# 7 Trunk Management

Session Initiation Protocol (SIP) trunking is a digital method for making and receiving calls—and other real-time communications—over an IP network using SIP, an application-layer signaling protocol. In this context, **“trunking”** means aggregating multiple concurrent call paths (channels) into a single logical connection between your PBX and a carrier or service provider.

A SIP trunk typically provides **VoIP connectivity between an on-premises PBX and the Public Switched Telephone Network (PSTN)**. For example, an office may run an internal PBX for extension-to-extension calling. By connecting the PBX to a SIP trunk, users can place and receive external calls to/from the public telephone network.

SIP trunking is commonly used to **establish, manage, and terminate call sessions** (call setup, mid-call signaling, and teardown). It is widely adopted because it’s flexible, scalable, and standards-based—helping organizations connect their phone system to external calling services without traditional physical trunks.

PortSIP PBX supports a wide range of mainstream SIP trunk providers worldwide, including (but not limited to):Topics Covered

This article includes the following topics:

* [Vonage](https://www.vonage.com/)
* [QuestBlue](https://questblue.com/)
* [VoIP.ms](https://voip.ms/) 
* [Voxtelesys](https://voxtelesys.com/)
* [Flowroute](https://flowroute.com/)
* [Skyetel](https://skyetel.com/)
* [Wavix](https://wavix.com/)
* [Bandwidth](https://www.google.com/aclk?sa=l\&ai=DChcSEwjP4Z7F04mGAxWv1MIEHcavBZsYABAAGgJwdg\&ase=2\&gclid=CjwKCAjw0YGyBhByEiwAQmBEWt0-86eUzdm8dvIhQPbhC0MFJ_iY0a-UAgyis1Kao874WgSy0MGNIhoCsocQAvD_BwE\&ei=ioRBZu2MC6yF0PEP0NKHiAI\&sig=AOD64_2iLhFzhgCJBcCnSRVqnrIcSWO_Vg\&q\&sqi=2\&nis=4\&adurl\&ved=2ahUKEwjt-ZXF04mGAxWsAjQIHVDpASEQ0Qx6BAgJEAE)
* [Twilio](https://www.twilio.com/en-us)
* [Telnyx](https://telnyx.com/)
* [Callcentric](https://www.callcentric.com)
* [Telstra](https://www.telstra.com.au/)
* [CM.com](https://www.cm.com)
* [Aire Network](https://airenetworks.es/)
* [Gamma](https://gammagroup.co/)
* [VoIP Innovation](https://carrierservices.sangoma.com/)
* [VoiceMeUp](https://www.voicemeup.com/)
* [SIPTRUNK](https://www.siptrunk.com)

### Topics Covered

This article includes the following topics:

* [Configuring SIP Trunk](https://support.portsip.com/portsip-communications-solution/portsip-pbx-administration-guide/7-trunk-management/configuring-sip-trunk)
* [Handle Outbound Calls Through SIP Trunk](https://support.portsip.com/portsip-communications-solution/portsip-pbx-administration-guide/7-trunk-management/handle-outbound-calls-through-sip-trunk)