strand
1/18/2002
41
Domains Of Transparency
Ultra Long-Haul (ULH) Economics
ULH/Standard2
Cost Ratio
Transponder
OA/OADM
DWDM
~500 km
OTS Type
Standard
A
.
.
B
C
D
Utilization (%)
100
0
Ultra-Long
Haul (ULH)
1.75
1.5
Standard
Wins 1.25
1
~5000 km
Typical ULH Technology Enhancements:
• Strong Forward Error Correction
• Raman Amplification
• Dynamic Power Management
ULH
Wins
3
5
7
9
No. Of Standard OTS Systems (5 span) In Series
• More Expensive Terminals & OA’s
• Fewer Transponders
At Intermediate Locations
John Strand
1/18/2002
42
Contained Domain of Transparency
TDRs
TDRs
TDRs
Optical Domain Circuit Switch
Issues:
•Transmission Engineering Concerns Especially For Non-Tree Topologies
• Fault Detection & Localization
• Without Wavelength Conversion Becomes Separate Single-l Networks
• Single-Vendor For The Forseeable Future
John Strand
1/18/2002
43
Distance Before OEO Regen
Limiting Factors
Launch
Power
(PL)
Nonlinearities
PMD Constraint
~ (B * DPMD)-2
Operating Region
Other
System
Parameters
ASE Constraint
~ PL/SNRmin
In Large All-Optical Domains
• Each Vendor Trades Off The
Design Parameters Differently
• This Makes Routing In Multi-Vendor
Networks Difficult To Standardize
Length Of All-Optical Path
Refs: A. Chiu, J. Strand, R. Tkach, "Issues for Routing In The Optical Layer",
IEEE Communications (2001)
J. Strand (ed.), IETF I-D "Impairments And Other Constraints
On Optical Layer Routing", draft-ietf-ipo-impairments-01.txt
PL
Launch Power
SNRmin Min SNR
PMD Polarization Mode Dispersion
B
Bandwidth of l
DPMD PMD Parameter (fiber dependent)
ASE
Amplified Spontaneous
John Strand
Emission
1/18/2002
44
Outline
• Transport - Traditional TDM Networks
• Optical Networking
• Optical Networking & IP
Concentrate On Intercity Networks
• Time Constraint
• Metro, Access Optical Networks More Complex, Less Mature
John Strand
1/18/2002
45
IP Transport
Data Services
(Mostly IP-Based)
Voice & Other
TDM-Based Services
DS1 (1.5 Mb/Sec)
Wideband & Broadband
DCS Layers
Transport For IP Defining Functionality
Of These Interfaces
DS3 (45 Mb/Sec) STM-4 (622 Mb/Sec)
Digital Transmission
Layer
IP For Transport Introducing IP Functionality
Into The Optical Layer
STM-16c (2.5 Gb/Sec) STM-64c (10 Gb/Sec)
Optical Layer
Proprietary
(20 Gb/Sec - 400+ Gb/Sec)
Media Layer
John Strand
1/18/2002
46
IP Transport
Data Services
(Mostly IP-Based)
Voice & Other
TDM-Based Services
DS1 (1.5 Mb/Sec)
Wideband & Broadband
DCS Layers
Transport For IP Defining Functionality
Of These Interfaces
DS3 (45 Mb/Sec) STM-4 (622 Mb/Sec)
Digital Transmission
Layer
IP For Transport Introducing IP Functionality
Into The Optical Layer
STM-16c (2.5 Gb/Sec) STM-64c (10 Gb/Sec)
Optical Layer
Proprietary
(20 Gb/Sec - 400+ Gb/Sec)
Media Layer
John Strand
1/18/2002
47
IP For Transport
Replacing The OLXC With A Router
IP
Services
Non-IP
Services
OXC
OLXC
Office Architecture
Non-IP
Services
IP Router
“Big Fat Router”
Office Architecture
John Strand
1/18/2002
48
IP For Transport
Comparing The Architectures
IP Router
Terminating (1 – a)
Ports & Assumed Costs
OLXC
$x Per OC48
IP Router $y Per OC48
OLXC
IP Router
Through (a)
OLXC
Office Architecture
•
•
“Big Fat Router”
Office Architecture
OLXC Architecture Less Expensive If:
OLXC Cost x
<a
Router Cost y
Typical Values:
•
a = 0.8
•
x/y << 0.2
John Strand
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49
MPLS Transport Hierarchy
MPLS
IP
X s
Physical Transmission System
• SONET (STS-N)
• OCh
• Etc.
