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Architecture Optimization in IP over WDM Core Networks
Serge Melle, Drew Perkins, Curtis Villamizar
Infinera Confidential and Proprietary | 2
Optical Bandwidth Drivers
Access/Aggregation
IP/MPLS
Transport: Long-Haul, Metro
Cisco white paper: “The Exabyte Era”
Infinera Confidential and Proprietary | 3
The Result – Increasing WDM Bandwidth Needs Typical US Long-Distance Core Backbone
1
10
100
1000
10000
100000
Aver
age
WD
M L
ink
Cap
acity
(Gb/
s)
50% growth 75% growth 100% growth
IP Network Growth Expected to Scale WDM Networks >10Tb/s by 2020
Infinera Confidential and Proprietary | 4
Defining The Problems
Need to drive out CapEx Simplify layers? Remove equipment?
Need to drive out OpEx IP and optical have different skill sets Must reduce the operational burden as new service
demands escalate?
Improve service delivery time Why do I have to wait between 6 and 20 weeks just to
get a transponder card? Too many different transponder types!!!
Infinera Confidential and Proprietary | 5
IP – Optical Network Evolution Objectives
Enable IP network capacity scaling
Minimize network costs
Maximize network resiliency & reliability
Minimize latency
Unconstrained network reconfigurability
IP Network
Transport Network
Infinera Confidential and Proprietary | 6
Cost Issues in IPoWDM Networks
1. High cost of IP router ports
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Industry Data Points
Significant difference between IP and transport equipment costs
Up to 5x differential between router & transport DWDM optics
Opportunity for greatest CapEx savings: Cap or reduce router scaling Cap or reduce number of router
ports required Maintain DWDM functionality in
transport layer Focus should be on minimizing
total network cost… …optimizing between IP and
transport layers 0%
20% 40% 60% 80%
100% 120%
Rel
ativ
e co
st p
er G
b/s
40G SR POS (router) 40G POS
DWDM (router)
10G SR POS (router) 10G DWDM
Transponder (<500km)
10G DWDM Transponder
(1500km)
Infinera Confidential and Proprietary | 8
Cost Issues in IPoWDM Networks
1. High cost of IP router ports 2. High cost of IP router ports
Infinera Confidential and Proprietary | 9
The image cannot be dis
The image ca
The image can
T
The
Th
0% 2% 4% 6% 8%
10% 12% 14% 16% 18% 20%
The image cannot
The image cann
The image ca
The im
T
Th
T
0% 10% 20% 30% 40% 50% 60% 70% 80% 90%
100%
Network Cost vs. Interface Type
High cost of Layer 3 POS router ports Historically lower cost points for Ethernet interfaces & switches Cost savings from use of converged Layer 2/3 switches (“Ethernet
router”)
IP Traffic Volume (Tb/s)
IP N
etw
ork
Cos
t/Tra
ffic
Volu
me
10GbE OC-768 POS OC-192 POS Mixed OC-192/768 POS
Infinera Confidential and Proprietary | 10
Cost Issues in IPoWDM Networks
1. High cost of IP router ports 2. High cost of IP router ports 3. High cost of IP router ports
Infinera Confidential and Proprietary | 11
IP Network Architecture Present Mode of Operation
IP core links (router trunks) primarily connected between adjacent router-adjacent router
IP core links carried over dedicated wavelengths on WDM network
Little/no router bypass (and thus little pass-through traffic in WDM layer)
End-end IP demands pass through multiple router hops Consume routing capacity
for pass-through demands Increasing inefficiency &
cost as traffic volume scales
Infinera Confidential and Proprietary | 12
IP Network Architecture Future Mode of Operation
As IP traffic volume grows…. Minimize end-end IP demands
transiting through intermediate router hops
Increase number of direct router-to-router core links (router trunks) Router “bypass” for end-end
demands between nodes
Service demand
Traffic offloaded from three pairs of router ports
Infinera Confidential and Proprietary | 13
IP Network Architecture Future Mode of Operation
As IP traffic volume grows…. Minimize or reduce amount of
end-end IP demands transiting through multiple router hops
Increase number of direct router-to-router core links (router trunks) Router “bypass” for end-end
demands between nodes Optical bypass in WDM layer
Wavelength “pass-through” at intermediate WDM nodes
Leverage optical express and ROADM technologies
Minimize use of high-cost router ports and capacity Optical layer bypass for lower
total network cost Cost-efficient scaling of IP and
WDM layers
Infinera Confidential and Proprietary | 14
Fiber Network - Typical N. American Backbone
18,000km coast-coast network
96 cities & nodes 18 “Tier 1” cities or
junctions 13 “Tier 2” major cities 24 “Tier 3” regional cities 41 “Tier 4” regional cities
“Next-Gen” network: G.655 fiber
Infinera Confidential and Proprietary | 15
IP Network A-Z Demands
Develop complete city-city (A-Z) IP demand set (ie: gravity model)
Adjust model for real-world characteristics: Unequal source/sink
tendencies statistical multiplexing time-of-day demand
effects Randomization atypical cities (ie: SF
Bay area) etc.
