I need Arris CMTS 1000 firmware albums

Hello,

I have some some Arris CMTS 1000 for testing CATV measurement equipments.
Now I have trouble. Some equipments can't link up to CMTS 1000.
Therefor I want to change firmware version (Current my CMTS1000 version is 3.3.318).
But I don't have firmware files.

Could anybody give me firmware files?

Sincerely,