1. SMS, short messages service, communication that sends text between cell phones, or from a PC or a handheld to cell phones.
2. Toll-free, such as 800 services, where the caller call specific number, for example 800-xxx-xxx, and the charges will be billed to called-party, free from caller side.
3. Basic telephone, caller calling called number.
That's it for today. Soon, we will start with each layer of SS7 stack protocol.
