There are several reason that they need to get IP address. Some videophone requires to get IP address in order to make a call. Like for example: If someone uses OJO (another type of videophone), and if they want to call to someone who has Sorenson VP-200, they had to call to them using IP address. Some routers such as SR-200 which it was provided by SorensonVRS, it has firewall installed inside the router which your computer will be safe from hackers. But if it was from HOVRS, they would need to use IP address in order for them to call you from MVP (mobile video phone). I know Sorenson has Local Numbers and DirectVP numbers. Local numbers can be used for hearing to call locally to your videophone and for 866 numbers can be used for hearing people like if you had family from out of state, they can call you directly using 866 numbers.
I did tried to call DirectVP numbers to my friend who has DirectVP numbers when I was at the DeafNation Expo when I tried using their videophone, Z-340, but it didn't work. The staff who worked for CSDVRS told me it will only work if you have IP address in order to make a call from videophone. It won't happen without the IP address to make a call if they get hold of your computer using IP address if someone making a call....the phone calls will go directly to your videophone by using IP address, DirectVP phone numbers or your 10-digits local phone numbers.
I did tried to call DirectVP numbers to my friend who has DirectVP numbers when I was at the DeafNation Expo when I tried using their videophone, Z-340, but it didn't work. The staff who worked for CSDVRS told me it will only work if you have IP address in order to make a call from videophone. It won't happen without the IP address to make a call if they get hold of your computer using IP address if someone making a call....the phone calls will go directly to your videophone by using IP address, DirectVP phone numbers or your 10-digits local phone numbers.