LSP
X
LSP s
LSP t
LSP u
LSP
Y
LSP a
LSP s
LSP t
• Label Switched Path's (LSP's) Are LOGICAL, NOT PHYSICAL
• Need Not Occupy Bandwidth
•Specific LSP’s Change At Each MPLS Node:
z End-to-end connection defined at set-up
John Strand
1/18/2002
50
MPLS Tunneling
POP 3
PUSH
7
42 11
7
LSP 7
88 11
SWAP 7=>11
PUSH 42
3
POP 88
SWAP 11=>3
SWAP 42 => 88
LSP 3
LSP 11
LSP 42
LSP 88
• "Virtual" Muxing - No Utilization Penalty
• This Is A Key Driver For Replacing TDM
John Strand
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51
TDM Multiplexing
Tunneling Using MPLS LSP's Is Analogous To TDM Multiplexing
DS1
DS3
STS-48
STS-48
DS3
DS3
John Strand
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From MPLS To GMPLS
Implicit Label
(1)
PUSH
7
42 11
7
LSP 7
Implicit Label
(2)
SWAP 7=>11
PUSH 42
POP 3
88 11
3
POP 88
SWAP 11=>3
SWAP 42 => 88
LSP 3
LSP 11
LSP 42(1)
STS-192
LSP 88(2)
STS-192
GMPLS: Generalized MPLS
John Strand
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53
GMPLS In An OXC Network
1. Select source, destination, and service
2. OSPF determines optimal route
3. RSVP-TE/CR-LDP establishes circuit
Label Request Message
Label Mapping Message
Vision:
• Provisioning Time: Weeks To Milliseconds
• Greatly Simplify Process
ISSUE: Standards Lagging Need - Proprietary Control Planes
Source: Sycamore OFC2000
Are Being Deployed Rapidly
John Strand
1/18/2002
54
GMPLS Vision
Many Technologies - One Network
LS: Lambda Switched
FS: Fiber Switched
PS: Packet Switched
FA: Forwarding Adjacency
John Strand
1/18/2002
55
GMPLS Overlay Network Model
~
~
~
~
Connection
Requests, etc.
~
~
Router
Optical
Network
~
~
Router
UNI
~
~
• Overlay Network
– Optical Network (OXC) computes the path
– Network Level Abstraction For IP Control Plane
John Strand
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56
GMPLS Peer Network Model
~
~
~
~
Topology &
Capacity Information
Router
~
~
Network
Signalling
Optical
Network
~
~
Router
~
~
• Peer Network
– Router computes the path
(Routers have enough information about the characteristics of the optical
devices/network)
– Link-level abstraction For IP Layer Control Plane
John Strand
1/18/2002
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Canarie OBGP
Current View of Optical Internets
Customers buy managed
service at the edge
ISP
AS 4
AS 1
Optical VLAN
AS 1
Customer
AS 3
BGP Peering is
done at the
edge
Big Carrier Optical Cloud using MPLS
and IGP for management of wavelengths
for provisioning, restoral and protection
AS 2
B. St. Arnaud
John Strand
1/18/2002
58
Canarie OBGP Vision
School
Aggregating Router
ISP Controlled
Optical Switch
ISP A
Dark Fiber
IGP
OiBGP
BGP
Multi Home Router
IGP
University
X
Dark Fiber
Mapped to
Dim
Wavelength
IGP
Customer Owned
Dark Fiber
B. St. Arnaud
Customer Controlled BGP neighbors
Optical Switch
ISP Controlled
Optical Switch
IGP
OBGP
OBGP
OBGP
University
Y
ISP B
John Strand
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60
Optical Interworking Forum
Services Concept
Customers buy managed
service at the edge
ISP
AS 4
AS 1
Optical VLAN
AS 1
Customer
AS 3
BGP Peering is
done at the
edge
• Bandwidth On Demand - Connection Request
Over UNI Specifying QoS Desired - Overlay Model
• OVPN - Dedicated Subnet Configured By
John Strand
AS 2 Customer - Peer Model
1/18/2002
61
Examples of network views
• View from domain A via a distance-vector or pathvector protocol
Domain 2
Reachable
Address list
Domain 1
Reachable
Address list
Domain 4
Reachable
Address list
Domain 3
Reachable
