This directory was not on the original beta distribution tape. It contains a more developed version of the networking kernel, presumably from October 1982 (one year later than the tape). This version has support for UDP and several bug fixes; it would have been the version used on 'flag day'. These files were found in the online archives of the Stanford AI Laboratory (SAIL): https://www.saildart.org/[IP,SYS]/ The files are mixed in with what looks like the TCP/IP implementation for WAITS, where it may have been used as a reference.