Latency, thou art fickle

Got hyped up during the pandemic. Built 2 analog bridges and a digital bridge. Never could find a way to get latency down to a useable level, so never used any of them (but could probably sell the pi’s for a profit). Also, other musicians around here are largely computer-phobic, so I couldn’t interest anyone else. We are in Spectrum cable territory for internet, with fiber not available. I had a few musicians ping me or I pinged them to see if I needed to figure out how to run a server here, but the results were always 45ms or longer, and we know adding audio processing to that would only increase that, so it didn’t seem worth pursuing.

I’m in a small Zoom group and a few of us are discussing online jamming, so I’m exploring this again.

I am in Akron Ohio and have the nearest Jacktrip server in Columbus, about 120 miles away. After examining a bunch of Jacktrip servers all over the Eastern US, it turns out the server with the lowest latency for me (most days) is in Chicago, about 380 miles away. I’ve attached a spreadsheet where I have tested different servers at different times and days. It pays to check it out and not assume closest is best. Note that all these latencies are for ping -n 25. After deciding on a “server of the day” for a particular session, I plan to use PingPlotter to plot the latency over 10 minutes and determine jitter. My prospective collaborator is in Atlanta and isn’t available until after the holidays, at which time we will add to this spreadsheet, all the ping times from his location to the various servers. Then we will have to find a compromise and see what our latency tolerance is.

It seems like the latency is dependent on the routing between me and the AWS servers, and apparently the routing is generally better between me and Chicago. A question which I cannot get answered is, is there anything I can request of my ISP in terms of getting better routing? I noticed that I can ping the Columbus ookla SpeedTest server (about the same distance as the Columbus JackTrip server) and I get a 1 ms time, which is a special one-hop routing to make our internet service look better than it is, but this makes me think the routing to AWS could be optimized to a lesser degree if they wanted to. Anyone know the best way to explore this with them. I have attached a picture of the ping time to the Columbus Jacktrip server (left side) and the Columbus SpeedTest server (right side).
Any thoughts???

Edited: to add, that using a Focusrite Scarlett 2i4 with ASIO driver, my latency reported in the Chicago studio seems to be about 2ms greater than my ping time.


Welcome @dconklinai8p ! This is very interesting! Thanks for posting. @miked what do you think?

Great analysis, @dconklinai8p!

You are correct that geography is only indirectly related to Internet latency. Spectrum likely routes all their traffic for your region through their nearest major POP (Chicago), such that any traffic going to Columbus has to traverse a greater distance, even though Columbus is closer to you geographically. Peering relationships are complex and results are going to vary for everyone. In the future, we plan to make it easier to pick the best studio location by automating the testing you have done manually.

The ping results on the right side are almost certainly using the public (WAN) IP address of the router that is inside your house. Note that they are the same results as your router’s (LAN) IP address, and anything 1ms or less is definitely not traversing the cables between your house and ISP. Even best of class fiber has a few ms latency to the first hop.

Honestly, I doubt you will make much progress trying to convince Spectrum to improve their network. Your efforts would be better spent trying to get a fiber provider to offer service in your area, or convincing your municipality to pursue their own FTTH initiative. Fiber internet is for live collaboration as broadband was for video streaming. The hard truth is that you are unlikely to have a good experience collaborating with your friend in Atlanta without it. You may want to double-check here what options are available in your area.

Thanks for that reply. The worse news is that a week ago when my buddy was last available, he pinged my IP from his PC and the result was 44ms roundtrip, so P2P is unlikely to be the magic solution either - glad I know that before I started down that rabbit hole.