Address list
Domain 5
Reachable
Address list
John Strand
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62
Examples of Network views
• View from any domain of the rest of the network via a link state
protocol
Protection 1:N, N=3
Available BW = …
SRLG = …
Domain 1
Reachable
Address list
Protection 1+1
Available BW = …
SRLG = …
Protection 1+1
Available BW = …
SRLG = …
Protection 1+1
Available BW = …
SRLG = …
Domain 4
Reachable
Address list
Domain 3
Reachable
Address list
Protection 1:N, N=10
Available BW = …
SRLG = …
Domain 2
Reachable
Address list
Protection 1+1
Available BW = …
SRLG = …
Protection 1:N, N=7
Available BW = …
SRLG = …
Domain 5
Reachable
Address list
John Strand
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Initial OIF NNI Target
User control
Domain
User control
Domain
Load
Balancer
L2/L3
Load
Balancer
firewall
L2/L3
firewall
L2/L3
Load
L2/L3
firewall
Balancer
Load
Balancer
NNI
UNI
Control Domain
C
firewall
UNI
Control Domain
A
NNI
NNI
Control Domain
B
Single carrier’s network
User control
Domain
Load
Balancer
L2/L3
firewall
L2/L3
Load
Balancer
firewall
Why Single Carrier Multi-Domain First?
• Standards Lag Deployment - Vendor Proprietary Control Planes
• Rapid & Unpredictable Technological Change Makes It Unlikely
That Standards Will Keep Up
• Uncertain Business Model
Initial Multi-Carrier NNI Likely To Be LEC/IXC (JLS Opinion)
64
John Strand
1/18/2002
oif2001.639 - Application-Driven Assumptions And Requirements
Metro/Core Characteristics
1. Significant Differences In Technology, Economic Trade-Offs, & Services Supported
2. Likely To Be Multi-Vendor
3. Proprietary Or Customized IGP's Are Likely
4. Significant Operational Autonomy
• Information Trust, Not Always Policy Trust
• Domains Likely To Require Control Of The Use Of Their Resources
5. Routing
• Carrier-Specific
• NMS May Be Involved
• High Unit Costs, Long Connection Times Make Economics An Important Consideration
Metro
Metro
Y
Metro
X
J
K
A
6. Conduit & Fiber Cable Sharing Make SRG Information Across
Domains Complex - Will Frequently Not Be Available
John Strand
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65
oif2001.639 - Application-Driven Assumptions And Requirements
Metro/Core Characteristics
1. Significant Differences In Technology, Economic Trade-Offs, & Services Supported
2. Likely To Be Multi-Vendor
3. Proprietary Or Customized IGP's Are Likely
4. Significant Operational Autonomy
• Information Trust, Not Always Policy Trust
• Domains Likely To Require Control Of The Use Of Their Resources
5. Routing
• Carrier-Specific
• NMS May Be Involved
• High Unit Costs, Long Connection Times Make Economics An Important Consideration
Y
Metro
Metro
Metro
Y
J
K
A
6. Conduit & Fiber Cable Sharing Make SRG Information Across
Domains Complex - Will Frequently Not Be Available
John Strand
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oif2001.639 - Application-Driven Assumptions And Requirements
Multi-Vendors In Backbone - Characteristics
1. Proprietary Or Customized IGP's Are Likely
2. Information & Policy Trust Not Likely To Be An Issue
3. Vendor-Specific Technologies & Constraints Not Captured In Standards Are Likely
(E.g., All-Optical, Tunable Lasers, Adaptive Wavebands)
B
M
S
T
K
S
T
B
M
N
S
Q
P
T
Large A Small B
R
Express
Domain of
Transparency
(Vendor B)
Small A
Large B
U
K
J
Routing Costs: A(nodes) + B(distance)
(Vendor A)
L
P
N
Z
Y Opaque
Network
R
U
J
A
Q
P
N
M
L
K
J
A
L
Q
U
Z
Y
R
John Strand
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IP Transport
