making PABX local.

hello evryone.

i hav got a project in hand. but i m not sure how to do it?

actually an enterprise got 3 offices in same city. and each office got its own PABX.
Office A (PABX)
Office B (PABX)
Office C (PABX)

question: is it possible to interconnect ever PABX with each other, so that it work like one single PABX or a intercom type of thing.

i would connect three offices with each other using mikrotik over RF.

plzz, tell me it it possible?

All Mikrotik can provide you is the capability to bridge the networks at layer-2 or route the networks at layer-3. The capabilities of the PABX’s is up to the PABX’s and their manufacture, so you would have to ask them.