FreeSWITCH can be used to conquer NAT by simply wedging it between devices. You can configure a local FreeSWITCH and register all of your phones to it, then register that instance of FreeSWITCH to the SIP provider on behalf of all of your phones, carving a hole right through the NAT and keeping everyone happy. Also, you can set up FreeSWITCH on a public IP somewhere on the Internet, then register all of your phones or local FreeSWITCH instances from multiple locations to that common server, so even if both locations are behind NAT, they can still make calls between sites without a problem.
Germany
Slovakia
Canada
Brazil
Singapore
Hungary
Philippines
Mexico
Thailand
Ukraine
Luxembourg
Estonia
Lithuania
Norway
Chile
United States
Great Britain
India
Spain
South Korea
Ecuador
Colombia
Taiwan
Switzerland
Indonesia
Cyprus
Denmark
Finland
Poland
Malta
Czechia
New Zealand
Austria
Turkey
France
Sweden
Italy
Egypt
Belgium
Portugal
Slovenia
Ireland
Romania
Greece
Argentina
Malaysia
South Africa
Netherlands
Bulgaria
Latvia
Australia
Japan
Russia