The CS7000 is a full feature SIP phone system that runs on top of the SME linux distribution. It is commercial software (we have to buy groceries) but the cost is a small fraction of traditional phone systems with features they can only dream of. The latest release has integral support for Internet Telephony Service Providers (ITSP's) which can save you tons of money on those monthly phone bills. I have been running the server at my home in Ottawa for the last 6 months and although callers don't notice any difference, I no longer have traditional phone lines. I have local phone numbers in Vancouver, Ottawa and Oklahoma City to make it easy for family to call me and I pay less than I paid to Bell Canada for one traditional phone line.
My internet connection is a cable modem which allows me to have multiple calls in progress at the same time so my number is never busy (Even with 2.5 teenagers). The system uses Linux traffic shaping to make sure that data doesn't compromise phone call quality and the firewall that comes standard with SME Linux has repelled numerous attacks.
For a complete list of features and applications, visit our web site: