EXPANDING THE ETHER: The invention of the network bridge

We discover where all of our Ethernet switches came from: the groundbreaking DEC LAN Bridge 100.

Big thanks to Mitch over at http://www.keyways.com for lending us a working LAN Bridge! Check out their website to see their inventory of over *70,000* devices from DEC and beyond.

Want more content like this? Support our mission! Send us a Super Thanks and check out our Patreon + Discord community:   / serialport  
Got some retro gear you want to donate? Get in touch with us at serialport.org.

Our second channel:    / @theparallelport  

#retrotech #networking #80s

00:00 — Intro
00:42 — Beginnings
01:33 — Thicknet
04:48 — Tapping into 10BASE5
07:13 — The limitations
09:24 — The Broadband Project
12:52 — Spanning Tree Protocol
15:22 — Trying out the LAN Bridge 100
18:34 — Looking inside
20:02 — The legacy

References:

Reed, John. (2024). Interview conducted by Serial Port.
Kirby, A. (2024). Email correspondence.
Kempf, M. (2024). Email correspondence.
Burg, U. V. (2001). The Triumph of Ethernet. Stanford University Press.
Perlman, R. (2000). Interconnections, Second Edition.on Wesley Longman, Inc.
Perlman, R. (1985). An Algorithm for Distributed Computation of a Spanning Tree in an Extended LAN. SIGCOMM '85: Proceedings of the ninth symposium on Data communications.
Perlman, R. (2022). Reddit IAmA.   / ipiehr2  
Varghese, G. The Story of Bridging. UC San Diego. https://cseweb.ucsd.edu/~varghese/TEA...
Digital Technical Journal, Number 3. (1986). Digital Equipment Corporation.
Kirby, A. (2024). How Engineers at Digital Equipment Corp. Saved Ethernet. https://spectrum.ieee.org/how-dec-eng...
Ethernet Design Rules. Boston Technology. http://jkob.fizyka.umk.pl/_downloads/...
History of Networking: How Bridging Saved Ethernet. Packet Pushers.    • History of Networking:  How Bridging ...  
Interview with Radia Perlman by Steven Johnson | Hidden Heroes. Netguru.    • Interview with Radia Perlman by Steve...  

Resources:

Dicklyon (1977). CC-BY-SA 4.0. Xerox PARC in 1977.jpg.
Xerox PARC Archives. Photo of Xerox Alto computers.
Joe Mabel (2014). CC-BY-SA 3.0. DEC VAX 11-780-5 - 01.jpg.
Telegram & Gazette (1985). A picture of Digital headquarters in Maynard from 1985.
Loz Pycock (2009). CC-BY-SA 3.0. DEC PDP-11 Minicomputer in extended variant (edited).jpg
Microsoft Research. Photo of C. Gordon Bell.
Internet Hall of Fame 2014: Radia Perlman (2014). CC-BY. Imagining the Digital Future Center.    • Internet Hall of Fame 2014: Radia Per...  
Kempf, M. (1986). US Patent 4,597,078. https://patentimages.storage.googleap...