[ih] The origin of variable length packets

[Miles Fidelman]

*Noel Chiappa* jnc at mercury.lcs.mit.edu 
<mailto:internet-history%40postel.org?Subject=%5Bih%5D%20The%20origin%20of%20variable%20length%20packets&In-Reply-To=> 
wrote:
>      >  From: Stephen Suryaputra<ssurya at ieee.org  <http://mailman.postel.org/mailman/listinfo/internet-history>>
>
>      >  Any pointer or reasons why the packet becomes variable length later on?
>
> I would assume/guess that the first well-known and wide-scale use was in the
> ARPANet. (Which was pretty much the first general packet network I know of -
> were they any proprietary things before that, does anyone know?)
>
> The first variable length data items transmitted between compturers (although
> I would tend to doubt they thought of them as packets) might be hard to track
> down.
>
> It might have been some of the early computer-computer experiments, e.g. the
> kind of thing Larry Roberts did at Lincoln Labs (which definitely had variable
> length messages); another early system that might have had variable length
> data items was SAGE (since that also had computer-computer links between
> centers, although I don't know offhand of a source that talks about that level
> of detail on the communication aspects of SAGE).
>    
IBM BISYNC predated ARPANET (1967 I think), and probably falls into 
"well-known and wide-scale use," at least for its day.  It wasn't quite 
a packet protocol, but it was used on multi-drop links - so it dealt 
with addressing, link access control (master-slave controller I think), 
and such.  It was variable length, but accomplished by trailing 
"completion codes" rather than encoding the number of bytes-to-follow in 
a header.

I expect Burroughs, Honneywell, and the other Seven Dwarfs had something 
comparable in the same time frame.

Miles Fidelman

-- 
In theory, there is no difference between theory and practice.
In<fnord>  practice, there is.   .... Yogi Berra