[Cake] fq_codel on 3g network in Mauritius

[Loganaden Velvindron]

On Tue, Jul 19, 2016 at 12:09 PM, Jonathan Morton <chromatix99 at gmail.com> wrote:
>
>> On 19 Jul, 2016, at 07:29, Loganaden Velvindron <loganaden at gmail.com> wrote:
>>
>> I've been playing with fq_codel on 3g internet connection. the 3g
>> internet box has no bridge mode, and just forwards every packet to the
>> Openwrt router.
>>
>> Here are the results without:
>> http://www.dslreports.com/speedtest/4470186
>>
>> And here is the result with fq_codel on and 300 ms target latency:
>>
>> http://www.dslreports.com/speedtest/4470286
>>
>> Is there anything that could be done to get the rating up to A+ by
>> tweaking the code ?
>
> You say fq_codel, rather than Cake.  Presumably it is paired with some sort of shaper, such as HTB?  This is important, because I think the shaper is influencing part of your results.
>
> On downstream, you have one high latency sample (750ms) in the middle of a series of reasonable ones (250ms).  This implies a momentary glitch in your connection, which isn’t unusual with wireless links.  Re-measuring might eliminate it.
>
> On upstream, you have two very high latency samples at the *beginning* of the run, which then clear out to approximately the baseline latency.  This is a classic sign that your shaper is letting a burst of traffic through before actually starting to control it, which is typical behaviour for token-bucket shapers.  That initial burst collects in the dumb queue of your 3G modem and takes time to drain away.
>
> Cake uses a shaper carefully designed to *not* burst in that manner, while still maintaining full throughput regardless of timer resolution and latency.  Using Cake instead of fq_codel+HTB will therefore probably improve your upload characteristics.
>

here's the output from tc:

qdisc fq_codel 0: dev eth0 root refcnt 2 limit 1024p flows 1024
quantum 300 target 5.0ms interval 100.0ms ecn
qdisc htb 1: dev eth1 root refcnt 2 r2q 10 default 12
direct_packets_stat 0 direct_qlen 1000
qdisc fq_codel 110: dev eth1 parent 1:11 limit 1001p flows 1024
quantum 300 target 300.0ms interval 100.0ms
qdisc fq_codel 120: dev eth1 parent 1:12 limit 1001p flows 1024
quantum 300 target 300.0ms interval 100.0ms
qdisc fq_codel 130: dev eth1 parent 1:13 limit 1001p flows 1024
quantum 300 target 300.0ms interval 100.0ms
qdisc ingress ffff: dev eth1 parent ffff:fff1 ----------------
qdisc mq 0: dev wlan0 root
qdisc htb 1: dev ifb4eth1 root refcnt 2 r2q 10 default 10
direct_packets_stat 0 direct_qlen 32
qdisc fq_codel 110: dev ifb4eth1 parent 1:10 limit 1001p flows 1024
quantum 300 target 300.0ms interval 100.0ms ecn

I will give CAKE a try. However, I'm not sure if there's enough space
(4mb NAND flash) on the tp-link wr841nd for sqm-qos. I will need to
get another box like the tp-link archer c7.