simple multicast protocol <communications, protocol> A proposed {mulitcast} {protocol} that would ease the requirements for {IP} Multicast, such as no longer mandating that routers be able to calculate the source of a multicast stream. This has not been adopted by the {IETF}. (http://infoworld.com/cgi-bin/displayStory.pl?981125.whmulti.htm). [Reference?] (2001-07-02)