CompTIA 220-801 Certification Practice Test

Answer - D - An OC-1 link offers 51.48 Mbps, a T1 line offers 1.544 Mbps a T3 line offers 44.736 Mbps, and an ISDN PRI offers 1.544 Mbps.

Key Takeaway: Optical carrier classifications are based on the abbreviation OC followed by a number specifying a multiple of 51.84 Mbit/s i.e. n × 51.84 Mbit/s. For example, OC-1 is a SONET line with transmission speeds of up to 51.84 Mbit/s, payload of 50.112 Mbit/s, and overhead of 1.728 Mbit/s.