In tower king function

摘要

(57) Abstract N-ISDN (20) with B-ISDN (10) with in order to give in tower king function between, B-ISDN (10), the data communication protocol which is based on the 2nd signaling system 7 which includes MTP2 level (90 and 100) it includes, function of MTP2 level is divided the 1st sublevel (92) with the 2nd sublevel (MTP2 high).