# Configure VoIP Switch in UI

## How it works

Each Class 4 platform can run multiple softswitch instances*.*  Each of softswitch can connect to the UI via the following section:

![](/files/-MYT_-eQKxMMwqdwFhPs)

Within the VoIP Gateway, you can add your softswitch instance:

![](/files/-MYT_PThiI3QER9F-96L)

Each softswitch has a "name" and this name is configured in the following config:

```
/opt/denovo/dnl_softswitch/conf/dnl_softswitch.conf 

```

Inside the file, you can see the name :

```
################################################
#
# Denovolab softswitch configuration
#
################################################

[general]
 #....
switch_name = class4

[CLI]
cli_listen_ip = 127.0.0.1
cli_listen_port = 4320
cli_connection_expires = 600
cli_connection_limit = 200


```

The CLI interface allow the UI to telnet into the switch and query for switch information.

If started correctly, you should see the following CLI port is up:

```
tcp        0      0 127.0.0.1:4320          0.0.0.0:*               LISTEN      9559/dnl_softswitch 
tcp        0      0 127.0.0.1:49292         127.0.0.1:6240          ESTABLISHED 9559/dnl_softswitch 
tcp        0      0 127.0.0.1:44122         127.0.0.1:6230          ESTABLISHED 9559/dnl_softswitch 
udp        0      0 176.31.100.14:4319      0.0.0.0:*                           9559/dnl_softswitch 
unix  3      [ ]         STREAM     CONNECTED     1175410976 9559/dnl_softswitch  
unix  2      [ ]         DGRAM                    1175410045 9559/dnl_softswitch  

```

Once CLI port is up, you can configure the VoIP Gateway as follows:

![](/files/-MYTaiBQN3dAycCyNYRv)

Now, notice that SIP is not up.

![](/files/-MYTasS_gK6uPBVOndTN)

Our next step is to add SIP interface to the VoIP gateway.

![](/files/-MYTbHQ4Uqdo4ZFLdI0W)

After you add a new SIP interface, you can restart softswitch using the following command:

```
systemctl restart dnl_softswitch
```

After you restart Class4 softswtich, you can see the SIP interface with 6060 port is started. 

```
[root@ns389055 denovo]# netstat -anp |grep dnl_softswitch
tcp        0      0 127.0.0.1:4320          0.0.0.0:*               LISTEN      13446/dnl_softswitc 
tcp        0      0 127.0.0.1:56574         127.0.0.1:6240          ESTABLISHED 13446/dnl_softswitc 
tcp        0      0 127.0.0.1:51428         127.0.0.1:6230          ESTABLISHED 13446/dnl_softswitc 
udp        0      0 176.31.100.14:4319      0.0.0.0:*                           13446/dnl_softswitc 
udp        0      0 176.31.100.14:6060      0.0.0.0:*                           13446/dnl_softswitc 
```


---

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