Network Congestion and Local Instability | Generated by AI

Home 2026.04

Question: How to interpret this second MTR result showing ~6% packet loss and high jitter to 104.21.78.239?

Answer:

This second test is different from your previous one — now there is real packet loss and jitter. The key is the final hop, which shows actual end-to-end quality.

12. 104.21.78.239   Loss 6.2%   Avg 276 ms   Worst 580 ms   StDev 40 ms

This means:

So this time there IS a real network problem.

Where the problem starts

Look at hop 9:

9. 202.97.116.250   Loss 7.0%   Avg 276 ms

From this hop onward:

9  loss 7%
10 loss 43%
11 loss 13%
12 loss 6%

Since loss starts at hop 9 and continues to destination, the issue is real congestion after hop 9.

This hop:

202.97.116.250

This is:

So the problem is:

China Telecom international congestion

Very common.

Your route visualization

Your Mac
  ↓
Home router (192.168.1.1)
  ↓
ISP CGNAT (100.69.0.1)
  ↓
China Telecom Guangdong
  ↓
China Telecom backbone
  ↓
202.97.x.x  ← congestion starts here
  ↓
International transit
  ↓
Cloudflare
  ↓
104.21.78.239

The bottleneck is the international exit.

Another warning sign

Your first hop already unstable:

1. 192.168.1.1  
Loss 2.3%  
Avg 21.9 ms  
Worst 194 ms

This is not normal.

Your local network should be:

0% loss
< 3 ms latency

This suggests:

So you may have two problems:

  1. Local WiFi/router instability
  2. China Telecom international congestion

Severity

6% packet loss causes:

You will definitely feel this.

How to confirm

Run:

mtr -rwzc 100 1.1.1.1

and

mtr -rwzc 100 8.8.8.8

If both show loss → ISP problem If only this host → route-specific congestion

Quick fixes

Best → worst:

1. Use wired Ethernet

Eliminate hop 1 instability

2. Switch DNS (Cloudflare / Google)

1.1.1.1
8.8.8.8

May route to better PoP.

3. Try IPv6

Sometimes avoids congested IPv4 path

4. Use different network

5. Use tunnel/VPN (not ideal but works)

Because:

VPN may exit China using better route

Final verdict

Your second test shows:

So this connection is unstable right now.

Your first test was healthy. This second test shows temporary congestion (very common in evening).

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