How many techs have systems in where they don't hear from a client for years and then get call for additions,upgrade,etc. If you put in new voip, you can keep up with client on a monthly basis just adding patchs,checking on gateways etc.The billable hours are incredible,the customer will treat phone system like his computer and expect downtime,our hourly rate will double.-------Our satisfaction in well done jobs will fall but what the hell were earning big bucks.Enough patchs and you have a quilt.--John