Asterisk on Virtual Box audio

Hi all,
I have a small asterisk server set up in VirtualBox. I can call extensions inside my network with no audio problems what so ever. But, when I call an outside line say, a cell phone, the audio that the cell phone receives is super choppy and the audio lags about 1 second behind. The audio that the asterisk extension receives is crystal clear but also lags. It is almost like it is having trouble sending the packets. I have forwarded ports 10000-20000 on my router and I have forwarded 5060 so its not like the packets should have trouble getting through. Also, my asterisk server is behind a NAT.

What maximum scheduling latency does Virtual Box guarantee?

What do you mean?

What is the longest time from a packet arriving on an ethernet interface until code starts running in an application to handle that packet. For VoIP, it should really be less than 20ms. Virtual machines can have much larger values, unless specifically configured for real time use.

Sorry it took me a while to respond. I did end up fixing the problem. I decided that running Asterisk on a VM was just not going to work all that well. I installed Asterisk on a linux box and it is working just fine now!

Thanks for your help,