TUDPBlockSocket.MulticastTTL
TUDPBlockSocket

property MulticastTTL: Integer;

Unit
blcksock

Description
Set Time-to-live value for multicasts packets.It is define numer of routers for transfer of datas.

If you set this to 1 (dafault system value), then multicasts packet goes only to you local network. If you need transport multicast packet to worldwide, then increase this value, but be carefull, lot of routers on internet does not transport multicasts packets!