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MTR show latency in trace to my Miami Virtual Machine
I run a VPS with Vultr in Miami data center which host a Amateur Radio Digital Voice Reflector.
I am experiencing reported voice drop outs from many users. I have contacted Vultr and they have tracked it down to a Comcast point in Miami.
I am including the MTR from my office to the Vultr VPS.
Any help would be apprieciated.
LAPTOP-2S5KH4R9 (172.20.12.76) -> 207.246.112.46 (207.246.112.46) 2026-03-31T10:47:38-0400
Keys: Help Display mode Restart statistics Order of fields quit
Packets Pings
Host Loss% Snt Last Avg Best Wrst StDev
1. LAPTOP-2S5KH4R9.mshome.net 0.0% 71 0.8 15.1 0.5 1022. 121.3
2. 192.168.0.1 0.0% 71 1.5 1.5 1.2 2.0 0.1
3. 10.0.0.1 0.0% 71 4.0 17.9 3.2 1014. 120.0
4. 10.144.236.227 0.0% 71 14.8 29.3 11.9 1027. 120.2
10.144.236.226
5. po-57-rur301.foxboro.ma.boston.comcast.net 0.0% 71 14.0 15.2 12.9 26.2 2.2
po-57-rur302.foxboro.ma.boston.comcast.net
6. po-300-xar01.foxboro.ma.boston.comcast.net 0.0% 71 13.0 15.3 12.8 28.9 2.8
po-2-rur301.foxboro.ma.boston.comcast.net
7. po-300-xar01.foxboro.ma.boston.comcast.net 0.0% 71 16.3 32.5 12.8 1045. 122.4
be-302-arsc1.needham.ma.boston.comcast.net
8. be-302-arsc1.needham.ma.boston.comcast.net 0.0% 71 16.6 34.0 14.5 1040. 121.2
be-32041-cs04.newyork.ny.ibone.comcast.net
be-32021-cs02.newyork.ny.ibone.comcast.net
be-32031-cs03.newyork.ny.ibone.comcast.net
be-32011-cs01.newyork.ny.ibone.comcast.net
9. be-2212-pe12.nota.fl.ibone.comcast.net 0.0% 71 53.9 36.6 18.6 57.5 16.0
be-2312-pe12.nota.fl.ibone.comcast.net
be-32011-cs01.newyork.ny.ibone.comcast.net
be-32031-cs03.newyork.ny.ibone.comcast.net
be-2412-pe12.nota.fl.ibone.comcast.net
be-2112-pe12.nota.fl.ibone.comcast.net
be-32041-cs04.newyork.ny.ibone.comcast.net
be-32021-cs02.newyork.ny.ibone.comcast.net
10. be-2212-pe12.nota.fl.ibone.comcast.net 56.3% 71 54.9 85.6 50.2 1072. 183.2
be-2112-pe12.nota.fl.ibone.comcast.net
be-2412-pe12.nota.fl.ibone.comcast.net
be-2312-pe12.nota.fl.ibone.comcast.net
11. (waiting for reply)
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13. (waiting for reply)
14. 207.246.112.46.vultrusercontent.com 47.9% 71 58.7 53.7 50.2 60.7 2.8
user_v43rek
Visitor
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3 Messages
1 month ago
Is this forum monitored by Xfinity and is so how long does it take for a reply?
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XfinitySara
Official Employee
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2.5K Messages
29 days ago
Hello, @user_v43rek! Thank you for creating a new post, then giving our community time to respond. Our apologies for the delay while we work hard to respond to every post as quickly as we can, in the order we receive them. Not to worry! One way or another, we're always happy to take a look, and help in any way we can :)
This MTR (My Traceroute) provides a very clear "smoking gun" for the issues you're experiencing. While high latency is annoying, packet loss is the absolute killer for Amateur Radio Digital Voice (like DMR, D-STAR, or Fusion), as these protocols rely on a steady stream of UDP packets that cannot be retransmitted. Here is the breakdown of what is happening in your network path:
1. The Local Jitter (Hops 1–4)
Before we even look at Florida, there is a significant issue at your home/office starting at the very first hop:
- Hop 1 (Your Laptop): You have a Worst (Wrst) time of 1022ms.
- Hop 3 & 4: Similarly, you're seeing spikes over 1000ms.
- The Cause: This usually indicates a local Wi-Fi issue, a saturated upload link, or a faulty local cable/router. Even though the average is low, that "StDev" (Standard Deviation) of 121.3 is massive. Your voice packets are likely getting bunched up before they even leave your building.
2. The Comcast "Black Hole" (Hops 9–10)
This confirms what Vultr told you. The transition into the Miami "NOTA" (Network Access Point of the Americas) is failing:
- Hop 10 (nota.fl.ibone.comcast.net): You are seeing 56.3% packet loss.
- Analysis: While some routers use "ICMP Rate Limiting" (where they ignore ping requests but pass normal traffic fine), the fact that this loss carries through to the final destination (47.9% loss at the Vultr IP) proves this is real data loss, not just a router ignoring pings.
3. Impact on Digital Voice
Digital Voice reflectors require very low jitter and near-zero packet loss.
- 47.9% Packet Loss: This means nearly half of every sentence spoken is being dropped. The vocoder cannot reconstruct the audio, resulting in the "R2-D2" robot sounds or total silence your users are reporting.
Recommended Actions
Step 1: Fix the "First Mile" (Your Side)
Even if we fix the Miami node, your local jitter will still cause dropouts.
- If you are on Wi-Fi, switch to an Ethernet cable immediately.
- Check if someone on your local network is running a backup or large upload.
- Your goal is to get that StDev on Hop 1 down to under 5ms.
Step 2: Escalating Through Our Team
We can take a closer look if necessary, and even schedule a Trouble Call (tech visit) for in-person analysis.
Step 3: The "Vultr Workaround"
If we're unable to fix the Miami routing quickly:
- Try a different Vultr location: If your users are spread out, try moving the reflector to Vultr Atlanta or New Jersey. This will change the path we take and likely bypass the congested Miami NOTA node.
- VPN: Running a VPN on your local machine might "tunnel" your traffic through a different entry point into the backbone, potentially avoiding the bad Miami hop.
Let me know how things go after the first step, and we'll take it from there!
(edited)
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