RIM is an acronym for Remote Integrated Multiplexer. These devices connect to the phone exchange line into a housing estate and sets up a 'daisy chain' link from each house in the neighbourhood and then back to the exchange.

RIM's work well for voice, but cannot handle data very well. This poses a problem if your neighbourhood is connected to a RIM and you want DSL or another form of high-speed internet, seeing most telecommunications companies would rather listen to you complain about the extremely low speed you would encounter rather than upgrading.