This document discusses future trends in optical networking from Microsoft's perspective. It summarizes Microsoft's global datacenter network footprint and describes the evolution of optical networking technologies used within datacenters and between datacenters and regions. Current technologies include 100G PAM4 superchannels for inter-datacenter links and flexible modulation formats up to 200G for inter-region links. The document also discusses challenges around scaling bandwidth beyond 1.6T, further optical integration, interoperability between vendors, and the potential roles of techniques like flexible-QAM, open line systems, and space division multiplexing going forward.
CCS335 _ Neural Networks and Deep Learning Laboratory_Lab Complete Record
OFC 2018 - ON2020: future trends in optical networking: a cloud service provider's perspective
1. ON2020: future trends in optical networking
A cloud service provider’s perspective
Mark Filer
Optical Network Architecture, Azure Networking
2. Microsoft’s global datacenter network
United States
United States
Canada
Mexico
Venezuela
Colombia
Peru
Bolivia
Brazil
Argentina
Atlanta Ocean
Algeria
Mali
Niger
Nigeria
Chad
Libya Egypt
Sudan
Ethiopia
Dr Congo
Angola
Zambia
Nambia
South
Africa
Greenland
Svalbard
Sweden
Norway
United
Kingdom
France
Poland
Ukraine
Turkey
Saudi
Arabia
Iran
Kazakistan
India
Russia
Russia
China
Myanmar
(Burma)
Indian Ocean
Indonesia
Australia
Pacific Ocean
Pacific Ocean
Data centerOwned capacity
Future capacity
Leased capacity
Edge site
DCs and network sites not exhaustive
7. Inside DC: integration and controlling cost
Cost effective scaling
beyond 1.6T generation
not solved. All optical
packet switches to the
rescue?
Lane speed stalls
Optics in Package
Optics on Die
PCB
ASIC Optics
Fiber
Switch
PCB
ASIC Optics
Fiber
?
8. • sources: dedicated coherent transponders
• line system:
• proprietary closed system compatible with
sources
• proprietary NMS for control/monitoring
• expensive and power-hungry!
Yesterday
Inter-DC
to/from
far-end
RNG
9. • sources: 2-carrier 100G PAM4 (i.e. super-
channel)
• line system
• auto gain config
• auto chromatic dispersion comp
• fixed channel grid in C-band - maximally
lighting multiple fiber pairs day 1
Today
Inter-DC (2)
to/from
far-end
RNG
10. • sources: single-carrier 400G 16QAM (OIF
400ZR)
• line system
• Same but simplified specifications due to
coherent sources
• Re-use of PAM4 line systems possible
Tomorrow (2020+)
Inter-DC
to/from
far-end
RNG
11. • 1.6T: super-channel solution?
• Fiber relatively plentiful in DCI – likely still C-
band only
• Architectural optimizations: fast optical circuit
switching?
Beyond (2023+)
Inter-DC (3)
to/from
far-end
RNG
12. • sources: dedicated coherent transponders
• line system:
• proprietary closed system compatible with
sources
• proprietary NMS for control/monitoring –
internal SDN unaware of optical layer
• expensive and power-hungry!
Yesterday
Inter-region: optical architecture
UI
13. • sources: ICO with bandwidth-variable
100G/150G/200G QPSK/8QAM/16QAM
• line system
• OLS with full alien-wave support
• colorless / directional / flex-grid (C-band)
• p2p topology – no mesh or CDC
• lighting up segments in 2.4 Tb/s blocks
Today
Inter-region: optical architecture (2)
SwitchFabric
Layer 2/3 coherent line card
switch
chip
MACsec
switch
chip
MACsec
switch
chip
MACsec
switch
chip
MACsec
DSP
CFP2-
ACO
RX
TX
CFP2-
ACO
RX
TX
DSP
CFP2-
ACO
RX
TX
CFP2-
ACO
RX
TX
DSP
CFP2-
ACO
RX
TX
CFP2-
ACO
RX
TX
DSP
CFP2-
ACO
RX
TX
CFP2-
ACO
RX
TX
14. • sources: ICO with embedded “flex-QAM”
100G-600G, dynamic modulation changes ?
• line system
• C&L band day 1
• further disaggregation possible assuming
standardized data models and APIs
• in-house layer 0 controller
• CDC / mesh ? benefits aren’t clear… layer 3
Tomorrow (2020+)
Inter-region: optical architecture (3)
SwitchFabric
Layer 2/3 coherent line card
switch
chip
MACsec
switch
chip
MACsec
switch
chip
MACsec
switch
chip
MACsec
DSP
+
OBO
RX
TX
RX
TX
DSP
+
OBO
RX
TX
RX
TX
DSP
+
OBO
RX
TX
RX
TX
DSP
+
OBO
RX
TX
RX
TX
15. • maximally lighting fiber day 1 ? (more DCI-like)
• when does regen everywhere make sense ?
• further photonic integration will enable this
from cost/power standpoint
• benefits of SDM ? tough sell…
Beyond (2023+)
Inter-region: optical architecture (4)
16. Capacity granularity
• 70% capacity gain possible
100G
150G
99%
43%
200G
100G
100G
150G
100G
150G
200G
OFC 2016, paper M2J.2, Evaluation of Elastic Modulation Gains
in Microsoft’s Optical Backbone in North America, M. Ghobadi
17. Inter-region: interop
M.Filer, H. Chaouch, X. Wu, Toward
Transport Ecosystem Interoperability
Enabled by Vendor-Diverse Coherent
Optical Sources Over an Open Line
System, OSA JOCN vol 10 (2), 2018
18. Inter-region: interop (2)
DUT
bulk-
mod
bulk-
mod shaped ASEshaped ASE
bulk
mod
bulk
mod
M.Filer, H. Chaouch, X. Wu, Toward
Transport Ecosystem Interoperability
Enabled by Vendor-Diverse Coherent
Optical Sources Over an Open Line
System, OSA JOCN vol 10 (2), 2018
19. SiPh: Intra-/Inter-DC 100G Optic Allocation
SiPh parts averaging
<0.11% failure
Real-time poll 02/2018
Note: only 100G deployed optics
shown – not representative of
total DC ecosystem distributions