Not sure if this topic should be under Telco Talk or networking. 

Last week DiGi upgraded service with VoLTE, on handphone it showed the icon. 
I have Huawei E5186 router that supports VoLTE, I search in internet but can't find info about setting up VoLTE on router, not even sure if it is automatically setup or what. 

Connect normal phone to the RJ11 port the dial tone is engaged dial tone not working.
If set to 3G or Auto then can make call, but it is not VoLTE just normal call, and at LTE when make call it will drop to 3G and come back to LTE after the call, with this the ping and speed is haywire.

Expert please advise