Meet Radia Perlman: Mother of the Internet
24th October 2018
Tim Berners Lee may be the Father of the World Wide Web but have you ever heard of Mother of the Internet, Radia Perlman? Where Berners Lee invented the world wide web, the first web browser and some fundamental protocols, it’s Perlman who’s credited with providing the final piece in the puzzle. This piece paved the way for the modern internet that is enjoyed by the masses today.
Let’s take a look at how Pearlman earned such a prestigious nickname.
The spanning-tree protocol
In 1985, Perlman was a network engineer and Ph.D in computer science, working for Digital Equipment Corporation. They were trying to solve the problem of file sharing between computers.
Her manager was due to go on holiday for the week and it was a Friday, which meant the young software engineer had time to test a theory of hers. Perlman was determined to prove the concept and got to work on the spanning-tree protocol immediately.
In Perlman’s words,
‘I wrote the specification on Monday and Tuesday… it was such a simple protocol the specification was about 25 pages. Then I had the remainder of the week where I couldn’t concentrate because I was so excited to show off to my manager.’
‘So, the remainder of the week I worked on the poem that goes along with the algorithm and is the abstract for the paper in which it was published.’
Originally, Perlman foresaw the algorithm being used for 6 months at most. She now acknowledges that the spanning-tree protocol hasn’t changed in all of its 30+ years of existence and is still used in computing today.
Perlman’s poem
The following is the abstract for the paper ‘An Algorithm for Distributed Computation of a Spanning Tree in an Extended LAN’.
Algorhyme
I think that I shall never see
A graph more lovely than a tree.
A tree whose crucial property
Is loop-free connectivity.
A tree which must be sure to span
So packets can reach every LAN.
First the root must be selected.
By ID it is elected.
Least cost paths from root are traced.
In the tree these paths are placed.
A mesh is made by folks like me
Then bridges find a spanning tree.
Present day
Today, Radia Perlman holds over 100 individual issued patents and multiple awards. She rebukes her title to some extent, suggesting that the spanning-tree protocol is a very simple solution. She has lectured in the best American universities and is currently working on replacing the spanning-tree protocol with something she calls TRILL, or ‘transparent interconnection of lots of links’.