You need to change the APN in your motorhome's router, for which you may need to consult the manual, or google it if you dont have the manual.
You need to change the APN to 'mob.asm.net' (without the ' quotations of course)
The moderator team posted the following instructions, which are for Android phones, but the basic principle will.still.apply for the router in your motorhome :
"Your SMARTY SIM will not work abroad unless you make a one-off change to your phone settings. We’ve created a step-by-step guide to easily set up your phone to work for roaming.
Follow these steps to get your phone ready:
Go to ‘Settings’
Tap ‘More…’ under ‘Wireless & Networks’ or 'Connections'
Open ‘Mobile Network’
Open ‘Access Point Names’ - If you don’t have any access point you’ll need to create a new one and skip to step number 7.
Open ‘3’
Open ‘Edit Access Point’
Change the APN to: mob.asm.net
Your settings should look lie this:
Name: 3
APN: mob.asm.net
User name: [leave this field blank]
Password: [leave this field blank]
MMSC: http://mms.um.three.co.uk:10021/mmsc
MMS proxy: mms.three.co.uk
MMS port: 8799
APN type: [leave this field blank]"
