I will explain again a bit diffrent to you just in case you still not sure.

Voip is one HOME A and NanoTEl is an other HOME B so you can uses some of the furtniture from HOME A to be used on HOME B but not building a bridge between HOUSE A and HOUSE B. We are not going to pay you again for fixing anything if you git it wrong.

Again the team putting a huge budget to you as you requested to run notification system ON NANOTEL only. We hired a better server paid a lot of arangments to make it separet so NO ANY RELATION BETWEEN VOIP and NANOTEL.