[FS#958] Archer C2600 - high latency over 5GHz wireless & no intermediate software queues

[LEDE Bugs]

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FS#958 - Archer C2600 - high latency over 5GHz wireless & no intermediate software queues
User who did this - Jannis Pinter (jannispinter)

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I have the same problem with my Archer C5 (**QCA9880**). I can reproduce this issue with LEDE 17.01, LEDE 17.01.3 and trunk.

Latency is between 20ms and 100ms. Essentially the wifi is unusable with this router.

64 bytes from fd9d:512:d5f2::d5b: icmp_seq=1 ttl=64 time=26.0 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=2 ttl=64 time=48.9 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=3 ttl=64 time=71.7 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=4 ttl=64 time=93.8 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=5 ttl=64 time=14.4 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=6 ttl=64 time=2.07 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=7 ttl=64 time=59.7 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=8 ttl=64 time=81.8 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=9 ttl=64 time=103 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=10 ttl=64 time=24.4 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=11 ttl=64 time=46.7 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=12 ttl=64 time=68.8 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=13 ttl=64 time=90.9 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=14 ttl=64 time=114 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=15 ttl=64 time=33.8 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=16 ttl=64 time=55.7 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=17 ttl=64 time=77.8 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=18 ttl=64 time=99.9 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=19 ttl=64 time=20.4 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=20 ttl=64 time=42.7 ms
64 bytes from fd9d:512:d5f2::d5b: icmp_seq=21 ttl=64 time=64.8 ms


I do not have any latency issues with OpenWrt 15.01.1.

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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=958#comment3578