2. Core-to-core transfers between HOSTS

At another level, perhaps not involving HOST-IMP protocol or IMP software changes, is a HOST-HOST protocol wherein cooperating HOSTS agree to lock appropriate programs in core for the duration of a multi-message file transfer on an auxiliary connection. This could greatly reduce the time to transfer such a file to and from a swap-bound HOST. Unfortunately, the numbers mitigate possible advantages of this approach to some extent: if we assume a 50 kilobit/sec line and support further that it is dedicated at 100% efficiency to this transfer (which may require slightly different handling of RFNMs in this case) this comes out to just over 6 8-kilobit messages per second. It may be impolitic in a timeshare environment to lock a single program in core for more than about 2 seconds. If this is the case, then the method would be applicable only for the rather limited range of file sizes of 2-16 messages. Nevertheless, the time to move a large file could be so greatly enhanced by this approach that I think it deserves consideration.