Total traffic volume representative of real-world IP network
Sensitivity analysis: scale IP network capacity from 1x to 256x
Infinera Confidential and Proprietary | 16
IP Core and Regional Links
Map A-Z IP demands onto fiber network and considering IP multiplexing gain Ensure equipment and path redundancy
Select core nodes Core nodes will generally be at the largest cities which are
often major junctions. Initial design assumes common IP provider practice to
deploy core links between physically adjacent core nodes.
Map IP core demands into router-to-router core links (router trunks)
Associate regional nodes to core nodes based on proximity. Each non-core node must be associated with a region
containing one or more core node. Non-core nodes are selected based on lower demands and
proximity to core nodes. Defines total IP demands for core and regional traffic Vary degree of IP router bypass & impact on IP core link
size, router size, etc.
IP Core Links IP Regional Links
Infinera Confidential and Proprietary | 17
Network Cost vs. IP Bypass (10GbE)
Relative IP Network Costs (10GbE Ports)
Number of IP Bypass Links
Relative WDM Network Costs (10GbE Ports)
Number of IP Bypass Links
0.298Tb/s
0.849Tb/s
2.384Tb/s
6.75Tb/s
19.072Tb/s
38.145Tb/s
0.298Tb/s
0.849Tb/s
2.384Tb/s
6.75Tb/s
19.072Tb/s
38.145Tb/s
85%
90%
95%
100%
0 10 20 30 40 50 60 70 80 70%
75%
80%
85%
90%
95%
100%
0 10 20 30 40 50 60 70 80
Infinera Confidential and Proprietary | 18
Network Cost vs. IP Bypass (40G POS)
Relative IP Network Costs (40G POS Ports)
Number of IP Bypass Links
Relative WDM Network Costs (40G POS Ports)
Number of IP Bypass Links
1.192Tb/s
2.384Tb/s
4.768Tb/s 9.536Tb/s
19.072Tb/s
38.145Tb/s
1.192Tb/s
2.384Tb/s
4.768Tb/s
9.536Tb/s
19.072Tb/s
38.145Tb/s
85%
90%
95%
100%
0 10 20 30 40 50 60 70%
75%
80%
85%
90%
95%
100%
0 10 20 30 40 50 60
Infinera Confidential and Proprietary | 19
Cost Issues in IPoWDM Networks
1. High cost of IP router ports 2. High cost of IP router ports 3. High cost of IP router ports 4. Optical network costs
Infinera Confidential and Proprietary | 20
Transport Layer Architecture Options
“IP over Optical” formerly known as
IPoWDM
IP over WDM a.k.a “alien waves”
IP over WDM Router client to WDM
Architecture
Router interface SR - POS LR DWDM OTN SR – POS or 10GbE
WDM Node WDM Terminal
(point-point) All-Optical ROADM
Optical ROADM or Digital ROADM
Pass through IP traffic Back-back transponders Optical Express Optical or Digital Express
Protection Router - Layer3 Router - Layer 3 Router- Layer 3
Digital ROADM: <50ms
OAMP Limited (DWDM) Medium
(WDM PHY with OTN) Medium (Optical)
High (Digital)
O-E-O O-E-O O-E-O
O-E-O O-E-O O-E-O
OE
O
OE
O
OE
O
OE
O
Infinera Confidential and Proprietary | 21
“Alien” Wavelengths Practical Considerations & Operational Implications
Interconnect IP routers to WDM transport via short-reach optics Clear demarcation between client signal and
transport layer Full end-end optimization, control &
management over transport network “Best-in breed” IP and transport systems
WD
M
WD
M
Optical Transport Network
IP Network
Optical Transport Network
IP Network SR
SR
SR
SR
Native Wavelengths
“Alien” Wavelengths
