We are unable to make more than 3 party conference calls when registered to a Cisco VOIP server, How can we enable it to make 5 party calls ?

We are unable to make more than 3 party conference calls when registered to a Cisco VOIP server, How can we enable it to make 5 party calls ?

In Cisco CUCM enable the third party SIP device option as "Advanced" instead of "Basic" to enable 5 party conference calls.