Pokud mas WinXP, na firewallu nic nastavovat nemusis. Pokud mas Win7, bylo by dobre otevrit ten port i ve firewallu pro prichozi komunikaci.

Samozrejme to musis nastavit v routeru.
Zkus si najit svuj router, tam uvidis, jak to nastavit:
http://portforward.com/english/routers/port_forwar ding/routerindex.htm
Pripadne to muzes na stejne strance najit i podle jmena programu