If you mean 'Can u do _IP_ multicast with TCP', no. plain TCP requires the sender & receiver to establish a 3 way handshake and this is only between two parties.  TCP also uses other mechanisms for flow control etc which are geared towards a two party only config. Having said that TCP maybe used to setup multicast topologies in higher layers (see above discussions on IRC etc). There might also be other reliable & possiblly connection oriented layer 4 protocols that support IP multicast.  203.173.11.157