Modem sharing device

A modem sharing device ('MSD), also commonly known as a line device (LSD), sharer, or sharer, allows multiple devices to share a se connection. Only multipoint serial protocols such as Bisync are supported. Both synchronous and asynchronous data-streams can not be used. A common example would be a Tandem as host connected to multiple automatic teller machines often with a modem or Cisco router in-between.