Asterisk as only an answering machine

Can I setup and asterisk install using a Digium Wildcard as an endpoint and only use it for an answering machine. I know this sounds a little crazy and it’s total overkill, but I work with idiots, and my boss won’t pay to rewire the office (even if I do it). So I just want to setup an asterisk box to work as a voicemail for all 3 lines like a traditional answering machine does, without routing allof my calling through it. Does the topology need to be PSTN -> DAHDI -> ASTERISK - > PHONES or could it go to PSTN -> DAHDI AND PHONES and then have Asterisk setup as an end of line device like a phone. Will it still pick up the calls after a certain amount of time.

I’m basically trying to build a 3 line answering machine that will email the voicemails, I don’t need any other features.

id lay it out as such -
pstn trunks <-> dahdi fxo <-> ASTERISK <-> dahdi fxs <-> phones

i suppose you could do some type of line sharing splitter where the desk phones rang along with the dahdi fxo trunk and delay asterisk answering

with the exception of the desk phones using FXS all of the same pieces are present in either scenario and the splitting inbound to phones and asterisk simultaneously could be problematic

This can be tottaly done
PSTN -> DAHDI -> ASTERISK ->VOICEMAIL app->EMAIL

My concern is that the phones in the office are already wired, and poorly at that. I can’t rewire the phone system easily because the demarc is on another floor and the wiring is a disaster right now, and I can’t shut the system down. I want to know if I can install the Asterisk box at a phone jack and just set it up to pickup after a certain amount of time. Will I run into issue is someone picks up a call that asterisk has answered. Am I setting myself up for failure, or should I just wait until it can be re-wired (likely never).

You can send all calls to Asterisk using an FXO card, as you already described also you could foward call to an external phone number, once the call is answered by Asterisk as you re using analog, not sure if some one else could hear or speak… I have a while without use analog phones

Also will the voicemail be able to handle multiple analog phones at once. I’m using a 24 port card

each port it is a channel, so 1 call per channel at the time

What would make it problematic? I can’t really re-wire the office at this point and the demarc is on another floor.

You can only have one port per phone jack, so if you only connect it to one phone jack, you can only handle one call at a time. (If the jacks are wired in parallel, connecting to multiple jacks will not increase the number of calls.)

Yes you can do this for a ‘no-answer’ voicemail, but not for a ‘busy’ voicemail.

In your dialplan use a Wait() to allow the user to answer the phone.

You will want to create a context per port of your card

[voicemail-line1]
exten => s,1,Wait(24)
 same => n,Answer()
 same => n,Voicemail(5551212@voicemail,u)
 same => n,Hangup()

[voicemail-line2]
exten => s,1,Wait(24)
 same => n,Answer()
 same => n,Voicemail(5551213@voicemail,u)
 same => n,Hangup()

[voicemail-line3]
exten => s,1,Wait(24)
 same => n,Answer()
 same => n,Voicemail(5551214@voicemail,u)
 same => n,Hangup()

Your chan_dahdi config would look something like this, beware I haven’t done Dahdi in like a decade so this may not be exactly right…

signalling=fxs_ks
context=voicemail-line1
group=0
channel=>1

signalling=fxs_ks
context=voicemail-line2
group=0
channel=>2

signalling=fxs_ks
context=voicemail-line3
group=0
channel=>3

signalling=fxs_ks
context=voicemail-line4
group=0
channel=>4

Then you just wire the 4 lines so they connect to both the PBX and the existing phones.