At office I am considering setting up an asterisk server to that we can route calls that come into the office internally so that they reach the correct person and to implement a menu system as well.
I have managed to set up a server so that we can call each other internally however I would like to know how we could connect it to our existing phone line to make and receive calls via that if it is at all possible.
Best Answer
You need what Asterisk calls a telephony interface card ; a PCI or PCI Express expansion card that connects the server running Asterisk directly to your (legacy) phone line(s).
Depending on your locality you might be able to port you existing landline number to a (current or new) VoIP provider and save yourself the hassle maintaining the existing landline.