I'm now working with AVAYA mainly! but with ocassional Panasonic works - and coincidencially got a case with similar behaviour, here it's
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Keywords: voip, ip, tda100, udp, port, firewall, nat, vpn
I’m setting up a ip connection inside a new company.
The company have two Offices.
Office A: public IP address
Office B: public IP address
Connection UDP port: 8000
Both offices have KX TDA100 PBX’s with their respective IP TRUNKS and IP EXTENSIONS cards.
They have two Panasonic IP phones.
When a call is made from a ip phone to any other phone inside the same LAN (using lan only) the call is established without flaw
When the call is made from an ip phone to any phone outside, at the other office (using internet) the call is established but half way, i.e. from the extension that’s inside the LAN one can speak but not to listen, and from the extension outside the LAN one can listen but not to speak (note: both sides transmit DTMF tones without trouble)
We’ve called the ISP to report this problem and says that his router is not blocking anything, but making a IP-map between ip public address and ip private address, this private address is 192.168.0.55 that corresponds to IP EXTENSION CARD ip address.
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