Last mile is symmetric 5.6. Upload dies the moment traffic hits Lumen.

Verdict

AS path: customer → Brightspeed AS19901 → Lumen / Level 3 AS3356 (Charlotte or Jacksonville). Those are the only two exits seen from this circuit.

On-net — Brightspeed Beaufort

This is the last-mile control. The path never leaves Brightspeed. Upload matches download.

Ashburn (IAD)

East Coast interconnect destination. Same Lumen Charlotte handoff both times. Download is ~5.7G. Upload is not.

Cloudflare

Not Ookla. speed.cloudflare.com, colo ATL from cdn-cgi/trace. Traceroute still Brightspeed → Lumen Charlotte → Cloudflare. Same cliff, second public IP too.

Other off-net paths

Atlanta and Miami still fill ~5G down after Lumen. Upload still dies. Peak upload was not worse than 4 AM.

Where it breaks

Hop 3 is still Brightspeed and healthy. Hop 4 is Lumen.

On-net Beaufort never takes hop 4 Lumen. Destination picks CLT vs JAX; it does not flip at random. The two Lumen ears also hairpin through each other.

Traceroutes

Wired 10G client · 8 Sep 2026, ~16:28–16:31 EDT · -n -w 2 -q 1 -m 12. Scroll sideways on the dumps if needed.

On-net Beaufort — no Lumen

traceroute to 207.50.80.247
 1  10.10.10.1      0.310 ms
 2  143.103.168.1   2.561 ms
 3  207.50.80.64    3.317 ms
 4  207.50.80.253   4.399 ms
 5  207.50.80.247   2.695 ms !X

Frontier Ashburn — Charlotte Lumen

traceroute to 74.32.190.33
 1  10.10.10.1      0.457 ms
 2  143.103.168.1   2.194 ms
 3  207.50.80.64    2.005 ms
 4  64.159.215.1   10.420 ms     ear1.Charlotte1.Level3.net
 5  4.69.136.66    19.214 ms     ae2.3601.edge2.Washington111.net.lumen.tech
 6  4.37.99.246    18.043 ms
 7  74.32.190.33   18.025 ms

Same hour Ookla: 5.68 down / 1.13 up.

Cloudflare ATL — Charlotte Lumen

traceroute to speed.cloudflare.com (172.66.0.218)
 1  10.10.10.1      1.007 ms
 2  143.103.168.1   4.316 ms
 3  207.50.80.64    4.311 ms
 4  64.159.215.1   10.479 ms     ear1.Charlotte1.Level3.net
 6  4.43.9.210     13.721 ms
 7  108.162.235.109 14.405 ms    Cloudflare
 9  172.66.0.218   13.693 ms

Clouvider Atlanta — Jacksonville Lumen

traceroute to 92.119.16.139
 1  10.10.10.1      0.436 ms
 2  143.103.168.1   2.447 ms
 3  207.50.80.66    2.268 ms
 4  4.42.103.21     8.204 ms     ear1.Jacksonville5.Level3.net
 7  62.115.134.246 15.151 ms     Arelion
11  92.119.16.139  14.258 ms

Direct to the Lumen ears

64.159.215.1  Charlotte
 1  10.10.10.1      0.828 ms
 2  143.103.168.1   2.815 ms
 3  207.50.80.64    2.029 ms
 4  64.159.215.1   10.391 ms

4.42.103.21  Jacksonville
 1  10.10.10.1      0.330 ms
 2  143.103.168.1   1.863 ms
 3  207.50.80.66    1.675 ms
 4  4.42.103.21     8.683 ms

Ping and MTR — idle path is clean

ICMP -c 20 and MTR -n -r -c 20, 8 Sep 2026 16:28–16:31 EDT. Dest loss 0% except ICMP-filtering targets. The upload collapse is not on idle probes.

MTR ICMP — Beaufort

Start: 2026-09-08T16:28:25-0400
HOST: client        Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 10.10.10.1     0.0%    20    0.5   0.4   0.3   0.6   0.1
  2.|-- 143.103.168.1  0.0%    20    1.9   2.4   1.5   3.9   0.6
  3.|-- 207.50.80.66   0.0%    20    2.2   1.8   1.3   2.2   0.3
  4.|-- 207.50.80.247  0.0%    20    1.9   1.7   1.2   2.2   0.3

MTR ICMP — Frontier Ashburn

Start: 2026-09-08T16:29:51-0400
HOST: client        Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 10.10.10.1     0.0%    20    0.5   0.5   0.3   0.6   0.1
  2.|-- 143.103.168.1  0.0%    20    1.8   2.0   1.6   3.0   0.4
  3.|-- 207.50.80.66   0.0%    20    1.5   1.6   1.4   2.2   0.2
  4.|-- 4.42.103.21    0.0%    20    6.8   7.0   6.4   8.0   0.4
  5.|-- ???           100.0    20    0.0   0.0   0.0   0.0   0.0
 10.|-- 74.32.190.33   0.0%    20   28.1  28.0  27.1  28.7   0.3

MTR ICMP — Lumen Charlotte ear

Start: 2026-09-08T16:28:54-0400
HOST: client        Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 10.10.10.1     0.0%    20    0.3   0.4   0.2   0.7   0.1
  2.|-- 143.103.168.1  0.0%    20    2.1   2.1   1.1   2.6   0.4
  3.|-- 207.50.80.66   0.0%    20    1.6   1.8   1.3   2.3   0.3
  4.|-- 4.42.103.21    0.0%    20    7.3   7.4   6.9   8.6   0.4
  5.|-- 64.159.215.1   0.0%    20   13.5  12.9  12.4  13.5   0.3

What this is not

• Not the ONT / last mile. On-net Beaufort is 5.6/5.6 off-peak and peak.
• Not Wi-Fi, not a 1G NIC. Wired 10G Ethernet. WAN into the CPE is 10G.
• Not idle packet loss. ICMP to Beaufort, both Lumen ears, Ashburn, Atlanta, and Cloudflare: 0% dest loss.
• Not a per-IP cap. Second public address 208.160.55.18 got Cloudflare 5.15 / 1.65 vs 4.93 / 1.80 on 67.146.210.204.
• Not only late-night. Peak 16:03 EDT is the same cliff.
• Not “the internet is far.” Download through the same Lumen hop is still ~5G. Only customer→internet falls over.

What to look at