A few questions to all knowledgeable heads out there: Everything I read so far about how to set up and configure my FS external sip profile tells me that I need to have IP address/interface and port (default being 5080) to bind to in order to receive inbound calls via the external sip profile. Is that really the case? Is this the only way I could receive such calls? The reason I am asking is this: my Internet-facing interface cannot receive calls (or any connections from outside) unless it initiates these connection first, simply because my ISP is blocking "server" connections (i.e. connections initiated from outside, destined to my IP address/interface). If my Internet-facing machine initiates the connection first (therefore punching a "hole" through the ISPs firewall), then that's allowed - no restrictions of any sort are applied by my ISP. So, I guess what I am asking is this: Is it possible to configure my external sip profile in FS in such a way so that it does not listen to a particular interface:port in order to receive external sip calls, but to use the control channel/connection established to my external SIP provider (on sip provider's IP address and port 5060) in order to find out which ports to use and initiate rtp connections on my machine, instead of waiting for such connections on a specific port? As I already pointed out above - such connections initiated from outside will be blocked by my ISP, but if these are started from my machine they will be allowed, no problem. Hope I am making myself clear with this. Many thanks!