IP mpticasting is a set of technologies that enable efficient depvery of data to many locations on a network. Rather than making mptiple copies of a message intended to be distributed to mptiple recipients at the （请作答此选项） of origin of a message, mpticasting initially sends just one （ ） and does not copy it to the individual recipients until it reaches the closest common point on the network, thereby （ ） the bandwidth consumed. Network performance is significantly （ ） because it isn’t bogged down with the processing and transmission of several large data files; each receiving computer doesn’t have to （ ） the transmitting server for the file.