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VOIP Babyphone
So at one time in my life I was confronted with the problem that a baby would need to be monitored. Being a geek I couldn't go out and just buy a babyphone. That would have been too easy. So I started fiddling around with asterisk, and my two cisco 7960 phones.
Finally, after many hours of investigation I got that thing to work. What does it do?
The phone next to the baby places a call to number "2" (in hands-free mode, the microphone of the cisco phone is very good so this works very well), which invokes asterisk to open up a conference room, call the other phone in our living-room (which picks up automatically) and mutes the output-sound to the baby (you can't talk back as you could on more expensive babyphones, but right now this is not necessary).
Asterisk Configuration
I assume you have a working asterisk setup, with SIP accounts enabled. If not, I can't help you here. The phone next to the baby is connected via sip.conf:
[babyphone]
type=friend
username=mybabyphone
secret=asdf
host=dynamic
dtmfmode=rfc2833
context=babyphone
canreinvite=yes
nat=yes
allow=all
and the phone that receives the call can also be found in sip.conf:
[babyphoneclient]
type=friend
username=mybabyphoneclient
secret=xxx
host=dynamic
dtmfmode=rfc2833
context=add-to-conference
canreinvite=yes
nat=yes
allow=all
And here's my relevant extensions.conf:
[babyphone]
exten => 3,1,Playback(baerenkinder) # if I dial 3, play the sleeping song and then activate the babyphone
exten => 3,2,Goto(2,1)
exten => 2,1,AGI(callall) # 2 is the extension that the baby unit needs to dial
exten => 2,2,MeetMe(2,dtqp) ; press # to exit the conference
exten => 2,3,MeetMeAdmin(2,K) ; kick all users out
exten => 2,4,Hangup
exten => h,1,Hangup
[add-to-conference]
exten => start,1,MeetMe(2,dmqp)
exten => h,1,Hangup
the AGI Part is the most important. It instructs asterisk to execute a binary called callall. More on that later.
Here's my meetme.conf:
[rooms]
conf => 2
And in the asterisk AGI directory (in my case /usr/share/asterisk/agi-bin/) the callall shellscript, which just copies a couple of files to the outgoing directory of asterisk, which simply invokes a call from asterisk (which monitors that directory).
callall:
#!/bin/sh
cp /etc/asterisk/intercom/*conf /var/spool/asterisk/outgoing
Now what's in those intercom-files? looks like that:
Channel: SIP/mybabyphoneclient
Context: add-to-conference
WaitTime: 2
Extension: start
Priority: 1
CallerID: Baby
So this basically calls the phone registered as "mybabyphoneclient" in the living room and the add-to-converence context is applied, so it is joining the meetme-room. So much for the asterisk config.
Cisco Phone Configuration
The cisco phone configuration is straightforward. On my tftp-server resides a file called SIPDefault.cnf with the following content:
services_url: "http://www.wogri.at/path/to/menu.xml"
telnet_level: "2"
sntp_server: "193.171.23.163"
sntp_mode: "unicast"
time_zone : "CET"
date_format : "D/M/Y"
messages_uri: "50000"
time_format_24hr : 1
proxy_register : 1
and the phone-config file (SIPXXX.cnf) - where XXX is the mac address of the phone:
image_version: P0S3-8-12-00
logo_url: "http://www.wogri.at/path/to/wophone.bmp"
phone_label: "1234/57890"
phone_prompt : "WoPhone"
line3_name : "xxx"
line2_name : "yyy"
line1_name : "zzz"
line4_name : "mybabyphoneclient"
...
line4_authname : "mybabyphoneclient"
...
line4_password : "xxx"
...
line4_shortname : "babyphone"
...
proxy4_address : "my.proxy.wogri.at"
...
proxy4_port : 5060
And that should do the trick. Except for the automatic pickup in the living-room. This must be configured directly on the phone (can't remember where, you'll figure it out), there is no config-file option for that. The cool part is, that I also have got a wireless SIP-Phone, so I can hook up into any wireless network and use my babyphone. I like that :)