A SIP trunk is a virtual version of an analog phone line, eliminating the physical connection to a phone company. Using SIP trunks, a SIP provider can connect multiple channels to your PBX, allowing you to instantly provision global voice connectivity for your Voice over IP (VoIP) infrastructure.
SIP trunking allows you to extend VoIP beyond your organization’s firewall and bypasses the need for an IP-PSTN gateway by carrying many signals at once to connect nodes in a communications system.
While typically used for voice calls, SIP trunks can also carry instant messages, multimedia conferences, user presence information, E-911 emergency calls, and other SIP-based, real-time communications services.
The basis of SIP trunking is Session Initiation Protocol (SIP). SIP is an application layer protocol for setting up real-time sessions of audio or video between two endpoints and is leveraged to produce a VoIP call. You can learn more about SIP and how to leverage SIP for your business.
The “trunk” in SIP Trunking derives from circuit-switched telecommunications and refers to a dedicated physical line that connects switching equipment. A SIP trunk accomplishes a similar task as its circuit-switched predecessor but works over a virtual connection on the internet.
Twilio’s Elastic SIP Trunking makes SIP trunking configuration easy, and grants you the freedom to manage your SIP connectivity however you like. Check out some video tutorials to get started with trunking termination (placing outbound calls), trunking origination (receiving incoming calls), and international trunking.
With Twilio and SIP trunking, you can instantly provision global voice connectivity for your VoIP infrastructure. Whatever your current company’s scale and needs, Twilio offers a SIP trunking service that’s right for you.
With Twilio’s Elastic SIP trunking, you can instantly provision a SIP network worldwide. Connect to a SIP URI that's local to your company, and we’ll do the rest. Check out some of the possible SIP Trunking setups and our SIP Trunking Overview to see how you can leverage SIP trunking for your business. We can’t wait to help you build and scale!