I used asterisk before as the only phone service for my house (meaning i don't have a pots line anymore), and I now use Asterisk in linuxmce. It is very reliable and does not crash. I was able to setup emailing of voicemails via the Freepbx admin pannel. You can even tell it to email the voicemail and delete it from the mailbox. I was meaning to try and setup fax reception, which seems to be available in freepbx, but didn't get around to it yet.
There also seems to be a linuxmce event for receiving new voicemails and even one for when the mailbox is full, so it's possible to trigger certain events based on voicemail reception from within lmce (such as turning on a light somewhere for example).
The only problem face is that when the phone rings while I am watching MythTV or a Video, the video or Tv will systematically stop and exit, instead of pausing, and simplephone will not display, which is very frustrating.
Other users do not seem to hav ethis problem and I did not find any difference with my system when comparing to other users in a thread a while ago. I was hoping that this may be fixed in 0810 when it comes out...
Dave: to answer your question, H323 is a different protocol for the transmission of voip calls, like sip or IAX. SIP and IAX are supported in Asterisk natively (hence also in Linuxmce) but H323 is not without special plugins. Also, less and less carriers are supporting H323, and while it is, in my opinion, a superior protocol from a telecom perspective, sip is better suited to deal with NAT situations of end users.