Generally, no VM providers equipment is compatable with others. You have AMIS analog which nobody uses due to poor voice quality (additional degredation with each successive analog transfer). AMIS digital never materialized.
Now, we have VPIM the digital internet messaging standard. Theoretically, any vendor who supports VPIM can exchange digital quality messages with any other VPIM enabled VM. I don'st know what impact VPIM will have on the market. In theory, it enables VM users a path out of one particular brand to another. Also, it allows VM users to buy a large sytem from say Octel, CGRM, BSN, and use cheaper systems for satelite offices.
A PBX is a Private Brance Exchange. Generally, a business that requires multiple lines can either buy a multi-line solution from the phone company (i.e. centrex), or they can buy one or more trunks, and buy a switch (PBX) from a third party to handle internal calls. If you ever have to dial '9' for an outside line, you are likely on a PBX. THis presents a much cheaper way for a business to get phones on all of the desks of it's employees. They buy a switch, and a block of external trunks. Since most employee calls are to other employees, you only need a few trunks.
CPE refers to customer premise equipment. Generally, a PBX is CPE. Also, in VM land, there are two main VM markets. Service Provider and CPE. Service provider is the companies that use the VM equipment to generate revenue (i.e. PacBell, cell providers, etc.). CPE is the VM that connects to the customer PBX(or Centrex). |
