Verify the PVC vpi/vci numbers of your service and those that are in the Alcatel or other hub. These numbers must match, at the ISP "stack" or ATM hardware and at your end.
Be advised you may have to get level two tech support to get this answered. Also, you may have to call the tech support numbers for the Alcatel. Different models of their hubs/routers may be burned with different numbers.
Common numbers are 0/35 or 8/35, but less expensive equipment has them burned in and they are provided to customers for whom there is a match.
It is possible, though, to have them change the vpi/vci settings if you can get to that level of tech support.
Best
Mike