Scientists on Reddit

Radia Perlman

Network engineer who invented the spanning tree protocol

u/rjp2022Redmond ↗AMA only

How we know it's theirs

Named in her 2022 r/IAmA AMA

We retrieved 30 comments from u/rjp2022Redmond, all from 2022, most often in r/IAmA.

Best moment

A redditor wrote in r/IAmA

On “I am Radia Perlman, the network engineer behind STP, the Spanning Tree Protocol. Ask me anything!”

firstly, thank you. then.. what was the biggest challenge in developing the STP successfully?

u/rjp2022Redmond replied

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There actually were no challenges. My manager thought it was going to be a really hard thing, but it turned out to be really simple, once I realized the "obvious" solution. He proposed the problem to me late on a Friday, before disappearing on vacation for a week. This was before cellphones, or people reading email on vacation. That Friday night I realized just how to do it. Monday and Tuesday I wrote the spec, in enough details that the implementers got it working quickly without asking me a single question. But I couldn't concentrate on anything else because I had to show off to my manager, and he was going to be gone until Monday. So Wednesday-Friday I worked on the poem, which is the abstract of the paper in which I published the algorithm. The poem is called Algorhyme (easily found on the Internet). So, given how much time I spent on various aspects, I'd have to say the hardest thing was the poem, since I spent more time on that than on inventing the algorithms or writing the spec.

More moments

A redditor wrote in r/IAmA

On “I am Radia Perlman, the network engineer behind STP, the Spanning Tree Protocol. Ask me anything!”

How/why did you name it Spanning Tree Protocol? I see the visual analogy of the interconnected tree branches to the connected internet, and am wondering how that name/title came to you, were there other candidates for names?

u/rjp2022Redmond replied

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When my manager proposed the problem to me, he was saying "have bridges break all the symmetries and find a loop-free subset of the topology that reaches everyone". It was that night that I realized "Hey! A tree! That's a loop-free topology. Just build a tree! Well...you need to agree on a root. Use ID!" Anyway, then it was all obvious. So, "tree". And "spanning" means reach everyone.

A redditor wrote in r/IAmA

On “I am Radia Perlman, the network engineer behind STP, the Spanning Tree Protocol. Ask me anything!”

Hello Radia! Thank you for your work on STP - my brother is a network engineer and speaks fondly of STP but I can't profess to understand it as I once began to as I changed field. If I may, I have two questions that are completely unrelated. 1. If I stack two lasagnas atop each…

u/rjp2022Redmond replied

I love this question! I've always hated the term "Internet"....to me, if you have two networks, and connect them, you don't get an "Internet"...you get a bigger network. So I'd say that two lasagnas stacked on top of each other…

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I love this question!

I've always hated the term "Internet"....to me, if you have two networks, and connect them, you don't get an "Internet"...you get a bigger network. So I'd say that two lasagnas stacked on top of each other are just a taller lasagna. Unless it overflows your pan, in which case you get a lasagna and a messy oven.

Not sure about pigeons, but they must have at least two, or else they couldn't have them point at each other and be called pigeon-toed.

A redditor wrote in r/IAmA

On “I am Radia Perlman, the network engineer behind STP, the Spanning Tree Protocol. Ask me anything!”

What did you study , did you study coding ?

u/rjp2022Redmond replied

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I took a programming class in high school, which (from the answer to another question) I basically didn't learn anything, and was sure at that point that I wanted to avoid computers. I was taking a physics class. The TA approached me and said "I have a project and need a programmer. Would you like to be my programmer?" I said "I don't know how to program." He said "Yes, I know. That's why I'm asking you. I have no money to pay you, and if you knew how to program you'd expect to be paid. You're obviously bright (I was doing well in the class) so I'm sure you could learn." The reason I agreed was that my boyfriend at the time knew how to program, so I figured he could help me. And indeed, programming was fun. I had the whole computer (Supernova) to myself. No operating system. Only a few commands. (maybe 10 instructions?) In that environment, I enjoyed programming. But not everyone in the field just does coding. Some people enjoy it, and that's great, but I'm happy I've managed to find an ecological niche where I design distributed systems and algorithms and don't do the actual implementation.