How to use SMS over IP (SMSoIP) to improve SMS delivery against an unstable phone network
Use case:
On your site, you may have trouble accessing the phone network, and it can badly impact the delivery of SMS. You can use SMS over IP (or SMSoIP) to solve this issue. Like VoIP, with SMSoIP, you can send an SMS over wifi and receive them. To do that, several steps must be followed first.
Step 1: Open SMSoIP traffic on your firewall
To use SMSoIP, some modifications have to be done on your firewall.
SMSoIP uses particular ports. You have to allow DNS to access the Internet, but it’s insufficient. You have to enable the ports UDP 4500 and UDP 500.
|
ID |
Name |
Source |
Destination |
Service |
Protocol |
Action |
| 1 |
DNS resolution |
Guest subnet | Any | 53 | UDP/TCP |
Accept |
| 2 |
SMSoIP traffic |
Guest subnet | Any | 500/4500 | UDP |
Accept |
Step 2: Allow SMSoIP on your user’s device
If you are using an Apple device:
- Go to your Settings app Cellular.
- Go to Wi-Fi calls and activate them.
If you are using an Android device
- Go to your Settings Mobile network.
- Go to your SIM Wi-Fi Calling and activate it.
- Depending on your device, this option may be in “Calls & SMS” instead of your SIM.
If you are using a Samsung device
- Go to your Phone app click on the three points.
- Go to Settings activate Wi-Fi calls.
Warning: some phone providers don’t allow this option. If you are on a trip abroad, this option may not work.
What's Next?
Congratulations on enabling SMS over IP for your devices!