I'm new to Freeswitch so if this has been discussed, please send me to the proper link.

I need to setup a trunk to Level3  (I've heard that's not popular at Freeswitch too :) ) Level3 does not use authentication but restricts based on IP address.  When I setup the SIP profile, the username and password fields are required so I put in anything and set register to false.  Whatever I put in the username field gets passed to Level3 as <username@xxx.xxx.xxx.xxx> in the FROM, Contact, and Remote-Party-ID fields.  I've tried putting in nothing, but then I get <null@xxx.xxx.xxx.xxx> instead.  How do set this to the E164 number of the calling party instead of the username?