A leased, dedicated high-speed connection supplied by a local telephone…
2010
A leased, dedicated high-speed connection supplied by a local telephone carrier transmits data at 1.544 Mbps. This connection is known as which T-carrier level?
Answer: A. T₁ — ConceptA T-carrier level is identified by its standardized digital transmission rate and channel aggregation. Successive levels multiplex lower-rate digital…
- A.
T₁
- B.
T₂
- C.
T₃
- D.
T₄
Attempted by 16 students.
Show answer & explanation
Correct answer: A
Concept
A T-carrier level is identified by its standardized digital transmission rate and channel aggregation.
Successive levels multiplex lower-rate digital channels into progressively higher-capacity carriers.
Application
Match the stated rate with the standard T-carrier hierarchy.
A DS0 voice-grade channel carries 64 kbps; T₁ combines 24 DS0 channels in a DS1 frame.
The payload rate is 24 × 64 kbps = 1.536 Mbps.
Adding the DS1 framing bit in each 125-microsecond frame contributes 8 kbps, giving 1.536 + 0.008 = 1.544 Mbps.
Contrast
T₂ has a nominal rate of 6.312 Mbps.
T₃ has a nominal rate of 44.736 Mbps.
T₄ has a nominal rate of 274.176 Mbps.
Cross-check
The independently reconstructed rate, 1.544 Mbps, matches the rate in the question.
Therefore, the leased carrier described is T₁.