TELNET

Set to 2 different clues across 2 published puzzles, most often “PC communications link” — The New York Times, Thursday, 14 July 2011.

6 letters

Every clue on record, most used first

PC communications linkonce
The New York Times — Thursday, 14 July 2011
Online protocol for remote log-inonce
The New York Times — Sunday, 30 March 2008