Which term describes the smallest UNI Layer 2 maximum frame size in this context?

• A. 1522 IP packet with one service tag
• B. Smallest UNI L2 Max frame size
• C. Maximum L2 frame size
• D. Standard MTU

Answer: (B)

The key idea is that end-to-end Layer 2 frame size across a service is limited by the smallest capability along the path. In MEF SD-WAN, each UNI has its own maximum L2 frame size, so the frames you can successfully deliver across the entire service must be no larger than the smallest of those UNI limits. That exact description—capturing the limiting, smallest UNI L2 maximum frame size—fits the concept precisely.

The other options describe specific frame sizes or generic MTU values rather than the limiting concept. A size like 1522 bytes refers to a particular framing scenario, not the general bottleneck. The maximum L2 frame size is the opposite of what’s constraining the service here. A standard MTU is a common Ethernet value, but the MEF term for the bottleneck across UNIs is the smallest UNI L2 Max frame size.