# Elastic SIP trunking

## Overview

With a Trunk you can receive inbound calls from PSTN/mobile or SIP and you can send calls to PSTN/mobile or SIP from multiple SIP users through the single number. You can also run a single Call Flow for multiple SIP users multiplexed on a single SIP domain

There is no limit on how many concurrent calls (aka. *channels*) can run through a single trunk. The only limiting factor may be your internet bandwidth (for calls made on a single host)

<figure><img src="/files/JpR4a4HFu8MBLDXIXlT8" alt=""><figcaption></figcaption></figure>

Learn how to set up a Trunk: [Trunk](/components/trunk.md) , [Voicemail Trunk](/how-to/voicemail-trunk.md)


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