[ih] Early internetworking

[Lawrence Stewart]

In 1978 the Packet Radios for PRNet were built by Collins and indeed had BBN-1822 host interfaces.

I was an intern at PARC at the time and designed the Alto-1822(1) to work with it.  The low level link protocol was indeed not like the IMPs. The one we used was called CAP for Channel Access Protocol.

The MTU was quite small and we had to fragment PUPs for transit.  Hal Murray had written a Pup Stack/gateway in Mesa and we used that for our work.

There are great PRNet stories though. According to lore, the Collins manager wanted absolute control over the radio software and insisted it be kept in a box of punched cards in his office.

IEN 78 has more information, and the software is still out there in the computer museum’s collection.

(1) Dave Boggs looked at my draft design and said “You obviously do not know what you are doing.” and then taught me the right way to design state machines.

-L