Zwift Power -Login

I’ve had more drop outs. What do these UDP errors mean and how do I fix them? Thanks in advance!

It was in the 18:45 WTRL race around france.

Hi @Tim_Burn

Thanks for your question!

What is that data source from the screenshot you shared? Is that

I’m by no means an expert or authority on computer networks, but it sounds like “UDP Network Disconnects” could be the result of a firewall blocking your connection to Zwift. It could be a computer firewall (e.g. antivirus app) or a router firewall.

Also, you mentioned in the title of your post “Zwift Power - Login”, but the body of your message didn’t seem to mention anything about logging in to Zwift Power. Are you having ZP login issues?

For general internet troubleshooting, I’d suggest you start with this article, and see if it helps.

UDP sent is used for time sensitive data, like rider position, your speed/power etc. UDP received is the opposite, you get other rider data/positioning etc.

Disconnects are a sign of the network getting busy somewhere. Could be your environment, your ISP and even Zwift servers. You shouldnt need to worry about them unless they become more frequent and do impact your rides in some way. The fact that you got them towards what could be the end of your ride suggests that you entered a new world that was busy (middle of pace partner for eg), or another event in the network was causing congestion (someone started streaming a 4k vid type of thing).

What was the impact on your ride Tim?


Sorry I should have said. This was the WTRL Race emea at 18:45 today.
I didn’t come up in the race results only shown in the live section so seem to have had a drop out.
Name is Tim Burn
It’s just annoying as it has happened a few times in the ZRL series and caused me to loose points etc.
The pic is from zwiftaliser to see the UDP drop outs which is what I’ve assumed if must be?

Hi @Tim_Burn ,

Thanks for getting back to me with the answers to my questions.

I just checked on my side and noticed you’ve opened a support request with our team, so I’ll go ahead and continue working with you on this issue via email support. Keep an eye out for my reply. Thanks!

It’s happened again! This is so annoying. reset the router and wifi is working fine.
shows a few UDP errors at the end again, but after the race has finished? I finished 2nd in 53:12 and was in top 10 of each KOM.

ZWIFT Racing League | WTRL - EMEA Africa DIV1 (Mixed/Men’s) 18:45

what else can i do?!

You can share a link to the Zwiftalizer log that will give more detail.


Very sorry to hear that you’re still having this issue, and I can see it’s caused considerable frustration on your part (understandably so).

You still have an open support request in with our team on this one, so we’ll be responding via email. Please keep an eye out for that, and we’ll keep working with you, Tim. Thanks for your continued patience.

Ride On.

Thanks Gerrie, didnt know that! Link attached - any ideas?

take that back - zwiftforum doesnt allow links it says… I’ve tried to screenshot below

I have a few questions looking at that picture.

  1. are you using a laptop, that is a powerfull cpu but I don’t see a GPU
  2. do you have a bluetoothe dongle or using the internal laptop dongle

ANT+ on windows is a lot more stable.

Hi Gerrie,
yes its my work laptop - i must admit i don’t know if it has a GPU.
its just the bluetooth that is built into the laptop. but it doesnt seem to show any connection ANT or BLE drop outs?

to use ANT+ would i need to order a special dongle for that to work?
Does connecting through the companion app make it any better?


Yes for ANT+ you will need to order a ANT+ dongle and a 1m - 1.5m extension cable.

You can test the companion app but that is just adding another point of failure to the mix.

I don’t know if is picking up Bluetooth dropouts. @zwiftalizer does pick up Bluetooth dropouts. There aren’t any. There is no need to change from Bluetooth to ANT+. That won’t make any difference to the network UDP disconnects.

1 Like

Thanks Mike.

I don’t use BLE so I did not know what to expect.

Thanks both. so no issues with my equipment connection, it must be something to do with the network. ive asked zwift support to look at the log files in detail and advise if anything i can do to help. Its just so strange as no dropouts in race or anything.

Isn’t the Bluetooth dropout analysis by (the excellent) Zwiftalizer only as good as the Zwift log file though?

I.e. a lack of dropouts doesn’t guarantee that you had no issues, just that Zwift didn’t log any disconnects. You still could have had interference or other BT issues.

I’m not saying that I think that this particular issue is necessarily a BT one though.

Looking at Companion App - the 2 races mentioned above dont show you in the finishing list, as you pointed out. I can see a couple of other events where you completed the race but didnt appear in the results as well (21 Dec FZR, 31 Dec Scannellatori and 14 Jan WTRL TTT).

I checked Zwiftpower and as it only goes back a limited time, I can see that the 3 most recent events - they list you as a non-finisher (in live tab) meaning a data issue popped up somewhere between you and Zwift servers.

So I’m fairly convinced you have network issues periodically somewhere, or your Zwift device has network issues (unlikely to be Zwift as ZP would show a large occurrence of the same issue in those events, which it doesnt). Troubleshooting will be a challenge as is doesnt manifest itself all the time (otherwise all your events would have same issue). And the issue could be your device, your local network or your ISP .

Firstly, I’d get off your work device and find a clean device you can Zwift on few a week or two as an alternative. If still occurs, then I’d be stopping every device in the environment attaching to your network and also turn off every bluetooth/wireless device in the house (during Zwift events). Also see if you ISP can monitor your network/modem for a few weeks - they may have you on a bad port somewhere.

Another week , another ZRL WTRL race issue.
The same thing has happened again- this can’t be a coincidence?!
I’ve raced some races in the week leading up to as well and had no issues , can anyone see my zwift power and explain what is happening again. It looks like based on the distance, it cuts me off just before the finish line agajn?!
This is the third week of this and it’s getting v annoying when every other race works fine!!

Hi Tim, I took a peek at todays ride and I am seeing a number of connection errors causing our system to not be able to actively track your progress throughout the event which would be why you didn’t show up in the results on ZwiftPower. I’m also not seeing the event finished marker, but that is most likely a symptom of those connection errors.

That you’re only seeing UDP drops in your Zwiftalizer report and not TCP network drops as well can be a sign that your on an overly congested network or a network that’s encountering a high amount of interference. Zwift uses UDP for event data and other riders because it has a smaller network footprint and is faster than the heartier TCP that is used for your ride uploads. The tradeoff of this lighter footprint and speed is less redundancy to catch dropped packets. BLE usually plays pretty nice with wifi since it has a very wide signal range, but there are a number of other wireless technologies that have more narrow ranges and can clutter the range that your router is using. A quick test to see if this is the case is to change the channel on your router. The most common wifi channels are 1, 6, and 11 as those have a good degree of separation from each other so you might want to try each of them to see if it helps any. It also would be worth trying out the 5GHz if your router, and other devices, supports it since that bandwidth tends to be less cluttered by other household wireless devices.

Hi Lucas, there were no UDP errors or connection errors according to zwiftalizer from todays race (now yesterday)
Ill check the channels later when I am home.
We have the bandwidth split and my laptop is on the 5ghz channel so it isnt that cluttered. There are only 2 of us in the household so we dont have that many wifi devices.
Is there a way to test the setting and connection without being in a ZRL race? I only find out at the finish line that ive got 0 points for the team, when ive finished in the top 3 most weeks!