Data Services
(Mostly IP-Based)
Voice & Other
TDM-Based Services
DS1 (1.5 Mb/Sec)
Wideband & Broadband
DCS Layers
Transport For IP Defining Functionality
Of These Interfaces
DS3 (45 Mb/Sec) STM-4 (622 Mb/Sec)
Digital Transmission
Layer
IP For Transport Introducing IP Functionality
Into The Optical Layer
STM-16c (2.5 Gb/Sec) STM-64c (10 Gb/Sec)
Optical Layer
Proprietary
(20 Gb/Sec - 400+ Gb/Sec)
Media Layer
John Strand
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68
Traffic On U.S. Long Distance Network
1997 – 1999
100%
Private Line
80%
Other Public
Data Networks
60%
Internet
40%
20%
U.S. Voice
0%
EOY 1997
Source: K. Coffman & A. Odlyzko
EOY 1999
1997-99
Growth
John Strand
1/18/2002
69
Entering The Transport Network
64 kb/s
POTS
&
VG PL
1.5 Mb/s
1
O
O
O
O
45 - 622
Mb/s
2.5 - 10
Gb/s
1
O
O
o
24
o
o
o
1.5 Mb/s PL
45 - 622 Mb/s PL
1 - 10 Gb/s PL
28
BW
Growth
Rates
Backbone
Fiber
Network
POTS: "Plain Old Telephone Service"
VG:
Voice Grade
PL:
Private Line
John Strand
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70
US Domestic Backbone (Mid-’99)
268,794 OC-12 Miles
John Strand
1/18/2002
71
Transport Layering
Data Services
(Mostly IP-Based)
Voice & Other
TDM-Based Services
DS1 (1.5 Mb/Sec)
XX
X
X
Wideband & Broadband
DCS Layers
DS3 (45 Mb/Sec) OC-12 (622 Mb/Sec)
OC-48c (2.5 Gb/Sec) OC-192c (10 Gb/Sec)
Digital Transmission Layer
• ADM's
•Rings
Functionality
& Value Added
Optical Layer
• Optical Transport Systems (DWDM, OA,OADM)
•"Optical Cross-Connects"
Proprietary
(20 Gb/Sec - 400+ Gb/Sec)
Media Layer
•Fiber
•Conduit
John Strand
1/18/2002
72
Transport For IP
Customer Drivers
Possible Solution Elements
• Price - $/OC48/month
•Rapid Provisioning
• Availability
• How Quickly
• Where
• Optical Network Interworking
•Heterogeneous Technologies
• Metro/Core
• Other Backbone Providers
• Displacement Of Internal ISP Costs
• Interfaces
• Cost Of Reliability
• Buffer Capacity
• Peak Loads
• Traffic Shifts
• Traffic Growth
• Network Management
• Differentiators
• Availability
• QoS
•Flexible Bandwidth
• Asymmetric Circuits
• Concatenated Links
• Virtual Concatenation
• Inverse Multiplexing
•Additional Customer Restoration Options
• Re-Provisioning
• Customer Control
• Speed Options
• Sub-OC48 Functionality
• Layer 1 Interface Enhancements
John Strand
1/18/2002
73
Restoration Refresher
Key Trade-Off
Restoration Granularity
Services
Layers
DCS
Layers
Unit Capacity Cost
Connection
STS-1 => STS-12
Digital
Transmission
Layer
STS-48+
Optical
Layer
l or Fiber
• Services Layer (IP) Can Restore Exactly The Right Connections
• Optical Layer More Economical If Large Bundles Of Connections Need
To Be Restored
John Strand
1/18/2002
74
ISP Peering Relationships
Peer
Provider
Peer
(Frequently) No $$
Customer EXPENSIVE
John Strand
1/18/2002
75
Transport For IP
Reducing The BGP Hop Count
R
C
B
A
X
Hi-Usage
Trunks
Tier 1 ISP
Optical
Direct Connects
Y
Z
Toll Switching Hierarchy
Regional ISP
Local ISP
Internet ISP Hierarchy
Typical Transit Cost (Telia): $1K - 10K / Mbps /Year
John Strand
1/18/2002
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References
• T. E. Stern & K. Bala, Multiwavelength Optical Networks, Addison-Wesley, 1999
• J. L. Strand, “Optical Network Architecture Evolution”, chapter in I. Kaminow and T. Li (eds.),
Optical Fiber Telecommunications IV, Academic Press, to appear March 2002
• R. Ramaswami and K. N. Sivarajan, Optical Networks: A Practical Perspective,
San Francisco: Morgan Kaufmann, 1998.
