Question

__________ was developed by CCITT to provide standard connectionless network access protocols for three layers of OSI model.

(a) Packet switching

(b) Datagram routing

(c) X.25

(d) CDPD

This question was addressed to me by my school teacher while I was bunking the class.

My question is taken from Traffic Routing in Wireless Networks topic in chapter Wireless Networking of Wireless/Mobile

Answer 1

The correct choice is (c) X.25

The best I can explain: X.25 was developed by CCITT (now ITU-T) to provide standard connectionless network access (packet switching) protocols for the three layers (layer 1, 2 and 3) of the open systems interconnection (OSI) model.