Yahoo Voice And

I'm on yahoo chat a lot and i tend to hang out in rooms that are not really safe to be in... but any way my router is blocking voice for yahoo. i want to how safe it is to open ports on my router i don't really like having open ports on my router but i would like to have voice working. chat suck without voice.. yahoo voice run on different ports most one are 5001 and up tcp udp is there a safer way to do this or a better way to do so without some trying to exploit the open ports i have open kind of paranoid i might be a little bit.. i am running a dlink 4500 router. i do get port scan a lot i i just don't one some one port scanning me and find port 5001 open and have a field day with me and my computer i do also run outpost firewall to 7.0.. need some info on this Spanks