# The Sidecar Switch

- Show: [Oxide and Friends](https://hardwarepodcasts.com/podcast/oxide-and-friends)
- Published: 2021-11-30
- Length: 1h 14m
- Episode: 24
- Page: https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-11-30-the-sidecar-switch
- Listen: https://share.transistor.fm/s/c80a79d8

## Summary

Arjen Roodselaar, a hardware engineer at Oxide Computer Company, details the design of the 'Sidecar Switch,' a custom rack-scale networking solution built around the Intel Tofino 2 programmable ASIC. He explains the decision to bypass off-the-shelf Broadcom switches due to their fixed-function limitations and opaque firmware, opting instead for a P4-programmable architecture that allows for custom data plane applications like load balancing and high-performance DNS. The team also addresses the complexity of the management network, rejecting the unreliable NCSI sideband in favor of a dedicated industrial Ethernet switch to ensure robust out-of-band control and security. Finally, Roodselaar highlights the engineering challenges of power delivery, signal integrity over blind-mated backplanes, and the critical role of Intel's RTL simulation model in enabling software development before silicon availability.

## Chapters

- [2:39](https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-11-30-the-sidecar-switch#t=159) Introduction: Arjen Roodselaar and the Sidecar Switch PCB
- [11:33](https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-11-30-the-sidecar-switch#t=693) Decision to Build Custom Switch vs. Off-the-Shelf
- [23:57](https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-11-30-the-sidecar-switch#t=1437) Intel Tofino 2 ASIC: Programmability and Power Requirements
- [33:24](https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-11-30-the-sidecar-switch#t=2004) Cable Backplane, Sleds, and Sidecar Architecture
- [37:11](https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-11-30-the-sidecar-switch#t=2231) Management Network: Rejecting NCSI for Dedicated Switch
- [55:12](https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-11-30-the-sidecar-switch#t=3312) Tofino Simulator and Hardware-Software Co-Design
- [59:47](https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-11-30-the-sidecar-switch#t=3587) Trust Model, Root of Trust, and Service Processor
- [1:02:31](https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-11-30-the-sidecar-switch#t=3751) Failure Domains, Redundancy, and Graceful Degradation
- [1:08:08](https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-11-30-the-sidecar-switch#t=4088) Physical Engineering: Heat Sinks, Shock, and Vibration

## Topics

- [PCB design & layout](https://hardwarepodcasts.com/topic/pcb-design)
- [Chips, FPGAs & semiconductors](https://hardwarepodcasts.com/topic/chips-and-fpgas)
- [Embedded firmware](https://hardwarepodcasts.com/topic/embedded-firmware)
- [Security & privacy](https://hardwarepodcasts.com/topic/security-and-privacy)
- [Mechanical engineering](https://hardwarepodcasts.com/topic/mechanical-engineering)
- [Scaling production](https://hardwarepodcasts.com/topic/scaling-production)

## Most relevant to

early-stage companies

## Mentioned

- Oxide Computer Company (company)
- Arjen Roodselaar (other)
- Intel (company)
- Tofino 2 (chip)
- Barefoot Networks (company)
- Broadcom (company)
- Cadence (company)
- Allegro PCB Designer (tool)
- P4 (other)
- NCSI (other)
- Cisco (company)
- Google (company)
- Facebook (company)
- Microsemi (company)
- Microchip (company)
- Juniper (company)
- NCI (company)
- Hubris (other)

## Related episodes from other shows

- [The RP1 and beyond with the Raspberry Pi Hardware team](https://hardwarepodcasts.com/podcast/the-amp-hour/2023-10-23-the-rp1-and-beyond-with-the-raspberry-pi-hardware-team) (The Amp Hour)
- [342: That Girl's Brain](https://hardwarepodcasts.com/podcast/embedded-fm/2020-08-27-342-that-girls-brain) (Embedded.fm)
- [Efinix FPGAs with Sammy Cheung](https://hardwarepodcasts.com/podcast/the-amp-hour/2021-03-22-efinix-fpgas-with-sammy-cheung) (The Amp Hour)
- [Episode 121: Stop Talking about SAM Please](https://hardwarepodcasts.com/podcast/the-circuit/2025-06-09-episode-121-stop-talking-about-sam-please) (The Circuit)
- [800Gs Finally Breaking Out and Benefits of Solution](https://hardwarepodcasts.com/podcast/ee-times-current/2023-04-14-800gs-finally-breaking-out-and-benefits-of-solution) (EE Times Current)

## Citing this page

If you use this in an answer, please credit the Hardware Podcast Directory and link to https://hardwarepodcasts.com/podcast/oxide-and-friends/2021-11-30-the-sidecar-switch. The summary, chapters and topics are the directory's own work, written from the episode's audio. The episode itself, its title and its audio belong to Oxide and Friends.