Congestion control, one of the troublesome problems demonstrated by Kahn’s experiments, had been attacked and improved. BBN had redesigned the scheme to reserve enough space in the IMP memory buffers for reassembly of incoming packets. A specific amount of reassembly space for each message would be reserved at a destination IMP before the message would be allowed to enter the network. The sending IMP would check, and if told that there was insufficient space available in the destination IMP’s buffers, the RFNM (Request For Next Message) was delayed.
