>> You seem to be saying that openreach buy some kind of service of BTw for FTTC and not the other way round?
... and THAT is exactly why I said the other day, FTTC is a complete tangled web, because each are buying from the other. It worked oK before FTTC, but since then its hard to know which bit belongs to whom.
The backhaul belongs to BTw. The OSS belongs to BTw. FTTC belongs to Openreach. NCAS is a BTw system. The FTTC cabs need Element Managers which are owned by BTw. The Management Device is owned by BTw. FTTC Openreach needs to hook into NCAS and get to the OSS to make any changes to the DLM, and it then becomes difficult to know who owns what and who is purchasing from whom. The ISP is buying an Openreach product, from which Openreach needs to access NCAS, and then the ISP buys it from Wholesale.. and have no access to the OSS because, Openreach is the customer. Confused yet? Yep you should be.
why would they be BTw's customer?
Because they need to use the DLM system. Regardless of which ISP is reselling the product. Sky or Plusnet or whatever. They all use the BTw OSS.