If you want to call from one office to another, there is a very cheap solution available.
You will need:
1) Real public I.P. addresses on both ends
2) About 15 kb of bandwith for each call (max of four calls at the same time)
3) A conection to your PBX or phone system (unless sinlge line phones are O.K. with you) if you have a “key” system, you will need available C.O. trunks.
If you meet all the above, buy yourself a couple of Ericsson VOIP WEB 100 ‘s from e-bay. There is a guy out there selling them for about $250 each pair.
Setup the two boxes, it only takes about 10 minutes and you will be talking from point “A” to point “B” like a champ.
So far the cheapest solution that I have found.
By the way, I am not the person selling those boxes. Just a satisfied buyer.
Long live VOIP!!! Keep the savings and have a good vacation somewhere.