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From: George Michaelson <>
To: The Eunuchs Hysterical Society <>
Subject: [TUHS] Re: when did v8 or later get networking?
Date: Sat, 12 Aug 2023 15:41:28 +1000	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

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Someone who worked at BBN told me they had no overhang budget for
improvements, they wrote code to fixed price contracts with DARPA and
'maybe we could do that better' was impossible without a second grant.

The butterfly we had at UCL had issues. No support worth writing home for.
Pre BGP routing was a bit of a disaster. Fixed size prefix tables and LRU
ejection. You could time out a telnet to the USA before the login: prompt
assuming you even had a route.

"Diamond" their SGML multimedia mailer was great, but a one-shot.

Smart people. Very focused on the bottom line.

(Apologies if this offends anyone ex BBN it's recollection of coffee room
gossip from 1985)


On Sat, 12 Aug 2023, 3:08 pm Warner Losh, <> wrote:

> On Fri, Aug 11, 2023 at 3:05 AM Paul Ruizendaal <> wrote:
>> Bill Joy of CSRG concluded that the BBN stack did not perform according
>> to his expectations. Note that CSRG was focused on usage over (thick)
>> ethernet links, and BBN was focused on usage over Arpanet and other
>> wide-area networks (with much lower bandwidth, and higher latency and error
>> rates). He then in 1982 rewrote the stack to match the CSRG environment,
>> changing the design to use software interrupts instead of a kernel thread
>> and optimising the code (e.g. checksumming and fast code paths). It was a
>> matter of debate how new the code was, with the extremes being that it was
>> written from scratch using the spec versus it being mostly copied. Looking
>> at it with a nearly 50 year distance, it seems in between: small bits of
>> surviving SCCS suggest CSRG starting with parts of BBN code followed by
>> rapid, massive modification; the end result is quite different but retained
>> the ‘mbuf’ core data structure and a BBN bug (off-by-one for OOB TCP
>> segments).
> When Kirk McKusick tells  the story, UCB got a beta release (or early
> access) of the BBN stack. UCB was supposed to add the socket interface to
> whatever was there. But Bill Joy found it performed terribly (multiple
> seconds to connect sometimes, single digit kB over 10Mb media, etc). He
> optimized it to make it perform well. This was a combination of rewriting
> chunks and tweaking other chunks, which matches your analysis of SCCS. When
> BBN came back with their new, release ready stack Bill supposedly said
> something like 'no thanks, we already got one that works way better.' This
> is why much of the structure of the original BBN stack survived the
> rewrite: if there wasn't a big issue with them, the design and mechanisms
> wound up being conserved by this effort. It was too much work to move from
> mbuf to something else, and too little gain.
> I tried to find a good link, but they are in his BSD history retrospective
> talks to differing degrees. Sorry I don't have an exact reference.
> Warner

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  reply	other threads:[~2023-08-12  5:41 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-11  9:05 Paul Ruizendaal
2023-08-12  5:08 ` Warner Losh
2023-08-12  5:41   ` George Michaelson [this message]
2023-08-12  9:06   ` Paul Ruizendaal
2023-08-12 10:29   ` Paul Ruizendaal
2023-08-12 15:20     ` Warner Losh
2023-08-12 15:24       ` Dan Cross
2023-08-12 16:12         ` Paul Ruizendaal
  -- strict thread matches above, loose matches on Subject: below --
2023-08-12 15:05 Noel Chiappa
2023-08-12 18:00 ` Paul Ruizendaal
2023-08-10  1:09 [TUHS] " Larry McVoy
2023-08-10  2:38 ` [TUHS] " segaloco via TUHS
2023-08-10  2:45   ` Warner Losh
2023-08-10  3:17     ` segaloco via TUHS
2023-08-10  3:18     ` Rob Pike
2023-08-10  5:44       ` John Cowan
2023-08-10 12:41 ` Douglas McIlroy
2023-08-10 14:00 ` Jonathan Gray

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