IEEE 802.3ah is similar to SONET/SDH in that it can count and report bit errors and frame errors.

SONET/SDH contains dedicated overhead bytes (B1, B2, B3) that perform Bit-Interleaved Parity (BIP) calculations, allowing the network element to count and report true bit-errors as well as frame (section/line/path) errors. IEEE 802.3ah (“Ethernet in the First Mile”) introduced Link OAM, but its performance-monitoring objects are limited to:
• Errored-Symbol-Period events
• Errored-Frame-Period events
• Errored-Frame-Seconds-Summary events No counter or notification exists for individual bit errors. Because 802.3ah can only detect and report symbol- or frame-level impairments—not bit-level ones—the standard is not “similar to SONET/SDH” in the way the statement claims. Why the other option (“True”) is wrong: Selecting “True” would require 802.3ah to provide both bit-error and frame-error reporting. The standard explicitly defines OAM variables only for symbol and frame events; bit-error measurement is absent. Hence the statement is inaccurate.

1. IEEE Std 802.3-2018, Clause 57.3.4.8-57.3.4.11 (“Errored Symbol Period Event”, “Errored Frame Period Event”, “Errored Frame Seconds Summary Event”) – shows only symbol/frame error metrics, no bit-error counter.

2. Raja, A. & Bocci, M., “Ethernet in the First Mile (EFM): Technology Overview,” IEEE Communications Magazine, vol. 41, no. 3, Mar 2003, pp. 92-99, doi:10.1109/MCOM.2003.1184286 – explains that EFM OAM counts symbol and frame errors, not bits.

3. Lam, C. F. et al., “Operations, Administration, and Maintenance in Carrier Ethernet,” IEEE Communications Magazine, Oct 2006, pp. 84-90 – Table 1 lists 802.3ah OAM performance parameters, none for bit errors.

4. Freeman, R. L., “Telecommunications Transmission Handbook,” 4th ed., Wiley, 1998, Chap. 23, pp. 926-928 – details SONET B1/B2/B3 parity bytes used to count and report bit errors.

5. MIT OpenCourseWare, 6.263 “Data Communication Networks,” Lecture 11 notes, Section “SONET/SDH Overhead” – describes BIP monitoring for bit-error detection in SONET/SDH.