[Cerowrt-devel] [Bloat] uplink bufferbloat and scheduling problems

David Lang david at lang.hm
Thu Dec 2 04:09:49 EST 2021

On Thu, 2 Dec 2021, Toke Høiland-Jørgensen wrote:

> "Valdis Klētnieks" <valdis.kletnieks at vt.edu> writes:
>> On Wed, 01 Dec 2021 13:09:46 -0800, David Lang said:
>>> with wifi where you can transmit multiple packets in one airtime slot, you need
>>> enough buffer to handle the entire burst.
>> OK, I'll bite... roughly how many min-sized or max-sized packets can you fit
>> into one slot?
> On 802.11n, 64kB; on 802.11ac, 4MB(!); on 802.11ax, no idea - the same as 802.11ac?

As I understnad it, 802.11ax can do 16MB (4MB to each of 4 different endpoints)

This is made significantly messier because the headers for each transmission are 
sent at FAR slower rates than the data can be, so if you send a single 64 byte 
packet in a timeslot that could send 4/16MB, it's not a matter of taking 
1/128,000 of the time (the ratio of the data), it's more like 1/2 of the 

So it's really valuable for overall throughput to fill those transmit slots 
rather than having the data trickle out over many slots.

David Lang

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