Question: ESXi AsteriskNow and ISDN card

Hey everybody,

I want to test AsteriskNow… for this study I use an ESXi 5.1 Server + AsteriskNow and an additional physical ISDN card… Is it working in the VM or not? I was reading already on the internet that there are problems with ISDN cards and VM’s … Any suggestion?

It would be really nice to get an reply on this… a google search didnt show me the content I needed…
Thank you
best regards


By pure definition the use of a physical card in a virtual server is not a supported or even an expected solution. Where we have deployed on virtual servers we have external gateways such as the Digium ones. These work well.

I believe some virtual machine hosts will allow one VM to access real hardware.

Yeah, I just can’t see a virtual machine, which itself isn’t timed very reliably, accessing real hardware connected to lines that need very good timing, working out very well in practice. Maybe as a demo, but I’d be hesitant to deploy such a thing.

Definitly use a VoIP - ISDN gateway instead of the ISDN card. VM should handle a VoIP-only Asterisk setup OK. Under the condition that the Virtualization server does not have a high load on it.

Yep, We have 20 -30 extension systems on ESXI 5.1 with Digium gatesway and pure voip running fine.
wouldnt even try it with real hardware.