[Asterisk-Users] No sound with SIP Phones on the Internet

[duncan]

>Dunca:
>I am not sure I understand your statemnet.
>SIP devices (UA) on the other side of the Internet behnid a NAT communicate
>to * on the public Internet.  Then this Asterisk connects to other Asterisks
>(via IAX) that can be behind Firwalls (or NATS).  am I understanding
>correctly?

this is possible yes.

or wherever you have a firewall - make sure theres an asterisk server 
behind each one.  then open up IAX or IAX2 through your firewall and let 
the SIP clients connect "locally" to the asterisk server.  remember you can 
run asterisk on very little processing power and it doesnt need any 
specific hardware to just do VoIP stuff.

my setups are something like this:

branch office
sip phones -> asterisk server -> firewall -> internet

datacenter

internet -> firewall -> asterisk server -> pstn


so i dont have any problems with trying to get SIP working through 
firewalls - i just put a local asterisk server wherever theres going to be 
sip phones.  because IAX is so flexible with regard to firewalls it doesnt 
matter if the main asterisk server is on the public internet or behind a 
firewall with the IAX/2 ports opened up.


duncan