English laboratorium is not one way to practice english conversation in your school. We can use computer to develop english conversation in our school. Technical requirment to english conversation :
1. PC Network
2. LAN
3. Head Set
4. LAN Chat Software

recently, in quick search from internet, i found some resources that would be helpfull to understand term multicast and IPV6.

MUlticast
http://id.wikipedia.org/wiki/Multicast
http://lecturer.eepis-its.edu/~amang/pdf/IP_multicast.ppt
http://onno.vlsm.org/v11/ref-ind-1/network/manajemen-trafik-ip-multicast...

Technology now feels more easy.