[ih] Global congestion collapse

[David L. Mills]

Perry,

Well, if your incident was during 1986-1988 and involved transit of the 
NSFnet Phase-I backbone, I'm the perp. The NSFnet routers ran my code, 
which was horribly overrun by supercomputer traffic. I found the best 
way to deal with the problem was to find the supercomputer elephants and 
shoot them. More is in a 1988 SIGCOMM Symposium paper. More recently the 
USNO and NIST time servers are being overrun with NTP traffic. See my 
recent PTTI paper at www.eecis.udel.edu/+mills/papers.html.

The NSFnet meltdown occured primarily because the fuzzball routers used 
smart interfaces that retransmitted when either an error occured or the 
receiver ran dry of buffers. The entire network locked up for a time 
because all the buffers in all six machines filled up with retransmit 
traffic and nothing could get in or out. As I recall, the ARPAnet also 
had a similar problem with reassembly buffers.

Dave

Perry E. Metzger wrote:

>Sorry for not replying for a long time...
>
>Michael Welzl <michael.welzl at uibk.ac.at> writes:
>  
>
>>Does anybody here have stories about the Internet's congestion
>>collapse(s) during the 80's? Some details would be great!
>>    
>>
>[...]
>  
>
>>So, I wonder, what was it like? What are your experiences?
>>When did folks first notice it?
>>    
>>
>
>I strongly remember a point in '88 or so (perhaps it was 87 -- it
>probably wasn't '89) when it became impossible to move data back and
>forth between Bellcore and NYNEXs research lab in White Plains over
>the net because of congestion related problems. I was working on some
>collaboration with them and suddenly found myself forced to make use
>of mag tapes as the only practical way to move even fairly small files
>back and forth. A mailing list I ran off of one of my machines also
>started having trouble moving bits through efficiently.
>
>As I recall, the arrival of kernel patches implementing congestion
>control rapidly began to reverse the situation.
>
>The first time I saw such patches was when Phil Karn handed them to me
>one day, and I swiftly added them to the kernels of my lab's
>Sun-3s. The world was somewhat different back then... :)
>
>Perry
>  
>