I am configuring a cisco 3640 with IOS ver 12.4(13b) wich has 2 fxs ports and I want to use them with an ITSP. I can register each port using diferent usenames. everything works fine for a while, but then, when I want to place a call, the gateway sends the INVITE and receives a 407 Proxy Authentication Required from the sip-proxy...as far as I know the GW must reply with an ACK followed by an INVITE message with credentials...the problem is that the GW is replying with an ACK but never sends the new INVITE with credentials. Do I have to configure such reply anywhere via CLI?
I am attaching my GW's VoIP config and the sip debug.
Thank you all in advance!!