[ih] IANA

[jnc at mercury.lcs.mit.edu (Noel Chiappa)]

Before something which is not complete gets into the online record:

    > On Aug 29, 2009, at 1:05 PM, Steve Crocker wrote:

    > The IMPs were numbered from 1 to 63. The interfaces were numbered from
    > 0 to 3.

That was of course in the original (32-bit?) header. In the new, 96-bit,
headers, the 'host' (interface) number was 8 bits (i.e. 0-255, with 252-255
being used for virtual 'fake' hosts in the IMP itself), and the IMP number
was 16 bits (0-65,535).

    > The host address was the IMP address plus 64 times the interface.

That was for the 32-bit header I assume (I can't my old copy of 1822, only
the new one, which dropped the 32-bit header description). It was stored in
different ways in different headers; e.g. in the 96-bit header, the host was
the low byte of the third 16-bit word, and the IMP was in the fourth word.

Just for grins, in the IP header, the host was stored in the high byte of the
'rest', a 'logical host' (for Port Expanders) in the middle byte, and an
_8-bit_ IMP number in the low byte.

	Noel