Three 4G router, worked fine for 14 months, suddenly getting low MTU, stopping Xbox online play.

[ro55cco]

@PeteG @StephR 

Equipment has been working fine for 14 months.

We live in a semi rural area so opted for a 4G setup.  ZTE MF286D router with poynting omni directional external antenna, direct line of sight to mast 1.1 miles away.  House is a smart house, router connected to  TP link TLSG1024 ethernet switch and everything that can be on a wired connection is, only devices on wifi are phones and Nintendo switch.

5 days ago I got error messages on the Xbox saying there was an MTU problem and cross platform play was disabled.  Its causing issues as my kids use Nintendo switches and Xbox for gaming and now they cant play together online anymore.  

Xbox requires MTU to be minimum 1384, Xbox network test is currently reporting 1360.  Logged into router, MTU setting currently at 1500.  Carried out ping tests from the home PC.  No issues inside the house, can ping the three router with packet sizes up to 1472 undefragmented and get 4/5ms.  Did this via wifi i.e. laptop>access point>POE switch>router and also via wired LAN i.e. desktop PC>ethernet switch>router.

Once I start to ping external websites like google, the maximum packet size I can send is 1324 undefragmented, higher than that I get 75% or 100% loss.  I have called Three tech support, they got me to reset everything, they reset everything at their end, no improvement.  I disconnected everything in the house from the LAN and wifi and had only the Xbox connected directly to the router, still had low MTU.  Ive tried using the DMZ and Upnp and the problem remained.  They suggested my Xbox was at fault, but we have 2 and they both developed the same problem on the same day.  They then said there was maintenance going on in the area to improve speeds, and that could be affecting us, I checked the network status checker for IV30 5SX and it did indicate maintenance was ongoing, but that maintenance was completed later the same day and my problem remained.

I also have Three contracts for our phones, I hotspotted the Xbox using my Three phone, and the problem remained the same.  I used my friends phone (O2) to hotspot the Xbox and even though he only had 1 bar signal on 4G the problem went away.

How can it be that Ive had no issues at all Since October 2022 and now suddenly I have this MTU problem on the Three network, can anyone shed any light?

[Anonymous]

Hi ro55cco,

Up unto recently the network actually advertised an MTU of 1380, but that seems to have changed.  Three seem to be making major changes to the network at the moment.  I noticed "issues" the week starting 27th Nov which seemed to lead to the national outage on the 1st December.  Bar switching it off and on again, Technical Support are as useful as an ashtray on a motorbike, they really have no idea about the network nor how it functions just read questions on a screen and tick boxes.

My connection is up and down like a yo-yo today again, so basically I don't think it has anything to do with your setup, more the upgrade to the network Three seem to be engaged in right now.

Nice set-up by the way, is there a reason you went for omi over directional?

[sc1999]

I always had an ashtray on my CB250, it was the perfect size for the chocolate teapot.

[Cedric]

Hi @ro55cco 

Could you answer a question for me please.

I have recently moved to a semi rural area. The landline broadband upload speed was non existent due to our distance from the telephone exchange. I have the same router now and trialling on the 30 day money back guarantee.

There's one window sill where I receive a reasonable 4G signal. It generally has 2 to 3 bars, now and again will rise to 4 and sometimes 5 bars.

I have purchased an external antenna and so far no difference. Did you change any settings in the router, or modify it in any way? Or does the router automatically detect and switch to external antenna? 

Many Thanks

[PeteG]

Hello.

You don't need to do anything to get the antenna working. Once they are connected, the router can use them. 
If they haven't made any difference for you, it's possible that the issue you're experiencing isn't related to something the antenna can fix. 

Pete.