Internet latency problems

[StuartR]

I play with a 4-piece band and we are using JamKazam to rehearse during lockdown. We all live within 10 miles of each other and are all using wired ethernet connections. The other 3 band members experience very little latency between them, but I seem to have a much greater Internet latency and one that varies wildly from about 20ms to over 100ms. I use the same ISP as 2 of the other band members. 

I am using a Behringer UM2 interface and a MacBook running Catalina. My interface latency is 10ms, using a frame size of 2ms. This is not great but within usable limits.

I have tried leaving JamKazam and doing an internet speed test, using one of the publicly-available test sites. Having done this a few times, the results are always around 20Mb/s downstream, 1.8Mb/s upstream and a ping latency of around 15ms (to a server in London, at least 70 miles away). This looks as though my internet connection is OK.

Lowering my outgoing bitrate to 128kbit/s improves things a little, but not sufficiently.

Can anyone please suggest what I might do to diagnose or fix this problem--or is it simply that there is a poor internet service in my neighbourhood?

Any suggestions much appreciated.
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First observation is that your local audio interface latency is way too high. By tweaking the frame size to 1 msec (Audio Booster in JK client), buffer size and recording frequency (ASIO driver) you should be able to achieve less than 4 msec. Don't settle for any more, period.

Forget doing PING tests. they use a dedicated IP protocol (ICMP) and aren't representative of your Internet latency. Speed tests are also usually a waste of time unless you have very little of it.

It's all about total latency...

You can check latency to known sites on the Internet using the LATENCY option at TESTMY.NET.  Use that to try and find a time of day where the Internet traffic congestion is the lowest. Then schedule your group at that time if you can.

I've got a group in the same boat as you folks. We all live within the same community and still have varying amounts of latency. It's a killer. Another thing that can help is the use of a drum machine or having your real drummer play to a click track and ignore the latency effects he hears from the rest of the band. Everyone else can just play to that beat. Works ok even with siginficant latency.

Report back with your results...

Stuart.