V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

T3
       [digital] Transmission link 3 [44.736 Mbps] (DS3)


The Free On-line Dictionary of Computing (30 December 2018):

T3
T3 line

    A digital carrier facility used to transmit
   a DS3 formatted digital signal at 44.736 megabits per
   second.

   See also Integrated Services Digital Network.

   (1994-11-23)