Abstract: A broadband switching system and method switches asynchronously transferred cells of data using a dynamic bandwidth controller to control application of data cells from a number of transmitting end systems to an input port of the system. The dynamic bandwidth controller provides cell buffering from each source and controls output of data cells to the system according to a current cell rate assigned to cells from the respective end system. When an end system begins transmitting data cells, the controller detects the presence of incoming cells and requests bandwidth from a connection admission control forming part of the system. A default cell rate is provided for the end system so that transmission can continue until an appropriate bandwidth is allocated. The controller contains a buffer for buffering cells in this situation.

Abstract: This invention relates to sealing compositions and, more particularly, sealing compositions for use in conjunction with tail seals of tunnelling machines. In particular a sealing composition according to the invention comprises, by mass, from 10 to 55% of a petroleum-derived wax, or wax-consistency hydrogenated vegetable oil or fat, or a polyisoobutane of oil, grease or wax consistency, or any combination of the above, from 0.5 to 15% of a lipophilic emulsifier, and water in sufficient concentration (at least 20% preferably 20-75%) to inhibit combustion of the composition.