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explanation of various PDUs

1 posts by 1 authors in: Forums > CWDP & CWAP - Enterprise Wi-Fi Design & Analysis
Last Post: April 3, 2008:

By GTHill April 3, 2008

Reply

SDU = Service Data Unit = Raw data from an above layer

PDU = Protocol Data Unit = Raw data from an above layer, plus the headers from the current layer.

MSDU = MAC (Layer) SDU = Raw data from the IP layer. Does not currently include the MAC header.

MPDU = MAC (Layer) PDU = Raw data from the IP layer with the Wi-Fi header and Frame Check Sequence (FCS). This is a fully formed Wi-Fi Frame

PSDU = Physical SDU = Raw data from the MAC (Data Link) layer without the Physical layer header. This is exactly the same thing as the MPDU, it has just moved from layer 2 to layer 1.

PPDU = Physical PDU = Raw data from the MAC layer plus the Physical layer headers (Preamble, Length, etc)

Let me know if you need further explanation.

Gene

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