Send SMS from SAP

Hi,

I´m very confused with the several threads, and notes about the setting SMS from SAP to Cellulars.

If I want to configure the sending of sms from SAP, I´ve to declare the NODE with HTTP? Or can to setup as SMTP?

If I setting the node with HTTP, I´ve to use my smsprovider, that is not mandatory what my own company mobile,not?