network availability standards

Hi, we are looking for some standards of network availability for
broadband networks. Specificaly for backbone availability, last mile
availability, mean time to repair, and so on.

We have and HFC network (yes, CATV and cablemodems). These
customers range from the home users, SOHO, point-to-point and
VPNs. Any pointer to these info would be very appreciated.

We are trying to set up a SLA paperwork for commercial and
corporate customers.