I want to make and receive calls by connecting to a VOIP provider that uses separate servers for SIP messaging and RTP.
Does Asterisk support this ?
if a VoIP provider has such a setup it might be possible. don’t know for sure though.
Yes.
Do any configuration changes or other modifications need to be made or can Asterisk do this automatically ?
Provided that you do not have any network address translation, Asterisk will connect the RTP to wherever the incoming SIP SDP payload tells it to connect it. It will not assume that RTP goes to the same address as the SIP came from.
(It will even tell both parties to connect their RTP streams directly, subject to some limitations.)