# Configuring Flowroute IP Authentication Trunk
Before proceeding with the next steps, you need to purchase a DID on the [Flowroute ](https://www.flowroute.com)platform.
This section explains how to configure **IP Authentication** and **Inbound Routes** in the Flowroute portal so the trunk can successfully interoperate with PortSIP PBX.
***
### Configure IP Authentication
The **IP Authentication** section defines which PBX is allowed to send and receive SIP traffic and provides key information used later in PortSIP PBX.
#### Steps
1. Log in to your Flowroute portal.
2. Navigate to the **IP Authentication** section.
3. Add the **public static IP address** of your PortSIP PBX server.
After configuring IP authentication, Flowroute will provide:
* **SIP Host** for the trunk
* **Call Prefix**
> **Important**\
> Make a note of the **Call Prefix**. You will need it later when configuring **Outbound Rules** in PortSIP PBX.
***
### Configure Inbound Routes
Inbound routes define where incoming calls from Flowroute are delivered.
#### Steps
1. In the Flowroute portal, navigate to **Inbound Routes**.
2. Create a new inbound route.
3. Set the **Route Type** to **Host**.
4. In the **Route** field, enter your PortSIP PBX address using the following format:
```
sip::
```
**Example (default SIP port):**
```
sip:1.2.3.4:5060
```
**Example (custom SIP port):**
```
sip:1.2.3.4:5081
```
> Replace `1.2.3.4` with the **actual static public IP address** of your PBX.
5. In the **Edge Strategy** drop-down list, select the **SIP Proxy Host** noted earlier in the **IP Authentication** section.
6. Save the inbound route.
***
### Associate DIDs with Inbound Routes
To ensure inbound calls reach your PBX, each DID must be linked to the correct inbound route.
#### Steps
1. In the Flowroute portal, navigate to the **DIDs** section.
2. Select your purchased DID(s).
3. Associate the DID(s) with the **inbound route** you just created.
4. Save the changes.
***
### Configure an IP Authentication Trunk in PortSIP PBX
To integrate Flowroute with PortSIP PBX, you must configure Flowroute as an **IP-Based Trunk** at the **System Administrator** level.\
Once configured, the trunk can be **shared with one or more tenants**.
***
#### Step 1: Create an IP-Based Trunk
1. Sign in to the PortSIP PBX Web Portal as a **System Administrator**.
2. From the left-hand navigation menu, go to:\
**Call Manager > Trunks**
3. Click **Add**.
4. From the menu, select **IP Based Trunk**.
***
#### Step 2: Configure Basic Trunk Settings
Enter the following information:
* **Name**\
Enter a friendly name for the trunk\
(for example, *Flowroute-Trunk*).
* **Brand**\
Select **Flowroute**.
* **Hostname or IP Address**\
Enter the Flowroute SIP host:
```
us-west-or.sip.flowroute.com
```
* **Associated IP Addresses**
* Contact [Flowroute Support](https://flowroute.com/contact-us/) to obtain the IP addresses for your SIP trunk.
* Flowroute typically provides **one or more IP addresses**.
* Add all provided IP addresses in this field.
**Example:**
```
210.82.221.12
210.82.221.13
```
5. Click **Next**.
***
#### Step 3: Configure Trunk Options
1. Review the trunk options.
2. Configure the following field if required:
* **Max Concurrent Calls**\
Sets the maximum number of simultaneous calls PortSIP PBX can establish using this trunk.\
Adjust this value according to your capacity planning and Flowroute service agreement.
> **Best Practice**\
> Keep all other options at their default values unless Flowroute has provided specific requirements.
3. Click **Next**.
***
#### Step 4: Assign Tenants and Configure the DID Pool
1. Select one or more **tenants** to grant access to this trunk.
2. Configure the **DID Pool** to assign Flowroute DIDs to tenants.
> **Important**
>
> * Each DID can be assigned to **only one tenant**.
> * A tenant can use **only the DIDs in its assigned DID Pool** to:
> * Create inbound rules
> * Create outbound rules
> * Configure outbound caller ID for extensions
**DID Pool Format Examples**
* Single number
```
16468097065
```
* Multiple individual numbers
```
16468097065;16468097066
```
* Range of numbers
```
16468097065-16468097066
```
* Combination of ranges and individual numbers
```
16468097065-16468097066;16468097070-16468097080
```
3. Click **OK** to save the configuration.
***
#### Expected Result
* The Flowroute IP-Based Trunk is created successfully.
* In the trunk list, the status displays as **Online.**\
(for IP-Based Trunks, the status always shows *On line*).
***
### Next Steps
The VoIP.ms Register Authentication Trunk is now ready for use.
You can proceed to:
* Configure outbound call routing rules
* Configure inbound DID routing
* Assign outbound caller IDs
Refer to the next guide section: [Configuring Outbound & Inbound Calls](https://support.portsip.com/portsip-communications-solution/configuring-sip-trunks/flowroute-sip-trunk/configuring-outbound-and-inbound-calls).