• B. Mukherjee, Optical Communications Networks, New York: McGraw Hill, 1997.
• R. H. Cardwell, O. J. Wasem, H. Kobrinski, “WDM Architectures and Economics in Metropolitan Areas",
Optical Networks, vol. 1 no.3, pp. 41-50
• O. Gerstel and R. Ramaswami, "Optical Layer Survivability: A Services Perspective",
IEEE Communications Magazine, vol. 38 no. 3, March 2000, pp. 104-113.
• R. D. Doverspike, S. Phillips, and Jeffery R. Westbrook, "Future Transport Network Architectures",
IEEE Communications Magazine, vol. 37 no. 8, August 1999, pp. 96-101.
• R. Doverspike and J. Yates, "Challenges for MPLS in Optical Network Restoration", IEEE Communications
Magazine, vol. 39 no. 2, Feb. 2001, pp. 89-96.
• M. W. Maeda, "Management and Control of Transparent Optical Networks", IEEE J. on Selected Areas In
Communications, vol. 16, no. 7, Sept. 1998, pp. 1008-1023.
• J. L. Strand, J.; A. L. Chiu, , R. Tkach,. “Issues For Routing In The Optical Layer”, IEEE Communications Magazine,
2/2001, vol. 39, no. 2, pp. 81 –87
• John Strand, Robert Doverspike, Guangzhi Li, “Importance of Wavelength Conversion In An Optical Network”,
Optical Networks Magazine, vol. 2 No. 3 (May/June 2001), pp. 33-44
•R. W. Tkach, E. L. Goldstein, J. A. Nagel, J. L. Strand, “Fundamental limits of optical transparency”,
OFC '98, pp. 161 -162
John Strand
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Some Relevant U.S. Web Sites
“Tier 1” Inter City Service Providers
• AT&T
• MCI Worldcom
• Sprint
http://www.att.com
http://www.wcom.com
http://www.sprint.com
New Entrants
• Qwest
• Level3
• Frontier
• Williams
http://www.qwest.com
http://www.Level3.com
http://www.frontiercorp.com
http://www.williams.com
Major Equipment Providers
• Lucent
• Alcatel
• Nortel
• Cisco
• NEC
http://www.lucent.com
http://www.alcatel.com
http://www.nortel.com
http://www.cisco.com
http://www.nec.com
Standards Organizations
• ITU
• T1
• OIF
• IETF
• ATM Forum
http://www.itu.int
http://www.t1.org
http://www.oiforum.com
http://www.ietf.org
http://www.atmforum.com
New Business Models
• Band-X
•Arbinet
http://www.band-x.com
http://www.arbinet.com
Government Sites:
• FCC
• NTIA
http://www.fcc.gov
http://www.ntia.doc.gov
New Equipment Vendors
• Ciena & Lightera
• Cisco & Monterey
• Avici
• Juniper
• Sycamore
http://www.ciena.com
http://www.montereynets.com
http://www.avici.com
http://www.juniper.net
http://www.sycamore.com
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