The serial number is probably getting too much attention, consider the OLT as the mid point between the customer house (ONT ) and the ISP network , Openreach records the addresses and the ONT serial numbers of each connected house ( that is connected even if there is no ISP giving service , so say the house had Virgin and was using that, the PON light would still be lit and steady and connected as far as Openreach are concerned ) .
Customer orders service from an ISP that uses Openreach , the ISP uses the address (not the ONT serial number ) to set up service with Openreach , ….Openreach know the address and the ONT serial number at the address and ISP wanting to serve that address (OR don’t know or care who the customer is , they just require the ISP and address ) Openreach connect the ISP network in ‘software’ at the OLT to the ONT recorded at the address the ISP requested , which is already connected to the OLT and that should be it , ISP sends a router to address for it’s customer.
OR simply arrange the interconnection between the two, the address and the ISP ..although the serial number was used to set up initially , it’s not necessary when an ISP starts delivering service , although it can be ‘seen’ and used for physical cross checking etc if it’s suspected of being incorrect, it’s not normally anything to be checked , if it were wrong the OLT couldn’t talk to it and the PON light would flash to indicate this lack of communication within Openreach , not the ISP network.
