7940 SIP>SIP Proxy>Polycom and Cisco SPA5xx lines work great using outbound proxy. So I’m certain this is a Cisco 7940
problem not accepting RTP due to some internal security check with SIP
signaling and media coming from different ip addresses or something like that.
So testing a bit more, I put the Cisco 7940 on a Public IP, seems to work fine, audio sets up 2-way inbound and outbound calls. So now I’m thinking it is a NAT issue, but only when using outbound proxy, doesn’t make sense, now I’m really confused.
Any feedback is appreciated.