Hi,   after I get some questions over PN about VTO2000A with SIP and Asterisk, I think it is usefull to make this Thread. So everyone could ask here or post solutions for problems.   I have an VTO2000A and an VTH1550CH. But I want more flexibility.   What do I wanna have at end? If someone rings the bell of VTO, I want ringing the VTH1550CH, ringing my FritzFon (over Fritzbox) and when I'm not at home, my Android-Smartphone should ringing to. And everything with Video. Well ringing with Videostream over Fritzbox will not work because the Fritzbox doesn't support SIP Video. But there is a possibility to use Snapshots instead.   My problems so far: - Main problem with SIP Firmware is that there will be no Push Notification on Dahua Android App gDMSS
- When I use SIP Firmware with VTH1550 I only could use VTO as SIP Server to get connection between those two. But then my FritzFon will not ring.
- When I use Asterisk as SIP Server my FritzFon are ringing but I get no Snapshot and I couldn't connect my VTH. I could insert the Dahua URL for Snapshots but this will not work with Fritzbox.
- When I use Fritzbox as SIP Server, the FritzFon are ringing but when I pick up the FritzFon the VTO will end call after a few seconds because Fritzbox sends "183 Session Progress" as Answer and the VTO only accept "180 Ringing" as answer.
  Solution for connection between Fritzbox and VTO. If you wanna use Fritzbox with Telephone for ringing you have to use Asterisk as SIP Server and send an "180 Ringing" before Dial(). I will post my extensions.conf and sip.conf.   My Fritzbox will give "621" as number for Doorstation and callingnumber is 9901. So I gave the VTO as No. 8001 and 9901 as Villa Call Number. On Lan-Config / Server Type is Asterisk and Network Config / SIP Server Conifg is IP of Asterisk Username "8001" password you entered on extensions.conf and Realm is "asterisk". The VTO-No. must be something like 800x. I've added pictures of settings. I think this will be much easier to understand   Here my extensions.conf: [general] static=yes writeprotect=no [ausgehend] exten => _9901,1,Set(CALLERID(num)=9901) exten => _9901,n,Dial(Local/alle@tfe-zuhause,50,w) [tfe-zuhause] exten => alle,1,Ringing() exten => alle,n,Dial(SIP/9901@videodoorgateway,50,w) [default] include => ausgehend include   sip.conf: [general] language=de bindport = 5060 bindaddr = 0.0.0.0 type=friend context=eingehend externrefresh=30 nat=force_rport,comedia srvlookup=yes transport=udp localnet=192.168.1.xxx/255.255.255.0 ;directmedia=no [8001] host=dynamic username=VTO2000A type=friend secret=qwertz context=ausgehend disallow=all allow=ulaw allow=h264 [videodoorgateway] context=eingehend type=friend insecure=invite nat=force_rport,comedia instead username=621 fromuser=621 fromdomain=fritz.box secret=AnyPassword host=192.168.1.xxx dtmfmode=rfc2833 disallow=all allow=ulaw ;allow=h264   I'm not very familiar with Asterisk, but with this settings connection between Fritzbox and VTO will work. What is missing is to create an URL with Snapshot when someone rings the bell.   Maybe someone has solutions and will post it here so everyone could pick up what he needs to get this real good hardware work well. Because Dahua will not give support. So we have to help ourselves.   If you post any solution, please write what system will work e.g. Android App or IPhone App with Asterisk (Videostream will work or not) and then what settings are needed to get it working.   I'm anxious to see your solutions or questions   EDIT: Here screenshots of settings in VTO:   That's all