Broadband telecommunications switch

A broadband telecommunications switch for switching packets of data received on a plurality of input ports to a plurality of bandwidth limited output ports, said switch comprising:

• for each input port a control processor which operates to communicate request data across the switch for each of a plurality of switching periods, to each of a plurality of bandwidth allocators operatively associated with said output ports, which request data is representative of a request for communications bandwidth from said output ports sufficient to accommodate packets of data received at said input ports during a corresponding switching period, each of said bandwidth allocators responding to said request data by generating bandwidth allocation data appertaining to an allocation of a share of the bandwidth of an output port to the input ports, and communicating bandwidth allocation data to each of said input ports, and said input ports using said share of bandwidth to switch data to said output ports;
• and
• a data store means, for storing limit table data appertaining to a predefined relationship between an amount of data to be switched from an inlet port to an outlet port in correspondence with a bandwidth of the output port to be allocated to the input port for switching said data;
• wherein each bandwidth allocator operates in combination with the limit table data to generate a limited bandwidth allocation, determined in dependence upon an amount of data to be switched from the input ports and a share of the bandwidth of the output ports to be allocated to the input ports, whereby an allocation of an excessive amount of bandwidth of an output port to one of said input ports for switching a relatively small amount of data is avoided.