Integrated ITU-grid WDM optics on router input directly to WDM line system No end-end control/management plane Design optical link budgets to worse-case Loss of end-end turn-up automation Complex or no inter-network protection Loss of PM and fault sectionalization
capabilities Complex service activation CapEx savings – if any – from transponder
reduction need to be significant to outweigh design tradeoffs and operational complexity
Vend
or A
Ve
ndor
B
Vend
or A
Ve
ndor
B
Infinera Confidential and Proprietary | 22
Alien Wave Economics 10GbE Router-to-Router Connections
Network Traffic Volume (Tb/s) Network Traffic Volume (Tb/s)
Transponder-based WDM Alien Waves WDM
Infinera Confidential and Proprietary | 23
Alien Wave Economics 40G Router-to-Router Connections
Transponder-based WDM Alien Waves WDM
Network Traffic Volume (Tb/s) Network Traffic Volume (Tb/s)
Infinera Confidential and Proprietary | 24
Impact of “Alien Waves”
Little/no cost savings versus use of transponders Alien waves essentially results in a “cost transfer” from WDM layer to IP
layer
For 40G, regen costs contribute major portion of WDM layer costs Not impacted by alien waves
Operational impact of multi-vendor alien waves not considered Potential for significant costs and complexity for system turn-up,
provisioning, management and trouble-shooting
IPoWDM architecture with IP bypass enables significantly greater savings
Infinera Confidential and Proprietary | 25
Conclusions
IPoWDM network cost optimization includes both simple fixes… Minimize use of expensive router ports
…more complex optimization… Increase degree of IP mesh to maximize router bypass
on high-bandwidth links Providing cost savings in IP layer, and transport layer
…and uncertainties… Real-world cost savings of alien waves? Operational considerations
Bandwidth Virtualization Enabled by Digital Optical Networks
Serge Melle
Infinera Confidential and Proprietary | 27
Agile Optical Networks: Theory vs. Reality
The Theory: Agile optical networks can transparently transport and switch any service, end-to-end
2.5G 10G 40G
100G
2.5G 10G 40G 100G
The Reality: “All-optical” implementation of many optical networks impedes service and network agility
Infinera Confidential and Proprietary | 28
Conventional Transponder-Based WDM
New services are added optically
Trans- mission
Fiber
Dispersion comp.
(R)OADM N-stage
Filter or WSS
2.5G
10G
40G
Amp
Transponders or Muxponders
Infinera Confidential and Proprietary | 29
All-Optical WDM/ROADM Networks
All-optical wavelength switching using filters, ROADM, WSS, etc.
OEO only for local add/drop No sub-wavelength add/drop No inter-wavelength grooming No digital PM or OAMP
End-end services over wavelengths Wavelength contention and blocking Service limited by wavelength path
Optical reach Number of (R)OADM nodes passed Fiber characteristics
All-optical pass-through
“express” traffic
Add/Drop “local” traffic
O-E-O
O-E-O
O-E-O
O-E-O
λ1 …λN
λ1 …λN
λi, λj
O-E-O
λ1 …λN
New service blocking due to wavelength contention
End-end wavelength service
Infinera Confidential and Proprietary | 30
Conventional WDM/ROADMs Tie Services to Optics
• Loss = ? • Channels lit ? • Dispersion = ?
