[Asterisk-Dev] Uncommon callback

[Rich Adamson]

> > And you don't really want to tunnel VoIP at all over TCP if  
> > you can avoid it, because if you drop a couple of packets, you end up
> > with a lot of latency.  Same goes for PPP over SSH, for the same
> > reason.
> 
> Indeed. I keep intending to play with VoIP over ICMP echo packets,
> partly because the muppets in my employer's IS department have seen fit
> to block all outgoing UDP connections, but ICMP still works. 
> 
> But some ISPs' routers will actually prioritise ICMP in order to do well
> in latency tests, so VoIP over ICMP might actually do better than VoIP
> over UDP :)

A very large number of isp's block icmps due to the cisco ios bug
from a year or so ago. Don't expect to get very far.