You are going to want to set it up on a separate static port. You can use one set of SIP credentials for multiple servers. However to avoid some potential problems with call forking, for inbound calls we recommend that you use host-based routing. For more information regarding host-based routing please see below:
To use Host-based routing for your DID:
1) Login to your Flowroute Manager and navigate to the Interconnection tab.
2) At the bottom – in the Inbound Routes section type in your IP/hostname into the text box which reads “Enter Route”.
3) Once you have this information inputted, select the Host option from the drop-down menu to the right.
4) Next, navigate to the DIDs tab, and select the DID you wish to change by place a check-mark next to it.
5) Finally, once you have selected the DIDs you wish to change, click on the functions drop down menu and set the Route to the IP/host of your server you wish to direct the calls to.