> For the complete documentation index, see [llms.txt](https://en-api.decisiontele.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://en-api.decisiontele.com/voice-api.md). # Voice API VoIP Telephony for Effective Communication. Use DecisionTelecom’s VoIP services and offer highquality calls through IP protocol to your customers, regardless of their location. #### Worldwide calls Use verified local numbers to call anywhere in the world and become even closer to your foreign customers. #### Voice features VoIP telephony offers you and your customers access to uninterrupted connection and a much better alternative to roaming calls. #### Transparent payment system Pay only for the actual time of talking. Our system charges for calls by the second, which means you won’t have to overpay. #### SIP trunk As MVNO we provide to our clients VoIP Gateway for reliable worldwide calling. We provide interconnection via SIP protocol. Session Initiation Protocol (SIP) calling, it's process of transmitting voice calls over a SIP trunk or a SIP channel. SIP calling generally uses VoIP to move your analog call traffic over an internet connection. We can provide to as many SIP trunks as you need, it could be two or more, just let us know you needs. #### Interconnection configuration To create interconnection, we have to know your IP address. The DecisionTelecom IP: 178.22.10.79 After creating SIP trunks, our Voice Support Team will provide to you with information about amount of SIP trunks, correspondent Prefixes and IPs. #### **Questions?** We are always happy to help with code or other doubts you may have! Check out our API, SDK reference or contact our support team: .