Comment 271 for bug 836250

even with current 5.4 kernels from 20.04 (9 years after this bug was reported), it's neccessary to set

options iwlwifi 11n_disable=2

if you have a Intel Centrino Ultimate-N 6300 card. Otherwise there is packet loss that prevents usable throughput rates.

If this is not getting fixed upstream in the kernel, then Ubuntu should ship a configuration for systems with those chipsets, that mitigates the problem. Finding the cause of this problem is only possible for people with expert knowledge. Can you please add a mitigation for this issue in Ubuntu by default?