• Loss = ? • Channels lit ? • Dispersion = ?
• Loss = ?
• Loss = ? • Channels lit ? • Dispersion = ?
• Loss = ? • Loss = ?
• Loss = ? • Channels lit ? • Dispersion = ?
• Loss = ?
• Loss = ?
Service is specifically assigned to a specific end-to-end wavelength
Impacts: Planning Service support Wavelength engineering Deployment time Cost
Infinera Confidential and Proprietary | 31
Why Have We Gotten Here? The Original Problem Statement
Cost of optics is the bottleneck to wide-spread use of electronics
What has this led to…? “Shoot the messenger” – Drive to reduce/eliminate the
need for OEO rather than reducing the cost of OEO…
…which then limits the use of digital electronics…
…which reduces network functionality and service flexibility (ie: less switching, less PM data, less reconfigurability, etc.)
Infinera Confidential and Proprietary | 32
Relative Costs – The “O” vs. the “E”
High cost of OEO conversion compared to the cost for manipulating the data
Implementing feature-rich network & service functionality incurs a cost premium
Silicon cost is not the problem
Rel
ativ
e C
osts
per
10G
Accessing the Data Manipulating the Data
Infinera Confidential and Proprietary | 33
100 Gb/s Transmit
100 Gb/s Receive
Changing the Paradigm #1: Lower the Cost Barrier to OEO Use
Monolithic, large-scale InP Photonic Integrated Circuits
100Gb/s “WDM system on a chip” 62 components on Tx & Rx PICs
Photonic Integration
Infinera Confidential and Proprietary | 34
1001 0101 0101 1010 1101 0101 0101 1010 1101 0101
Changing the Paradigm #2: Digital, instead of Optical, Add/Drop
100101011101010000101011 100101010101101011010101 110101000010101110010101 001010111011010110010101
Inte
grat
ed P
hoto
nics
Inte
grat
ed P
hoto
nics
OEO conversion enables “digital” functionality Multi-wavelength scaling using PICs Sub-λ bandwidth management (ODU1) Separate tribs (service) from line (capacity) Digital ROADM add/drop, muxing & switching
Digital ROADM
Optical (O) Electrical (E) Optical (O)
Trib
Photonic Integration
Infinera Confidential and Proprietary | 35
1001 0101 0101 1010 1101 0101 0101 1010 1101 0101
Changing the Paradigm #3 Increase Service Agility
100101011101010000101011 100101010101101011010101 110101000010101110010101 001010111011010110010101
Inte
grat
ed P
hoto
nics
Inte
grat
ed P
hoto
nics
Digital Optical Network
Digital ROADM
Photonic Integration
10010101110101010000 10010101010110101011
optical link management
De-couple service provisioning from optical engineering
GMPLS software intelligence Digital switching at every node Unconstrained service delivery anywhere
10010101110101010000 10010101010110101011
end-end service
Infinera Confidential and Proprietary | 36
Service Adapters
PIC + Digital Switch
Digital ROADM Architecture
New services are added digitally Wavelengths are virtualized into digital bandwidth
Trans- mission
Fiber
Dispersion Comp.
