Thanks in advance for any info. I have a customer who would like to have an entry system at an external door where certain extensions (a total of three I am told) would ring when someone is at the door, and they could trigger an electric strike to open from inside the offices. Does the Definity switch have this type of capability? They have a decent sized Definity with an "A" and a "B" box. They also want video of the entrance but I can easily put that on a separate system either IP based or a normal analog camera. I am a low-voltage contractor for 25 years but I just know enough about phone switches to be dangerous, and I usually just provide structured wiring systems to support voice/data/video/control etc.