[ih] UDP Length Field?

[Stephen Casner]

On Wed, 2 Dec 2020, Jack Haverty via Internet-history wrote:

> There was an "uncontrolled mode" of operation possible within the
> ARPANET, which wouldallow a user computer to send packets bypassing all
> of the reliability mechanisms.   That could be used to deliver datagram
> Internet service.   However, the ARPANET managers (at DCA and BBN) were
> extremely reluctant to permit hosts (e.g., gateways) to use that mode,
> for fear that the uncontrolled traffic would crash the ARPANET.   I
> recall being involved in several "discussions" about using ARPANET
> uncontrolled mode for Internet experiments, but I don't remember any
> permissions ever being granted.

We definitely did get permission to use this for packet voice
experiments between ISI and LL, for example.  What I recall is that
initially we were required to arrange with BBN for a specific
experiment time between specific hosts and the uncontrolled mode (Type
0, Subtype 3 -- BBN 1822 p. 3-17) would be enabled only for those
hosts.  But later I believe our packet voice hosts were enabled all
the time.

                                                        -- Steve