2.5G
10G
40G
Amp
Serv
ice
Inde
pend
ent
Electrical Interface
Infinera Confidential and Proprietary | 37
Digital ROADM Functionality
2.5G 10G
40G
1G
De-couple services (tribs) from waves (line) Manage 100G per line card (400G per chassis) Manage all bandwidth at 2.5G (ODU1) granularity Multiplex, switch, groom at every node
01
02
03
04
Number of λs O
DU
1s p
er λ
100Gb/s “pool of bandwidth” per line card (40 x ODU1)
λ 1
05
06
07
08 λ 2
09
10
11
12 λ 3
13
14
15
16 λ 4
17
18
19
20 λ 5
21
22
23
24 λ 6
25
26
27
28 λ 7
29
30
31
32 λ 8
33
34
35
36 λ 9
37
38
39
40 λ 10
Infinera Confidential and Proprietary | 38
Digital ROADM Enables “Bandwidth Virtualization”
Waves are resources, not services
Capacity and services mix are independent
Any service anywhere, without pre-planning or forklifts
20G
ava
ilabl
e
125G available
65G
ava
ilabl
e
85G available
22.5
G a
vaila
ble
105G
ava
ilabl
e
2.5G
40G
Virtu
aliz
atio
n 127.5G available 85G available
Infinera Confidential and Proprietary | 39
Implementing Bandwidth Virtualization
Service – Wave Decoupling
Virtualized Bandwidth Pool 100 Gb/s per DLM/XLM
Client Interfaces
100G Line-Side DWDM Capacity
100 Gb/s OTM-10.2
2.5G
10G
40G
Bandwidth Virtualization decouples service provisioning from wavelength engineering
02
01
03
04 O
DU
1s p
er λ
λ 1
05
06
07
08
λ 2
09
10
11
12
λ 3
13
14
15
16
λ 4
17
18
19
20
λ 5
21
22
23
24
λ 6
25
26
27
28
λ 7
29
30
31
32
λ 8
33
34
35
36
λ 9
37
38
39
40
λ 10
Infinera Confidential and Proprietary | 40
Sub-lambda and Super-lambda Services
01
02
03
04
OD
U1s
per
λ
λ 1
05
06
07
08
λ 2
09
10
11
12
λ 3
13
14
15
16
λ 4
17
18
19
20
λ 5
21
22
23
24
λ 6
25
26
27
28
λ 7
29
30
31
32
λ 8
33
34
35
36
λ 9
37
38
39
40
λ 10
02
13
14
15
16
25
26
27
28
29
31
32
33
34
35
36
37
38
39
40
30
One Digital Virtual Concatenation (DVC) Group
Service – Wave Decoupling
Super-lambda services (>10 Gb/s) • OC-768/STM-256
Sub- lambda services (<10 Gb/s) • 2 x 1 GbE • OC-48/STM-16 • OTU1*
Lambda services (10 Gb/s) • 10 GbE • OC-192/STM-64 • OTU2*
Enabled by Digital Virtual Concatenation (DVC)
1GbE
10G
40G
2.5G
08
* Future Release
Infinera Confidential and Proprietary | 41
Bandwidth Virtualization Digital switching – line/trib separation - VCAT
---
A Programmable Optical Network
OC-48
100 GbE
40G GbE 2G
FC OTU2 ???
PIC-based Optical Engine
Network Intelligence
10G waves
40G waves
Add/ Drop
Reach Options
CD/PMD Comp
Service Adapters
Infinera Confidential and Proprietary | 42
“Service ready” capacity
10 day Just-In-TAM™
GMPLS lightpaths
Plan & light each service independently
Speed as a Sales Advantage
Win deals with shorter lead times Get revenue & cash earlier
Forecast tolerance
Vs.
Vs.
Vs.
8-20 week transponder lead time
Manual processes
-based network Competitor-based network
Infinera Confidential and Proprietary | 43
Enabling New Business Models
Level3: 10GbE LAN PHY
10G in 10 days
Interoute 10G in 10 Days
XO: 10G in 10 Days
Cox: Owned backbone
Carphone Warehouse: Owned backbone
“We've pretty much built a national network in eight weeks since signing the contract, and we can increase capacity pretty much at the touch of a button. It has taken the guesswork out of the optical network. We often get last-minute demand from the sales teams, and you need a technology partner that can help meet that demand….” - Paul Jackson, Head of Transmission
Infinera Confidential and Proprietary | 44
Summary
IP networks want service transparency Provide whatever connectivity I want, where I want, when I want, at
the lowest cost
Best approach to service transparency is an optically opaque network Optical transparency:
Forces IP layer to deal with analog optics Adds complexity Adds significant operational cost
The economic driver for optical transparency (high-cost OEO) is rendered moot with PICs
Allowing Digital ROADMs to maximize service agility