- Authentic SMS texting and contacting, real next contact number: text and call ANY cellular phone that accepts SMS texts, and ANY mobile phone for calling. : Deploy backup battery/generator ability for SIP phones. Think about trying to keep analog cellular phone strains for emergency use. The good news is, https://techchronicle.net/exploring-the-world-of-text-messaging-providers-voip-api-cpaas-sip-trunking-and-twilio-byoc/