> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getsmartalex.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Yeastar

> Connect Yeastar P-Series or S-Series PBX to SmartAlex via SIP trunk.

<Info>
  **Audience**: Yeastar admin. **Time**: 10 to 15 minutes. **Models**: P-Series (PBX) and S-Series (VoIP PBX appliance).
</Info>

## Prerequisites

* Yeastar admin credentials
* A DID routed to this Yeastar
* PBX SIP Domain (the Yeastar's FQDN or public IP)
* List of extensions

## Step 1: create the trunk in SmartAlex

Phone Numbers, then Connect Your Carrier, then SIP Trunk, then pick Yeastar. Fill the form. The Yeastar defaults are pre-set: UDP transport, digest authentication, G.711 codecs. Save and copy the connection details.

## Step 2: add the trunk in Yeastar

<Steps>
  <Step title="Open VoIP settings">
    Yeastar admin console, then Settings, then PBX, then Trunks, then Add.
  </Step>

  <Step title="Choose trunk type">
    Select **Register Trunk** (credentials-based, matches digest auth).
  </Step>

  <Step title="Fill connection">
    * **Provider Name**: `SmartAlex`
    * **Hostname / IP**: `sip.voice.getsmartalex.com`
    * **Port**: `5060`
    * **Transport**: `UDP`
    * **Username**: (from SmartAlex)
    * **Password**: (from SmartAlex)
    * **Authentication Name**: same as username
    * **From User**: blank
  </Step>

  <Step title="Codecs">
    Enable PCMU and PCMA. Prioritise PCMU first unless a specific region requires otherwise.
  </Step>

  <Step title="Save and verify">
    Yeastar should show the trunk **Registered** within 30 seconds.
  </Step>
</Steps>

## Step 3: inbound routing

Settings, then PBX, then Call Control, then Inbound Routes. Add a route that routes the DID to this trunk (outbound forward).

Alternatively, if SmartAlex provisioned a new DID, you don't need an inbound route on Yeastar.

## Step 4: add extensions in SmartAlex

Settings, then PBX. Add each extension with its number, name, owner, department, and aliases.

## Step 5: link the agent

Agent Studio, then Telephony tab, then pick the trunk.

## Step 6: test

Call the DID. AI answers. Ask for a transfer. Yeastar extension rings.

## Yeastar-specific notes

* **P-Series firmware**: v84.x and later work without issues.
* **S-Series firmware**: v30.x and later work. Very old firmware may not support re-INVITE correctly. Upgrade if you see media issues.
* **NAT handling**: Yeastar has a built-in STUN option. Enable under Network settings if the unit is behind NAT.
* **Codec priority**: Yeastar defaults can be aggressive on G.729. Force G.711 first.

## Next steps

<CardGroup cols={2}>
  <Card title="Troubleshooting" href="/telephony/troubleshooting">
    Error reference.
  </Card>

  <Card title="Testing" href="/telephony/testing-validation">
    Validation procedure.
  </Card>
</CardGroup>