Is it a simple procedure to configure ISA Server 2000 to allow an Asterisk IPPBX connect to SIP provider. On asterisk forums they say the ISA has difficulties handling SIP, softphones that i have installed behind the firewall work fine with the provider when the firewall client is installed on the workstation. With asterisk being a linux based system this will not be an option. Is the config a matter setting up port forwarding, is this a more complicated task on ISA server than just selecting the ports i need and then the ip of the internal machine i want to forward them to?
UPDATE: I dont think this is possible from what ive researched