[ih] Origin of "best effort"

[Brian E Carpenter]

http://mailman.postel.org/pipermail/internet-history/2010-June/001360.html
offered another take. However, I haven't actually found a contemporary
publication by Pouzin that uses the phrase. Secondary sources cite his
1974 paper "CIGALE, the packet switching machine of the CYCLADES". That
has a nice summary of the e2e argument 10 years before Saltzer et al:
"However node and line failures coupled with adaptive routing may result
in packets being lost or duplicated. Consequently, some control mechanism
is necessary to catch this type of error. It can only be done as part of
a transmission procedure between a pair of correspondents."
It also covers TOS: "...it is clear that various traffic classes might be
accommodated, e.g. a shortest delay class,..."
It's a brilliant paper for its date, but it does not describe "best effort"
service.

In fact it seems to me that most work at that time (ALOHA, for example)
worried extensively about errors and repeating faulty packets at layer 2.
Even CSMA/CD and WiFi do that to this day. So even admiring Pouzin's
contribution, I'm still puzzled about when "best effort" (which is not an
empty phrase) entered the formal discourse. It doesn't appear in any of
Pouzin's publications from that era in the IEEE and ACM libraries, and
I can't find it in the 1979 edition of Davies et al "Computer Networks
and Their Protocols", which cites Pouzin's work.

Regards
   Brian

On 20/01/2017 08:35, John Day wrote:
> For most of my life, the term “to make a best effort” had more the latter meaning that the former. It was just a colloquial phrase. I wouldn’t call it slang but similar.  As I said, in networking the phrase originates with Pouzin and CYCLADES and the invention of the datagram. That would put it in the early 1970s.
> 
> John
> 
>> On Jan 19, 2017, at 14:09, Guy Almes <galmes at tamu.edu> wrote:
>>
>> Hi Brian,
>>   This is actually an interesting question.
>>   During the 1990s we had a discussion in which this phrase came up, 
>> used in the now-typical networking sense.
>>   One colleague in the conversation, a lawyer, who had done work in the 
>> construction industry, found the usage very odd because, he said, in 
>> contracts within that industry the phrase had a specific meaning and it 
>> obliged a person/company to a very very high standard of "best effort". 
>> In that context, for example, it might oblige a company to spend 
>> money/effort to a degree that would keep a promise but ruin any hope for 
>> making money in the deal.  He noted that we computer engineers were 
>> using the term in an almost opposite (and, to him, an ironic) sense, 
>> viz., "do whatever is normal, but *not* heroic, and if it works, good 
>> and if it doesn't, don't worry about it".
>>
>>   If the phrase is connected that older "contract language" usage, it 
>> would indeed be interesting to see how it came to have almost a reversal 
>> or sense.
>>
>> 	-- Guy
>>
>> On 1/18/17 2:34 PM, Brian E Carpenter wrote:
>>> I learnt very early on that the Internet offered a "best effort" service
>>> for the delivery of datagrams.
>>>
>>> Where did that meme come from, and when?
>>>
>>> The earliest trace I found in a quick trawl was 1986 (RFC992). But RFC791
>>> doesn't mention it, and defined TOS, such that all packets were *not* assumed
>>> to be created equal. The 1984 Saltzer et al paper doesn't mention it either.
>>>
>>> (RFC768 does say that UDP delivery is "not guaranteed" but that is not
>>> the same thing as "best effort".)
>>>
>>> The question is of interest because some analyses of network neutrality,
>>> including a student dissertation I was reviewing yesterday, conflate the
>>> end-to-end principle with best-effort packet delivery.
>>>
>>> Regards
>>>     Brian
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