so i've been toying around with voip again, and found it kind of useful, mostly cos i can have phone calls straight to my cellphone over wifi which i tend to have on me.  but i also have a standalone voip phone too.

so after my cellphone battery went dead, and i get an email saying there was voice mail, i decided to setup a pabx for home.

after screwing around for a bit i manage to figure out dialplans to let me choose to make calls through open vfx (free local calling) or 2talk plus (prepay) i realise that i can have redundancy for outgoing calling (as long as i top up 2talk every now and then).

then i'm thinking, i have no incoming redundancy, and i'm dependent on my net connection.  well, there's actually another net connection here, which with a wireless card i could fallback on.  but it appears open vfx doesn't mention anything about multiple registrations at once, and while screwing around with the pabx, and trying to have both on at once, i kind of just switched the 2talk over.

i also appear to get voice mail when i call myself on open vfx.  whereas 2talk seems to let me call myself to test my incoming ringing is working.

so i seem to have two options here, i could do number divert to ptsn, but then what if i want to make ptsn be forwarded through to the pabx, and i can't detect if it's a diverted number or not?  or i can get another sip number for open vfx and divert on that, and then do a double registration one against the wireless connection?

but then on the wireless connection how do i make it less preferrable?  and do i have to waste a registration/number on openvfx?

what are other people doing for fail over?  i've read about orcon having reoccuring issues with their voip service, and although i'm not using orcon for voip, i'm still slightly uneasy about the idea of calls being dropped.  i'd probably be ok if i knew who rang me - but it appears that i get emails for voice mails but not for missed calls?  both my cellphone and desktop phone will list missed calls... but only if it gets through to them.

and then what if the pabx goes down?  it's only running on a virtual machine on a pc, it doesn't have redundant power supplies, or ups, but tbh i wouldn't want the noise associated with such. would i be wiser just to have the whole pabx setup external and stick some small (silent? can you get silent?) ups on my adsl modem?