The Benefits of Fixed IP SIM Cards
The easiest way to connect over the Internet to your 3G or 4G router is by using a Fixed IP SIM Card. This will give your router a mobile broadband connection with a fixed, public IP address so you can access your router from anywhere on the Internet.
This means that you can now use your 3G or 4G Router just like any Internet router that has a fixed, public IP address - you can connect directly to the router web management and use port forwarding to connect to your devices on the LAN.
So, if you need 4G CCTV connectivity to remotely access your DVR then a 4G router combined with a 4G Fixed IP SIM whill give you a high speed 4G mobile Internet connection and easily allow you connect from anywhere to your DVR and security devices.
What are the Alternatives to using a Fixed IP SIM card?
If you don't want the convenience and reliability of using a Fixed IP SIM and just want to use a normal SIM card obtained directly from the mobile networks then your only choice is to use a SIM card from THREE Mobile, configure your router to connect at 3G only and use the APN of '3internet'. When your router connects to 3mobile 3G network with this APN your router should receive a public IP address so you can use DYNDNS - however you do not always receive a public IP address so it might not always work and this is not a guaranteed or contracted part of the Three Mobile Network offering and may be stopped at any time without notice or penalty and you will need to replace all of your SIM cards at this stage with a Fixed IP SIM card service.
Any other standard mobile network SIM card will use CGNAT (Carrier Grade NAT) and will only allocate your 3G or 4G connection with a PRIVATE IP Address on the mobile networks private network. This means you will not be able to connect to your 3G/4G router which of course means that things like Dynamic DNS will not work, neither will router functions like port forwarding.
How Can we provide a Fixed IP SIM Card when the mobile networks don't offer this service?
The Fixed IP / Public IP service is provided by an MVNO (Mobile Virtual Network Operator) who invest in the equipment, network and skilled staff to integrate their front end network offering with the mobile networks.
You have probably heard of other MVNO companies like Tesco Mobile and Virgin Mobile who offer a mobile phone service but did not invest billions of pounds in licenses and building a mobile network - so an MVNO that offers a Fixed IP SIM card service like ours has links into the mobile networks and can then add valuable services with their own infrastructure and that is how, as an MVNO, Fixed IP SIM card services are available using all the UK mobile networks.