Frame Aggregation: A-MSDU vs A-MPDU
Wi-Fi packs many packets into one transmission to pay the overhead once. See how A-MSDU, A-MPDU and both build a frame, how much airtime they save, and what happens when errors hit.
How to use this tool controls and what to look for
Choose how packets are bundled and compare the airtime and throughput, then add channel errors to see what each method loses.
Controls to change
- Aggregation: compare None, A-MSDU, A-MPDU, and Both (A-MSDU in A-MPDU).
- Wi-Fi generation: choose Wi-Fi 4, 5 or 6. Each has its own data rate and size limits.
- Packets to send: set how many packets go in one batch.
- Typical packets: choose voice or game (100 B), web (600 B) or full size (1,500 B).
- Channel errors: set Low, Medium or High, and press New random errors for another roll.
What to look for
- Without aggregation, every packet pays for its own preamble, headers, wait and ACK, so small packets waste most of the airtime.
- An error in an A-MSDU loses the whole frame. In an A-MPDU only the damaged subframe is sent again.
- Both together packs the most data per transmission, and faster generations gain the most from it.
About this tool
Every Wi-Fi transmission pays a fixed price before any data moves: waiting for the channel, a preamble and an acknowledgement. Frame aggregation packs many packets into one transmission so that price is paid once. This tool shows how A-MSDU, A-MPDU and both together build a frame, how much airtime they save, and what happens when errors hit.
What you'll learn
- How A-MSDU and A-MPDU pack packets differently
- How much airtime aggregation saves at each Wi-Fi generation
- Why a single error costs more with A-MSDU than with A-MPDU
- The size limits from Wi-Fi 4 to Wi-Fi 7
Common questions
What is the difference between A-MSDU and A-MPDU?
A-MSDU joins several packets into one frame with one checksum, so one error loses them all. A-MPDU sends several frames back to back, each with its own checksum, and a Block Ack says which arrived.
Which is used more, A-MSDU or A-MPDU?
A-MPDU is used almost everywhere. A-MSDU is often used in small amounts inside A-MPDUs, or not at all, depending on the device.
How many frames can an A-MPDU hold?
Up to 64 in Wi-Fi 4 and 5, 256 in Wi-Fi 6 and 1024 in Wi-Fi 7, within the maximum size and transmission time.
Free for private and educational use. This interactive model is a simplified teaching aid and may contain mistakes. It is provided as is, without warranty. Use it to understand the concepts, not as a substitute for a site survey, vendor documentation or professional design advice.