A Wifi phone is as the name suggests, a phone exclusively using Wifi to connect. This will be a touchscreen Android powered phone with the dialer connecting directly to the Wifi network. Since this not a cellular phone, there is no need for a SIM slot, and the 128GB of storage in the phone should be more than sufficient not only for OS/Security updates, but all of the contacts, and call logs that the phone will recognize. The phone will have a 6.9 16:9 aspect ratio with a 450ppi resolution. As by requirements, the phone will have 128GB of integrated storage, and a micro-SD card slot supporting up to 1TB of storage. There will be no other options for this phone.
The phone will support up to 5 SIP accounts with SIP 1 being for incoming and outgoing calls and lines 2-5 for incoming calls only. This might be a little inconvenient, but it will be too messy to define which line calls what contact. Also, there is a Messages app, but this will only support the Unify Messages system rather than offering SMS like messaging. This means the SIP phone does not natively support SMS.