[Asterisk-Users] A room full of Cisco 7960s behind NAT

[Rich Adamson]

> My main problem local servers is that I need to (a) be able to forward 
> voicemails between users at multiple locations and (b) have all the message 
> waiting lights working.
> 
> Otherwise I'd be doing just that.
> 
> Meanwhile I'll check out qualify=yes - I already have nat=yes.

We have several distributed 7960's working from behind nat boxes.
Config the phone itself with nat=yes (via the phone's keypad), and
in sip.conf use both nat=yes and qualify=5000. Have not had any
problems with MWI on these either.

Over the past 2+ years, I've seen various nat boxes that do not 
handle nat/pat correctly when two or more phones are behind the
same nat box. So, don't bet you're nat box is necessarily working
correctly on this.  The only way that I know of to actually verify
it is to use something like ethereal to inspect the packets, looking
specifically for the mwi packet, etc.