Technology History | Boelter Hall 3420, UCLA — The Network's First Message Got Two Letters Out

The log entry is four words and a time: 22:30, talked to SRI, host to host. Charley Kline, a student programmer, sat at a terminal in room 3420 on the night of 29 October 1969, trying to log in to a machine roughly 350 miles north at the Stanford Research Institute. He typed L, and Bill Duvall confirmed by telephone that it had arrived at the other end. He typed O, and that arrived too. He typed G, and SRI's machine crashed. The first message passed between two host computers on the network that became the internet was therefore the word LO, and it was an accident of truncation rather than anyone's idea of a historic sentence. Two things in this story are routinely collapsed into it and should not be. The refrigerator-sized Interface Message Processor that made the connection possible, a ruggedised Honeywell built by BBN in Cambridge, had been delivered here weeks earlier, and the permanent UCLA-SRI link was not established until 21 November. The qualifier matters just as much. This was ARPANET's first host-to-host connection, not the internet's birth: TCP/IP, the protocol that made a network of networks possible, was still years off, and calling either moment the invention of the internet flattens a decade of work by a great many people. Leonard Kleinrock's group had the node because his queueing-theory work on packet networks made UCLA the sensible place to put the first one. The room was an ordinary university machine room, which is most of the point. Room 3420 is now the Kleinrock Internet History Center, restored toward its 1969 appearance with an IMP in it. Boelter Hall is a working engineering building on the UCLA campus and the room is not always open, so a visit is worth arranging in advance. The building itself is the plainest object in the story. Red brick, wide steps, BOELTER HALL in metal letters on a low garden wall, and no external hint that the first two letters of the network age were typed on the third floor. Cover: photo by legge_e_mare, CC BY 2.0, via Wikimedia Commons. It shows the Boelter Hall entrance, not room 3420, for which no freely licensed photograph has been found.