Internet problems, high latency and high jitter

Erik Mcfrazier
Erik Mcfrazier used Ask the Experts™

I am troubleshooting a network and looking for advice.

The network has 1 physical server with 2 VMs. There are about 38 clients on the network. It is a Windows based network. They are currently using a 12Mbps down x 2Mbps up internet line. They primarily use all web applications including a remote desktop app, which most users are logged into all the time.

- They have recently started really having major issues with internet. It's very slow, mostly noticeable within the rdp sessions.
- When running speed tests at the high of the day, I pretty regularly can report speeds of 12Mbps/1Mbps
- When running speed tests at night with no users, I get about the same speeds
- I have have the ISP test the line, they see high latency
- When I do broadband quality tests, I also see the latency issues, jitter is usually between 30ms and 80ms
- When I try to upload a 500meg file it completely chokes the internet, it just stops working.

I already know that they are over utilizing their current internet line, but what is confusing me is that they were using a T1 line when I came in, and I got them to upgrade (which was like pulling teeth), it was always slow before, it got better with the upgrade, but still fairly slow. But in the last 2 months, it has gotten terrible.

I am unable to do a traceroute to see where the latency starts. I am assuming because they use a vpn, but I don't have any control over the vpn settings at this point.

My next step is to go onsite after hours, disconnect everything from the network and test with the ISP, and slowly add computers back to the network to see when the problems start.

Any ideas of what I can test, or where I should be looking?

Any help is appreciated.

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Top Expert 2016
jitter and latency is primarily at the network provider (ISP)

if the users are on the local network and RDP into the server they should have no issues if they have issues on the Local Network then their internet speed is not an issue.
if the users are on the WAN and RDP into the server then the receive speed is not an issue but the send speed is.
You say they have a VPN .. I'm guessing this is for remote users.
Erik McfrazierOwner - Technician


They rdp into a remote server, that's what the vpn is for. Locally, everything seems fine.
Erik McfrazierOwner - Technician


There turned out to be multiple issues, but the main issue was out at the DMARC. However, it took the ISP about 4 visits to actually find it.

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