An SMS gateway is a location where SMS messages enter or depart. It’s a network node with the capability of connecting to another network using the same or other protocols. The most widely used protocols for SMS gateway are SMPP and HTTP.
With SMS gateway, a computer can receive from or send text messages to compatible devices usually mobile phones using a global telecommunication network.
At the early stage of SMS gateway, it was in physical hardware with SIM cards and radios. Each gateway was attached to an individual mobile phone network to send text messages.
In modern times, SMS gateways route text messages to telecommunication networks using SMPP (short message peer-to-peer) interface either through an aggregator that sells messages or directly