MTU for XBOX live mutliplayer gaming on 5g home broadband

[Lexx289]

I am struggling to get my Xbox to work on Xbox live. Doing some googling it seems that the MTU is too low, it is 1360 and should be about 1385 to be able to work properly. I have rung three who seem to have no knowledge of what an MTU is and have sent me to the ombudsman. I have logged into the router (H122-373) and increased the MTU manually however it will not pull through onto my XBOX. I have put it in the DMZ, enabled UPNP and generally faffed with it as much as i can but the MTU on the XBOX does not change. I am assuming this is what is being sent from three and so it is something to be changed at three's end...

Does anyone else have any experience of this, or have any issues with XBOX live and home broadband 5g? or can they get it to work, cheers

[DontMindMe4524]

Just got my Three broadband yesterday. Read the whole thread. Describes my exact issues.

Luckily I get good speeds and actually managed to play some online games (Smite) without a problem, even though I get the MTU problem. However last night during peak times I was getting 100% packet loss and not able to play anything.

I'll test the speeds/packet loss again tonight. If it's just during peak hours I might be able to work around it. But I'll also have to see how this is gonna work with my streaming...

[CSpec01]

I read @TheJunglist's post and reapplied UPnP enabled (as it was already enabled from my previous attempts of solving this) and it appeared to solve the MTU problem! Until I tested the connection again 5 seconds later... 

Disabling the router firewall also appears to temporarily fix the problem too, but of course not ideal.

If I were to guess, as someone who knows only the basics about networking, neither of these are actually solving the issue but that something happens during the period the router updates its settings where the MTU issue is fixed for a small moment? 

[MrSimo98]

Sadly I ended up returning my Three 5G router. Although the speeds were great for me this MTU problem was really effecting my online experience.

I was told I would have a phone call from three to discuss this issue and I hadn’t heard a thing. Sorry guys but don’t think this will be sorted out. 

[Chris7197]

Is there any news on this? It’s also causing me real problems on Xbox where certain games do not work online most of the time, and the Xbox multiplayer test points to the MTU being a problem 

[Cerberus73]

1360MTU won’t cut it for Xbox’s online service anymore. Being that it’s at THREE’s end why haven’t they done anything about it ? it’s over halfway through 2023 and still not resolved ?

Customer service eh 😂🤣🤣 ffs!

[Anvil_Iron]

Are you able to see what the MTU value is when 4G only is set?

[Trickyhenry]

Not sure how,  if I do a multi player connection test it stil says there's a MTU issue .. but it's better and I'm able to play Vigor. It's bumped me out a few times though. It's the only game I'm having an issue with. Maybe we need a firmware update. Seems b14 is out and I'm on b12

[Kal]

I'm on version b15 and it still won't work with the Xbox.

[Trickyhenry]

The only fix I have found is to set the router to 4g only. My speed goes from 150 to 26 but I know with these speeds games are playable. 

[TheJunglist]

After trying several different things static ip>add to dmz, port forwarding etc with no joy. I've resolved the issue described on my son's xbox series s by enabling UPnP in the router's settings, then by selecting a different port on the xbox the NAT type went from strict to open and issue is resolved - You may have to try a few different ports, luckily it was the first port I tried!  Hope this helps 🙂