Asterisk/iPhone SIP config


I have an asterisk box running behind a NAT firewall on my ADSL.

I have 3 extentions running internally and 2 iphones using 3g and iSIP that connect externally to the asterisk server. I can call from iphone to iphone but it is really laggy and is not really clear or working.

When I try to call out to the PSTN the called party gets choppy audio/hangup after 20 or so seconds. Is there anything I can look at to optimise this?


I am going to go out on a limb and say that AT$T’s 3g network is not “optimized” for sip… Can that app work over wifi? If so what are the results.