I have Jamulus issues all of a sudden...

[noddyspuncture]

Hi folks,

Hoping someone here might be able to help..? I just started getting Jamulus issues a few weeks ago.
Everything has been great for ages... years even. Then all of a sudden Jamulus became un-useable..!

I started getting garble audio for long durations and it seemed to cycle/oscillate...?
Everything would sound like a Dalek and for long periods of time and my delay would be in the red - whereas before I was getting 20 to 30Ms for long periods of time and clean audio before hearing the odd pop or glitch.

I checked my broadband speed and found my fibre to the house was down at about 80Mbs. My package was 150Mbps - but apparently only 75 was 'guaranteed'. (I used to get 74Mbps with my copper cable telephone line before I had fibre installed.)

So I called my ISP and have now upgraded to 910Mbps (445 guaranteed) and when I do a speed check I am actually seeing as much as 1,200 Mbps at times - but I am still getting the garbled cycling... once about every 10 - 15 seconds but now the garbled audio only lasts about a second, but it is still frustrating and makes it un-usable. During the garbling, my delay jumps up to around 300Ms for a second or so... but with annoying regularity. PreviouslyI used to get the odd glitch and it was totally random... but the repetitiveness of this makes it even more annoying.

So I know it's not a speed issue as the upgrade has made my connection 12 to 15 time faster.
It is definitely me because no matter where I connect - I can 'server hop' - and the issue stays with me.

Would anyone know what I could do to try and get it back to like it was before...?

Thanks.
Tom

[dcorson-ticino-com]

Unfortunately it is certainly your ISP.
Broadband speed is only one parameter that can cause problems.
Others are jitter and packet loss.
Even your 75MBps guaranteed rate should be way enough as long as you are running just a client and not a server.
But if the packets are not sent at a constant rate you will have problems.
Do you have the possibility to try out another provider? Even a connection through a cell phone could give you a hint.
With that you may have a big delay, but if the jitter is low the sound should be fine.
Sorry I don't have better news, but maybe another call to your ISP talking about jitter could help.
Don

[pljones]

Our "80Mbps / 20Mbps" (actual 72 / 18) has degraded over the last couple of weeks to "13Mbps / 18Mbps" -- just after they announced FTTP. They probably think we'll take a 100Mbps package for the same price we were getting 72Mbps (we used to get 90Mbps regularly...).

So yes, blame your ISP.

[noddyspuncture]

Thanks for the replies guys.
The thing is, I went with this new ISP a while back, had fibre installed to the house and got the 150Mbs package. I regularly checked it and I was actually getting 150. And I had no issues back then. All of a sudden the issues started and when I checked my speed I could see it was much lower. So I decided to upgrade, assuming it was speed related and I think I am now in a contract and have to stay with them for a period. I'd need to look into it.

Anyway, I have a question... is the 'jitter' and 'packet loss' something the ISP can tweak to my requirements..? I suppose I could ask to talk to their technical department and explain it all to them.... but I didn't know ISP's did their thing in different ways and one might be better for us than another.
Cheers.

[pljones]

Your ISP is only responsible for the connection from you to them. They've no control over what the rest of the planet is doing. I was going to type "unfortunately" there... but that's probably not the right word!

Oh, and I did just find out, after we finally got onto our ISP... It wasn't them, it was me. I'd obviously been checking the QoS settings on the router and somehow reset a field that really did not want touching (from unlimited to "17"). Changing that magically unblocked the connection. Not directly the QoS settings but the overall throughput. I'd say I'd never intentionally touched the fields -- but both "upload" and "download" caps were set. Can't think why I thought that was a good idea.

[noddyspuncture]

Hello again, well... after lengthy conversations with my ISP and I even had them call me back the next day... they asked me to do the ping test on my computer and it always reports back "zero % packet loss". So my question is - if it's not packet loss the what's my next step...?

[pljones]

Packet loss has nothing to do with throughput. If Jamulus isn't getting audio round tripped from Client to Server and back in time to keep your buffers full, you'll get glitches. If the ISP asked for a ping test to diagnose that, they don't really understand the problem.

[noddyspuncture]

OK - but then I don't understand. If it's not packet loss then what is my problem...? And should the ISP be able to sort it...?

[dcorson-ticino-com]

The problem is not the speed with which the packets are sent, but the regularity with which they are sent.
A speed of 10Mbps should be good for Jamulus assuming that the packets are sent regularly and not in bunches.
Your problem is probably that your ISP is sending, for example, bunches of packets very quickly and then for a while nothing.
It looks like a good transmission rate, but any particular packet can arrive very late.
So the packets are not lost, they are just not arriving in time.
That is what causes jitter.
Imagine the jitter buffer has two packets left, but the sender waits another 10 packet times before sending 15 packets very quickly.
The speed is good, but during 8 packet times you would be missing the next packets.
Neither the broadband speed nor the ping time is a useful measure for this problem.
It is difficult to explain, but unfortunately the only instance that can solve it is your provider.

[noddyspuncture]

OK, thanks for the detailed explanation. I'll tell them - they are calling me again.
So is this something they can tweak and change for me or am I stuck with it and the only answer would be to leave them and try another ISP...?

[pljones]

And it might not be your provider. It could be the next link away. Or the next. Or the next... etc, all the way around the planet and back.

[mcfnord]

Sorry if you tried this already, but if you have Small Network Buffers on, turn it off. See if that helps.

My experience is that wireless connections (one of my ISPs has a wireless device from my house to some nearby radio tower) can perform worse when Small Network Buffers is on.

Perhaps your ISP has added high-speed wireless hops that change UDP packet ordering in a new way.

Not sure why, but it was a configuration I had to change after many years.

[noddyspuncture]

Yes, I have tried every possible combination of every available setting.
Nothing improves it... and some variations make it worse.