Free outbound voip calls

[phreak]

Im not into hacking any voip yet
but being an old school phreak
if we can hack any boxs to get free outgoing calls what boxs are best to hack and what do we need to do to them
im not really interested in unlocking them to change providers
but free calls through a hacked voip box and modem
and lets talk about the best setup
i have my USBjtagnt waiting on it