[Freeswitch-users] Implications of using -nonat

Hi What are the implications of using the -nonat flag when starting FreeSWITCH? When should it be used? I have started FreeSWITCH with -nonat and it registers with my external VOIP gateway (Pennytel) and users can make calls using the external sip profile. Clients outside of my network are not able to see or register with FreeSWITCH which is expected behaviour. What am I missing in terms of functionality because of disabling NAT? Thanks in advance O.