Very simple query: If I configure my (external) gateway to use 
SRTP/ZRTP/SKYPE and then configure all my internal clients to register 
to FS using "regular" (understand unsecured) sip, would it be possible 
to route (i.e make and receive) calls between the gateway and the 
internally registered clients? If so, what are the likely problems I 
could face? Many thanks!