gbit-bandwidth-ecn expected to reach 0.6 of maximum bandwidth

[larseggert]

Seeing a lot of test failures with gbit-bandwidth-ecn expected to reach 0.6 of maximum bandwidth messages:

• https://github.com/mozilla/neqo/actions/runs/19731606723/job/56533731078?pr=3148
• https://github.com/mozilla/neqo/actions/runs/19731606723/job/56533731058?pr=3148
• https://github.com/mozilla/neqo/actions/runs/19714921993/job/56484642503

Any idea what caused this?

[larseggert]

@mxinden, possibly related:

Got receive window of 1024 KiB (effectively 768 KiB) on connection with observed bandwidth 1.411764705882353 MBit/s. Expected: bandwidth 2 MBit/s (2000000 Bit/s), rtt 3ms, bdp 0 KiB. Observed bandwidth is smaller than the link rate.

in https://github.com/mozilla/neqo/actions/runs/19741498008/job/56566263577?pr=3123

[larseggert]

Same in https://github.com/mozilla/neqo/actions/runs/19741419014/job/56565986352?pr=3175