Hi friend.
Yes, you can configure the functions you describe on the web page.
Perform the following steps:
Click the Voice tab, and choose SIP/H.248 Protocol Conversion from the navigation tree on the left.
In the right pane, you can change the VoIP protocol (SIP or H.248) by changing the value of the Voice parameter, as shown in the following figure.

NOTE: Exercise caution when performing this operation because it will interrupt the ongoing call and delete current data.
Click Apply.
Thanks.