You used to be able to add a dialer but PSTN will be switched off soon so nobody is making them. There are GSM dialers available subscription to a mobile phone network required. You can by IP communicators but I am not sure that there are any that will allow you to diy it, and most have a subscription, the ones that are free are rubbish. As swb says if your not paying for someone to look after the server that monitors your alarm then someone is not going to look after it. There were a few free servers at one time, but every time they went down there was no rush to fix them, and most now charge for the service and to be fair they are fixed quicker. The 800l is a 30 year old panel now, maybe its time to get a proper alarm