CenturyLink Fiber Latency Issues (Seattle, WA)

Ryan Hamel administrator at rkhtech.org
Tue Nov 2 03:52:37 UTC 2021


Neel,

Sounds like buffer bloat.

Run a speed test, whatever is your maximum for your download and upload take
10% away from it, and setup traffic shaping in OPNsense
(https://docs.opnsense.org/manual/shaping.html) with those values. If the
issue goes away, then you're exceeding the buffer of CenturyLink's device
with the bursts of traffic.

Ryan

-----Original Message-----
From: NANOG <nanog-bounces+ryan=rkhtech.org at nanog.org> On Behalf Of Neel
Chauhan
Sent: Monday, November 1, 2021 6:44 PM
To: nanog at nanog.org
Subject: CenturyLink Fiber Latency Issues (Seattle, WA)

Hi NANOG Mailing List,

I don't know if any of you work at CenturyLink/Lumen, very less on their
Fiber network in Seattle, WA. However, here's my story.

If I attempt to run certain applications that use 1000, or 10000 TCP
connections, I get latency spikes. It is based on how many connections, but
also how much bandwidth is used. This means certain things like Tor relays
are off limits to me (which I wish to run).

On an idle connection, the PingPlotter outputs look like this: 
https://centurylinklatencyissues.com/image-000.png

If I attempt to run BitTorrent with 1000 connections in Deluge, PingPlotter
looks like this: 
https://centurylinklatencyissues.com/image-002.png

Getting support, or even executive contacts to admit the issue hasn't
worked. They all love to blame my equipment or applications, when CL routers
also show the issue when I run the same things whereas my same exact
OPNsense box on Google Fiber Webpass running Tor at another address had no
issues whatsoever, and I can ping other Tor relays on CenturyLink AS209 just
fine (from a VPS).

The most competent person I dealt with was actually one tech. He told me
there was "capacity issues" in our neighborhood, and that's the reason for
the issues. However, nothing was done about it afterwards, I'm guessing
since I turned off my Tor relay after the visit to avoid complaints from
family members.

On an AT&T forum, people have said GPON gives latency spikes/packet loss on
congestion: 
https://www.dslreports.com/forum/r33242889-How-rare-is-GPON-XGSPON-saturatio
n

The capacity managers in Seattle are literally dragging their feet: it's
100x worse than AT&T's 802.1X. I know AT&T and CenturyLink don't compete,
but if I had to choose between AT&T Fiber and CenturyLink, I'll take AT&T in
a heartbeat, no ifs, no buts, even if I have to use AT&T's crappy router
instead of my OPNsense box.

Going back, do any of you who work at CenturyLink/Lumen can get me to the
right people, hopefully the capacity managers in Seattle?

I could go with Comcast, but it's either (a) 35 Mbps uploads or (b) $329/mo
for "Gigabit Pro" with a 2-year contract and a steep install fee. I am
seriously considering Gigabit Pro even if it breaks the bank, but hope I
won't have to go there.

I don't need 2 Gbps and would rather pay $65 than $329. 300-500 Mbps uploads
when I need it is the sweet spot for me (even without Tor) which CL GPON
should easily handle without a sweat. I also don't exactly
**trust** Comcast, they're a horrible company in many metrics, but in some
ways Comcast is more competent than CenturyLink.

Best,

Neel Chauhan



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