Broadcasting packets using ath10k

Raj Joshi rajjoshi at
Sat Jul 30 01:26:44 PDT 2016

Hi all,

For some research experiments, I need to broadcast packets (at
different fixed rates using the bitrates mask). Think of it as a
standalone rudimentary 802.11ac wireless traffic generator.

Simply using iperf for a broadcast address is not allowed (in managed
mode at least) and so I have tried the multicast option. The multicast
option has the following issues:
1) The STA or the AP cannot be standalone: if STA is to be a
multicaster it needs to be associated with an AP and if the AP is to
be a multicaster it needs at least one STA to be associated with it.
2) Traffic direction: When the STA sends a packet to a multicast
address, the packet is first unicasted to the AP at the rate set by
the bitrates mask. The AP then acknowledges it with a blockACK and
further retransmits (multicasts) it with a basic rate (802.11a 6
Mbps). So there is no pure traffic generation. I even tried setting
TTL (number of hops) to zero, but no avail.
3) Cannot fix the rates: On the other hand, when the AP multicasts,
the traffic pattern is as expected - simple outgoing packets with no
blockACKs or other redirection. However, the AP doesn't honor the
bitrates masks and multicast traffic is sent using the basic rate. For
other traffic such as a regular UDP/TCP flow, the AP does honor the
bitrates mask.

Anyone has better ideas on putting together a rudimentary 802.11ac
traffic generator? It would be great to know :)

Raj Joshi

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