DP 750 + DP 720 requirements to work


Hi there!
My question should be easy for people with some experience.

I am considering to get a DP750 base and DP phones.
There is no landline available!
The only thing available is a modem with a mobile phone chip, that has 5 ethernet ports!
I thought that I rent a skype IP phone number, and configure the base to attach to that number. And all phones would ring if there are incoming calls.
They would not be used to make outbound calls, just to receive calls.

Will it work the way I imagine it, or does the base have a different function?
Since it is an IP phone system, it should work through ethernet network and not through an analogic phone line, right?


There is a difference -

The DP product uses the SIP protocol to communicate. So, there is a little more to it than just IP and Ethernet. It is like using the air to carry our voices, but in doing so we need to communicate in the same language in order to be able to understand one another.

Skype reportedly supports SIP, but I suggest you do a Google search of “Skype and SIP” to determine your willingness to go down this path.

The other thing to be concerned about is using a 3g/4g/LTE cellular data modem. In many cases the latency may be more than can be supported, the provider may alter the messaging, bandwidth may not be enough, etc.

Find someone who uses the same wireless carrier and do your homework as the service needs to be stable, reliable and able to handle the traffic without alteration and preferable with a static IP from the provider.

The bottom line is that it is not as easy as you may think and the cellular cost may be extreme.


As long as you can get the Skype IP Phone number to be registered on DP750, that would work.I have never tried myself, according to this article: https://support.skype.com/en/faq/FA10306/how-do-i-assign-skype-numbers-to-a-sip-profile, you can get the SIP profile in the Skype Manager, then use the SIP profile to register the account on DP750.


Thanks for the answers so long! I had no idea that a SIP protocol compatibility had to be assured! I saw other providers that offer numbers and explicitly say they support SIP. I will re-check them!

The installation is meant to have a way to communicate with the people, and calls will be just a few per month.
My brother in law does not answer mobile phone calls, he has a caretaker because he doesn’t move alone, and a phone would be different, because the caretaker would have to answer.
It would be only for incoming calls covered by most providers of phone numbers.

btw. the cellular phone modem has unlimited data usage (100GB at 10Mbps per month and afer that, at 2Mbps. Actual usage is probably less than 5 GB per month!)