Test

1. Co-Packaged Optical (CPO)
Eco-System Development
Jock Bovington
Lightwave Webinar December 5, 2023
Acknowledgements to the entire Cisco CPO team and our
invaluable partners without whom we could not be successful.

2. 2
* -Can be interconnected to create a disaggregated chassis
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3. 3
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4. Co-Packaging Applications
Source: OIF CPO Webinar, Ram Huggahalli (Microsoft), 10-14-2020
4
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5. Co-Packaged Optics (CPO)
•
•
• Power consumed by front panel pluggable optics is becoming restrictive
Total front panel pluggable optics power consumption of Web DCs is
rapidly increasing – estimated 10x increase from today to 2030 (ref: Light
Counting)
Driving unnatural DC architectural decisions which drives higher cost
• Cisco believes CPO is inevitable, but the timeline remains unclear –
potential intercept with 51.2Tb switch
• Many implementation and deployment challenges to overcome
• Estimated ~30% system power reduction (from 50% lower optical
interconnect power)
•
• Requires extensive expertise in Systems, Silicon (ASICs) and Optics
Cisco is uniquely positioned because of expertise in all three
• Cisco is focused on developing the core technologies required to
productize CPO reliably
• Looking to partner with key Web customers
100
1,000
10,000
2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
Power
(MW)
Power consumption of optical transceivers and CPO
deployed in Cloud Datacenters
No CPO adoption Gradual adoption of CPO
Silicon
Systems
Optics
Cisco
Expertise
5
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6. Cisco’s CPO Proof-of-Concept Demo Platform
ELSFP
ELSFP
…
ELSFP
ELSFP
Cisco 25.6/51.2T
CPO Switch Platform
PCB
Opt
Conn
Laser
Package
DC-DC C
Optical
Engines
SIDE VIEW
…
Mid-Board
Connectors
Faceplate
Connectors
6
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7. • Cisco CPO proof-of-concept demonstrator:
• Cisco Silicon One™ 25.6T G100 switch ASIC
• 8 x 3.2Tbps socketed optics tiles co-packaged with switch ASIC
• 64 x 400G-FR4 fully functional optics ports on front panel
• Multi-vendor OIF spec compliant ELSFP modules
• Monolithic integrated optics Mux/Demux’s in PIC
• ~5.5W / 800G optical interconnect power consumption
• Functional demo in Cisco’s demo suite OFC’23
Cisco’s LIVE 25.6Tbps CPO Demo
~100x volume reduction
Power
Consumption
Monitors
4x OSFP800 => 1x 3.2T CPO
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7

8. Where is the Power Savings Coming From?
• Reduction in or omission
of SerDes/ Retimers (and
PAM4 DSP)
• CPO reduces both
electrical signal integrity
challenges and total
power
• CPO is perfect for linear
drive schemes because
it is a tightly controlled
interface
Source: IEEE Standards, Tobey P.-R. Li, Mau Mau-Lin Wu (MediaTek), 11-15-2022
https://www.ieee802.org/3/df/public/22_11/prli_3df_01_2211.pdf
8
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9. When does the transition from pluggables to CPO make sense?
9
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We will likely need ALL of the following:
• Lower power
• Lower cost
• Lower failure rate
• Supply chain diversity
AND…
• Prove all of this at scale

10. OIF 3.2T CPO Module
• Implementation Agreement Published at oiforum.com
• Example: 16 x 3.2T Modules for 51.2T Switch Capacity
Co-Packaged Assembly Substrate (Interposer)
3.2T Modules
LGA Socket
Optical
Copper Cable
ELSFP
10
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Channel components cross-section
Mechanical demonstrators have been shown at OFC and OCP

11. External Laser Small Form-factor Pluggable (ELSFP)
ELSFP
ELSFP
• Provides CW laser power for optical engines (OEs)
• Decreases thermal power density in the system
• CPO systems will likely need multiple (i.e. 4, 8, or 16) ELSFPs
(Compared to 32 or 64 Pluggable Transceivers)
• The light from a given ELSFP can feed more than a single OE.
• A pluggable form factor helps to ensure total system reliability
and a “hot swap” replacement if a single laser or ELSFP
module fails.
• Eye safety is achieved by a blind mate optical connector
internal to the system.
• CMIS compatible
ELSFP
ELSFP
Switches and
ASICs for AI/ML
SIDE VIEW
ELSFP PCB
Optical
Conn Packaged
Laser
DC-DC C
Optical
Engines
or
Switch
or AI
ASIC
Servers,
ELSFP
ELSFP
ELSFP
…
ELSFP
ELSFP
…
Mid-Board
Connectors
Faceplate
Connectors
ELSFP
ELSFP
Implementation Agreement
Linecards, etc. Published at oiforum.com 11
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12. ELSFP Optical Blind-Mate System
Press fit host connector
Riding heat sink
Optical connectors
snap into host
connector housing
Separately applied connector and cage
Large riding
heat sink area
OSFP style latch
Shroud providing paddle card and optical connector protection
12
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13. Laser Failure Rates
EOLmean - Average end of life for population of lasers
Ea - Activation energy
Tj - Laser junction temperature
I - Operating current
m - Current acceleration factor
kB - Boltzmann’s constant
• Uncooled lasers must be packaged carefully and away from significant heat sources
• Transceiver DSP/Retimers/SerDes chips and Switch ASICs are significant heat sources
• ELSFP’s front panel pluggable location, large module surface area, and flexible riding heat sink
design allow maximum flexibility to keep lasers well below temperature limits.
13
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14. ELSFP Development Progress
• Growing supplier list:
• 2021 – (2) DR, Cooled
• 2022 – (2) DR, (2) FR, Cooled
• 2023 – (4) DR, (4) FR, Cooled or Uncooled
• 2024 - ?
• Steadily improving power conversion
efficiency:
• Laser die development
• Laser packaging development
• Laser driver development
0.0%
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2.0%
4.0%
6.0%
8.0%
10.0%
12.0%
14.0%
16.0%
18.0%
May-22 Aug-22 Dec-22 Mar-23 Jun-23 Oct-23
ELSFP
Power
Conversion
Efficiency
Date
"In-Fiber" Efficiency in 8x100mW ELSFPs
by Case Temperature
15 35 45 55
Case Temperature (°C)
14

15. Summary
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Cisco is uniquely positioned to bring CPO to the market:
• Systems, Silicon, and Optics
We will likely need ALL of the following:
• Lower power (Cisco’s CPO Optimized Silicon One)
• Lower cost (Web-scale Volume + Cisco’s Silicon Photonic Integration)
• Lower failure rate (ELSFP Laser Solution + Cisco’s Silicon Photonic Integration)
• Supply chain diversity (Standards supported eco-system, Thank you OIF!)
Headwinds for CPO:
• Prove it works at scale
• Uncertainty about the technical necessity…though this is not required for CPO transition