Network Congestion and Local Instability | Generated by AI

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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:

• ❌ Real packet loss: 6.2% (not good)
• ⚠️ High jitter: 40 ms
• ⚠️ Latency spikes: 580 ms
• ⚠️ Connection unstable

So this time there IS a real network problem.

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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:

• China Telecom international gateway
• leaving mainland China
• entering global transit

So the problem is:

China Telecom international congestion

Very common.

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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.

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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:

• WiFi interference
• router overloaded
• bufferbloat
• LAN congestion

So you may have two problems:

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

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Severity

6% packet loss causes:

• slow HTTPS
• broken downloads
• SSH lag
• git clone failures
• API timeout
• streaming buffering

You will definitely feel this.

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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

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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

• mobile hotspot
• different ISP
• company network

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

Because:

VPN may exit China using better route

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Final verdict

Your second test shows:

• ❌ Real packet loss (6%)
• ❌ High jitter
• ⚠️ Local router instability
• ⚠️ China Telecom international congestion

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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