We are thinking of getting a few Sipstation trunks.
We can source-restrict SIP 5060 to a SIPstation IP address or domain name, so that's good.
We don't feel comfortable opening RTP ports to the internet at large though . Although there is no threat of hacking into our system, Dos attacks would still be possible.
What is your take/experience on this, and how does Asterisk deal with a ton of unauthorized RTP traffic?